Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 240 insertions, 0 deletions

diff --git a/drivers/pci/pcie/edr.c b/drivers/pci/pcie/edr.c
new file mode 100644
index 000000000..87734e4c3
--- /dev/null
+++ b/drivers/pci/pcie/edr.c
@@ -0,0 +1,240 @@
+// 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;
+
+	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");
+}