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authorPaolo Bonzini <pbonzini@redhat.com>2019-08-09 16:53:39 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2019-08-09 16:53:39 +0200
commit0e1c438c44dd9cde56effb44c5f1cfeda72e108d (patch)
treefa3492d4d7d8b7444e5d8ebe6c78210826333e4b /drivers/acpi/pci_root.c
parentc096397c78f766db972f923433031f2dec01cae0 (diff)
parentcdb2d3ee0436d74fa9092f2df46aaa6f9e03c969 (diff)
Merge tag 'kvmarm-fixes-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm fixes for 5.3 - A bunch of switch/case fall-through annotation, fixing one actual bug - Fix PMU reset bug - Add missing exception class debug strings
Diffstat (limited to 'drivers/acpi/pci_root.c')
-rw-r--r--drivers/acpi/pci_root.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 39f5d172e84fe..314a187ed5728 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -881,6 +881,7 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
int node = acpi_get_node(device->handle);
struct pci_bus *bus;
struct pci_host_bridge *host_bridge;
+ union acpi_object *obj;
info->root = root;
info->bridge = device;
@@ -917,6 +918,17 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
host_bridge->native_ltr = 0;
+ /*
+ * Evaluate the "PCI Boot Configuration" _DSM Function. If it
+ * exists and returns 0, we must preserve any PCI resource
+ * assignments made by firmware for this host 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)
+ host_bridge->preserve_config = 1;
+ ACPI_FREE(obj);
+
pci_scan_child_bus(bus);
pci_set_host_bridge_release(host_bridge, acpi_pci_root_release_info,
info);