Revert "arm64: acpi/pci: invoke _DSM whether to preserve firmware PCI setup"

hulk inclusion
category: feature
bugzilla: 23453
CVE: NA

-------------------------------------------

The following mainline patch has added support for '_DSM' method. So let's
revert the 'hulk inclusion' patch and apply the mainline patch.

a78cf96 PCI/ACPI: Evaluate PCI Boot Configuration _DSM

This reverts commit 7155715e63b7854413b8ac37101b5fc11ae2894c.
Signed-off-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/arm64/kernel/pci.c

@@ -169,7 +169,6 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 	struct acpi_pci_generic_root_info *ri;
 	struct pci_bus *bus, *child;
 	struct acpi_pci_root_ops *root_ops;
-	union acpi_object *obj;
 
 	ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
 	if (!ri)
@@ -195,23 +194,8 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 	if (!bus)
 		return NULL;
 
-	/*
-	 * Invoke the PCI device specific method (_DSM) #5 'Ignore PCI Boot
-	 * Configuration', which tells us whether the firmware wants us to
-	 * preserve the configuration of the PCI resource tree for this root
-	 * bridge.
-	 */
-	obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 1,
-				IGNORE_PCI_BOOT_CONFIG_DSM, NULL);
-	if (obj && obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 0) {
-		/* preserve existing resource assignment */
-		pci_bus_claim_resources(bus);
-	} else {
-		/* reconfigure the resource tree from scratch */
-		pci_bus_size_bridges(bus);
-		pci_bus_assign_resources(bus);
-	}
-	ACPI_FREE(obj);
+	pci_bus_size_bridges(bus);
+	pci_bus_assign_resources(bus);
 
 	list_for_each_entry(child, &bus->children, node)
 		pcie_bus_configure_settings(child);

include/linux/pci-acpi.h

@@ -107,7 +107,6 @@ static inline void acpiphp_check_host_bridge(struct acpi_device *adev) { }
 #endif
 
 extern const guid_t pci_acpi_dsm_guid;
-#define IGNORE_PCI_BOOT_CONFIG_DSM	0x05
 #define DEVICE_LABEL_DSM	0x07
 #define RESET_DELAY_DSM		0x08
 #define FUNCTION_DELAY_DSM	0x09