[PATCH v2 1/3] ACPI/APEI: Add hest_parse_pcie_aer()

[LeoLiu-oc <LeoLiu-oc@zhaoxin.com>]

From: LeoLiuoc <LeoLiu-oc@zhaoxin.com>

The purpose of the function apei_hest_parse_aer() is used to parse and
extract register value from HEST PCIe AER structures.

Signed-off-by: LeoLiuoc <LeoLiu-oc@zhaoxin.com>
---
 drivers/acpi/apei/hest.c | 69 ++++++++++++++++++++++++++++++++++++++--
 include/acpi/apei.h      | 17 ++++++++++
 2 files changed, 84 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/apei/hest.c b/drivers/acpi/apei/hest.c
index 6aef1ee5e1bd..7e7026c0001b 100644
--- a/drivers/acpi/apei/hest.c
+++ b/drivers/acpi/apei/hest.c
@@ -22,6 +22,7 @@
 #include <linux/kdebug.h>
 #include <linux/highmem.h>
 #include <linux/io.h>
+#include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <acpi/apei.h>
 #include <acpi/ghes.h>
@@ -86,9 +87,73 @@ static int hest_esrc_len(struct acpi_hest_header *hest_hdr)
 	return len;
 };
 
-typedef int (*apei_hest_func_t)(struct acpi_hest_header *hest_hdr, void *data);
+#ifdef CONFIG_ACPI_APEI
+static bool hest_match_pci_devfn(struct acpi_hest_aer_common *p, struct pci_dev *dev)
+{
+	return ACPI_HEST_SEGMENT(p->bus) == pci_domain_nr(dev->bus) &&
+		ACPI_HEST_BUS(p->bus) == dev->bus->number &&
+		p->device == PCI_SLOT(dev->devfn) &&
+		p->function == PCI_FUNC(dev->devfn);
+}
+
+static bool hest_source_is_pcie_aer(struct acpi_hest_header *hest_hdr, struct pci_dev *dev)
+{
+	u16 hest_type = hest_hdr->type;
+	u8 pcie_type = pci_pcie_type(dev);
+	struct acpi_hest_aer_common *common;
+
+	switch (hest_type) {
+	case ACPI_HEST_TYPE_AER_ROOT_PORT:
+		if (pcie_type != PCI_EXP_TYPE_ROOT_PORT)
+			return false;
+		break;
+	case ACPI_HEST_TYPE_AER_ENDPOINT:
+		if (pcie_type != PCI_EXP_TYPE_ENDPOINT)
+			return false;
+		break;
+	case ACPI_HEST_TYPE_AER_BRIDGE:
+		if (pcie_type != PCI_EXP_TYPE_PCI_BRIDGE &&
+			pcie_type != PCI_EXP_TYPE_PCIE_BRIDGE)
+			return false;
+		break;
+	default:
+		return false;
+	}
+
+	common = (struct acpi_hest_aer_common *)(hest_hdr + 1);
+	if (common->flags & ACPI_HEST_GLOBAL)
+		return true;
+
+	if (hest_match_pci_devfn(common, dev))
+		return true;
+
+	return false;
+}
+
+int hest_parse_pcie_aer(struct acpi_hest_header *hest_hdr, void *data)
+{
+	struct hest_parse_aer_info *info = data;
+
+	if (!hest_source_is_pcie_aer(hest_hdr, info->pci_dev))
+		return 0;
+
+	switch (hest_hdr->type) {
+	case ACPI_HEST_TYPE_AER_ROOT_PORT:
+		info->hest_aer_root_port = (struct acpi_hest_aer_root *)hest_hdr;
+		return 1;
+	case ACPI_HEST_TYPE_AER_ENDPOINT:
+		info->hest_aer_endpoint = (struct acpi_hest_aer *)hest_hdr;
+		return 1;
+	case ACPI_HEST_TYPE_AER_BRIDGE:
+		info->hest_aer_bridge = (struct acpi_hest_aer_bridge *)hest_hdr;
+		return 1;
+	default:
+		return 0;
+	}
+}
+#endif
 
-static int apei_hest_parse(apei_hest_func_t func, void *data)
+int apei_hest_parse(apei_hest_func_t func, void *data)
 {
 	struct acpi_hest_header *hest_hdr;
 	int i, rc, len;
diff --git a/include/acpi/apei.h b/include/acpi/apei.h
index dc60f7db5524..82d3cdf53e22 100644
--- a/include/acpi/apei.h
+++ b/include/acpi/apei.h
@@ -23,6 +23,15 @@ enum hest_status {
 	HEST_NOT_FOUND,
 };
 
+#ifdef CONFIG_ACPI_APEI
+struct hest_parse_aer_info {
+	struct pci_dev *pci_dev;
+	struct acpi_hest_aer *hest_aer_endpoint;
+	struct acpi_hest_aer_root *hest_aer_root_port;
+	struct acpi_hest_aer_bridge *hest_aer_bridge;
+};
+#endif
+
 extern int hest_disable;
 extern int erst_disable;
 #ifdef CONFIG_ACPI_APEI_GHES
@@ -33,10 +42,18 @@ void __init acpi_ghes_init(void);
 static inline void acpi_ghes_init(void) { }
 #endif
 
+typedef int (*apei_hest_func_t)(struct acpi_hest_header *hest_hdr, void *data);
+int apei_hest_parse(apei_hest_func_t func, void *data);
+
 #ifdef CONFIG_ACPI_APEI
 void __init acpi_hest_init(void);
+int hest_parse_pcie_aer(struct acpi_hest_header *hest_hdr, void *data);
 #else
 static inline void acpi_hest_init(void) { }
+static inline int hest_parse_pcie_aer(struct acpi_hest_header *hest_hdr, void *data)
+{
+	return 0;
+}
 #endif
 
 int erst_write(const struct cper_record_header *record);
-- 
2.34.1