ubuntu-linux-kernel/drivers/pci/pcie/pcie-dpc.c

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2024-04-01 15:06:58 +00:00
/*
* PCI Express Downstream Port Containment services driver
* Author: Keith Busch <keith.busch@intel.com>
*
* Copyright (C) 2016 Intel Corp.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/pcieport_if.h>
#include "../pci.h"
struct rp_pio_header_log_regs {
u32 dw0;
u32 dw1;
u32 dw2;
u32 dw3;
};
struct dpc_rp_pio_regs {
u32 status;
u32 mask;
u32 severity;
u32 syserror;
u32 exception;
struct rp_pio_header_log_regs header_log;
u32 impspec_log;
u32 tlp_prefix_log[4];
u32 log_size;
u16 first_error;
};
struct dpc_dev {
struct pcie_device *dev;
struct work_struct work;
int cap_pos;
bool rp;
u32 rp_pio_status;
};
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 status;
pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS, &status);
while (status & PCI_EXP_DPC_RP_BUSY &&
!time_after(jiffies, timeout)) {
msleep(10);
pci_read_config_word(pdev, dpc->cap_pos + 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)
{
unsigned long timeout = jiffies + HZ;
struct pci_dev *pdev = dpc->dev->port;
struct device *dev = &dpc->dev->device;
u16 lnk_status;
pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
while (lnk_status & PCI_EXP_LNKSTA_DLLLA &&
!time_after(jiffies, timeout)) {
msleep(10);
pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
}
if (lnk_status & PCI_EXP_LNKSTA_DLLLA)
dev_warn(dev, "Link state not disabled for DPC event\n");
}
static void interrupt_event_handler(struct work_struct *work)
{
struct dpc_dev *dpc = container_of(work, struct dpc_dev, work);
struct pci_dev *dev, *temp, *pdev = dpc->dev->port;
struct pci_bus *parent = pdev->subordinate;
pci_lock_rescan_remove();
list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
bus_list) {
pci_dev_get(dev);
pci_dev_set_disconnected(dev, NULL);
if (pci_has_subordinate(dev))
pci_walk_bus(dev->subordinate,
pci_dev_set_disconnected, NULL);
pci_stop_and_remove_bus_device(dev);
pci_dev_put(dev);
}
pci_unlock_rescan_remove();
dpc_wait_link_inactive(dpc);
if (dpc->rp && dpc_wait_rp_inactive(dpc))
return;
if (dpc->rp && dpc->rp_pio_status) {
pci_write_config_dword(pdev,
dpc->cap_pos + PCI_EXP_DPC_RP_PIO_STATUS,
dpc->rp_pio_status);
dpc->rp_pio_status = 0;
}
pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS,
PCI_EXP_DPC_STATUS_TRIGGER | PCI_EXP_DPC_STATUS_INTERRUPT);
}
static void dpc_rp_pio_print_tlp_header(struct device *dev,
struct rp_pio_header_log_regs *t)
{
dev_err(dev, "TLP Header: %#010x %#010x %#010x %#010x\n",
t->dw0, t->dw1, t->dw2, t->dw3);
}
static void dpc_rp_pio_print_error(struct dpc_dev *dpc,
struct dpc_rp_pio_regs *rp_pio)
{
struct device *dev = &dpc->dev->device;
int i;
u32 status;
dev_err(dev, "rp_pio_status: %#010x, rp_pio_mask: %#010x\n",
rp_pio->status, rp_pio->mask);
dev_err(dev, "RP PIO severity=%#010x, syserror=%#010x, exception=%#010x\n",
rp_pio->severity, rp_pio->syserror, rp_pio->exception);
status = (rp_pio->status & ~rp_pio->mask);
for (i = 0; i < ARRAY_SIZE(rp_pio_error_string); i++) {
if (!(status & (1 << i)))
continue;
dev_err(dev, "[%2d] %s%s\n", i, rp_pio_error_string[i],
rp_pio->first_error == i ? " (First)" : "");
}
dpc_rp_pio_print_tlp_header(dev, &rp_pio->header_log);
if (rp_pio->log_size == 4)
return;
dev_err(dev, "RP PIO ImpSpec Log %#010x\n", rp_pio->impspec_log);
for (i = 0; i < rp_pio->log_size - 5; i++)
dev_err(dev, "TLP Prefix Header: dw%d, %#010x\n", i,
rp_pio->tlp_prefix_log[i]);
}
static void dpc_rp_pio_get_info(struct dpc_dev *dpc,
struct dpc_rp_pio_regs *rp_pio)
{
struct pci_dev *pdev = dpc->dev->port;
struct device *dev = &dpc->dev->device;
int i;
u16 cap;
u16 status;
pci_read_config_dword(pdev, dpc->cap_pos + PCI_EXP_DPC_RP_PIO_STATUS,
&rp_pio->status);
pci_read_config_dword(pdev, dpc->cap_pos + PCI_EXP_DPC_RP_PIO_MASK,
&rp_pio->mask);
pci_read_config_dword(pdev, dpc->cap_pos + PCI_EXP_DPC_RP_PIO_SEVERITY,
&rp_pio->severity);
pci_read_config_dword(pdev, dpc->cap_pos + PCI_EXP_DPC_RP_PIO_SYSERROR,
&rp_pio->syserror);
pci_read_config_dword(pdev, dpc->cap_pos + PCI_EXP_DPC_RP_PIO_EXCEPTION,
&rp_pio->exception);
/* Get First Error Pointer */
pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS, &status);
rp_pio->first_error = (status & 0x1f00) >> 8;
pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CAP, &cap);
rp_pio->log_size = (cap & PCI_EXP_DPC_RP_PIO_LOG_SIZE) >> 8;
if (rp_pio->log_size < 4 || rp_pio->log_size > 9) {
dev_err(dev, "RP PIO log size %u is invalid\n",
rp_pio->log_size);
return;
}
pci_read_config_dword(pdev,
dpc->cap_pos + PCI_EXP_DPC_RP_PIO_HEADER_LOG,
&rp_pio->header_log.dw0);
pci_read_config_dword(pdev,
dpc->cap_pos + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 4,
&rp_pio->header_log.dw1);
pci_read_config_dword(pdev,
dpc->cap_pos + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 8,
&rp_pio->header_log.dw2);
pci_read_config_dword(pdev,
dpc->cap_pos + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 12,
&rp_pio->header_log.dw3);
if (rp_pio->log_size == 4)
return;
pci_read_config_dword(pdev,
dpc->cap_pos + PCI_EXP_DPC_RP_PIO_IMPSPEC_LOG,
&rp_pio->impspec_log);
for (i = 0; i < rp_pio->log_size - 5; i++)
pci_read_config_dword(pdev,
dpc->cap_pos + PCI_EXP_DPC_RP_PIO_TLPPREFIX_LOG,
&rp_pio->tlp_prefix_log[i]);
}
static void dpc_process_rp_pio_error(struct dpc_dev *dpc)
{
struct dpc_rp_pio_regs rp_pio_regs;
dpc_rp_pio_get_info(dpc, &rp_pio_regs);
dpc_rp_pio_print_error(dpc, &rp_pio_regs);
dpc->rp_pio_status = rp_pio_regs.status;
}
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 status, source;
pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS, &status);
pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_SOURCE_ID,
&source);
if (!status || status == (u16)(~0))
return IRQ_NONE;
dev_info(dev, "DPC containment event, status:%#06x source:%#06x\n",
status, source);
if (status & PCI_EXP_DPC_STATUS_TRIGGER) {
u16 reason = (status >> 1) & 0x3;
u16 ext_reason = (status >> 5) & 0x3;
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 (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;
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, interrupt_event_handler);
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 = (cap & PCI_EXP_DPC_CAP_RP_EXT);
ctl = (ctl & 0xfff4) | PCI_EXP_DPC_CTL_EN_NONFATAL | 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 & 0xf, FLAG(cap, PCI_EXP_DPC_CAP_RP_EXT),
FLAG(cap, PCI_EXP_DPC_CAP_POISONED_TLP),
FLAG(cap, PCI_EXP_DPC_CAP_SW_TRIGGER), (cap >> 8) & 0xf,
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_NONFATAL | 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,
};
static int __init dpc_service_init(void)
{
return pcie_port_service_register(&dpcdriver);
}
device_initcall(dpc_service_init);