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linux/drivers/fsi/fsi-sbefifo.c

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fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) IBM Corporation 2017
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERGCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/fsi.h>
#include <linux/fsi-sbefifo.h>
#include <linux/kernel.h>
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
#include <linux/cdev.h>
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/delay.h>
#include <linux/uio.h>
#include <linux/vmalloc.h>
fsi: sbefifo: Bump max command length Otherwise cronus putmem fails istep and BML fails to upload skiboot To do that, we still use our one-page command buffer for small commands for speed, and for anything bigger, with a limit of 1MB plus a page, we vmalloc a temporary buffer. The limit was chosen because Cronus will break up any data transfer into 1M chunks (the extra page is for the command header). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
2018-08-07 04:51:52 +03:00
#include <linux/mm.h>
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
/*
* The SBEFIFO is a pipe-like FSI device for communicating with
* the self boot engine on POWER processors.
*/
#define DEVICE_NAME "sbefifo"
#define FSI_ENGID_SBE 0x22
/*
* Register layout
*/
/* Register banks */
#define SBEFIFO_UP 0x00 /* FSI -> Host */
#define SBEFIFO_DOWN 0x40 /* Host -> FSI */
/* Per-bank registers */
#define SBEFIFO_FIFO 0x00 /* The FIFO itself */
#define SBEFIFO_STS 0x04 /* Status register */
#define SBEFIFO_STS_PARITY_ERR 0x20000000
#define SBEFIFO_STS_RESET_REQ 0x02000000
#define SBEFIFO_STS_GOT_EOT 0x00800000
#define SBEFIFO_STS_MAX_XFER_LIMIT 0x00400000
#define SBEFIFO_STS_FULL 0x00200000
#define SBEFIFO_STS_EMPTY 0x00100000
#define SBEFIFO_STS_ECNT_MASK 0x000f0000
#define SBEFIFO_STS_ECNT_SHIFT 16
#define SBEFIFO_STS_VALID_MASK 0x0000ff00
#define SBEFIFO_STS_VALID_SHIFT 8
#define SBEFIFO_STS_EOT_MASK 0x000000ff
#define SBEFIFO_STS_EOT_SHIFT 0
#define SBEFIFO_EOT_RAISE 0x08 /* (Up only) Set End Of Transfer */
#define SBEFIFO_REQ_RESET 0x0C /* (Up only) Reset Request */
#define SBEFIFO_PERFORM_RESET 0x10 /* (Down only) Perform Reset */
#define SBEFIFO_EOT_ACK 0x14 /* (Down only) Acknowledge EOT */
#define SBEFIFO_DOWN_MAX 0x18 /* (Down only) Max transfer */
/* CFAM GP Mailbox SelfBoot Message register */
#define CFAM_GP_MBOX_SBM_ADDR 0x2824 /* Converted 0x2809 */
#define CFAM_SBM_SBE_BOOTED 0x80000000
#define CFAM_SBM_SBE_ASYNC_FFDC 0x40000000
#define CFAM_SBM_SBE_STATE_MASK 0x00f00000
#define CFAM_SBM_SBE_STATE_SHIFT 20
enum sbe_state
{
SBE_STATE_UNKNOWN = 0x0, // Unkown, initial state
SBE_STATE_IPLING = 0x1, // IPL'ing - autonomous mode (transient)
SBE_STATE_ISTEP = 0x2, // ISTEP - Running IPL by steps (transient)
SBE_STATE_MPIPL = 0x3, // MPIPL
SBE_STATE_RUNTIME = 0x4, // SBE Runtime
SBE_STATE_DMT = 0x5, // Dead Man Timer State (transient)
SBE_STATE_DUMP = 0x6, // Dumping
SBE_STATE_FAILURE = 0x7, // Internal SBE failure
SBE_STATE_QUIESCE = 0x8, // Final state - needs SBE reset to get out
};
/* FIFO depth */
#define SBEFIFO_FIFO_DEPTH 8
/* Helpers */
#define sbefifo_empty(sts) ((sts) & SBEFIFO_STS_EMPTY)
#define sbefifo_full(sts) ((sts) & SBEFIFO_STS_FULL)
#define sbefifo_parity_err(sts) ((sts) & SBEFIFO_STS_PARITY_ERR)
#define sbefifo_populated(sts) (((sts) & SBEFIFO_STS_ECNT_MASK) >> SBEFIFO_STS_ECNT_SHIFT)
#define sbefifo_vacant(sts) (SBEFIFO_FIFO_DEPTH - sbefifo_populated(sts))
#define sbefifo_eot_set(sts) (((sts) & SBEFIFO_STS_EOT_MASK) >> SBEFIFO_STS_EOT_SHIFT)
/* Reset request timeout in ms */
#define SBEFIFO_RESET_TIMEOUT 10000
/* Timeouts for commands in ms */
#define SBEFIFO_TIMEOUT_START_CMD 10000
#define SBEFIFO_TIMEOUT_IN_CMD 1000
#define SBEFIFO_TIMEOUT_START_RSP 10000
#define SBEFIFO_TIMEOUT_IN_RSP 1000
/* Other constants */
fsi: sbefifo: Bump max command length Otherwise cronus putmem fails istep and BML fails to upload skiboot To do that, we still use our one-page command buffer for small commands for speed, and for anything bigger, with a limit of 1MB plus a page, we vmalloc a temporary buffer. The limit was chosen because Cronus will break up any data transfer into 1M chunks (the extra page is for the command header). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
2018-08-07 04:51:52 +03:00
#define SBEFIFO_MAX_USER_CMD_LEN (0x100000 + PAGE_SIZE)
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
#define SBEFIFO_RESET_MAGIC 0x52534554 /* "RSET" */
struct sbefifo {
uint32_t magic;
#define SBEFIFO_MAGIC 0x53424546 /* "SBEF" */
struct fsi_device *fsi_dev;
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
struct device dev;
struct cdev cdev;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
struct mutex lock;
bool broken;
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
bool dead;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
bool async_ffdc;
fsi: sbefifo: Add sysfs file indicating a timeout error The SBEFIFO timeout error requires special handling in userspace to do recovery operations. Add a sysfs file to indicate a timeout error, and notify pollers when a timeout occurs. This will be used by the openpower-occ-control application. Signed-off-by: Eddie James <eajames@linux.ibm.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20211019211749.38059-3-eajames@linux.ibm.com Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-10-20 00:17:49 +03:00
bool timed_out;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
};
struct sbefifo_user {
struct sbefifo *sbefifo;
struct mutex file_lock;
fsi: sbefifo: Bump max command length Otherwise cronus putmem fails istep and BML fails to upload skiboot To do that, we still use our one-page command buffer for small commands for speed, and for anything bigger, with a limit of 1MB plus a page, we vmalloc a temporary buffer. The limit was chosen because Cronus will break up any data transfer into 1M chunks (the extra page is for the command header). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
2018-08-07 04:51:52 +03:00
void *cmd_page;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
void *pending_cmd;
size_t pending_len;
};
static DEFINE_MUTEX(sbefifo_ffdc_mutex);
fsi: sbefifo: Add sysfs file indicating a timeout error The SBEFIFO timeout error requires special handling in userspace to do recovery operations. Add a sysfs file to indicate a timeout error, and notify pollers when a timeout occurs. This will be used by the openpower-occ-control application. Signed-off-by: Eddie James <eajames@linux.ibm.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20211019211749.38059-3-eajames@linux.ibm.com Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-10-20 00:17:49 +03:00
static ssize_t timeout_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct sbefifo *sbefifo = container_of(dev, struct sbefifo, dev);
return sysfs_emit(buf, "%d\n", sbefifo->timed_out ? 1 : 0);
}
static DEVICE_ATTR_RO(timeout);
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
fsi: sbefifo: Fix inconsistent use of ffdc mutex Some of the exit path missed the unlock. Move the mutex to an outer function to avoid the problem completely Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-23 09:27:21 +03:00
static void __sbefifo_dump_ffdc(struct device *dev, const __be32 *ffdc,
size_t ffdc_sz, bool internal)
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
{
int pack = 0;
#define FFDC_LSIZE 60
static char ffdc_line[FFDC_LSIZE];
char *p = ffdc_line;
while (ffdc_sz) {
u32 w0, w1, w2, i;
if (ffdc_sz < 3) {
dev_err(dev, "SBE invalid FFDC package size %zd\n", ffdc_sz);
return;
}
w0 = be32_to_cpu(*(ffdc++));
w1 = be32_to_cpu(*(ffdc++));
w2 = be32_to_cpu(*(ffdc++));
ffdc_sz -= 3;
if ((w0 >> 16) != 0xFFDC) {
dev_err(dev, "SBE invalid FFDC package signature %08x %08x %08x\n",
w0, w1, w2);
break;
}
w0 &= 0xffff;
if (w0 > ffdc_sz) {
dev_err(dev, "SBE FFDC package len %d words but only %zd remaining\n",
w0, ffdc_sz);
w0 = ffdc_sz;
break;
}
if (internal) {
dev_warn(dev, "+---- SBE FFDC package %d for async err -----+\n",
pack++);
} else {
dev_warn(dev, "+---- SBE FFDC package %d for cmd %02x:%02x -----+\n",
pack++, (w1 >> 8) & 0xff, w1 & 0xff);
}
dev_warn(dev, "| Response code: %08x |\n", w2);
dev_warn(dev, "|-------------------------------------------|\n");
for (i = 0; i < w0; i++) {
if ((i & 3) == 0) {
p = ffdc_line;
p += sprintf(p, "| %04x:", i << 4);
}
p += sprintf(p, " %08x", be32_to_cpu(*(ffdc++)));
ffdc_sz--;
if ((i & 3) == 3 || i == (w0 - 1)) {
while ((i & 3) < 3) {
p += sprintf(p, " ");
i++;
}
dev_warn(dev, "%s |\n", ffdc_line);
}
}
dev_warn(dev, "+-------------------------------------------+\n");
}
fsi: sbefifo: Fix inconsistent use of ffdc mutex Some of the exit path missed the unlock. Move the mutex to an outer function to avoid the problem completely Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-23 09:27:21 +03:00
}
static void sbefifo_dump_ffdc(struct device *dev, const __be32 *ffdc,
size_t ffdc_sz, bool internal)
{
mutex_lock(&sbefifo_ffdc_mutex);
__sbefifo_dump_ffdc(dev, ffdc, ffdc_sz, internal);
fsi: sbefifo: Add missing mutex_unlock There was no unlock of the FFDC mutex. Fixes: 9f4a8a2d7f9d ("fsi/sbefifo: Add driver for the SBE FIFO") Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-04 00:21:29 +03:00
mutex_unlock(&sbefifo_ffdc_mutex);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
}
int sbefifo_parse_status(struct device *dev, u16 cmd, __be32 *response,
size_t resp_len, size_t *data_len)
{
u32 dh, s0, s1;
size_t ffdc_sz;
if (resp_len < 3) {
pr_debug("sbefifo: cmd %04x, response too small: %zd\n",
cmd, resp_len);
return -ENXIO;
}
dh = be32_to_cpu(response[resp_len - 1]);
if (dh > resp_len || dh < 3) {
dev_err(dev, "SBE cmd %02x:%02x status offset out of range: %d/%zd\n",
cmd >> 8, cmd & 0xff, dh, resp_len);
return -ENXIO;
}
s0 = be32_to_cpu(response[resp_len - dh]);
s1 = be32_to_cpu(response[resp_len - dh + 1]);
if (((s0 >> 16) != 0xC0DE) || ((s0 & 0xffff) != cmd)) {
dev_err(dev, "SBE cmd %02x:%02x, status signature invalid: 0x%08x 0x%08x\n",
cmd >> 8, cmd & 0xff, s0, s1);
return -ENXIO;
}
if (s1 != 0) {
ffdc_sz = dh - 3;
dev_warn(dev, "SBE error cmd %02x:%02x status=%04x:%04x\n",
cmd >> 8, cmd & 0xff, s1 >> 16, s1 & 0xffff);
if (ffdc_sz)
sbefifo_dump_ffdc(dev, &response[resp_len - dh + 2],
ffdc_sz, false);
}
if (data_len)
*data_len = resp_len - dh;
/*
* Primary status don't have the top bit set, so can't be confused with
* Linux negative error codes, so return the status word whole.
*/
return s1;
}
EXPORT_SYMBOL_GPL(sbefifo_parse_status);
static int sbefifo_regr(struct sbefifo *sbefifo, int reg, u32 *word)
{
__be32 raw_word;
int rc;
rc = fsi_device_read(sbefifo->fsi_dev, reg, &raw_word,
sizeof(raw_word));
if (rc)
return rc;
*word = be32_to_cpu(raw_word);
return 0;
}
static int sbefifo_regw(struct sbefifo *sbefifo, int reg, u32 word)
{
__be32 raw_word = cpu_to_be32(word);
return fsi_device_write(sbefifo->fsi_dev, reg, &raw_word,
sizeof(raw_word));
}
static int sbefifo_check_sbe_state(struct sbefifo *sbefifo)
{
__be32 raw_word;
u32 sbm;
int rc;
rc = fsi_slave_read(sbefifo->fsi_dev->slave, CFAM_GP_MBOX_SBM_ADDR,
&raw_word, sizeof(raw_word));
if (rc)
return rc;
sbm = be32_to_cpu(raw_word);
/* SBE booted at all ? */
if (!(sbm & CFAM_SBM_SBE_BOOTED))
return -ESHUTDOWN;
/* Check its state */
switch ((sbm & CFAM_SBM_SBE_STATE_MASK) >> CFAM_SBM_SBE_STATE_SHIFT) {
case SBE_STATE_UNKNOWN:
return -ESHUTDOWN;
fsi: sbefifo: Don't fail operations when in SBE IPL state SBE fifo operations should be allowed while the SBE is in any of the "IPL" states. Operations should succeed in this state. Fixes: 9f4a8a2d7f9d fsi/sbefifo: Add driver for the SBE FIFO Reviewed-by: Joel Stanley <joel@jms.id.au> Tested-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Eddie James <eajames@linux.ibm.com> Link: https://lore.kernel.org/r/1561575415-3282-1-git-send-email-eajames@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-26 21:56:55 +03:00
case SBE_STATE_DMT:
return -EBUSY;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
case SBE_STATE_IPLING:
case SBE_STATE_ISTEP:
case SBE_STATE_MPIPL:
case SBE_STATE_RUNTIME:
case SBE_STATE_DUMP: /* Not sure about that one */
break;
case SBE_STATE_FAILURE:
case SBE_STATE_QUIESCE:
return -ESHUTDOWN;
}
/* Is there async FFDC available ? Remember it */
if (sbm & CFAM_SBM_SBE_ASYNC_FFDC)
sbefifo->async_ffdc = true;
return 0;
}
/* Don't flip endianness of data to/from FIFO, just pass through. */
static int sbefifo_down_read(struct sbefifo *sbefifo, __be32 *word)
{
return fsi_device_read(sbefifo->fsi_dev, SBEFIFO_DOWN, word,
sizeof(*word));
}
static int sbefifo_up_write(struct sbefifo *sbefifo, __be32 word)
{
return fsi_device_write(sbefifo->fsi_dev, SBEFIFO_UP, &word,
sizeof(word));
}
static int sbefifo_request_reset(struct sbefifo *sbefifo)
{
struct device *dev = &sbefifo->fsi_dev->dev;
fsi/sbefifo: Fix reset timeout On BMCs with lower timer resolution than 1ms, msleep(1) will take way longer than 1ms, so looping 10k times won't wait for 10s but significantly longer. Fix this by using jiffies like the rest of the code. Fixes: 9f4a8a2d7f9d ("fsi/sbefifo: Add driver for the SBE FIFO") Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com> Link: https://lore.kernel.org/r/20200724071518.430515-3-joel@jms.id.au Signed-off-by: Joel Stanley <joel@jms.id.au>
2020-07-24 10:15:18 +03:00
unsigned long end_time;
u32 status;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
int rc;
dev_dbg(dev, "Requesting FIFO reset\n");
/* Mark broken first, will be cleared if reset succeeds */
sbefifo->broken = true;
/* Send reset request */
rc = sbefifo_regw(sbefifo, SBEFIFO_UP | SBEFIFO_REQ_RESET, 1);
if (rc) {
dev_err(dev, "Sending reset request failed, rc=%d\n", rc);
return rc;
}
/* Wait for it to complete */
fsi/sbefifo: Fix reset timeout On BMCs with lower timer resolution than 1ms, msleep(1) will take way longer than 1ms, so looping 10k times won't wait for 10s but significantly longer. Fix this by using jiffies like the rest of the code. Fixes: 9f4a8a2d7f9d ("fsi/sbefifo: Add driver for the SBE FIFO") Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com> Link: https://lore.kernel.org/r/20200724071518.430515-3-joel@jms.id.au Signed-off-by: Joel Stanley <joel@jms.id.au>
2020-07-24 10:15:18 +03:00
end_time = jiffies + msecs_to_jiffies(SBEFIFO_RESET_TIMEOUT);
while (!time_after(jiffies, end_time)) {
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
rc = sbefifo_regr(sbefifo, SBEFIFO_UP | SBEFIFO_STS, &status);
if (rc) {
dev_err(dev, "Failed to read UP fifo status during reset"
" , rc=%d\n", rc);
return rc;
}
if (!(status & SBEFIFO_STS_RESET_REQ)) {
dev_dbg(dev, "FIFO reset done\n");
sbefifo->broken = false;
return 0;
}
fsi/sbefifo: Fix reset timeout On BMCs with lower timer resolution than 1ms, msleep(1) will take way longer than 1ms, so looping 10k times won't wait for 10s but significantly longer. Fix this by using jiffies like the rest of the code. Fixes: 9f4a8a2d7f9d ("fsi/sbefifo: Add driver for the SBE FIFO") Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com> Link: https://lore.kernel.org/r/20200724071518.430515-3-joel@jms.id.au Signed-off-by: Joel Stanley <joel@jms.id.au>
2020-07-24 10:15:18 +03:00
cond_resched();
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
}
dev_err(dev, "FIFO reset timed out\n");
return -ETIMEDOUT;
}
static int sbefifo_cleanup_hw(struct sbefifo *sbefifo)
{
struct device *dev = &sbefifo->fsi_dev->dev;
u32 up_status, down_status;
bool need_reset = false;
int rc;
rc = sbefifo_check_sbe_state(sbefifo);
if (rc) {
dev_dbg(dev, "SBE state=%d\n", rc);
return rc;
}
/* If broken, we don't need to look at status, go straight to reset */
if (sbefifo->broken)
goto do_reset;
rc = sbefifo_regr(sbefifo, SBEFIFO_UP | SBEFIFO_STS, &up_status);
if (rc) {
dev_err(dev, "Cleanup: Reading UP status failed, rc=%d\n", rc);
/* Will try reset again on next attempt at using it */
sbefifo->broken = true;
return rc;
}
rc = sbefifo_regr(sbefifo, SBEFIFO_DOWN | SBEFIFO_STS, &down_status);
if (rc) {
dev_err(dev, "Cleanup: Reading DOWN status failed, rc=%d\n", rc);
/* Will try reset again on next attempt at using it */
sbefifo->broken = true;
return rc;
}
/* The FIFO already contains a reset request from the SBE ? */
if (down_status & SBEFIFO_STS_RESET_REQ) {
dev_info(dev, "Cleanup: FIFO reset request set, resetting\n");
fsi/sbefifo: Clean up correct FIFO when receiving reset request from SBE When the SBE requests a reset via the down FIFO, that is also the FIFO we should go and reset ;) Fixes: 9f4a8a2d7f9d ("fsi/sbefifo: Add driver for the SBE FIFO") Signed-off-by: Joachim Fenkes <FENKES@de.ibm.com> Signed-off-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20200724071518.430515-2-joel@jms.id.au Signed-off-by: Joel Stanley <joel@jms.id.au>
2020-07-24 10:15:17 +03:00
rc = sbefifo_regw(sbefifo, SBEFIFO_DOWN, SBEFIFO_PERFORM_RESET);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
if (rc) {
sbefifo->broken = true;
dev_err(dev, "Cleanup: Reset reg write failed, rc=%d\n", rc);
return rc;
}
sbefifo->broken = false;
return 0;
}
/* Parity error on either FIFO ? */
if ((up_status | down_status) & SBEFIFO_STS_PARITY_ERR)
need_reset = true;
/* Either FIFO not empty ? */
if (!((up_status & down_status) & SBEFIFO_STS_EMPTY))
need_reset = true;
if (!need_reset)
return 0;
dev_info(dev, "Cleanup: FIFO not clean (up=0x%08x down=0x%08x)\n",
up_status, down_status);
do_reset:
/* Mark broken, will be cleared if/when reset succeeds */
return sbefifo_request_reset(sbefifo);
}
static int sbefifo_wait(struct sbefifo *sbefifo, bool up,
u32 *status, unsigned long timeout)
{
struct device *dev = &sbefifo->fsi_dev->dev;
unsigned long end_time;
bool ready = false;
u32 addr, sts = 0;
int rc;
dev_vdbg(dev, "Wait on %s fifo...\n", up ? "up" : "down");
addr = (up ? SBEFIFO_UP : SBEFIFO_DOWN) | SBEFIFO_STS;
end_time = jiffies + timeout;
while (!time_after(jiffies, end_time)) {
cond_resched();
rc = sbefifo_regr(sbefifo, addr, &sts);
if (rc < 0) {
dev_err(dev, "FSI error %d reading status register\n", rc);
return rc;
}
if (!up && sbefifo_parity_err(sts)) {
dev_err(dev, "Parity error in DOWN FIFO\n");
return -ENXIO;
}
ready = !(up ? sbefifo_full(sts) : sbefifo_empty(sts));
if (ready)
break;
}
if (!ready) {
fsi: sbefifo: Add sysfs file indicating a timeout error The SBEFIFO timeout error requires special handling in userspace to do recovery operations. Add a sysfs file to indicate a timeout error, and notify pollers when a timeout occurs. This will be used by the openpower-occ-control application. Signed-off-by: Eddie James <eajames@linux.ibm.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20211019211749.38059-3-eajames@linux.ibm.com Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-10-20 00:17:49 +03:00
sysfs_notify(&sbefifo->dev.kobj, NULL, dev_attr_timeout.attr.name);
sbefifo->timed_out = true;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
dev_err(dev, "%s FIFO Timeout ! status=%08x\n", up ? "UP" : "DOWN", sts);
return -ETIMEDOUT;
}
dev_vdbg(dev, "End of wait status: %08x\n", sts);
fsi: sbefifo: Add sysfs file indicating a timeout error The SBEFIFO timeout error requires special handling in userspace to do recovery operations. Add a sysfs file to indicate a timeout error, and notify pollers when a timeout occurs. This will be used by the openpower-occ-control application. Signed-off-by: Eddie James <eajames@linux.ibm.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20211019211749.38059-3-eajames@linux.ibm.com Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-10-20 00:17:49 +03:00
sbefifo->timed_out = false;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
*status = sts;
return 0;
}
static int sbefifo_send_command(struct sbefifo *sbefifo,
const __be32 *command, size_t cmd_len)
{
struct device *dev = &sbefifo->fsi_dev->dev;
size_t len, chunk, vacant = 0, remaining = cmd_len;
unsigned long timeout;
u32 status;
int rc;
dev_vdbg(dev, "sending command (%zd words, cmd=%04x)\n",
cmd_len, be32_to_cpu(command[1]));
/* As long as there's something to send */
timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_START_CMD);
while (remaining) {
/* Wait for room in the FIFO */
rc = sbefifo_wait(sbefifo, true, &status, timeout);
if (rc < 0)
return rc;
timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_IN_CMD);
vacant = sbefifo_vacant(status);
len = chunk = min(vacant, remaining);
dev_vdbg(dev, " status=%08x vacant=%zd chunk=%zd\n",
status, vacant, chunk);
/* Write as much as we can */
while (len--) {
rc = sbefifo_up_write(sbefifo, *(command++));
if (rc) {
dev_err(dev, "FSI error %d writing UP FIFO\n", rc);
return rc;
}
}
remaining -= chunk;
vacant -= chunk;
}
/* If there's no room left, wait for some to write EOT */
if (!vacant) {
rc = sbefifo_wait(sbefifo, true, &status, timeout);
if (rc)
return rc;
}
/* Send an EOT */
rc = sbefifo_regw(sbefifo, SBEFIFO_UP | SBEFIFO_EOT_RAISE, 0);
if (rc)
dev_err(dev, "FSI error %d writing EOT\n", rc);
return rc;
}
static int sbefifo_read_response(struct sbefifo *sbefifo, struct iov_iter *response)
{
struct device *dev = &sbefifo->fsi_dev->dev;
fsi: sbefifo: Fix sparse warnings fsi-sbefifo.c:547:58: warning: incorrect type in argument 2 (different base types) fsi-sbefifo.c:547:58: expected restricted __be32 [usertype] *word fsi-sbefifo.c:547:58: got unsigned int *<noident> fsi-sbefifo.c:635:16: warning: incorrect type in assignment (different base types) fsi-sbefifo.c:635:16: expected unsigned int [unsigned] <noident> fsi-sbefifo.c:635:16: got restricted __be32 [usertype] <noident> fsi-sbefifo.c:636:16: warning: incorrect type in assignment (different base types) fsi-sbefifo.c:636:16: expected unsigned int [unsigned] <noident> fsi-sbefifo.c:636:16: got restricted __be32 [usertype] <noident> Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-06-18 06:43:33 +03:00
u32 status, eot_set;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
unsigned long timeout;
bool overflow = false;
fsi: sbefifo: Fix sparse warnings fsi-sbefifo.c:547:58: warning: incorrect type in argument 2 (different base types) fsi-sbefifo.c:547:58: expected restricted __be32 [usertype] *word fsi-sbefifo.c:547:58: got unsigned int *<noident> fsi-sbefifo.c:635:16: warning: incorrect type in assignment (different base types) fsi-sbefifo.c:635:16: expected unsigned int [unsigned] <noident> fsi-sbefifo.c:635:16: got restricted __be32 [usertype] <noident> fsi-sbefifo.c:636:16: warning: incorrect type in assignment (different base types) fsi-sbefifo.c:636:16: expected unsigned int [unsigned] <noident> fsi-sbefifo.c:636:16: got restricted __be32 [usertype] <noident> Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-06-18 06:43:33 +03:00
__be32 data;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
size_t len;
int rc;
dev_vdbg(dev, "reading response, buflen = %zd\n", iov_iter_count(response));
timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_START_RSP);
for (;;) {
/* Grab FIFO status (this will handle parity errors) */
rc = sbefifo_wait(sbefifo, false, &status, timeout);
if (rc < 0)
return rc;
timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_IN_RSP);
/* Decode status */
len = sbefifo_populated(status);
eot_set = sbefifo_eot_set(status);
dev_vdbg(dev, " chunk size %zd eot_set=0x%x\n", len, eot_set);
/* Go through the chunk */
while(len--) {
/* Read the data */
rc = sbefifo_down_read(sbefifo, &data);
if (rc < 0)
return rc;
/* Was it an EOT ? */
if (eot_set & 0x80) {
/*
* There should be nothing else in the FIFO,
* if there is, mark broken, this will force
* a reset on next use, but don't fail the
* command.
*/
if (len) {
dev_warn(dev, "FIFO read hit"
" EOT with still %zd data\n",
len);
sbefifo->broken = true;
}
/* We are done */
rc = sbefifo_regw(sbefifo,
SBEFIFO_DOWN | SBEFIFO_EOT_ACK, 0);
/*
* If that write fail, still complete the request but mark
* the fifo as broken for subsequent reset (not much else
* we can do here).
*/
if (rc) {
dev_err(dev, "FSI error %d ack'ing EOT\n", rc);
sbefifo->broken = true;
}
/* Tell whether we overflowed */
return overflow ? -EOVERFLOW : 0;
}
/* Store it if there is room */
if (iov_iter_count(response) >= sizeof(__be32)) {
if (copy_to_iter(&data, sizeof(__be32), response) < sizeof(__be32))
return -EFAULT;
} else {
dev_vdbg(dev, "Response overflowed !\n");
overflow = true;
}
/* Next EOT bit */
eot_set <<= 1;
}
}
/* Shouldn't happen */
return -EIO;
}
static int sbefifo_do_command(struct sbefifo *sbefifo,
const __be32 *command, size_t cmd_len,
struct iov_iter *response)
{
/* Try sending the command */
int rc = sbefifo_send_command(sbefifo, command, cmd_len);
if (rc)
return rc;
/* Now, get the response */
return sbefifo_read_response(sbefifo, response);
}
static void sbefifo_collect_async_ffdc(struct sbefifo *sbefifo)
{
struct device *dev = &sbefifo->fsi_dev->dev;
struct iov_iter ffdc_iter;
struct kvec ffdc_iov;
__be32 *ffdc;
size_t ffdc_sz;
fsi: sbefifo: Fix sparse warnings fsi-sbefifo.c:547:58: warning: incorrect type in argument 2 (different base types) fsi-sbefifo.c:547:58: expected restricted __be32 [usertype] *word fsi-sbefifo.c:547:58: got unsigned int *<noident> fsi-sbefifo.c:635:16: warning: incorrect type in assignment (different base types) fsi-sbefifo.c:635:16: expected unsigned int [unsigned] <noident> fsi-sbefifo.c:635:16: got restricted __be32 [usertype] <noident> fsi-sbefifo.c:636:16: warning: incorrect type in assignment (different base types) fsi-sbefifo.c:636:16: expected unsigned int [unsigned] <noident> fsi-sbefifo.c:636:16: got restricted __be32 [usertype] <noident> Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-06-18 06:43:33 +03:00
__be32 cmd[2];
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
int rc;
sbefifo->async_ffdc = false;
ffdc = vmalloc(SBEFIFO_MAX_FFDC_SIZE);
if (!ffdc) {
dev_err(dev, "Failed to allocate SBE FFDC buffer\n");
return;
}
ffdc_iov.iov_base = ffdc;
fsi: sbefifo: Remove unneeded semicolon Spotted by kbuild-test-bot Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-06-14 07:01:46 +03:00
ffdc_iov.iov_len = SBEFIFO_MAX_FFDC_SIZE;
iov_iter: Separate type from direction and use accessor functions In the iov_iter struct, separate the iterator type from the iterator direction and use accessor functions to access them in most places. Convert a bunch of places to use switch-statements to access them rather then chains of bitwise-AND statements. This makes it easier to add further iterator types. Also, this can be more efficient as to implement a switch of small contiguous integers, the compiler can use ~50% fewer compare instructions than it has to use bitwise-and instructions. Further, cease passing the iterator type into the iterator setup function. The iterator function can set that itself. Only the direction is required. Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-20 02:57:56 +03:00
iov_iter_kvec(&ffdc_iter, WRITE, &ffdc_iov, 1, SBEFIFO_MAX_FFDC_SIZE);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
cmd[0] = cpu_to_be32(2);
cmd[1] = cpu_to_be32(SBEFIFO_CMD_GET_SBE_FFDC);
rc = sbefifo_do_command(sbefifo, cmd, 2, &ffdc_iter);
if (rc != 0) {
dev_err(dev, "Error %d retrieving SBE FFDC\n", rc);
goto bail;
}
ffdc_sz = SBEFIFO_MAX_FFDC_SIZE - iov_iter_count(&ffdc_iter);
ffdc_sz /= sizeof(__be32);
rc = sbefifo_parse_status(dev, SBEFIFO_CMD_GET_SBE_FFDC, ffdc,
ffdc_sz, &ffdc_sz);
if (rc != 0) {
dev_err(dev, "Error %d decoding SBE FFDC\n", rc);
goto bail;
}
if (ffdc_sz > 0)
sbefifo_dump_ffdc(dev, ffdc, ffdc_sz, true);
bail:
vfree(ffdc);
}
static int __sbefifo_submit(struct sbefifo *sbefifo,
const __be32 *command, size_t cmd_len,
struct iov_iter *response)
{
struct device *dev = &sbefifo->fsi_dev->dev;
int rc;
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
if (sbefifo->dead)
return -ENODEV;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
if (cmd_len < 2 || be32_to_cpu(command[0]) != cmd_len) {
dev_vdbg(dev, "Invalid command len %zd (header: %d)\n",
cmd_len, be32_to_cpu(command[0]));
return -EINVAL;
}
/* First ensure the HW is in a clean state */
rc = sbefifo_cleanup_hw(sbefifo);
if (rc)
return rc;
/* Look for async FFDC first if any */
if (sbefifo->async_ffdc)
sbefifo_collect_async_ffdc(sbefifo);
rc = sbefifo_do_command(sbefifo, command, cmd_len, response);
if (rc != 0 && rc != -EOVERFLOW)
goto fail;
return rc;
fail:
/*
* On failure, attempt a reset. Ignore the result, it will mark
* the fifo broken if the reset fails
*/
sbefifo_request_reset(sbefifo);
/* Return original error */
return rc;
}
/**
* sbefifo_submit() - Submit and SBE fifo command and receive response
* @dev: The sbefifo device
* @command: The raw command data
* @cmd_len: The command size (in 32-bit words)
* @response: The output response buffer
* @resp_len: In: Response buffer size, Out: Response size
*
* This will perform the entire operation. If the reponse buffer
* overflows, returns -EOVERFLOW
*/
int sbefifo_submit(struct device *dev, const __be32 *command, size_t cmd_len,
__be32 *response, size_t *resp_len)
{
fsi: sbefifo: Fix checker warning about late NULL check "dev" is dereferences before it's checked. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-12 04:53:37 +03:00
struct sbefifo *sbefifo;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
struct iov_iter resp_iter;
struct kvec resp_iov;
size_t rbytes;
int rc;
fsi: sbefifo: Fix checker warning about late NULL check "dev" is dereferences before it's checked. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-12 04:53:37 +03:00
if (!dev)
return -ENODEV;
sbefifo = dev_get_drvdata(dev);
if (!sbefifo)
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
return -ENODEV;
if (WARN_ON_ONCE(sbefifo->magic != SBEFIFO_MAGIC))
return -ENODEV;
fsi: sbefifo: Bump max command length Otherwise cronus putmem fails istep and BML fails to upload skiboot To do that, we still use our one-page command buffer for small commands for speed, and for anything bigger, with a limit of 1MB plus a page, we vmalloc a temporary buffer. The limit was chosen because Cronus will break up any data transfer into 1M chunks (the extra page is for the command header). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
2018-08-07 04:51:52 +03:00
if (!resp_len || !command || !response)
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
return -EINVAL;
/* Prepare iov iterator */
rbytes = (*resp_len) * sizeof(__be32);
resp_iov.iov_base = response;
resp_iov.iov_len = rbytes;
iov_iter: Separate type from direction and use accessor functions In the iov_iter struct, separate the iterator type from the iterator direction and use accessor functions to access them in most places. Convert a bunch of places to use switch-statements to access them rather then chains of bitwise-AND statements. This makes it easier to add further iterator types. Also, this can be more efficient as to implement a switch of small contiguous integers, the compiler can use ~50% fewer compare instructions than it has to use bitwise-and instructions. Further, cease passing the iterator type into the iterator setup function. The iterator function can set that itself. Only the direction is required. Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-20 02:57:56 +03:00
iov_iter_kvec(&resp_iter, WRITE, &resp_iov, 1, rbytes);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
/* Perform the command */
fsi: sbefifo: Use interruptible mutex locking Some SBE operations have extremely large responses and can require several minutes to process the response. During this time, the device lock must be held. If another process attempts an operation, it will wait for the mutex for longer than the kernel hung task watchdog allows. Therefore, use the interruptible function to lock the mutex. Signed-off-by: Eddie James <eajames@linux.ibm.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20210803213016.44739-1-eajames@linux.ibm.com Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-08-04 00:30:16 +03:00
rc = mutex_lock_interruptible(&sbefifo->lock);
if (rc)
return rc;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
rc = __sbefifo_submit(sbefifo, command, cmd_len, &resp_iter);
mutex_unlock(&sbefifo->lock);
/* Extract the response length */
rbytes -= iov_iter_count(&resp_iter);
*resp_len = rbytes / sizeof(__be32);
return rc;
}
EXPORT_SYMBOL_GPL(sbefifo_submit);
/*
* Char device interface
*/
fsi: sbefifo: Bump max command length Otherwise cronus putmem fails istep and BML fails to upload skiboot To do that, we still use our one-page command buffer for small commands for speed, and for anything bigger, with a limit of 1MB plus a page, we vmalloc a temporary buffer. The limit was chosen because Cronus will break up any data transfer into 1M chunks (the extra page is for the command header). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
2018-08-07 04:51:52 +03:00
static void sbefifo_release_command(struct sbefifo_user *user)
{
if (is_vmalloc_addr(user->pending_cmd))
vfree(user->pending_cmd);
user->pending_cmd = NULL;
user->pending_len = 0;
}
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
static int sbefifo_user_open(struct inode *inode, struct file *file)
{
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
struct sbefifo *sbefifo = container_of(inode->i_cdev, struct sbefifo, cdev);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
struct sbefifo_user *user;
user = kzalloc(sizeof(struct sbefifo_user), GFP_KERNEL);
if (!user)
return -ENOMEM;
file->private_data = user;
user->sbefifo = sbefifo;
fsi: sbefifo: Bump max command length Otherwise cronus putmem fails istep and BML fails to upload skiboot To do that, we still use our one-page command buffer for small commands for speed, and for anything bigger, with a limit of 1MB plus a page, we vmalloc a temporary buffer. The limit was chosen because Cronus will break up any data transfer into 1M chunks (the extra page is for the command header). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
2018-08-07 04:51:52 +03:00
user->cmd_page = (void *)__get_free_page(GFP_KERNEL);
if (!user->cmd_page) {
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
kfree(user);
return -ENOMEM;
}
mutex_init(&user->file_lock);
return 0;
}
static ssize_t sbefifo_user_read(struct file *file, char __user *buf,
size_t len, loff_t *offset)
{
struct sbefifo_user *user = file->private_data;
struct sbefifo *sbefifo;
struct iov_iter resp_iter;
struct iovec resp_iov;
size_t cmd_len;
int rc;
if (!user)
return -EINVAL;
sbefifo = user->sbefifo;
if (len & 3)
return -EINVAL;
mutex_lock(&user->file_lock);
/* Cronus relies on -EAGAIN after a short read */
if (user->pending_len == 0) {
rc = -EAGAIN;
goto bail;
}
if (user->pending_len < 8) {
rc = -EINVAL;
goto bail;
}
cmd_len = user->pending_len >> 2;
/* Prepare iov iterator */
resp_iov.iov_base = buf;
resp_iov.iov_len = len;
iov_iter_init(&resp_iter, WRITE, &resp_iov, 1, len);
/* Perform the command */
fsi: sbefifo: Use interruptible mutex locking Some SBE operations have extremely large responses and can require several minutes to process the response. During this time, the device lock must be held. If another process attempts an operation, it will wait for the mutex for longer than the kernel hung task watchdog allows. Therefore, use the interruptible function to lock the mutex. Signed-off-by: Eddie James <eajames@linux.ibm.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20210803213016.44739-1-eajames@linux.ibm.com Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-08-04 00:30:16 +03:00
rc = mutex_lock_interruptible(&sbefifo->lock);
if (rc)
goto bail;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
rc = __sbefifo_submit(sbefifo, user->pending_cmd, cmd_len, &resp_iter);
mutex_unlock(&sbefifo->lock);
if (rc < 0)
goto bail;
/* Extract the response length */
rc = len - iov_iter_count(&resp_iter);
bail:
fsi: sbefifo: Bump max command length Otherwise cronus putmem fails istep and BML fails to upload skiboot To do that, we still use our one-page command buffer for small commands for speed, and for anything bigger, with a limit of 1MB plus a page, we vmalloc a temporary buffer. The limit was chosen because Cronus will break up any data transfer into 1M chunks (the extra page is for the command header). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
2018-08-07 04:51:52 +03:00
sbefifo_release_command(user);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
mutex_unlock(&user->file_lock);
return rc;
}
static ssize_t sbefifo_user_write(struct file *file, const char __user *buf,
size_t len, loff_t *offset)
{
struct sbefifo_user *user = file->private_data;
struct sbefifo *sbefifo;
int rc = len;
if (!user)
return -EINVAL;
sbefifo = user->sbefifo;
fsi: sbefifo: Bump max command length Otherwise cronus putmem fails istep and BML fails to upload skiboot To do that, we still use our one-page command buffer for small commands for speed, and for anything bigger, with a limit of 1MB plus a page, we vmalloc a temporary buffer. The limit was chosen because Cronus will break up any data transfer into 1M chunks (the extra page is for the command header). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
2018-08-07 04:51:52 +03:00
if (len > SBEFIFO_MAX_USER_CMD_LEN)
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
return -EINVAL;
if (len & 3)
return -EINVAL;
mutex_lock(&user->file_lock);
fsi: sbefifo: Bump max command length Otherwise cronus putmem fails istep and BML fails to upload skiboot To do that, we still use our one-page command buffer for small commands for speed, and for anything bigger, with a limit of 1MB plus a page, we vmalloc a temporary buffer. The limit was chosen because Cronus will break up any data transfer into 1M chunks (the extra page is for the command header). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
2018-08-07 04:51:52 +03:00
/* Can we use the pre-allocate buffer ? If not, allocate */
if (len <= PAGE_SIZE)
user->pending_cmd = user->cmd_page;
else
user->pending_cmd = vmalloc(len);
if (!user->pending_cmd) {
rc = -ENOMEM;
goto bail;
}
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
/* Copy the command into the staging buffer */
if (copy_from_user(user->pending_cmd, buf, len)) {
rc = -EFAULT;
goto bail;
}
/* Check for the magic reset command */
if (len == 4 && be32_to_cpu(*(__be32 *)user->pending_cmd) ==
SBEFIFO_RESET_MAGIC) {
/* Clear out any pending command */
user->pending_len = 0;
/* Trigger reset request */
fsi: sbefifo: Use interruptible mutex locking Some SBE operations have extremely large responses and can require several minutes to process the response. During this time, the device lock must be held. If another process attempts an operation, it will wait for the mutex for longer than the kernel hung task watchdog allows. Therefore, use the interruptible function to lock the mutex. Signed-off-by: Eddie James <eajames@linux.ibm.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20210803213016.44739-1-eajames@linux.ibm.com Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-08-04 00:30:16 +03:00
rc = mutex_lock_interruptible(&sbefifo->lock);
if (rc)
goto bail;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
rc = sbefifo_request_reset(user->sbefifo);
mutex_unlock(&sbefifo->lock);
if (rc == 0)
rc = 4;
goto bail;
}
/* Update the staging buffer size */
user->pending_len = len;
bail:
fsi: sbefifo: Bump max command length Otherwise cronus putmem fails istep and BML fails to upload skiboot To do that, we still use our one-page command buffer for small commands for speed, and for anything bigger, with a limit of 1MB plus a page, we vmalloc a temporary buffer. The limit was chosen because Cronus will break up any data transfer into 1M chunks (the extra page is for the command header). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
2018-08-07 04:51:52 +03:00
if (!user->pending_len)
sbefifo_release_command(user);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
mutex_unlock(&user->file_lock);
/* And that's it, we'll issue the command on a read */
return rc;
}
static int sbefifo_user_release(struct inode *inode, struct file *file)
{
struct sbefifo_user *user = file->private_data;
if (!user)
return -EINVAL;
fsi: sbefifo: Bump max command length Otherwise cronus putmem fails istep and BML fails to upload skiboot To do that, we still use our one-page command buffer for small commands for speed, and for anything bigger, with a limit of 1MB plus a page, we vmalloc a temporary buffer. The limit was chosen because Cronus will break up any data transfer into 1M chunks (the extra page is for the command header). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
2018-08-07 04:51:52 +03:00
sbefifo_release_command(user);
free_page((unsigned long)user->cmd_page);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
kfree(user);
return 0;
}
static const struct file_operations sbefifo_fops = {
.owner = THIS_MODULE,
.open = sbefifo_user_open,
.read = sbefifo_user_read,
.write = sbefifo_user_write,
.release = sbefifo_user_release,
};
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
static void sbefifo_free(struct device *dev)
{
struct sbefifo *sbefifo = container_of(dev, struct sbefifo, dev);
put_device(&sbefifo->fsi_dev->dev);
kfree(sbefifo);
}
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
/*
* Probe/remove
*/
static int sbefifo_probe(struct device *dev)
{
struct fsi_device *fsi_dev = to_fsi_dev(dev);
struct sbefifo *sbefifo;
struct device_node *np;
struct platform_device *child;
char child_name[32];
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
int rc, didx, child_idx = 0;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
dev_dbg(dev, "Found sbefifo device\n");
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
sbefifo = kzalloc(sizeof(*sbefifo), GFP_KERNEL);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
if (!sbefifo)
return -ENOMEM;
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
/* Grab a reference to the device (parent of our cdev), we'll drop it later */
if (!get_device(dev)) {
kfree(sbefifo);
return -ENODEV;
}
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
sbefifo->magic = SBEFIFO_MAGIC;
sbefifo->fsi_dev = fsi_dev;
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
dev_set_drvdata(dev, sbefifo);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
mutex_init(&sbefifo->lock);
/*
* Try cleaning up the FIFO. If this fails, we still register the
* driver and will try cleaning things up again on the next access.
*/
rc = sbefifo_cleanup_hw(sbefifo);
if (rc && rc != -ESHUTDOWN)
dev_err(dev, "Initial HW cleanup failed, will retry later\n");
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
/* Create chardev for userspace access */
sbefifo->dev.type = &fsi_cdev_type;
sbefifo->dev.parent = dev;
sbefifo->dev.release = sbefifo_free;
device_initialize(&sbefifo->dev);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
/* Allocate a minor in the FSI space */
rc = fsi_get_new_minor(fsi_dev, fsi_dev_sbefifo, &sbefifo->dev.devt, &didx);
if (rc)
goto err;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
dev_set_name(&sbefifo->dev, "sbefifo%d", didx);
cdev_init(&sbefifo->cdev, &sbefifo_fops);
rc = cdev_device_add(&sbefifo->cdev, &sbefifo->dev);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
if (rc) {
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
dev_err(dev, "Error %d creating char device %s\n",
rc, dev_name(&sbefifo->dev));
goto err_free_minor;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
}
/* Create platform devs for dts child nodes (occ, etc) */
for_each_available_child_of_node(dev->of_node, np) {
snprintf(child_name, sizeof(child_name), "%s-dev%d",
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
dev_name(&sbefifo->dev), child_idx++);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
child = of_platform_device_create(np, child_name, dev);
if (!child)
dev_warn(dev, "failed to create child %s dev\n",
child_name);
}
fsi: sbefifo: Add sysfs file indicating a timeout error The SBEFIFO timeout error requires special handling in userspace to do recovery operations. Add a sysfs file to indicate a timeout error, and notify pollers when a timeout occurs. This will be used by the openpower-occ-control application. Signed-off-by: Eddie James <eajames@linux.ibm.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20211019211749.38059-3-eajames@linux.ibm.com Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-10-20 00:17:49 +03:00
device_create_file(&sbefifo->dev, &dev_attr_timeout);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
return 0;
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
err_free_minor:
fsi_free_minor(sbefifo->dev.devt);
err:
put_device(&sbefifo->dev);
return rc;
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
}
static int sbefifo_unregister_child(struct device *dev, void *data)
{
struct platform_device *child = to_platform_device(dev);
of_device_unregister(child);
if (dev->of_node)
of_node_clear_flag(dev->of_node, OF_POPULATED);
return 0;
}
static int sbefifo_remove(struct device *dev)
{
struct sbefifo *sbefifo = dev_get_drvdata(dev);
dev_dbg(dev, "Removing sbefifo device...\n");
fsi: sbefifo: Add sysfs file indicating a timeout error The SBEFIFO timeout error requires special handling in userspace to do recovery operations. Add a sysfs file to indicate a timeout error, and notify pollers when a timeout occurs. This will be used by the openpower-occ-control application. Signed-off-by: Eddie James <eajames@linux.ibm.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20211019211749.38059-3-eajames@linux.ibm.com Signed-off-by: Joel Stanley <joel@jms.id.au>
2021-10-20 00:17:49 +03:00
device_remove_file(&sbefifo->dev, &dev_attr_timeout);
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
mutex_lock(&sbefifo->lock);
sbefifo->dead = true;
mutex_unlock(&sbefifo->lock);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
fsi: sbefifo: Convert to use the new chardev This converts FSI sbefifo to use the new fsi-core controlled chardev allocator and use a real cdev instead of a miscdev. One side effect is to fix the object lifetime by removing the use of devm_kzalloc() for something that contains kobjects, and using proper reference counting. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2018-07-24 07:39:55 +03:00
cdev_device_del(&sbefifo->cdev, &sbefifo->dev);
fsi_free_minor(sbefifo->dev.devt);
device_for_each_child(dev, NULL, sbefifo_unregister_child);
put_device(&sbefifo->dev);
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
return 0;
}
fsi: sbefifo: Constify sbefifo_ids The only usage of sbefifo_ids is to assign its address to the id_table field in the fsi_driver struct, which is a const pointer, so make it const to allow the compiler to put it in read-only memory Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com> Signed-off-by: Joel Stanley <joel@jms.id.au>
2020-08-06 02:26:23 +03:00
static const struct fsi_device_id sbefifo_ids[] = {
fsi/sbefifo: Add driver for the SBE FIFO This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus. It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API. The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory: - The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response). - On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command. - A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out. - The command is limited to 4K bytes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Joel Stanley <joel@jms.id.au> ---
2018-05-17 08:58:00 +03:00
{
.engine_type = FSI_ENGID_SBE,
.version = FSI_VERSION_ANY,
},
{ 0 }
};
static struct fsi_driver sbefifo_drv = {
.id_table = sbefifo_ids,
.drv = {
.name = DEVICE_NAME,
.bus = &fsi_bus_type,
.probe = sbefifo_probe,
.remove = sbefifo_remove,
}
};
static int sbefifo_init(void)
{
return fsi_driver_register(&sbefifo_drv);
}
static void sbefifo_exit(void)
{
fsi_driver_unregister(&sbefifo_drv);
}
module_init(sbefifo_init);
module_exit(sbefifo_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Brad Bishop <bradleyb@fuzziesquirrel.com>");
MODULE_AUTHOR("Eddie James <eajames@linux.vnet.ibm.com>");
MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
MODULE_DESCRIPTION("Linux device interface to the POWER Self Boot Engine");
Reference in New Issue Copy Permalink