1 files changed, 409 insertions, 0 deletions

diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
new file mode 100644
index 000000000..a5d7c69b7
--- /dev/null
+++ b/drivers/pci/pcie/dpc.c
@@ -0,0 +1,409 @@
+// 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 DECLARE_WAIT_QUEUE_HEAD(dpc_completed_waitqueue);
+
+#ifdef CONFIG_HOTPLUG_PCI_PCIE
+static bool dpc_completed(struct pci_dev *pdev)
+{
+	u16 status;
+
+	pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_STATUS, &status);
+	if ((!PCI_POSSIBLE_ERROR(status)) && (status & PCI_EXP_DPC_STATUS_TRIGGER))
+		return false;
+
+	if (test_bit(PCI_DPC_RECOVERING, &pdev->priv_flags))
+		return false;
+
+	return true;
+}
+
+/**
+ * pci_dpc_recovered - whether DPC triggered and has recovered successfully
+ * @pdev: PCI device
+ *
+ * Return true if DPC was triggered for @pdev and has recovered successfully.
+ * Wait for recovery if it hasn't completed yet.  Called from the PCIe hotplug
+ * driver to recognize and ignore Link Down/Up events caused by DPC.
+ */
+bool pci_dpc_recovered(struct pci_dev *pdev)
+{
+	struct pci_host_bridge *host;
+
+	if (!pdev->dpc_cap)
+		return false;
+
+	/*
+	 * Synchronization between hotplug and DPC is not supported
+	 * if DPC is owned by firmware and EDR is not enabled.
+	 */
+	host = pci_find_host_bridge(pdev->bus);
+	if (!host->native_dpc && !IS_ENABLED(CONFIG_PCIE_EDR))
+		return false;
+
+	/*
+	 * Need a timeout in case DPC never completes due to failure of
+	 * dpc_wait_rp_inactive().  The spec doesn't mandate a time limit,
+	 * but reports indicate that DPC completes within 4 seconds.
+	 */
+	wait_event_timeout(dpc_completed_waitqueue, dpc_completed(pdev),
+			   msecs_to_jiffies(4000));
+
+	return test_and_clear_bit(PCI_DPC_RECOVERED, &pdev->priv_flags);
+}
+#endif /* CONFIG_HOTPLUG_PCI_PCIE */
+
+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)
+{
+	pci_ers_result_t ret;
+	u16 cap;
+
+	set_bit(PCI_DPC_RECOVERING, &pdev->priv_flags);
+
+	/*
+	 * 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.
+	 */
+	if (!pcie_wait_for_link(pdev, false))
+		pci_info(pdev, "Data Link Layer Link Active not cleared in 1000 msec\n");
+
+	if (pdev->dpc_rp_extensions && dpc_wait_rp_inactive(pdev)) {
+		clear_bit(PCI_DPC_RECOVERED, &pdev->priv_flags);
+		ret = PCI_ERS_RESULT_DISCONNECT;
+		goto out;
+	}
+
+	pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,
+			      PCI_EXP_DPC_STATUS_TRIGGER);
+
+	if (pci_bridge_wait_for_secondary_bus(pdev, "DPC",
+					      PCIE_RESET_READY_POLL_MS)) {
+		clear_bit(PCI_DPC_RECOVERED, &pdev->priv_flags);
+		ret = PCI_ERS_RESULT_DISCONNECT;
+	} else {
+		set_bit(PCI_DPC_RECOVERED, &pdev->priv_flags);
+		ret = PCI_ERS_RESULT_RECOVERED;
+	}
+out:
+	clear_bit(PCI_DPC_RECOVERING, &pdev->priv_flags);
+	wake_up_all(&dpc_completed_waitqueue);
+	return ret;
+}
+
+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) || PCI_POSSIBLE_ERROR(status))
+		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;
+
+	/* Quirks may set dpc_rp_log_size if device or firmware is buggy */
+	if (!pdev->dpc_rp_log_size) {
+		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);
+}