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-rw-r--r--drivers/pci/pci-acpi.c2
-rw-r--r--drivers/pci/pcie/Kconfig10
-rw-r--r--drivers/pci/pcie/Makefile1
-rw-r--r--drivers/pci/pcie/edr.c239
-rw-r--r--drivers/pci/probe.c1
5 files changed, 253 insertions, 0 deletions
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 0c02d500158f..1a6d2062cf8d 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -1241,6 +1241,7 @@ static void pci_acpi_setup(struct device *dev)
pci_acpi_optimize_delay(pci_dev, adev->handle);
pci_acpi_set_untrusted(pci_dev);
+ pci_acpi_add_edr_notifier(pci_dev);
pci_acpi_add_pm_notifier(adev, pci_dev);
if (!adev->wakeup.flags.valid)
@@ -1268,6 +1269,7 @@ static void pci_acpi_cleanup(struct device *dev)
if (!adev)
return;
+ pci_acpi_remove_edr_notifier(pci_dev);
pci_acpi_remove_pm_notifier(adev);
if (adev->wakeup.flags.valid) {
acpi_device_power_remove_dependent(adev, dev);
diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig
index 6e3c04b46fb1..772b1f4cb19e 100644
--- a/drivers/pci/pcie/Kconfig
+++ b/drivers/pci/pcie/Kconfig
@@ -140,3 +140,13 @@ config PCIE_BW
This enables PCI Express Bandwidth Change Notification. If
you know link width or rate changes occur only to correct
unreliable links, you may answer Y.
+
+config PCIE_EDR
+ bool "PCI Express Error Disconnect Recover support"
+ depends on PCIE_DPC && ACPI
+ help
+ This option adds Error Disconnect Recover support as specified
+ in the Downstream Port Containment Related Enhancements ECN to
+ the PCI Firmware Specification r3.2. Enable this if you want to
+ support hybrid DPC model which uses both firmware and OS to
+ implement DPC.
diff --git a/drivers/pci/pcie/Makefile b/drivers/pci/pcie/Makefile
index efb9d2e71e9e..68da9280ff11 100644
--- a/drivers/pci/pcie/Makefile
+++ b/drivers/pci/pcie/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_PCIE_PME) += pme.o
obj-$(CONFIG_PCIE_DPC) += dpc.o
obj-$(CONFIG_PCIE_PTM) += ptm.o
obj-$(CONFIG_PCIE_BW) += bw_notification.o
+obj-$(CONFIG_PCIE_EDR) += edr.o
diff --git a/drivers/pci/pcie/edr.c b/drivers/pci/pcie/edr.c
new file mode 100644
index 000000000000..594622a6cb16
--- /dev/null
+++ b/drivers/pci/pcie/edr.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI Error Disconnect Recover support
+ * Author: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
+ *
+ * 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;
+
+ pci_info(pdev, "ACPI event %#x received\n", event);
+
+ if (event != ACPI_NOTIFY_DISCONNECT_RECOVER)
+ return;
+
+ /* 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");
+ 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");
+}
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index c6f91f886818..f67c007edcae 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -598,6 +598,7 @@ static void pci_init_host_bridge(struct pci_host_bridge *bridge)
bridge->native_shpc_hotplug = 1;
bridge->native_pme = 1;
bridge->native_ltr = 1;
+ bridge->native_dpc = 1;
}
struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-21 17:12:13 +0000