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linux/drivers/pci/pcie/dpc.c
Oza Pawandeep b09803b5e5 PCI/DPC: Use the generic pcie_do_fatal_recovery() path 
Our goal is to handle ERR_FATAL errors similarly, whether they are reported
via AER or via DPC.  A previous commit changed AER so it handles ERR_FATAL
by calling driver .remove() methods and resetting the Link.  DPC already
does that (although the Link reset is done automatically by hardware and
happens before we call the driver .remove() methods).

Restructure the DPC code so it calls the same pcie_do_fatal_recovery()
interface used by AER.  This makes it clearer that we want to use the same
path.

Implement the .reset_link() method used by pcie_do_fatal_recovery().  For
DPC, the actual reset is done automatically by hardware, so we really only
have to wait for the Link to be inactive, then release the Port from DPC.

Signed-off-by: Oza Pawandeep <poza@codeaurora.org>
[bhelgaas: changelog, DPC_FATAL is not a bitfield, can be sequential]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-06-02 19:29:27 -05:00

311 lines
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// SPDX-License-Identifier: GPL-2.0
/*
* PCI Express Downstream Port Containment services driver
* Author: Keith Busch <keith.busch@intel.com>
*
* Copyright (C) 2016 Intel Corp.
*/
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/pci.h>
#include "portdrv.h"
#include "../pci.h"
#include "aer/aerdrv.h"
struct dpc_dev {
struct pcie_device *dev;
struct work_struct work;
u16 cap_pos;
bool rp_extensions;
u32 rp_pio_status;
u8 rp_log_size;
};
static const char * const rp_pio_error_string[] = {
"Configuration Request received UR Completion", /* Bit Position 0 */
"Configuration Request received CA Completion", /* Bit Position 1 */
"Configuration Request Completion Timeout", /* Bit Position 2 */
NULL,
NULL,
NULL,
NULL,
NULL,
"I/O Request received UR Completion", /* Bit Position 8 */
"I/O Request received CA Completion", /* Bit Position 9 */
"I/O Request Completion Timeout", /* Bit Position 10 */
NULL,
NULL,
NULL,
NULL,
NULL,
"Memory Request received UR Completion", /* Bit Position 16 */
"Memory Request received CA Completion", /* Bit Position 17 */
"Memory Request Completion Timeout", /* Bit Position 18 */
};
static int dpc_wait_rp_inactive(struct dpc_dev *dpc)
{
unsigned long timeout = jiffies + HZ;
struct pci_dev *pdev = dpc->dev->port;
struct device *dev = &dpc->dev->device;
u16 cap = dpc->cap_pos, status;
pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
while (status & PCI_EXP_DPC_RP_BUSY &&
!time_after(jiffies, timeout)) {
msleep(10);
pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
}
if (status & PCI_EXP_DPC_RP_BUSY) {
dev_warn(dev, "DPC root port still busy\n");
return -EBUSY;
}
return 0;
}
static void dpc_wait_link_inactive(struct dpc_dev *dpc)
{
struct pci_dev *pdev = dpc->dev->port;
pcie_wait_for_link(pdev, false);
}
static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
{
struct dpc_dev *dpc;
struct pcie_device *pciedev;
struct device *devdpc;
u16 cap, ctl;
/*
* DPC disables the Link automatically in hardware, so it has
* already been reset by the time we get here.
*/
devdpc = pcie_port_find_device(pdev, PCIE_PORT_SERVICE_DPC);
pciedev = to_pcie_device(devdpc);
dpc = get_service_data(pciedev);
cap = dpc->cap_pos;
/*
* Wait until the Link is inactive, then clear DPC Trigger Status
* to allow the Port to leave DPC.
*/
dpc_wait_link_inactive(dpc);
if (dpc->rp_extensions && dpc_wait_rp_inactive(dpc))
return PCI_ERS_RESULT_DISCONNECT;
if (dpc->rp_extensions && dpc->rp_pio_status) {
pci_write_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS,
dpc->rp_pio_status);
dpc->rp_pio_status = 0;
}
pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,
PCI_EXP_DPC_STATUS_TRIGGER | PCI_EXP_DPC_STATUS_INTERRUPT);
pci_read_config_word(pdev, cap + PCI_EXP_DPC_CTL, &ctl);
pci_write_config_word(pdev, cap + PCI_EXP_DPC_CTL,
ctl | PCI_EXP_DPC_CTL_INT_EN);
return PCI_ERS_RESULT_RECOVERED;
}
static void dpc_work(struct work_struct *work)
{
struct dpc_dev *dpc = container_of(work, struct dpc_dev, work);
struct pci_dev *pdev = dpc->dev->port;
/* We configure DPC so it only triggers on ERR_FATAL */
pcie_do_fatal_recovery(pdev, PCIE_PORT_SERVICE_DPC);
}
static void dpc_process_rp_pio_error(struct dpc_dev *dpc)
{
struct device *dev = &dpc->dev->device;
struct pci_dev *pdev = dpc->dev->port;
u16 cap = dpc->cap_pos, dpc_status, first_error;
u32 status, mask, sev, syserr, exc, dw0, dw1, dw2, dw3, log, prefix;
int i;
pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS, &status);
pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_MASK, &mask);
dev_err(dev, "rp_pio_status: %#010x, rp_pio_mask: %#010x\n",
status, mask);
dpc->rp_pio_status = status;
pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_SEVERITY, &sev);
pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_SYSERROR, &syserr);
pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_EXCEPTION, &exc);
dev_err(dev, "RP PIO severity=%#010x, syserror=%#010x, exception=%#010x\n",
sev, syserr, exc);
/* Get First Error Pointer */
pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &dpc_status);
first_error = (dpc_status & 0x1f00) >> 8;
status &= ~mask;
for (i = 0; i < ARRAY_SIZE(rp_pio_error_string); i++) {
if (status & (1 << i))
dev_err(dev, "[%2d] %s%s\n", i, rp_pio_error_string[i],
first_error == i ? " (First)" : "");
}
if (dpc->rp_log_size < 4)
return;
pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG,
&dw0);
pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 4,
&dw1);
pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 8,
&dw2);
pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 12,
&dw3);
dev_err(dev, "TLP Header: %#010x %#010x %#010x %#010x\n",
dw0, dw1, dw2, dw3);
if (dpc->rp_log_size < 5)
return;
pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_IMPSPEC_LOG, &log);
dev_err(dev, "RP PIO ImpSpec Log %#010x\n", log);
for (i = 0; i < dpc->rp_log_size - 5; i++) {
pci_read_config_dword(pdev,
cap + PCI_EXP_DPC_RP_PIO_TLPPREFIX_LOG, &prefix);
dev_err(dev, "TLP Prefix Header: dw%d, %#010x\n", i, prefix);
}
}
static irqreturn_t dpc_irq(int irq, void *context)
{
struct dpc_dev *dpc = (struct dpc_dev *)context;
struct pci_dev *pdev = dpc->dev->port;
struct device *dev = &dpc->dev->device;
u16 cap = dpc->cap_pos, ctl, status, source, reason, ext_reason;
pci_read_config_word(pdev, cap + PCI_EXP_DPC_CTL, &ctl);
if (!(ctl & PCI_EXP_DPC_CTL_INT_EN) || ctl == (u16)(~0))
return IRQ_NONE;
pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT))
return IRQ_NONE;
if (!(status & PCI_EXP_DPC_STATUS_TRIGGER)) {
pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,
PCI_EXP_DPC_STATUS_INTERRUPT);
return IRQ_HANDLED;
}
pci_write_config_word(pdev, cap + PCI_EXP_DPC_CTL,
ctl & ~PCI_EXP_DPC_CTL_INT_EN);
pci_read_config_word(pdev, cap + PCI_EXP_DPC_SOURCE_ID,
&source);
dev_info(dev, "DPC containment event, status:%#06x source:%#06x\n",
status, source);
reason = (status & PCI_EXP_DPC_STATUS_TRIGGER_RSN) >> 1;
ext_reason = (status & PCI_EXP_DPC_STATUS_TRIGGER_RSN_EXT) >> 5;
dev_warn(dev, "DPC %s detected, remove downstream devices\n",
(reason == 0) ? "unmasked uncorrectable error" :
(reason == 1) ? "ERR_NONFATAL" :
(reason == 2) ? "ERR_FATAL" :
(ext_reason == 0) ? "RP PIO error" :
(ext_reason == 1) ? "software trigger" :
"reserved error");
/* show RP PIO error detail information */
if (dpc->rp_extensions && reason == 3 && ext_reason == 0)
dpc_process_rp_pio_error(dpc);
schedule_work(&dpc->work);
return IRQ_HANDLED;
}
#define FLAG(x, y) (((x) & (y)) ? '+' : '-')
static int dpc_probe(struct pcie_device *dev)
{
struct dpc_dev *dpc;
struct pci_dev *pdev = dev->port;
struct device *device = &dev->device;
int status;
u16 ctl, cap;
if (pcie_aer_get_firmware_first(pdev))
return -ENOTSUPP;
dpc = devm_kzalloc(device, sizeof(*dpc), GFP_KERNEL);
if (!dpc)
return -ENOMEM;
dpc->cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC);
dpc->dev = dev;
INIT_WORK(&dpc->work, dpc_work);
set_service_data(dev, dpc);
status = devm_request_irq(device, dev->irq, dpc_irq, IRQF_SHARED,
"pcie-dpc", dpc);
if (status) {
dev_warn(device, "request IRQ%d failed: %d\n", dev->irq,
status);
return status;
}
pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CAP, &cap);
pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl);
dpc->rp_extensions = (cap & PCI_EXP_DPC_CAP_RP_EXT);
if (dpc->rp_extensions) {
dpc->rp_log_size = (cap & PCI_EXP_DPC_RP_PIO_LOG_SIZE) >> 8;
if (dpc->rp_log_size < 4 || dpc->rp_log_size > 9) {
dev_err(device, "RP PIO log size %u is invalid\n",
dpc->rp_log_size);
dpc->rp_log_size = 0;
}
}
ctl = (ctl & 0xfff4) | PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN;
pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl);
dev_info(device, "DPC error containment capabilities: Int Msg #%d, RPExt%c PoisonedTLP%c SwTrigger%c RP PIO Log %d, DL_ActiveErr%c\n",
cap & PCI_EXP_DPC_IRQ, FLAG(cap, PCI_EXP_DPC_CAP_RP_EXT),
FLAG(cap, PCI_EXP_DPC_CAP_POISONED_TLP),
FLAG(cap, PCI_EXP_DPC_CAP_SW_TRIGGER), dpc->rp_log_size,
FLAG(cap, PCI_EXP_DPC_CAP_DL_ACTIVE));
return status;
}
static void dpc_remove(struct pcie_device *dev)
{
struct dpc_dev *dpc = get_service_data(dev);
struct pci_dev *pdev = dev->port;
u16 ctl;
pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl);
ctl &= ~(PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN);
pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl);
}
static struct pcie_port_service_driver dpcdriver = {
.name = "dpc",
.port_type = PCIE_ANY_PORT,
.service = PCIE_PORT_SERVICE_DPC,
.probe = dpc_probe,
.remove = dpc_remove,
.reset_link = dpc_reset_link,
};
static int __init dpc_service_init(void)
{
return pcie_port_service_register(&dpcdriver);
}
device_initcall(dpc_service_init);
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