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dpc.c
314 lines (264 loc) · 9.14 KB
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dpc.c
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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/aer.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/pci.h>
#include "portdrv.h"
#include "../pci.h"
struct dpc_dev {
struct pcie_device *dev;
u16 cap_pos;
bool rp_extensions;
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 pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
{
struct dpc_dev *dpc;
struct pcie_device *pciedev;
struct device *devdpc;
u16 cap;
/*
* 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.
*/
pcie_wait_for_link(pdev, false);
if (dpc->rp_extensions && dpc_wait_rp_inactive(dpc))
return PCI_ERS_RESULT_DISCONNECT;
pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,
PCI_EXP_DPC_STATUS_TRIGGER);
return PCI_ERS_RESULT_RECOVERED;
}
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);
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;
for (i = 0; i < ARRAY_SIZE(rp_pio_error_string); i++) {
if ((status & ~mask) & (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)
goto clear_status;
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)
goto clear_status;
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);
}
clear_status:
pci_write_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS, status);
}
static int dpc_get_aer_uncorrect_severity(struct pci_dev *dev,
struct aer_err_info *info)
{
int pos = dev->aer_cap;
u32 status, mask, sev;
pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, &mask);
status &= ~mask;
if (!status)
return 0;
pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &sev);
status &= sev;
if (status)
info->severity = AER_FATAL;
else
info->severity = AER_NONFATAL;
return 1;
}
static irqreturn_t dpc_handler(int irq, void *context)
{
struct aer_err_info info;
struct dpc_dev *dpc = context;
struct pci_dev *pdev = dpc->dev->port;
struct device *dev = &dpc->dev->device;
u16 cap = dpc->cap_pos, status, source, reason, ext_reason;
pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
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);
else if (reason == 0 &&
dpc_get_aer_uncorrect_severity(pdev, &info) &&
aer_get_device_error_info(pdev, &info)) {
aer_print_error(pdev, &info);
pci_cleanup_aer_uncorrect_error_status(pdev);
pci_aer_clear_fatal_status(pdev);
}
/* We configure DPC so it only triggers on ERR_FATAL */
pcie_do_fatal_recovery(pdev, PCIE_PORT_SERVICE_DPC);
return IRQ_HANDLED;
}
static irqreturn_t dpc_irq(int irq, void *context)
{
struct dpc_dev *dpc = (struct dpc_dev *)context;
struct pci_dev *pdev = dpc->dev->port;
u16 cap = dpc->cap_pos, status;
pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT) || status == (u16)(~0))
return IRQ_NONE;
pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,
PCI_EXP_DPC_STATUS_INTERRUPT);
if (status & PCI_EXP_DPC_STATUS_TRIGGER)
return IRQ_WAKE_THREAD;
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;
set_service_data(dev, dpc);
status = devm_request_threaded_irq(device, dev->irq, dpc_irq,
dpc_handler, 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);