From 708b2000362476c9c7a3571c0cc774dffb91836a Mon Sep 17 00:00:00 2001
From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Date: Tue, 26 May 2020 16:18:29 -0700
Subject: [PATCH] PCI/AER: Remove HEST/FIRMWARE_FIRST parsing for AER ownership
Git-commit: 708b2000362476c9c7a3571c0cc774dffb91836a
Patch-mainline: v5.8-rc1
References: bsc#1174356

[ backport note: context changed to match with SLE15-SP1; especially this patch
  removes the remaining (stale) aerdrv_acpi.c code completely and adjusts
  Makefile as well -- tiwai ]

Commit c100beb9ccfb ("PCI/AER: Use only _OSC to determine AER ownership")
removed the use of HEST in determining AER ownership, but the AER driver
still used HEST to verify AER ownership in some of its APIs.

Per the ACPI spec v6.3, sec 18.3.2.4, some HEST table entries contain a
FIRMWARE_FIRST bit, but that bit does not tell us anything about ownership
of the AER capability.

Remove parsing of HEST to look for FIRMWARE_FIRST.

Add pcie_aer_is_native() for the places that need to know whether the OS
owns the AER capability.

[bhelgaas: commit log, reorder patch, remove unused __aer_firmware_first]
Link: https://lore.kernel.org/r/9a37f53a4e6ff4942ff8e18dbb20b00e16c47341.1590534843.git.sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/pci/pcie/aer/Makefile      |    1 
 drivers/pci/pcie/aer/aerdrv_acpi.c |  120 -------------------------------------
 drivers/pci/pcie/aer/aerdrv_core.c |   21 ++++--
 drivers/pci/pcie/dpc.c             |    2 
 drivers/pci/pcie/portdrv.h         |   13 ----
 include/linux/pci.h                |    2 
 6 files changed, 17 insertions(+), 142 deletions(-)

--- a/drivers/pci/pcie/aer/aerdrv_acpi.c
+++ /dev/null
@@ -1,120 +0,0 @@
-/*
- * Access ACPI _OSC method
- *
- * Copyright (C) 2006 Intel Corp.
- *	Tom Long Nguyen (tom.l.nguyen@intel.com)
- *	Zhang Yanmin (yanmin.zhang@intel.com)
- *
- */
-
-#include <linux/module.h>
-#include <linux/pci.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/pm.h>
-#include <linux/suspend.h>
-#include <linux/acpi.h>
-#include <linux/pci-acpi.h>
-#include <linux/delay.h>
-#include <acpi/apei.h>
-#include "aerdrv.h"
-
-#ifdef CONFIG_ACPI_APEI
-static inline int hest_match_pci(struct acpi_hest_aer_common *p,
-				 struct pci_dev *pci)
-{
-	return   ACPI_HEST_SEGMENT(p->bus) == pci_domain_nr(pci->bus) &&
-		 ACPI_HEST_BUS(p->bus)     == pci->bus->number &&
-		 p->device                 == PCI_SLOT(pci->devfn) &&
-		 p->function               == PCI_FUNC(pci->devfn);
-}
-
-static inline bool hest_match_type(struct acpi_hest_header *hest_hdr,
-				struct pci_dev *dev)
-{
-	u16 hest_type = hest_hdr->type;
-	u8 pcie_type = pci_pcie_type(dev);
-
-	if ((hest_type == ACPI_HEST_TYPE_AER_ROOT_PORT &&
-		pcie_type == PCI_EXP_TYPE_ROOT_PORT) ||
-	    (hest_type == ACPI_HEST_TYPE_AER_ENDPOINT &&
-		pcie_type == PCI_EXP_TYPE_ENDPOINT) ||
-	    (hest_type == ACPI_HEST_TYPE_AER_BRIDGE &&
-		(dev->class >> 16) == PCI_BASE_CLASS_BRIDGE))
-		return true;
-	return false;
-}
-
-struct aer_hest_parse_info {
-	struct pci_dev *pci_dev;
-	int firmware_first;
-};
-
-static int hest_source_is_pcie_aer(struct acpi_hest_header *hest_hdr)
-{
-	if (hest_hdr->type == ACPI_HEST_TYPE_AER_ROOT_PORT ||
-	    hest_hdr->type == ACPI_HEST_TYPE_AER_ENDPOINT ||
-	    hest_hdr->type == ACPI_HEST_TYPE_AER_BRIDGE)
-		return 1;
-	return 0;
-}
-
-static int aer_hest_parse(struct acpi_hest_header *hest_hdr, void *data)
-{
-	struct aer_hest_parse_info *info = data;
-	struct acpi_hest_aer_common *p;
-	int ff;
-
-	if (!hest_source_is_pcie_aer(hest_hdr))
-		return 0;
-
-	p = (struct acpi_hest_aer_common *)(hest_hdr + 1);
-	ff = !!(p->flags & ACPI_HEST_FIRMWARE_FIRST);
-
-	/*
-	 * If no specific device is supplied, determine whether
-	 * FIRMWARE_FIRST is set for *any* PCIe device.
-	 */
-	if (!info->pci_dev) {
-		info->firmware_first |= ff;
-		return 0;
-	}
-
-	/* Otherwise, check the specific device */
-	if (p->flags & ACPI_HEST_GLOBAL) {
-		if (hest_match_type(hest_hdr, info->pci_dev))
-			info->firmware_first = ff;
-	} else
-		if (hest_match_pci(p, info->pci_dev))
-			info->firmware_first = ff;
-
-	return 0;
-}
-
-static void aer_set_firmware_first(struct pci_dev *pci_dev)
-{
-	int rc;
-	struct aer_hest_parse_info info = {
-		.pci_dev	= pci_dev,
-		.firmware_first	= 0,
-	};
-
-	rc = apei_hest_parse(aer_hest_parse, &info);
-
-	if (rc)
-		pci_dev->__aer_firmware_first = 0;
-	else
-		pci_dev->__aer_firmware_first = info.firmware_first;
-	pci_dev->__aer_firmware_first_valid = 1;
-}
-
-int pcie_aer_get_firmware_first(struct pci_dev *dev)
-{
-	if (!pci_is_pcie(dev))
-		return 0;
-
-	if (!dev->__aer_firmware_first_valid)
-		aer_set_firmware_first(dev);
-	return dev->__aer_firmware_first;
-}
-#endif
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -246,7 +246,7 @@ static int dpc_probe(struct pcie_device
 	int status;
 	u16 ctl, cap;
 
-	if (pcie_aer_get_firmware_first(pdev))
+	if (!pcie_aer_is_native(pdev))
 		return -ENOTSUPP;
 
 	dpc = devm_kzalloc(device, sizeof(*dpc), GFP_KERNEL);
--- a/drivers/pci/pcie/portdrv.h
+++ b/drivers/pci/pcie/portdrv.h
@@ -27,8 +27,10 @@
 
 #ifdef CONFIG_PCIEAER
 int pcie_aer_init(void);
+int pcie_aer_is_native(struct pci_dev *dev);
 #else
 static inline int pcie_aer_init(void) { return 0; }
+static inline int pcie_aer_is_native(struct pci_dev *dev) { return 0; }
 #endif
 
 #ifdef CONFIG_HOTPLUG_PCI_PCIE
@@ -154,17 +156,6 @@ static inline bool pcie_pme_no_msi(void)
 static inline void pcie_pme_interrupt_enable(struct pci_dev *dev, bool en) {}
 #endif /* !CONFIG_PCIE_PME */
 
-#ifdef CONFIG_ACPI_APEI
-int pcie_aer_get_firmware_first(struct pci_dev *pci_dev);
-#else
-static inline int pcie_aer_get_firmware_first(struct pci_dev *pci_dev)
-{
-	if (pci_dev->__aer_firmware_first_valid)
-		return pci_dev->__aer_firmware_first;
-	return 0;
-}
-#endif
-
 struct pcie_port_service_driver *pcie_port_find_service(struct pci_dev *dev,
 							u32 service);
 struct device *pcie_port_find_device(struct pci_dev *dev, u32 service);
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -408,8 +408,6 @@ struct pci_dev {
 	 * mappings to make sure they cannot access arbitrary memory.
 	 */
 	unsigned int	untrusted:1;
-	unsigned int    __aer_firmware_first_valid:1;
-	unsigned int	__aer_firmware_first:1;
 	unsigned int	broken_intx_masking:1;
 	unsigned int	io_window_1k:1;	/* Intel P2P bridge 1K I/O windows */
 	unsigned int	irq_managed:1;
--- a/drivers/pci/pcie/aer/aerdrv_core.c
+++ b/drivers/pci/pcie/aer/aerdrv_core.c
@@ -31,12 +31,19 @@
 #define	PCI_EXP_AER_FLAGS	(PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
 				 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
 
-int pci_enable_pcie_error_reporting(struct pci_dev *dev)
+int pcie_aer_is_native(struct pci_dev *dev)
 {
-	if (pcie_aer_get_firmware_first(dev))
-		return -EIO;
+	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
 
 	if (!dev->aer_cap)
+		return 0;
+
+	return pcie_ports_native || host->native_aer;
+}
+
+int pci_enable_pcie_error_reporting(struct pci_dev *dev)
+{
+	if (!pcie_aer_is_native(dev))
 		return -EIO;
 
 	return pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
@@ -45,7 +52,7 @@ EXPORT_SYMBOL_GPL(pci_enable_pcie_error_
 
 int pci_disable_pcie_error_reporting(struct pci_dev *dev)
 {
-	if (pcie_aer_get_firmware_first(dev))
+	if (!pcie_aer_is_native(dev))
 		return -EIO;
 
 	return pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
@@ -70,7 +77,7 @@ int pci_cleanup_aer_uncorrect_error_stat
 	if (!pos)
 		return -EIO;
 
-	if (pcie_aer_get_firmware_first(dev))
+	if (!pcie_aer_is_native(dev))
 		return -EIO;
 
 	/* Clear status bits for ERR_NONFATAL errors only */
@@ -93,7 +100,7 @@ void pci_aer_clear_fatal_status(struct p
 	if (!pos)
 		return;
 
-	if (pcie_aer_get_firmware_first(dev))
+	if (!pcie_aer_is_native(dev))
 		return;
 
 	/* Clear status bits for ERR_FATAL errors only */
@@ -117,7 +124,7 @@ int pci_cleanup_aer_error_status_regs(st
 	if (!pos)
 		return -EIO;
 
-	if (pcie_aer_get_firmware_first(dev))
+	if (!pcie_aer_is_native(dev))
 		return -EIO;
 
 	port_type = pci_pcie_type(dev);
--- a/drivers/pci/pcie/aer/Makefile
+++ b/drivers/pci/pcie/aer/Makefile
@@ -7,6 +7,5 @@ obj-$(CONFIG_PCIEAER) += aerdriver.o
 obj-$(CONFIG_PCIE_ECRC)	+= ecrc.o
 
 aerdriver-objs := aerdrv_errprint.o aerdrv_core.o aerdrv.o
-aerdriver-$(CONFIG_ACPI) += aerdrv_acpi.o
 
 obj-$(CONFIG_PCIEAER_INJECT) += aer_inject.o