From 1543e317f1da31b75942316931e8f491a8920811 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Thu, 04 Jan 2024 10:08:02 +0000
Subject: [PATCH] disable FB

---
 kernel/drivers/pci/pcie/dpc.c |  265 +++++++++++++++++++++++++++++++++++-----------------
 1 files changed, 178 insertions(+), 87 deletions(-)

diff --git a/kernel/drivers/pci/pcie/dpc.c b/kernel/drivers/pci/pcie/dpc.c
index 118b5bc..f21d64a 100644
--- a/kernel/drivers/pci/pcie/dpc.c
+++ b/kernel/drivers/pci/pcie/dpc.c
@@ -6,6 +6,8 @@
  * Copyright (C) 2016 Intel Corp.
  */
 
+#define dev_fmt(fmt) "DPC: " fmt
+
 #include <linux/aer.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
@@ -14,13 +16,6 @@
 
 #include "portdrv.h"
 #include "../pci.h"
-
-struct dpc_dev {
-	struct pcie_device	*dev;
-	u16			cap_pos;
-	bool			rp_extensions;
-	u8			rp_log_size;
-};
 
 static const char * const rp_pio_error_string[] = {
 	"Configuration Request received UR Completion",	 /* Bit Position 0  */
@@ -44,12 +39,94 @@
 	"Memory Request Completion Timeout",		 /* Bit Position 18 */
 };
 
-static int dpc_wait_rp_inactive(struct dpc_dev *dpc)
+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 ((status != 0xffff) && (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;
-	struct pci_dev *pdev = dpc->dev->port;
-	struct device *dev = &dpc->dev->device;
-	u16 cap = dpc->cap_pos, status;
+	u16 cap = pdev->dpc_cap, status;
 
 	pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
 	while (status & PCI_EXP_DPC_RP_BUSY &&
@@ -58,62 +135,70 @@
 		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");
+		pci_warn(pdev, "root port still busy\n");
 		return -EBUSY;
 	}
 	return 0;
 }
 
-static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
+pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
 {
-	struct dpc_dev *dpc;
-	struct pcie_device *pciedev;
-	struct device *devdpc;
-
+	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.
 	 */
-	devdpc = pcie_port_find_device(pdev, PCIE_PORT_SERVICE_DPC);
-	pciedev = to_pcie_device(devdpc);
-	dpc = get_service_data(pciedev);
-	cap = dpc->cap_pos;
+	cap = pdev->dpc_cap;
 
 	/*
 	 * Wait until the Link is inactive, then clear DPC Trigger Status
 	 * to allow the Port to leave DPC.
 	 */
-	pcie_wait_for_link(pdev, false);
+	if (!pcie_wait_for_link(pdev, false))
+		pci_info(pdev, "Data Link Layer Link Active not cleared in 1000 msec\n");
 
-	if (dpc->rp_extensions && dpc_wait_rp_inactive(dpc))
-		return PCI_ERS_RESULT_DISCONNECT;
+	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);
 
-	return PCI_ERS_RESULT_RECOVERED;
+	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 dpc_dev *dpc)
+static void dpc_process_rp_pio_error(struct pci_dev *pdev)
 {
-	struct device *dev = &dpc->dev->device;
-	struct pci_dev *pdev = dpc->dev->port;
-	u16 cap = dpc->cap_pos, dpc_status, first_error;
+	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);
-	dev_err(dev, "rp_pio_status: %#010x, rp_pio_mask: %#010x\n",
+	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);
-	dev_err(dev, "RP PIO severity=%#010x, syserror=%#010x, exception=%#010x\n",
+	pci_err(pdev, "RP PIO severity=%#010x, syserror=%#010x, exception=%#010x\n",
 		sev, syserr, exc);
 
 	/* Get First Error Pointer */
@@ -122,11 +207,11 @@
 
 	for (i = 0; i < ARRAY_SIZE(rp_pio_error_string); i++) {
 		if ((status & ~mask) & (1 << i))
-			dev_err(dev, "[%2d] %s%s\n", i, rp_pio_error_string[i],
+			pci_err(pdev, "[%2d] %s%s\n", i, rp_pio_error_string[i],
 				first_error == i ? " (First)" : "");
 	}
 
-	if (dpc->rp_log_size < 4)
+	if (pdev->dpc_rp_log_size < 4)
 		goto clear_status;
 	pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG,
 			      &dw0);
@@ -136,18 +221,18 @@
 			      &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",
+	pci_err(pdev, "TLP Header: %#010x %#010x %#010x %#010x\n",
 		dw0, dw1, dw2, dw3);
 
-	if (dpc->rp_log_size < 5)
+	if (pdev->dpc_rp_log_size < 5)
 		goto clear_status;
 	pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_IMPSPEC_LOG, &log);
-	dev_err(dev, "RP PIO ImpSpec Log %#010x\n", log);
+	pci_err(pdev, "RP PIO ImpSpec Log %#010x\n", log);
 
-	for (i = 0; i < dpc->rp_log_size - 5; i++) {
+	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);
-		dev_err(dev, "TLP Prefix Header: dw%d, %#010x\n", i, 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);
@@ -175,23 +260,20 @@
 	return 1;
 }
 
-static irqreturn_t dpc_handler(int irq, void *context)
+void dpc_process_error(struct pci_dev *pdev)
 {
+	u16 cap = pdev->dpc_cap, status, source, reason, ext_reason;
 	struct aer_err_info info;
-	struct dpc_dev *dpc = context;
-	struct pci_dev *pdev = dpc->dev->port;
-	struct device *dev = &dpc->dev->device;
-	u16 cap = dpc->cap_pos, status, source, reason, ext_reason;
 
 	pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
 	pci_read_config_word(pdev, cap + PCI_EXP_DPC_SOURCE_ID, &source);
 
-	dev_info(dev, "DPC containment event, status:%#06x source:%#06x\n",
+	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;
-	dev_warn(dev, "DPC %s detected, remove downstream devices\n",
+	pci_warn(pdev, "%s detected\n",
 		 (reason == 0) ? "unmasked uncorrectable error" :
 		 (reason == 1) ? "ERR_NONFATAL" :
 		 (reason == 2) ? "ERR_FATAL" :
@@ -200,27 +282,33 @@
 				     "reserved error");
 
 	/* show RP PIO error detail information */
-	if (dpc->rp_extensions && reason == 3 && ext_reason == 0)
-		dpc_process_rp_pio_error(dpc);
+	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_cleanup_aer_uncorrect_error_status(pdev);
+		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_fatal_recovery(pdev, PCIE_PORT_SERVICE_DPC);
+	pcie_do_recovery(pdev, pci_channel_io_frozen, dpc_reset_link);
 
 	return IRQ_HANDLED;
 }
 
 static irqreturn_t dpc_irq(int irq, void *context)
 {
-	struct dpc_dev *dpc = (struct dpc_dev *)context;
-	struct pci_dev *pdev = dpc->dev->port;
-	u16 cap = dpc->cap_pos, status;
+	struct pci_dev *pdev = context;
+	u16 cap = pdev->dpc_cap, status;
 
 	pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
 
@@ -234,68 +322,72 @@
 	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;
+	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 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))
+	if (!pcie_aer_is_native(pdev) && !pcie_ports_dpc_native)
 		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;
-	set_service_data(dev, dpc);
 
 	status = devm_request_threaded_irq(device, dev->irq, dpc_irq,
 					   dpc_handler, IRQF_SHARED,
-					   "pcie-dpc", dpc);
+					   "pcie-dpc", pdev);
 	if (status) {
-		dev_warn(device, "request IRQ%d failed: %d\n", dev->irq,
+		pci_warn(pdev, "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;
-		}
-	}
+	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, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl);
+	pci_write_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, ctl);
+	pci_info(pdev, "enabled with IRQ %d\n", dev->irq);
 
-	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));
+	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 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);
+	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, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl);
+	pci_write_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, ctl);
 }
 
 static struct pcie_port_service_driver dpcdriver = {
@@ -304,7 +396,6 @@
 	.service	= PCIE_PORT_SERVICE_DPC,
 	.probe		= dpc_probe,
 	.remove		= dpc_remove,
-	.reset_link	= dpc_reset_link,
 };
 
 int __init pcie_dpc_init(void)

--
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