1 files changed, 307 insertions, 0 deletions
diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
new file mode 100644
index 000000000000..8c57d607e603
--- /dev/null
+++ b/drivers/pci/pcie/dpc.c
@@ -0,0 +1,307 @@
+// 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.
+ */
+
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+
+#include "portdrv.h"
+#include "../pci.h"
+#include "aer/aerdrv.h"
+
+struct dpc_dev {
+	struct pcie_device	*dev;
+	struct work_struct	work;
+	u16			cap_pos;
+	bool			rp_extensions;
+	u32			rp_pio_status;
+	u8			rp_log_size;
+};
+
+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 */
+};
+
+static int dpc_wait_rp_inactive(struct dpc_dev *dpc)
+{
+	unsigned long timeout = jiffies + HZ;
+	struct pci_dev *pdev = dpc->dev->port;
+	struct device *dev = &dpc->dev->device;
+	u16 cap = dpc->cap_pos, 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) {
+		dev_warn(dev, "DPC root port still busy\n");
+		return -EBUSY;
+	}
+	return 0;
+}
+
+static void dpc_wait_link_inactive(struct dpc_dev *dpc)
+{
+	unsigned long timeout = jiffies + HZ;
+	struct pci_dev *pdev = dpc->dev->port;
+	struct device *dev = &dpc->dev->device;
+	u16 lnk_status;
+
+	pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
+	while (lnk_status & PCI_EXP_LNKSTA_DLLLA &&
+					!time_after(jiffies, timeout)) {
+		msleep(10);
+		pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
+	}
+	if (lnk_status & PCI_EXP_LNKSTA_DLLLA)
+		dev_warn(dev, "Link state not disabled for DPC event\n");
+}
+
+static void dpc_work(struct work_struct *work)
+{
+	struct dpc_dev *dpc = container_of(work, struct dpc_dev, work);
+	struct pci_dev *dev, *temp, *pdev = dpc->dev->port;
+	struct pci_bus *parent = pdev->subordinate;
+	u16 cap = dpc->cap_pos, ctl;
+
+	pci_lock_rescan_remove();
+	list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
+					 bus_list) {
+		pci_dev_get(dev);
+		pci_dev_set_disconnected(dev, NULL);
+		if (pci_has_subordinate(dev))
+			pci_walk_bus(dev->subordinate,
+				     pci_dev_set_disconnected, NULL);
+		pci_stop_and_remove_bus_device(dev);
+		pci_dev_put(dev);
+	}
+	pci_unlock_rescan_remove();
+
+	dpc_wait_link_inactive(dpc);
+	if (dpc->rp_extensions && dpc_wait_rp_inactive(dpc))
+		return;
+	if (dpc->rp_extensions && dpc->rp_pio_status) {
+		pci_write_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS,
+				       dpc->rp_pio_status);
+		dpc->rp_pio_status = 0;
+	}
+
+	pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,
+		PCI_EXP_DPC_STATUS_TRIGGER | PCI_EXP_DPC_STATUS_INTERRUPT);
+
+	pci_read_config_word(pdev, cap + PCI_EXP_DPC_CTL, &ctl);
+	pci_write_config_word(pdev, cap + PCI_EXP_DPC_CTL,
+			      ctl | PCI_EXP_DPC_CTL_INT_EN);
+}
+
+static void dpc_process_rp_pio_error(struct dpc_dev *dpc)
+{
+	struct device *dev = &dpc->dev->device;
+	struct pci_dev *pdev = dpc->dev->port;
+	u16 cap = dpc->cap_pos, 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);
+	dev_err(dev, "rp_pio_status: %#010x, rp_pio_mask: %#010x\n",
+		status, mask);
+
+	dpc->rp_pio_status = status;
+
+	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);
+	dev_err(dev, "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;
+
+	status &= ~mask;
+	for (i = 0; i < ARRAY_SIZE(rp_pio_error_string); i++) {
+		if (status & (1 << i))
+			dev_err(dev, "[%2d] %s%s\n", i, rp_pio_error_string[i],
+				first_error == i ? " (First)" : "");
+	}
+
+	if (dpc->rp_log_size < 4)
+		return;
+	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);
+	dev_err(dev, "TLP Header: %#010x %#010x %#010x %#010x\n",
+		dw0, dw1, dw2, dw3);
+
+	if (dpc->rp_log_size < 5)
+		return;
+	pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_IMPSPEC_LOG, &log);
+	dev_err(dev, "RP PIO ImpSpec Log %#010x\n", log);
+
+	for (i = 0; i < dpc->rp_log_size - 5; i++) {
+		pci_read_config_dword(pdev,
+			cap + PCI_EXP_DPC_RP_PIO_TLPPREFIX_LOG, &prefix);
+		dev_err(dev, "TLP Prefix Header: dw%d, %#010x\n", i, prefix);
+	}
+}
+
+static irqreturn_t dpc_irq(int irq, void *context)
+{
+	struct dpc_dev *dpc = (struct dpc_dev *)context;
+	struct pci_dev *pdev = dpc->dev->port;
+	struct device *dev = &dpc->dev->device;
+	u16 cap = dpc->cap_pos, ctl, status, source, reason, ext_reason;
+
+	pci_read_config_word(pdev, cap + PCI_EXP_DPC_CTL, &ctl);
+
+	if (!(ctl & PCI_EXP_DPC_CTL_INT_EN) || ctl == (u16)(~0))
+		return IRQ_NONE;
+
+	pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
+
+	if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT))
+		return IRQ_NONE;
+
+	if (!(status & PCI_EXP_DPC_STATUS_TRIGGER)) {
+		pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,
+				      PCI_EXP_DPC_STATUS_INTERRUPT);
+		return IRQ_HANDLED;
+	}
+
+	pci_write_config_word(pdev, cap + PCI_EXP_DPC_CTL,
+			      ctl & ~PCI_EXP_DPC_CTL_INT_EN);
+
+	pci_read_config_word(pdev, cap + PCI_EXP_DPC_SOURCE_ID,
+			     &source);
+
+	dev_info(dev, "DPC 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;
+
+	dev_warn(dev, "DPC %s detected, remove downstream devices\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 (dpc->rp_extensions && reason == 3 && ext_reason == 0)
+		dpc_process_rp_pio_error(dpc);
+
+	schedule_work(&dpc->work);
+
+	return IRQ_HANDLED;
+}
+
+#define FLAG(x, y) (((x) & (y)) ? '+' : '-')
+static int dpc_probe(struct pcie_device *dev)
+{
+	struct dpc_dev *dpc;
+	struct pci_dev *pdev = dev->port;
+	struct device *device = &dev->device;
+	int status;
+	u16 ctl, cap;
+
+	if (pcie_aer_get_firmware_first(pdev))
+		return -ENOTSUPP;
+
+	dpc = devm_kzalloc(device, sizeof(*dpc), GFP_KERNEL);
+	if (!dpc)
+		return -ENOMEM;
+
+	dpc->cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC);
+	dpc->dev = dev;
+	INIT_WORK(&dpc->work, dpc_work);
+	set_service_data(dev, dpc);
+
+	status = devm_request_irq(device, dev->irq, dpc_irq, IRQF_SHARED,
+				  "pcie-dpc", dpc);
+	if (status) {
+		dev_warn(device, "request IRQ%d failed: %d\n", dev->irq,
+			 status);
+		return status;
+	}
+
+	pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CAP, &cap);
+	pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl);
+
+	dpc->rp_extensions = (cap & PCI_EXP_DPC_CAP_RP_EXT);
+	if (dpc->rp_extensions) {
+		dpc->rp_log_size = (cap & PCI_EXP_DPC_RP_PIO_LOG_SIZE) >> 8;
+		if (dpc->rp_log_size < 4 || dpc->rp_log_size > 9) {
+			dev_err(device, "RP PIO log size %u is invalid\n",
+				dpc->rp_log_size);
+			dpc->rp_log_size = 0;
+		}
+	}
+
+	ctl = (ctl & 0xfff4) | PCI_EXP_DPC_CTL_EN_NONFATAL | PCI_EXP_DPC_CTL_INT_EN;
+	pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl);
+
+	dev_info(device, "DPC 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), dpc->rp_log_size,
+		FLAG(cap, PCI_EXP_DPC_CAP_DL_ACTIVE));
+	return status;
+}
+
+static void dpc_remove(struct pcie_device *dev)
+{
+	struct dpc_dev *dpc = get_service_data(dev);
+	struct pci_dev *pdev = dev->port;
+	u16 ctl;
+
+	pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl);
+	ctl &= ~(PCI_EXP_DPC_CTL_EN_NONFATAL | PCI_EXP_DPC_CTL_INT_EN);
+	pci_write_config_word(pdev, dpc->cap_pos + 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,
+};
+
+static int __init dpc_service_init(void)
+{
+	return pcie_port_service_register(&dpcdriver);
+}
+device_initcall(dpc_service_init);