diff options
| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2019-06-15 10:23:57 +1000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2019-06-24 10:50:09 +1000 |
| commit | 20dfd66e81431e130fd53df38055947c5f0a1b5b (patch) | |
| tree | 716ec03f9e7b7f92061c55884ca2054f11fc0c38 | |
| parent | 4b972a01a7da614b4796475f933094751a295a2f (diff) | |
| download | pci-20dfd66e81431e130fd53df38055947c5f0a1b5b.tar.gz | |
PCI/ACPI: Evaluate PCI Boot Configuration _DSM
Evaluate _DSM Function #5, the "PCI Boot Configuration" function. If the
result is 0, the OS should preserve any resource assignments made by the
firmware.
Link: https://lore.kernel.org/r/20190615002359.29577-2-benh@kernel.crashing.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
| -rw-r--r-- | drivers/acpi/pci_root.c | 12 | ||||
| -rw-r--r-- | include/linux/pci-acpi.h | 7 | ||||
| -rw-r--r-- | include/linux/pci.h | 2 |
3 files changed, 18 insertions, 3 deletions
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 39f5d172e84fef..314a187ed57281 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); diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h index 8082b612f5612e..62b7fdcc661c30 100644 --- a/include/linux/pci-acpi.h +++ b/include/linux/pci-acpi.h @@ -107,9 +107,10 @@ static inline void acpiphp_check_host_bridge(struct acpi_device *adev) { } #endif extern const guid_t pci_acpi_dsm_guid; -#define DEVICE_LABEL_DSM 0x07 -#define RESET_DELAY_DSM 0x08 -#define FUNCTION_DELAY_DSM 0x09 +#define IGNORE_PCI_BOOT_CONFIG_DSM 0x05 +#define DEVICE_LABEL_DSM 0x07 +#define RESET_DELAY_DSM 0x08 +#define FUNCTION_DELAY_DSM 0x09 #else /* CONFIG_ACPI */ static inline void acpi_pci_add_bus(struct pci_bus *bus) { } diff --git a/include/linux/pci.h b/include/linux/pci.h index dd436da7eccc1f..e6c8f6f8e42fb1 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -506,6 +506,8 @@ struct pci_host_bridge { unsigned int native_shpc_hotplug:1; /* OS may use SHPC hotplug */ unsigned int native_pme:1; /* OS may use PCIe PME */ unsigned int native_ltr:1; /* OS may use PCIe LTR */ + unsigned int preserve_config:1; /* Preserve FW resource setup */ + /* Resource alignment requirements */ resource_size_t (*align_resource)(struct pci_dev *dev, const struct resource *res, |