123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240 |
- // SPDX-License-Identifier: GPL-2.0
- /*
- * PCI Error Disconnect Recover support
- * Author: Kuppuswamy Sathyanarayanan <[email protected]>
- *
- * Copyright (C) 2020 Intel Corp.
- */
- #define dev_fmt(fmt) "EDR: " fmt
- #include <linux/pci.h>
- #include <linux/pci-acpi.h>
- #include "portdrv.h"
- #include "../pci.h"
- #define EDR_PORT_DPC_ENABLE_DSM 0x0C
- #define EDR_PORT_LOCATE_DSM 0x0D
- #define EDR_OST_SUCCESS 0x80
- #define EDR_OST_FAILED 0x81
- /*
- * _DSM wrapper function to enable/disable DPC
- * @pdev : PCI device structure
- *
- * returns 0 on success or errno on failure.
- */
- static int acpi_enable_dpc(struct pci_dev *pdev)
- {
- struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
- union acpi_object *obj, argv4, req;
- int status = 0;
- /*
- * Behavior when calling unsupported _DSM functions is undefined,
- * so check whether EDR_PORT_DPC_ENABLE_DSM is supported.
- */
- if (!acpi_check_dsm(adev->handle, &pci_acpi_dsm_guid, 5,
- 1ULL << EDR_PORT_DPC_ENABLE_DSM))
- return 0;
- req.type = ACPI_TYPE_INTEGER;
- req.integer.value = 1;
- argv4.type = ACPI_TYPE_PACKAGE;
- argv4.package.count = 1;
- argv4.package.elements = &req;
- /*
- * Per Downstream Port Containment Related Enhancements ECN to PCI
- * Firmware Specification r3.2, sec 4.6.12, EDR_PORT_DPC_ENABLE_DSM is
- * optional. Return success if it's not implemented.
- */
- obj = acpi_evaluate_dsm(adev->handle, &pci_acpi_dsm_guid, 5,
- EDR_PORT_DPC_ENABLE_DSM, &argv4);
- if (!obj)
- return 0;
- if (obj->type != ACPI_TYPE_INTEGER) {
- pci_err(pdev, FW_BUG "Enable DPC _DSM returned non integer\n");
- status = -EIO;
- }
- if (obj->integer.value != 1) {
- pci_err(pdev, "Enable DPC _DSM failed to enable DPC\n");
- status = -EIO;
- }
- ACPI_FREE(obj);
- return status;
- }
- /*
- * _DSM wrapper function to locate DPC port
- * @pdev : Device which received EDR event
- *
- * Returns pci_dev or NULL. Caller is responsible for dropping a reference
- * on the returned pci_dev with pci_dev_put().
- */
- static struct pci_dev *acpi_dpc_port_get(struct pci_dev *pdev)
- {
- struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
- union acpi_object *obj;
- u16 port;
- /*
- * Behavior when calling unsupported _DSM functions is undefined,
- * so check whether EDR_PORT_DPC_ENABLE_DSM is supported.
- */
- if (!acpi_check_dsm(adev->handle, &pci_acpi_dsm_guid, 5,
- 1ULL << EDR_PORT_LOCATE_DSM))
- return pci_dev_get(pdev);
- obj = acpi_evaluate_dsm(adev->handle, &pci_acpi_dsm_guid, 5,
- EDR_PORT_LOCATE_DSM, NULL);
- if (!obj)
- return pci_dev_get(pdev);
- if (obj->type != ACPI_TYPE_INTEGER) {
- ACPI_FREE(obj);
- pci_err(pdev, FW_BUG "Locate Port _DSM returned non integer\n");
- return NULL;
- }
- /*
- * Firmware returns DPC port BDF details in following format:
- * 15:8 = bus
- * 7:3 = device
- * 2:0 = function
- */
- port = obj->integer.value;
- ACPI_FREE(obj);
- return pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
- PCI_BUS_NUM(port), port & 0xff);
- }
- /*
- * _OST wrapper function to let firmware know the status of EDR event
- * @pdev : Device used to send _OST
- * @edev : Device which experienced EDR event
- * @status : Status of EDR event
- */
- static int acpi_send_edr_status(struct pci_dev *pdev, struct pci_dev *edev,
- u16 status)
- {
- struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
- u32 ost_status;
- pci_dbg(pdev, "Status for %s: %#x\n", pci_name(edev), status);
- ost_status = PCI_DEVID(edev->bus->number, edev->devfn) << 16;
- ost_status |= status;
- status = acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_DISCONNECT_RECOVER,
- ost_status, NULL);
- if (ACPI_FAILURE(status))
- return -EINVAL;
- return 0;
- }
- static void edr_handle_event(acpi_handle handle, u32 event, void *data)
- {
- struct pci_dev *pdev = data, *edev;
- pci_ers_result_t estate = PCI_ERS_RESULT_DISCONNECT;
- u16 status;
- if (event != ACPI_NOTIFY_DISCONNECT_RECOVER)
- return;
- pci_info(pdev, "EDR event received\n");
- /* Locate the port which issued EDR event */
- edev = acpi_dpc_port_get(pdev);
- if (!edev) {
- pci_err(pdev, "Firmware failed to locate DPC port\n");
- return;
- }
- pci_dbg(pdev, "Reported EDR dev: %s\n", pci_name(edev));
- /* If port does not support DPC, just send the OST */
- if (!edev->dpc_cap) {
- pci_err(edev, FW_BUG "This device doesn't support DPC\n");
- goto send_ost;
- }
- /* Check if there is a valid DPC trigger */
- pci_read_config_word(edev, edev->dpc_cap + PCI_EXP_DPC_STATUS, &status);
- if (!(status & PCI_EXP_DPC_STATUS_TRIGGER)) {
- pci_err(edev, "Invalid DPC trigger %#010x\n", status);
- goto send_ost;
- }
- dpc_process_error(edev);
- pci_aer_raw_clear_status(edev);
- /*
- * Irrespective of whether the DPC event is triggered by ERR_FATAL
- * or ERR_NONFATAL, since the link is already down, use the FATAL
- * error recovery path for both cases.
- */
- estate = pcie_do_recovery(edev, pci_channel_io_frozen, dpc_reset_link);
- send_ost:
- /*
- * If recovery is successful, send _OST(0xF, BDF << 16 | 0x80)
- * to firmware. If not successful, send _OST(0xF, BDF << 16 | 0x81).
- */
- if (estate == PCI_ERS_RESULT_RECOVERED) {
- pci_dbg(edev, "DPC port successfully recovered\n");
- pcie_clear_device_status(edev);
- acpi_send_edr_status(pdev, edev, EDR_OST_SUCCESS);
- } else {
- pci_dbg(edev, "DPC port recovery failed\n");
- acpi_send_edr_status(pdev, edev, EDR_OST_FAILED);
- }
- pci_dev_put(edev);
- }
- void pci_acpi_add_edr_notifier(struct pci_dev *pdev)
- {
- struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
- acpi_status status;
- if (!adev) {
- pci_dbg(pdev, "No valid ACPI node, skipping EDR init\n");
- return;
- }
- status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
- edr_handle_event, pdev);
- if (ACPI_FAILURE(status)) {
- pci_err(pdev, "Failed to install notify handler\n");
- return;
- }
- if (acpi_enable_dpc(pdev))
- acpi_remove_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
- edr_handle_event);
- else
- pci_dbg(pdev, "Notify handler installed\n");
- }
- void pci_acpi_remove_edr_notifier(struct pci_dev *pdev)
- {
- struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
- if (!adev)
- return;
- acpi_remove_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
- edr_handle_event);
- pci_dbg(pdev, "Notify handler removed\n");
- }
|