linux-kernel - [PATCH 2/2] PCI/AER: Determine AER ownership based on

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Message-Id: <20181115231605.24352-3-mr.nuke.me@gmail.com>
Date:   Thu, 15 Nov 2018 17:16:03 -0600
From:   Alexandru Gagniuc <mr.nuke.me@...il.com>
To:     helgaas@...gle.com
Cc:     austin_bolen@...l.com, alex_gagniuc@...lteam.com,
        keith.busch@...el.com, Shyam_Iyer@...l.com, lukas@...ner.de,
        Alexandru Gagniuc <mr.nuke.me@...il.com>,
        Bjorn Helgaas <bhelgaas@...gle.com>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Len Brown <lenb@...nel.org>,
        Russell Currey <ruscur@...sell.cc>,
        Sam Bobroff <sbobroff@...ux.ibm.com>,
        "Oliver O'Halloran" <oohall@...il.com>, linux-pci@...r.kernel.org,
        linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org,
        linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH 2/2] PCI/AER: Determine AER ownership based on _OSC instead of HEST

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@...il.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