| // 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. |
| */ |
| |
| #define dev_fmt(fmt) "DPC: " fmt |
| |
| #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" |
| |
| 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 */ |
| }; |
| |
| void pci_save_dpc_state(struct pci_dev *dev) |
| { |
| struct pci_cap_saved_state *save_state; |
| u16 *cap; |
| |
| if (!pci_is_pcie(dev)) |
| return; |
| |
| save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_DPC); |
| if (!save_state) |
| return; |
| |
| cap = (u16 *)&save_state->cap.data[0]; |
| pci_read_config_word(dev, dev->dpc_cap + PCI_EXP_DPC_CTL, cap); |
| } |
| |
| void pci_restore_dpc_state(struct pci_dev *dev) |
| { |
| struct pci_cap_saved_state *save_state; |
| u16 *cap; |
| |
| if (!pci_is_pcie(dev)) |
| return; |
| |
| save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_DPC); |
| if (!save_state) |
| return; |
| |
| cap = (u16 *)&save_state->cap.data[0]; |
| pci_write_config_word(dev, dev->dpc_cap + PCI_EXP_DPC_CTL, *cap); |
| } |
| |
| static int dpc_wait_rp_inactive(struct pci_dev *pdev) |
| { |
| unsigned long timeout = jiffies + HZ; |
| u16 cap = pdev->dpc_cap, 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) { |
| pci_warn(pdev, "root port still busy\n"); |
| return -EBUSY; |
| } |
| return 0; |
| } |
| |
| pci_ers_result_t dpc_reset_link(struct pci_dev *pdev) |
| { |
| u16 cap; |
| |
| /* |
| * DPC disables the Link automatically in hardware, so it has |
| * already been reset by the time we get here. |
| */ |
| cap = pdev->dpc_cap; |
| |
| /* |
| * 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 (pdev->dpc_rp_extensions && dpc_wait_rp_inactive(pdev)) |
| return PCI_ERS_RESULT_DISCONNECT; |
| |
| pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS, |
| PCI_EXP_DPC_STATUS_TRIGGER); |
| |
| if (!pcie_wait_for_link(pdev, true)) |
| return PCI_ERS_RESULT_DISCONNECT; |
| |
| return PCI_ERS_RESULT_RECOVERED; |
| } |
| |
| static void dpc_process_rp_pio_error(struct pci_dev *pdev) |
| { |
| u16 cap = pdev->dpc_cap, 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); |
| pci_err(pdev, "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); |
| pci_err(pdev, "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)) |
| pci_err(pdev, "[%2d] %s%s\n", i, rp_pio_error_string[i], |
| first_error == i ? " (First)" : ""); |
| } |
| |
| if (pdev->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); |
| pci_err(pdev, "TLP Header: %#010x %#010x %#010x %#010x\n", |
| dw0, dw1, dw2, dw3); |
| |
| if (pdev->dpc_rp_log_size < 5) |
| goto clear_status; |
| pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_IMPSPEC_LOG, &log); |
| pci_err(pdev, "RP PIO ImpSpec Log %#010x\n", log); |
| |
| for (i = 0; i < pdev->dpc_rp_log_size - 5; i++) { |
| pci_read_config_dword(pdev, |
| cap + PCI_EXP_DPC_RP_PIO_TLPPREFIX_LOG, &prefix); |
| pci_err(pdev, "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; |
| } |
| |
| void dpc_process_error(struct pci_dev *pdev) |
| { |
| u16 cap = pdev->dpc_cap, status, source, reason, ext_reason; |
| struct aer_err_info info; |
| |
| pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); |
| pci_read_config_word(pdev, cap + PCI_EXP_DPC_SOURCE_ID, &source); |
| |
| pci_info(pdev, "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; |
| pci_warn(pdev, "%s detected\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 (pdev->dpc_rp_extensions && reason == 3 && ext_reason == 0) |
| dpc_process_rp_pio_error(pdev); |
| else if (reason == 0 && |
| dpc_get_aer_uncorrect_severity(pdev, &info) && |
| aer_get_device_error_info(pdev, &info)) { |
| aer_print_error(pdev, &info); |
| pci_aer_clear_nonfatal_status(pdev); |
| pci_aer_clear_fatal_status(pdev); |
| } |
| } |
| |
| static irqreturn_t dpc_handler(int irq, void *context) |
| { |
| struct pci_dev *pdev = context; |
| |
| dpc_process_error(pdev); |
| |
| /* We configure DPC so it only triggers on ERR_FATAL */ |
| pcie_do_recovery(pdev, pci_channel_io_frozen, dpc_reset_link); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static irqreturn_t dpc_irq(int irq, void *context) |
| { |
| struct pci_dev *pdev = context; |
| u16 cap = pdev->dpc_cap, 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; |
| } |
| |
| void pci_dpc_init(struct pci_dev *pdev) |
| { |
| u16 cap; |
| |
| pdev->dpc_cap = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC); |
| if (!pdev->dpc_cap) |
| return; |
| |
| pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CAP, &cap); |
| if (!(cap & PCI_EXP_DPC_CAP_RP_EXT)) |
| return; |
| |
| pdev->dpc_rp_extensions = true; |
| pdev->dpc_rp_log_size = (cap & PCI_EXP_DPC_RP_PIO_LOG_SIZE) >> 8; |
| if (pdev->dpc_rp_log_size < 4 || pdev->dpc_rp_log_size > 9) { |
| pci_err(pdev, "RP PIO log size %u is invalid\n", |
| pdev->dpc_rp_log_size); |
| pdev->dpc_rp_log_size = 0; |
| } |
| } |
| |
| #define FLAG(x, y) (((x) & (y)) ? '+' : '-') |
| static int dpc_probe(struct pcie_device *dev) |
| { |
| struct pci_dev *pdev = dev->port; |
| struct device *device = &dev->device; |
| int status; |
| u16 ctl, cap; |
| |
| if (!pcie_aer_is_native(pdev) && !pcie_ports_dpc_native) |
| return -ENOTSUPP; |
| |
| status = devm_request_threaded_irq(device, dev->irq, dpc_irq, |
| dpc_handler, IRQF_SHARED, |
| "pcie-dpc", pdev); |
| if (status) { |
| pci_warn(pdev, "request IRQ%d failed: %d\n", dev->irq, |
| status); |
| return status; |
| } |
| |
| pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CAP, &cap); |
| pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, &ctl); |
| |
| ctl = (ctl & 0xfff4) | PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN; |
| pci_write_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, ctl); |
| pci_info(pdev, "enabled with IRQ %d\n", dev->irq); |
| |
| pci_info(pdev, "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), pdev->dpc_rp_log_size, |
| FLAG(cap, PCI_EXP_DPC_CAP_DL_ACTIVE)); |
| |
| pci_add_ext_cap_save_buffer(pdev, PCI_EXT_CAP_ID_DPC, sizeof(u16)); |
| return status; |
| } |
| |
| static void dpc_remove(struct pcie_device *dev) |
| { |
| struct pci_dev *pdev = dev->port; |
| u16 ctl; |
| |
| pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, &ctl); |
| ctl &= ~(PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN); |
| pci_write_config_word(pdev, pdev->dpc_cap + 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, |
| }; |
| |
| int __init pcie_dpc_init(void) |
| { |
| return pcie_port_service_register(&dpcdriver); |
| } |