[PATCH 2/2] PCI/AER: Determine AER ownership based on _OSC instead of HEST

From: Alexandru Gagniuc <mr.nuke.me@gmail.com>
To: helgaas@google.com
Cc: alex_gagniuc@dellteam.com, Sam Bobroff <sbobroff@linux.ibm.com>,
	linux-pci@vger.kernel.org, Shyam_Iyer@Dell.com,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	linux-kernel@vger.kernel.org, keith.busch@intel.com,
	linux-acpi@vger.kernel.org, lukas@wunner.de,
	Oliver O'Halloran <oohall@gmail.com>,
	Alexandru Gagniuc <mr.nuke.me@gmail.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	austin_bolen@dell.com, linuxppc-dev@lists.ozlabs.org,
	Len Brown <lenb@kernel.org>
Subject: [PATCH 2/2] PCI/AER: Determine AER ownership based on _OSC instead of HEST
Date: Thu, 15 Nov 2018 17:16:03 -0600	[thread overview]
Message-ID: <20181115231605.24352-3-mr.nuke.me@gmail.com> (raw)
In-Reply-To: <20181115231605.24352-1-mr.nuke.me@gmail.com>

HEST is used to describe the meaning of errors received as part of ACPI
Platform Error Interfaces (APEI), however the correct way to determine
AER ownership is the _OSC method.

pci_dev->__aer_firmware_first is used to prevent modification of AER
registers when firmware owns AER. This is synonymous with the AER
ownership negotiated during _OSC. Thus _OSC is the correct way to
use to set this flag, not HEST.

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
---
 drivers/pci/pcie/aer.c | 57 ++----------------------------------------
 1 file changed, 2 insertions(+), 55 deletions(-)

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index ac014151b7a6..dd9594e8ed08 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -240,66 +240,13 @@ static inline bool hest_match_type(struct acpi_hest_header *hest_hdr,
 	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,
-	};
+	struct pci_host_bridge *host = pci_find_host_bridge(pci_dev->bus);
 
-	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 = !host->native_aer;
 	pci_dev->__aer_firmware_first_valid = 1;
 }
 
-- 
2.17.1

