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282a2feeb9
linux/drivers/ntb/ntb_transport.c
Jon Mason 282a2feeb9 NTB: Use DMA Engine to Transmit and Receive 
Allocate and use a DMA engine channel to transmit and receive data over
NTB.  If none is allocated, fall back to using the CPU to transfer data.

Signed-off-by: Jon Mason <jon.mason@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
2013-09-05 11:04:09 -07:00

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/*
* This file is provided under a dual BSD/GPLv2 license. When using or
* redistributing this file, you may do so under either license.
*
* GPL LICENSE SUMMARY
*
* Copyright(c) 2012 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* BSD LICENSE
*
* Copyright(c) 2012 Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copy
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Intel PCIe NTB Linux driver
*
* Contact Information:
* Jon Mason <jon.mason@intel.com>
*/
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/ntb.h>
#include "ntb_hw.h"
#define NTB_TRANSPORT_VERSION 3
static unsigned int transport_mtu = 0x401E;
module_param(transport_mtu, uint, 0644);
MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
static unsigned char max_num_clients;
module_param(max_num_clients, byte, 0644);
MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
static unsigned int copy_bytes = 1024;
module_param(copy_bytes, uint, 0644);
MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA");
struct ntb_queue_entry {
/* ntb_queue list reference */
struct list_head entry;
/* pointers to data to be transfered */
void *cb_data;
void *buf;
unsigned int len;
unsigned int flags;
struct ntb_transport_qp *qp;
union {
struct ntb_payload_header __iomem *tx_hdr;
struct ntb_payload_header *rx_hdr;
};
unsigned int index;
};
struct ntb_rx_info {
unsigned int entry;
};
struct ntb_transport_qp {
struct ntb_transport *transport;
struct ntb_device *ndev;
void *cb_data;
struct dma_chan *dma_chan;
bool client_ready;
bool qp_link;
u8 qp_num; /* Only 64 QP's are allowed. 0-63 */
struct ntb_rx_info __iomem *rx_info;
struct ntb_rx_info *remote_rx_info;
void (*tx_handler) (struct ntb_transport_qp *qp, void *qp_data,
void *data, int len);
struct list_head tx_free_q;
spinlock_t ntb_tx_free_q_lock;
void __iomem *tx_mw;
dma_addr_t tx_mw_phys;
unsigned int tx_index;
unsigned int tx_max_entry;
unsigned int tx_max_frame;
void (*rx_handler) (struct ntb_transport_qp *qp, void *qp_data,
void *data, int len);
struct tasklet_struct rx_work;
struct list_head rx_pend_q;
struct list_head rx_free_q;
spinlock_t ntb_rx_pend_q_lock;
spinlock_t ntb_rx_free_q_lock;
void *rx_buff;
unsigned int rx_index;
unsigned int rx_max_entry;
unsigned int rx_max_frame;
dma_cookie_t last_cookie;
void (*event_handler) (void *data, int status);
struct delayed_work link_work;
struct work_struct link_cleanup;
struct dentry *debugfs_dir;
struct dentry *debugfs_stats;
/* Stats */
u64 rx_bytes;
u64 rx_pkts;
u64 rx_ring_empty;
u64 rx_err_no_buf;
u64 rx_err_oflow;
u64 rx_err_ver;
u64 rx_memcpy;
u64 rx_async;
u64 tx_bytes;
u64 tx_pkts;
u64 tx_ring_full;
u64 tx_err_no_buf;
u64 tx_memcpy;
u64 tx_async;
};
struct ntb_transport_mw {
size_t size;
void *virt_addr;
dma_addr_t dma_addr;
};
struct ntb_transport_client_dev {
struct list_head entry;
struct device dev;
};
struct ntb_transport {
struct list_head entry;
struct list_head client_devs;
struct ntb_device *ndev;
struct ntb_transport_mw *mw;
struct ntb_transport_qp *qps;
unsigned int max_qps;
unsigned long qp_bitmap;
bool transport_link;
struct delayed_work link_work;
struct work_struct link_cleanup;
};
enum {
DESC_DONE_FLAG = 1 << 0,
LINK_DOWN_FLAG = 1 << 1,
};
struct ntb_payload_header {
unsigned int ver;
unsigned int len;
unsigned int flags;
};
enum {
VERSION = 0,
QP_LINKS,
NUM_QPS,
NUM_MWS,
MW0_SZ_HIGH,
MW0_SZ_LOW,
MW1_SZ_HIGH,
MW1_SZ_LOW,
MAX_SPAD,
};
#define QP_TO_MW(ndev, qp) ((qp) % ntb_max_mw(ndev))
#define NTB_QP_DEF_NUM_ENTRIES 100
#define NTB_LINK_DOWN_TIMEOUT 10
static int ntb_match_bus(struct device *dev, struct device_driver *drv)
{
return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
}
static int ntb_client_probe(struct device *dev)
{
const struct ntb_client *drv = container_of(dev->driver,
struct ntb_client, driver);
struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
int rc = -EINVAL;
get_device(dev);
if (drv && drv->probe)
rc = drv->probe(pdev);
if (rc)
put_device(dev);
return rc;
}
static int ntb_client_remove(struct device *dev)
{
const struct ntb_client *drv = container_of(dev->driver,
struct ntb_client, driver);
struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev);
if (drv && drv->remove)
drv->remove(pdev);
put_device(dev);
return 0;
}
static struct bus_type ntb_bus_type = {
.name = "ntb_bus",
.match = ntb_match_bus,
.probe = ntb_client_probe,
.remove = ntb_client_remove,
};
static LIST_HEAD(ntb_transport_list);
static int ntb_bus_init(struct ntb_transport *nt)
{
if (list_empty(&ntb_transport_list)) {
int rc = bus_register(&ntb_bus_type);
if (rc)
return rc;
}
list_add(&nt->entry, &ntb_transport_list);
return 0;
}
static void ntb_bus_remove(struct ntb_transport *nt)
{
struct ntb_transport_client_dev *client_dev, *cd;
list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
dev_name(&client_dev->dev));
list_del(&client_dev->entry);
device_unregister(&client_dev->dev);
}
list_del(&nt->entry);
if (list_empty(&ntb_transport_list))
bus_unregister(&ntb_bus_type);
}
static void ntb_client_release(struct device *dev)
{
struct ntb_transport_client_dev *client_dev;
client_dev = container_of(dev, struct ntb_transport_client_dev, dev);
kfree(client_dev);
}
/**
* ntb_unregister_client_dev - Unregister NTB client device
* @device_name: Name of NTB client device
*
* Unregister an NTB client device with the NTB transport layer
*/
void ntb_unregister_client_dev(char *device_name)
{
struct ntb_transport_client_dev *client, *cd;
struct ntb_transport *nt;
list_for_each_entry(nt, &ntb_transport_list, entry)
list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
if (!strncmp(dev_name(&client->dev), device_name,
strlen(device_name))) {
list_del(&client->entry);
device_unregister(&client->dev);
}
}
EXPORT_SYMBOL_GPL(ntb_unregister_client_dev);
/**
* ntb_register_client_dev - Register NTB client device
* @device_name: Name of NTB client device
*
* Register an NTB client device with the NTB transport layer
*/
int ntb_register_client_dev(char *device_name)
{
struct ntb_transport_client_dev *client_dev;
struct ntb_transport *nt;
int rc, i = 0;
if (list_empty(&ntb_transport_list))
return -ENODEV;
list_for_each_entry(nt, &ntb_transport_list, entry) {
struct device *dev;
client_dev = kzalloc(sizeof(struct ntb_transport_client_dev),
GFP_KERNEL);
if (!client_dev) {
rc = -ENOMEM;
goto err;
}
dev = &client_dev->dev;
/* setup and register client devices */
dev_set_name(dev, "%s%d", device_name, i);
dev->bus = &ntb_bus_type;
dev->release = ntb_client_release;
dev->parent = &ntb_query_pdev(nt->ndev)->dev;
rc = device_register(dev);
if (rc) {
kfree(client_dev);
goto err;
}
list_add_tail(&client_dev->entry, &nt->client_devs);
i++;
}
return 0;
err:
ntb_unregister_client_dev(device_name);
return rc;
}
EXPORT_SYMBOL_GPL(ntb_register_client_dev);
/**
* ntb_register_client - Register NTB client driver
* @drv: NTB client driver to be registered
*
* Register an NTB client driver with the NTB transport layer
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
int ntb_register_client(struct ntb_client *drv)
{
drv->driver.bus = &ntb_bus_type;
if (list_empty(&ntb_transport_list))
return -ENODEV;
return driver_register(&drv->driver);
}
EXPORT_SYMBOL_GPL(ntb_register_client);
/**
* ntb_unregister_client - Unregister NTB client driver
* @drv: NTB client driver to be unregistered
*
* Unregister an NTB client driver with the NTB transport layer
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
void ntb_unregister_client(struct ntb_client *drv)
{
driver_unregister(&drv->driver);
}
EXPORT_SYMBOL_GPL(ntb_unregister_client);
static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
loff_t *offp)
{
struct ntb_transport_qp *qp;
char *buf;
ssize_t ret, out_offset, out_count;
out_count = 1000;
buf = kmalloc(out_count, GFP_KERNEL);
if (!buf)
return -ENOMEM;
qp = filp->private_data;
out_offset = 0;
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"NTB QP stats\n");
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_bytes - \t%llu\n", qp->rx_bytes);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_pkts - \t%llu\n", qp->rx_pkts);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_memcpy - \t%llu\n", qp->rx_memcpy);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_async - \t%llu\n", qp->rx_async);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_ring_empty - %llu\n", qp->rx_ring_empty);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_err_ver - \t%llu\n", qp->rx_err_ver);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_buff - \t%p\n", qp->rx_buff);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_index - \t%u\n", qp->rx_index);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_max_entry - \t%u\n", qp->rx_max_entry);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_bytes - \t%llu\n", qp->tx_bytes);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_pkts - \t%llu\n", qp->tx_pkts);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_memcpy - \t%llu\n", qp->tx_memcpy);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_async - \t%llu\n", qp->tx_async);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_ring_full - \t%llu\n", qp->tx_ring_full);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_mw - \t%p\n", qp->tx_mw);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_index - \t%u\n", qp->tx_index);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_max_entry - \t%u\n", qp->tx_max_entry);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"\nQP Link %s\n", (qp->qp_link == NTB_LINK_UP) ?
"Up" : "Down");
if (out_offset > out_count)
out_offset = out_count;
ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
kfree(buf);
return ret;
}
static const struct file_operations ntb_qp_debugfs_stats = {
.owner = THIS_MODULE,
.open = simple_open,
.read = debugfs_read,
};
static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
struct list_head *list)
{
unsigned long flags;
spin_lock_irqsave(lock, flags);
list_add_tail(entry, list);
spin_unlock_irqrestore(lock, flags);
}
static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
struct list_head *list)
{
struct ntb_queue_entry *entry;
unsigned long flags;
spin_lock_irqsave(lock, flags);
if (list_empty(list)) {
entry = NULL;
goto out;
}
entry = list_first_entry(list, struct ntb_queue_entry, entry);
list_del(&entry->entry);
out:
spin_unlock_irqrestore(lock, flags);
return entry;
}
static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
unsigned int qp_num)
{
struct ntb_transport_qp *qp = &nt->qps[qp_num];
unsigned int rx_size, num_qps_mw;
u8 mw_num, mw_max;
unsigned int i;
mw_max = ntb_max_mw(nt->ndev);
mw_num = QP_TO_MW(nt->ndev, qp_num);
WARN_ON(nt->mw[mw_num].virt_addr == NULL);
if (nt->max_qps % mw_max && mw_num < nt->max_qps % mw_max)
num_qps_mw = nt->max_qps / mw_max + 1;
else
num_qps_mw = nt->max_qps / mw_max;
rx_size = (unsigned int) nt->mw[mw_num].size / num_qps_mw;
qp->rx_buff = nt->mw[mw_num].virt_addr + qp_num / mw_max * rx_size;
rx_size -= sizeof(struct ntb_rx_info);
qp->remote_rx_info = qp->rx_buff + rx_size;
/* Due to housekeeping, there must be atleast 2 buffs */
qp->rx_max_frame = min(transport_mtu, rx_size / 2);
qp->rx_max_entry = rx_size / qp->rx_max_frame;
qp->rx_index = 0;
qp->remote_rx_info->entry = qp->rx_max_entry - 1;
/* setup the hdr offsets with 0's */
for (i = 0; i < qp->rx_max_entry; i++) {
void *offset = qp->rx_buff + qp->rx_max_frame * (i + 1) -
sizeof(struct ntb_payload_header);
memset(offset, 0, sizeof(struct ntb_payload_header));
}
qp->rx_pkts = 0;
qp->tx_pkts = 0;
qp->tx_index = 0;
}
static void ntb_free_mw(struct ntb_transport *nt, int num_mw)
{
struct ntb_transport_mw *mw = &nt->mw[num_mw];
struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
if (!mw->virt_addr)
return;
dma_free_coherent(&pdev->dev, mw->size, mw->virt_addr, mw->dma_addr);
mw->virt_addr = NULL;
}
static int ntb_set_mw(struct ntb_transport *nt, int num_mw, unsigned int size)
{
struct ntb_transport_mw *mw = &nt->mw[num_mw];
struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
/* No need to re-setup */
if (mw->size == ALIGN(size, 4096))
return 0;
if (mw->size != 0)
ntb_free_mw(nt, num_mw);
/* Alloc memory for receiving data. Must be 4k aligned */
mw->size = ALIGN(size, 4096);
mw->virt_addr = dma_alloc_coherent(&pdev->dev, mw->size, &mw->dma_addr,
GFP_KERNEL);
if (!mw->virt_addr) {
mw->size = 0;
dev_err(&pdev->dev, "Unable to allocate MW buffer of size %d\n",
(int) mw->size);
return -ENOMEM;
}
/* Notify HW the memory location of the receive buffer */
ntb_set_mw_addr(nt->ndev, num_mw, mw->dma_addr);
return 0;
}
static void ntb_qp_link_cleanup(struct work_struct *work)
{
struct ntb_transport_qp *qp = container_of(work,
struct ntb_transport_qp,
link_cleanup);
struct ntb_transport *nt = qp->transport;
struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
if (qp->qp_link == NTB_LINK_DOWN) {
cancel_delayed_work_sync(&qp->link_work);
return;
}
if (qp->event_handler)
qp->event_handler(qp->cb_data, NTB_LINK_DOWN);
dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
qp->qp_link = NTB_LINK_DOWN;
if (nt->transport_link == NTB_LINK_UP)
schedule_delayed_work(&qp->link_work,
msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
}
static void ntb_qp_link_down(struct ntb_transport_qp *qp)
{
schedule_work(&qp->link_cleanup);
}
static void ntb_transport_link_cleanup(struct work_struct *work)
{
struct ntb_transport *nt = container_of(work, struct ntb_transport,
link_cleanup);
int i;
if (nt->transport_link == NTB_LINK_DOWN)
cancel_delayed_work_sync(&nt->link_work);
else
nt->transport_link = NTB_LINK_DOWN;
/* Pass along the info to any clients */
for (i = 0; i < nt->max_qps; i++)
if (!test_bit(i, &nt->qp_bitmap))
ntb_qp_link_down(&nt->qps[i]);
/* The scratchpad registers keep the values if the remote side
* goes down, blast them now to give them a sane value the next
* time they are accessed
*/
for (i = 0; i < MAX_SPAD; i++)
ntb_write_local_spad(nt->ndev, i, 0);
}
static void ntb_transport_event_callback(void *data, enum ntb_hw_event event)
{
struct ntb_transport *nt = data;
switch (event) {
case NTB_EVENT_HW_LINK_UP:
schedule_delayed_work(&nt->link_work, 0);
break;
case NTB_EVENT_HW_LINK_DOWN:
schedule_work(&nt->link_cleanup);
break;
default:
BUG();
}
}
static void ntb_transport_link_work(struct work_struct *work)
{
struct ntb_transport *nt = container_of(work, struct ntb_transport,
link_work.work);
struct ntb_device *ndev = nt->ndev;
struct pci_dev *pdev = ntb_query_pdev(ndev);
u32 val;
int rc, i;
/* send the local info, in the opposite order of the way we read it */
for (i = 0; i < ntb_max_mw(ndev); i++) {
rc = ntb_write_remote_spad(ndev, MW0_SZ_HIGH + (i * 2),
ntb_get_mw_size(ndev, i) >> 32);
if (rc) {
dev_err(&pdev->dev, "Error writing %u to remote spad %d\n",
(u32)(ntb_get_mw_size(ndev, i) >> 32),
MW0_SZ_HIGH + (i * 2));
goto out;
}
rc = ntb_write_remote_spad(ndev, MW0_SZ_LOW + (i * 2),
(u32) ntb_get_mw_size(ndev, i));
if (rc) {
dev_err(&pdev->dev, "Error writing %u to remote spad %d\n",
(u32) ntb_get_mw_size(ndev, i),
MW0_SZ_LOW + (i * 2));
goto out;
}
}
rc = ntb_write_remote_spad(ndev, NUM_MWS, ntb_max_mw(ndev));
if (rc) {
dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
ntb_max_mw(ndev), NUM_MWS);
goto out;
}
rc = ntb_write_remote_spad(ndev, NUM_QPS, nt->max_qps);
if (rc) {
dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
nt->max_qps, NUM_QPS);
goto out;
}
rc = ntb_write_remote_spad(ndev, VERSION, NTB_TRANSPORT_VERSION);
if (rc) {
dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
NTB_TRANSPORT_VERSION, VERSION);
goto out;
}
/* Query the remote side for its info */
rc = ntb_read_remote_spad(ndev, VERSION, &val);
if (rc) {
dev_err(&pdev->dev, "Error reading remote spad %d\n", VERSION);
goto out;
}
if (val != NTB_TRANSPORT_VERSION)
goto out;
dev_dbg(&pdev->dev, "Remote version = %d\n", val);
rc = ntb_read_remote_spad(ndev, NUM_QPS, &val);
if (rc) {
dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_QPS);
goto out;
}
if (val != nt->max_qps)
goto out;
dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
rc = ntb_read_remote_spad(ndev, NUM_MWS, &val);
if (rc) {
dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_MWS);
goto out;
}
if (val != ntb_max_mw(ndev))
goto out;
dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
for (i = 0; i < ntb_max_mw(ndev); i++) {
u64 val64;
rc = ntb_read_remote_spad(ndev, MW0_SZ_HIGH + (i * 2), &val);
if (rc) {
dev_err(&pdev->dev, "Error reading remote spad %d\n",
MW0_SZ_HIGH + (i * 2));
goto out1;
}
val64 = (u64) val << 32;
rc = ntb_read_remote_spad(ndev, MW0_SZ_LOW + (i * 2), &val);
if (rc) {
dev_err(&pdev->dev, "Error reading remote spad %d\n",
MW0_SZ_LOW + (i * 2));
goto out1;
}
val64 |= val;
dev_dbg(&pdev->dev, "Remote MW%d size = %llu\n", i, val64);
rc = ntb_set_mw(nt, i, val64);
if (rc)
goto out1;
}
nt->transport_link = NTB_LINK_UP;
for (i = 0; i < nt->max_qps; i++) {
struct ntb_transport_qp *qp = &nt->qps[i];
ntb_transport_setup_qp_mw(nt, i);
if (qp->client_ready == NTB_LINK_UP)
schedule_delayed_work(&qp->link_work, 0);
}
return;
out1:
for (i = 0; i < ntb_max_mw(ndev); i++)
ntb_free_mw(nt, i);
out:
if (ntb_hw_link_status(ndev))
schedule_delayed_work(&nt->link_work,
msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
}
static void ntb_qp_link_work(struct work_struct *work)
{
struct ntb_transport_qp *qp = container_of(work,
struct ntb_transport_qp,
link_work.work);
struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
struct ntb_transport *nt = qp->transport;
int rc, val;
WARN_ON(nt->transport_link != NTB_LINK_UP);
rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val);
if (rc) {
dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
return;
}
rc = ntb_write_remote_spad(nt->ndev, QP_LINKS, val | 1 << qp->qp_num);
if (rc)
dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
val | 1 << qp->qp_num, QP_LINKS);
/* query remote spad for qp ready bits */
rc = ntb_read_remote_spad(nt->ndev, QP_LINKS, &val);
if (rc)
dev_err(&pdev->dev, "Error reading remote spad %d\n", QP_LINKS);
dev_dbg(&pdev->dev, "Remote QP link status = %x\n", val);
/* See if the remote side is up */
if (1 << qp->qp_num & val) {
qp->qp_link = NTB_LINK_UP;
dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
if (qp->event_handler)
qp->event_handler(qp->cb_data, NTB_LINK_UP);
} else if (nt->transport_link == NTB_LINK_UP)
schedule_delayed_work(&qp->link_work,
msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
}
static int ntb_transport_init_queue(struct ntb_transport *nt,
unsigned int qp_num)
{
struct ntb_transport_qp *qp;
unsigned int num_qps_mw, tx_size;
u8 mw_num, mw_max;
u64 qp_offset;
mw_max = ntb_max_mw(nt->ndev);
mw_num = QP_TO_MW(nt->ndev, qp_num);
qp = &nt->qps[qp_num];
qp->qp_num = qp_num;
qp->transport = nt;
qp->ndev = nt->ndev;
qp->qp_link = NTB_LINK_DOWN;
qp->client_ready = NTB_LINK_DOWN;
qp->event_handler = NULL;
if (nt->max_qps % mw_max && mw_num < nt->max_qps % mw_max)
num_qps_mw = nt->max_qps / mw_max + 1;
else
num_qps_mw = nt->max_qps / mw_max;
tx_size = (unsigned int) ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw;
qp_offset = qp_num / mw_max * tx_size;
qp->tx_mw = ntb_get_mw_vbase(nt->ndev, mw_num) + qp_offset;
if (!qp->tx_mw)
return -EINVAL;
qp->tx_mw_phys = ntb_get_mw_base(qp->ndev, mw_num) + qp_offset;
if (!qp->tx_mw_phys)
return -EINVAL;
tx_size -= sizeof(struct ntb_rx_info);
qp->rx_info = qp->tx_mw + tx_size;
/* Due to housekeeping, there must be atleast 2 buffs */
qp->tx_max_frame = min(transport_mtu, tx_size / 2);
qp->tx_max_entry = tx_size / qp->tx_max_frame;
if (ntb_query_debugfs(nt->ndev)) {
char debugfs_name[4];
snprintf(debugfs_name, 4, "qp%d", qp_num);
qp->debugfs_dir = debugfs_create_dir(debugfs_name,
ntb_query_debugfs(nt->ndev));
qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
qp->debugfs_dir, qp,
&ntb_qp_debugfs_stats);
}
INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup);
spin_lock_init(&qp->ntb_rx_pend_q_lock);
spin_lock_init(&qp->ntb_rx_free_q_lock);
spin_lock_init(&qp->ntb_tx_free_q_lock);
INIT_LIST_HEAD(&qp->rx_pend_q);
INIT_LIST_HEAD(&qp->rx_free_q);
INIT_LIST_HEAD(&qp->tx_free_q);
return 0;
}
int ntb_transport_init(struct pci_dev *pdev)
{
struct ntb_transport *nt;
int rc, i;
nt = kzalloc(sizeof(struct ntb_transport), GFP_KERNEL);
if (!nt)
return -ENOMEM;
nt->ndev = ntb_register_transport(pdev, nt);
if (!nt->ndev) {
rc = -EIO;
goto err;
}
nt->mw = kcalloc(ntb_max_mw(nt->ndev), sizeof(struct ntb_transport_mw),
GFP_KERNEL);
if (!nt->mw) {
rc = -ENOMEM;
goto err1;
}
if (max_num_clients)
nt->max_qps = min(ntb_max_cbs(nt->ndev), max_num_clients);
else
nt->max_qps = min(ntb_max_cbs(nt->ndev), ntb_max_mw(nt->ndev));
nt->qps = kcalloc(nt->max_qps, sizeof(struct ntb_transport_qp),
GFP_KERNEL);
if (!nt->qps) {
rc = -ENOMEM;
goto err2;
}
nt->qp_bitmap = ((u64) 1 << nt->max_qps) - 1;
for (i = 0; i < nt->max_qps; i++) {
rc = ntb_transport_init_queue(nt, i);
if (rc)
goto err3;
}
INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup);
rc = ntb_register_event_callback(nt->ndev,
ntb_transport_event_callback);
if (rc)
goto err3;
INIT_LIST_HEAD(&nt->client_devs);
rc = ntb_bus_init(nt);
if (rc)
goto err4;
if (ntb_hw_link_status(nt->ndev))
schedule_delayed_work(&nt->link_work, 0);
return 0;
err4:
ntb_unregister_event_callback(nt->ndev);
err3:
kfree(nt->qps);
err2:
kfree(nt->mw);
err1:
ntb_unregister_transport(nt->ndev);
err:
kfree(nt);
return rc;
}
void ntb_transport_free(void *transport)
{
struct ntb_transport *nt = transport;
struct ntb_device *ndev = nt->ndev;
struct pci_dev *pdev;
int i;
nt->transport_link = NTB_LINK_DOWN;
/* verify that all the qp's are freed */
for (i = 0; i < nt->max_qps; i++) {
if (!test_bit(i, &nt->qp_bitmap))
ntb_transport_free_queue(&nt->qps[i]);
debugfs_remove_recursive(nt->qps[i].debugfs_dir);
}
ntb_bus_remove(nt);
cancel_delayed_work_sync(&nt->link_work);
ntb_unregister_event_callback(ndev);
pdev = ntb_query_pdev(ndev);
for (i = 0; i < ntb_max_mw(ndev); i++)
ntb_free_mw(nt, i);
kfree(nt->qps);
kfree(nt->mw);
ntb_unregister_transport(ndev);
kfree(nt);
}
static void ntb_rx_copy_callback(void *data)
{
struct ntb_queue_entry *entry = data;
struct ntb_transport_qp *qp = entry->qp;
void *cb_data = entry->cb_data;
unsigned int len = entry->len;
struct ntb_payload_header *hdr = entry->rx_hdr;
/* Ensure that the data is fully copied out before clearing the flag */
wmb();
hdr->flags = 0;
iowrite32(entry->index, &qp->rx_info->entry);
ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
if (qp->rx_handler && qp->client_ready == NTB_LINK_UP)
qp->rx_handler(qp, qp->cb_data, cb_data, len);
}
static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
{
void *buf = entry->buf;
size_t len = entry->len;
memcpy(buf, offset, len);
ntb_rx_copy_callback(entry);
}
static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset,
size_t len)
{
struct dma_async_tx_descriptor *txd;
struct ntb_transport_qp *qp = entry->qp;
struct dma_chan *chan = qp->dma_chan;
struct dma_device *device;
size_t pay_off, buff_off;
dma_addr_t src, dest;
dma_cookie_t cookie;
void *buf = entry->buf;
unsigned long flags;
entry->len = len;
if (!chan)
goto err;
if (len < copy_bytes)
goto err1;
device = chan->device;
pay_off = (size_t) offset & ~PAGE_MASK;
buff_off = (size_t) buf & ~PAGE_MASK;
if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
goto err1;
dest = dma_map_single(device->dev, buf, len, DMA_FROM_DEVICE);
if (dma_mapping_error(device->dev, dest))
goto err1;
src = dma_map_single(device->dev, offset, len, DMA_TO_DEVICE);
if (dma_mapping_error(device->dev, src))
goto err2;
flags = DMA_COMPL_DEST_UNMAP_SINGLE | DMA_COMPL_SRC_UNMAP_SINGLE |
DMA_PREP_INTERRUPT;
txd = device->device_prep_dma_memcpy(chan, dest, src, len, flags);
if (!txd)
goto err3;
txd->callback = ntb_rx_copy_callback;
txd->callback_param = entry;
cookie = dmaengine_submit(txd);
if (dma_submit_error(cookie))
goto err3;
qp->last_cookie = cookie;
qp->rx_async++;
return;
err3:
dma_unmap_single(device->dev, src, len, DMA_TO_DEVICE);
err2:
dma_unmap_single(device->dev, dest, len, DMA_FROM_DEVICE);
err1:
/* If the callbacks come out of order, the writing of the index to the
* last completed will be out of order. This may result in the
* receive stalling forever.
*/
dma_sync_wait(chan, qp->last_cookie);
err:
ntb_memcpy_rx(entry, offset);
qp->rx_memcpy++;
}
static int ntb_process_rxc(struct ntb_transport_qp *qp)
{
struct ntb_payload_header *hdr;
struct ntb_queue_entry *entry;
void *offset;
offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
if (!entry) {
dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
"no buffer - HDR ver %u, len %d, flags %x\n",
hdr->ver, hdr->len, hdr->flags);
qp->rx_err_no_buf++;
return -ENOMEM;
}
if (!(hdr->flags & DESC_DONE_FLAG)) {
ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
&qp->rx_pend_q);
qp->rx_ring_empty++;
return -EAGAIN;
}
if (hdr->ver != (u32) qp->rx_pkts) {
dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
"qp %d: version mismatch, expected %llu - got %u\n",
qp->qp_num, qp->rx_pkts, hdr->ver);
ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
&qp->rx_pend_q);
qp->rx_err_ver++;
return -EIO;
}
if (hdr->flags & LINK_DOWN_FLAG) {
ntb_qp_link_down(qp);
goto err;
}
dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
"rx offset %u, ver %u - %d payload received, buf size %d\n",
qp->rx_index, hdr->ver, hdr->len, entry->len);
qp->rx_bytes += hdr->len;
qp->rx_pkts++;
if (hdr->len > entry->len) {
qp->rx_err_oflow++;
dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
"RX overflow! Wanted %d got %d\n",
hdr->len, entry->len);
goto err;
}
entry->index = qp->rx_index;
entry->rx_hdr = hdr;
ntb_async_rx(entry, offset, hdr->len);
out:
qp->rx_index++;
qp->rx_index %= qp->rx_max_entry;
return 0;
err:
ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
&qp->rx_pend_q);
/* Ensure that the data is fully copied out before clearing the flag */
wmb();
hdr->flags = 0;
iowrite32(qp->rx_index, &qp->rx_info->entry);
goto out;
}
static void ntb_transport_rx(unsigned long data)
{
struct ntb_transport_qp *qp = (struct ntb_transport_qp *)data;
int rc, i;
/* Limit the number of packets processed in a single interrupt to
* provide fairness to others
*/
for (i = 0; i < qp->rx_max_entry; i++) {
rc = ntb_process_rxc(qp);
if (rc)
break;
}
if (qp->dma_chan)
dma_async_issue_pending(qp->dma_chan);
}
static void ntb_transport_rxc_db(void *data, int db_num)
{
struct ntb_transport_qp *qp = data;
dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%s: doorbell %d received\n",
__func__, db_num);
tasklet_schedule(&qp->rx_work);
}
static void ntb_tx_copy_callback(void *data)
{
struct ntb_queue_entry *entry = data;
struct ntb_transport_qp *qp = entry->qp;
struct ntb_payload_header __iomem *hdr = entry->tx_hdr;
/* Ensure that the data is fully copied out before setting the flags */
wmb();
iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
ntb_ring_sdb(qp->ndev, qp->qp_num);
/* The entry length can only be zero if the packet is intended to be a
* "link down" or similar. Since no payload is being sent in these
* cases, there is nothing to add to the completion queue.
*/
if (entry->len > 0) {
qp->tx_bytes += entry->len;
if (qp->tx_handler)
qp->tx_handler(qp, qp->cb_data, entry->cb_data,
entry->len);
}
ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
}
static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
{
memcpy_toio(offset, entry->buf, entry->len);
ntb_tx_copy_callback(entry);
}
static void ntb_async_tx(struct ntb_transport_qp *qp,
struct ntb_queue_entry *entry)
{
struct ntb_payload_header __iomem *hdr;
struct dma_async_tx_descriptor *txd;
struct dma_chan *chan = qp->dma_chan;
struct dma_device *device;
size_t dest_off, buff_off;
dma_addr_t src, dest;
dma_cookie_t cookie;
void __iomem *offset;
size_t len = entry->len;
void *buf = entry->buf;
unsigned long flags;
offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
entry->tx_hdr = hdr;
iowrite32(entry->len, &hdr->len);
iowrite32((u32) qp->tx_pkts, &hdr->ver);
if (!chan)
goto err;
if (len < copy_bytes)
goto err;
device = chan->device;
dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index;
buff_off = (size_t) buf & ~PAGE_MASK;
dest_off = (size_t) dest & ~PAGE_MASK;
if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
goto err;
src = dma_map_single(device->dev, buf, len, DMA_TO_DEVICE);
if (dma_mapping_error(device->dev, src))
goto err;
flags = DMA_COMPL_SRC_UNMAP_SINGLE | DMA_PREP_INTERRUPT;
txd = device->device_prep_dma_memcpy(chan, dest, src, len, flags);
if (!txd)
goto err1;
txd->callback = ntb_tx_copy_callback;
txd->callback_param = entry;
cookie = dmaengine_submit(txd);
if (dma_submit_error(cookie))
goto err1;
dma_async_issue_pending(chan);
qp->tx_async++;
return;
err1:
dma_unmap_single(device->dev, src, len, DMA_TO_DEVICE);
err:
ntb_memcpy_tx(entry, offset);
qp->tx_memcpy++;
}
static int ntb_process_tx(struct ntb_transport_qp *qp,
struct ntb_queue_entry *entry)
{
dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - tx %u, entry len %d flags %x buff %p\n",
qp->tx_pkts, qp->tx_index, entry->len, entry->flags,
entry->buf);
if (qp->tx_index == qp->remote_rx_info->entry) {
qp->tx_ring_full++;
return -EAGAIN;
}
if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) {
if (qp->tx_handler)
qp->tx_handler(qp->cb_data, qp, NULL, -EIO);
ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
&qp->tx_free_q);
return 0;
}
ntb_async_tx(qp, entry);
qp->tx_index++;
qp->tx_index %= qp->tx_max_entry;
qp->tx_pkts++;
return 0;
}
static void ntb_send_link_down(struct ntb_transport_qp *qp)
{
struct pci_dev *pdev = ntb_query_pdev(qp->ndev);
struct ntb_queue_entry *entry;
int i, rc;
if (qp->qp_link == NTB_LINK_DOWN)
return;
qp->qp_link = NTB_LINK_DOWN;
dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num);
for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
if (entry)
break;
msleep(100);
}
if (!entry)
return;
entry->cb_data = NULL;
entry->buf = NULL;
entry->len = 0;
entry->flags = LINK_DOWN_FLAG;
rc = ntb_process_tx(qp, entry);
if (rc)
dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
qp->qp_num);
}
/**
* ntb_transport_create_queue - Create a new NTB transport layer queue
* @rx_handler: receive callback function
* @tx_handler: transmit callback function
* @event_handler: event callback function
*
* Create a new NTB transport layer queue and provide the queue with a callback
* routine for both transmit and receive. The receive callback routine will be
* used to pass up data when the transport has received it on the queue. The
* transmit callback routine will be called when the transport has completed the
* transmission of the data on the queue and the data is ready to be freed.
*
* RETURNS: pointer to newly created ntb_queue, NULL on error.
*/
struct ntb_transport_qp *
ntb_transport_create_queue(void *data, struct pci_dev *pdev,
const struct ntb_queue_handlers *handlers)
{
struct ntb_queue_entry *entry;
struct ntb_transport_qp *qp;
struct ntb_transport *nt;
unsigned int free_queue;
int rc, i;
nt = ntb_find_transport(pdev);
if (!nt)
goto err;
free_queue = ffs(nt->qp_bitmap);
if (!free_queue)
goto err;
/* decrement free_queue to make it zero based */
free_queue--;
clear_bit(free_queue, &nt->qp_bitmap);
qp = &nt->qps[free_queue];
qp->cb_data = data;
qp->rx_handler = handlers->rx_handler;
qp->tx_handler = handlers->tx_handler;
qp->event_handler = handlers->event_handler;
qp->dma_chan = dma_find_channel(DMA_MEMCPY);
if (!qp->dma_chan)
dev_info(&pdev->dev, "Unable to allocate DMA channel, using CPU instead\n");
else
dmaengine_get();
for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
if (!entry)
goto err1;
entry->qp = qp;
ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
&qp->rx_free_q);
}
for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
if (!entry)
goto err2;
entry->qp = qp;
ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
&qp->tx_free_q);
}
tasklet_init(&qp->rx_work, ntb_transport_rx, (unsigned long) qp);
rc = ntb_register_db_callback(qp->ndev, free_queue, qp,
ntb_transport_rxc_db);
if (rc)
goto err3;
dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
return qp;
err3:
tasklet_disable(&qp->rx_work);
err2:
while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
kfree(entry);
err1:
while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
kfree(entry);
set_bit(free_queue, &nt->qp_bitmap);
err:
return NULL;
}
EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
/**
* ntb_transport_free_queue - Frees NTB transport queue
* @qp: NTB queue to be freed
*
* Frees NTB transport queue
*/
void ntb_transport_free_queue(struct ntb_transport_qp *qp)
{
struct pci_dev *pdev;
struct ntb_queue_entry *entry;
if (!qp)
return;
pdev = ntb_query_pdev(qp->ndev);
if (qp->dma_chan) {
struct dma_chan *chan = qp->dma_chan;
/* Putting the dma_chan to NULL will force any new traffic to be
* processed by the CPU instead of the DAM engine
*/
qp->dma_chan = NULL;
/* Try to be nice and wait for any queued DMA engine
* transactions to process before smashing it with a rock
*/
dma_sync_wait(chan, qp->last_cookie);
dmaengine_terminate_all(chan);
dmaengine_put();
}
ntb_unregister_db_callback(qp->ndev, qp->qp_num);
tasklet_disable(&qp->rx_work);
cancel_delayed_work_sync(&qp->link_work);
while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
kfree(entry);
while ((entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) {
dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n");
kfree(entry);
}
while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
kfree(entry);
set_bit(qp->qp_num, &qp->transport->qp_bitmap);
dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
}
EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
/**
* ntb_transport_rx_remove - Dequeues enqueued rx packet
* @qp: NTB queue to be freed
* @len: pointer to variable to write enqueued buffers length
*
* Dequeues unused buffers from receive queue. Should only be used during
* shutdown of qp.
*
* RETURNS: NULL error value on error, or void* for success.
*/
void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
{
struct ntb_queue_entry *entry;
void *buf;
if (!qp || qp->client_ready == NTB_LINK_UP)
return NULL;
entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
if (!entry)
return NULL;
buf = entry->cb_data;
*len = entry->len;
ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);
return buf;
}
EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
/**
* ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
* @qp: NTB transport layer queue the entry is to be enqueued on
* @cb: per buffer pointer for callback function to use
* @data: pointer to data buffer that incoming packets will be copied into
* @len: length of the data buffer
*
* Enqueue a new receive buffer onto the transport queue into which a NTB
* payload can be received into.
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
unsigned int len)
{
struct ntb_queue_entry *entry;
if (!qp)
return -EINVAL;
entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q);
if (!entry)
return -ENOMEM;
entry->cb_data = cb;
entry->buf = data;
entry->len = len;
ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, &qp->rx_pend_q);
return 0;
}
EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
/**
* ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
* @qp: NTB transport layer queue the entry is to be enqueued on
* @cb: per buffer pointer for callback function to use
* @data: pointer to data buffer that will be sent
* @len: length of the data buffer
*
* Enqueue a new transmit buffer onto the transport queue from which a NTB
* payload will be transmitted. This assumes that a lock is behing held to
* serialize access to the qp.
*
* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
*/
int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
unsigned int len)
{
struct ntb_queue_entry *entry;
int rc;
if (!qp || qp->qp_link != NTB_LINK_UP || !len)
return -EINVAL;
entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
if (!entry) {
qp->tx_err_no_buf++;
return -ENOMEM;
}
entry->cb_data = cb;
entry->buf = data;
entry->len = len;
entry->flags = 0;
rc = ntb_process_tx(qp, entry);
if (rc)
ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
&qp->tx_free_q);
return rc;
}
EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
/**
* ntb_transport_link_up - Notify NTB transport of client readiness to use queue
* @qp: NTB transport layer queue to be enabled
*
* Notify NTB transport layer of client readiness to use queue
*/
void ntb_transport_link_up(struct ntb_transport_qp *qp)
{
if (!qp)
return;
qp->client_ready = NTB_LINK_UP;
if (qp->transport->transport_link == NTB_LINK_UP)
schedule_delayed_work(&qp->link_work, 0);
}
EXPORT_SYMBOL_GPL(ntb_transport_link_up);
/**
* ntb_transport_link_down - Notify NTB transport to no longer enqueue data
* @qp: NTB transport layer queue to be disabled
*
* Notify NTB transport layer of client's desire to no longer receive data on
* transport queue specified. It is the client's responsibility to ensure all
* entries on queue are purged or otherwise handled appropraitely.
*/
void ntb_transport_link_down(struct ntb_transport_qp *qp)
{
struct pci_dev *pdev;
int rc, val;
if (!qp)
return;
pdev = ntb_query_pdev(qp->ndev);
qp->client_ready = NTB_LINK_DOWN;
rc = ntb_read_local_spad(qp->ndev, QP_LINKS, &val);
if (rc) {
dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS);
return;
}
rc = ntb_write_remote_spad(qp->ndev, QP_LINKS,
val & ~(1 << qp->qp_num));
if (rc)
dev_err(&pdev->dev, "Error writing %x to remote spad %d\n",
val & ~(1 << qp->qp_num), QP_LINKS);
if (qp->qp_link == NTB_LINK_UP)
ntb_send_link_down(qp);
else
cancel_delayed_work_sync(&qp->link_work);
}
EXPORT_SYMBOL_GPL(ntb_transport_link_down);
/**
* ntb_transport_link_query - Query transport link state
* @qp: NTB transport layer queue to be queried
*
* Query connectivity to the remote system of the NTB transport queue
*
* RETURNS: true for link up or false for link down
*/
bool ntb_transport_link_query(struct ntb_transport_qp *qp)
{
if (!qp)
return false;
return qp->qp_link == NTB_LINK_UP;
}
EXPORT_SYMBOL_GPL(ntb_transport_link_query);
/**
* ntb_transport_qp_num - Query the qp number
* @qp: NTB transport layer queue to be queried
*
* Query qp number of the NTB transport queue
*
* RETURNS: a zero based number specifying the qp number
*/
unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
{
if (!qp)
return 0;
return qp->qp_num;
}
EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
/**
* ntb_transport_max_size - Query the max payload size of a qp
* @qp: NTB transport layer queue to be queried
*
* Query the maximum payload size permissible on the given qp
*
* RETURNS: the max payload size of a qp
*/
unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
{
unsigned int max;
if (!qp)
return 0;
if (!qp->dma_chan)
return qp->tx_max_frame - sizeof(struct ntb_payload_header);
/* If DMA engine usage is possible, try to find the max size for that */
max = qp->tx_max_frame - sizeof(struct ntb_payload_header);
max -= max % (1 << qp->dma_chan->device->copy_align);
return max;
}
EXPORT_SYMBOL_GPL(ntb_transport_max_size);
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