diff options
Diffstat (limited to 'drivers/acpi/acpica/hwpci.c')
| -rw-r--r-- | drivers/acpi/acpica/hwpci.c | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/hwpci.c b/drivers/acpi/acpica/hwpci.c new file mode 100644 index 0000000000..3bd5ebc9c0 --- /dev/null +++ b/drivers/acpi/acpica/hwpci.c @@ -0,0 +1,384 @@ +// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 +/******************************************************************************* + * + * Module Name: hwpci - Obtain PCI bus, device, and function numbers + * + ******************************************************************************/ + +#include <acpi/acpi.h> +#include "accommon.h" + +#define _COMPONENT ACPI_NAMESPACE +ACPI_MODULE_NAME("hwpci") + +/* PCI configuration space values */ +#define PCI_CFG_HEADER_TYPE_REG 0x0E +#define PCI_CFG_PRIMARY_BUS_NUMBER_REG 0x18 +#define PCI_CFG_SECONDARY_BUS_NUMBER_REG 0x19 +/* PCI header values */ +#define PCI_HEADER_TYPE_MASK 0x7F +#define PCI_TYPE_BRIDGE 0x01 +#define PCI_TYPE_CARDBUS_BRIDGE 0x02 +typedef struct acpi_pci_device { + acpi_handle device; + struct acpi_pci_device *next; + +} acpi_pci_device; + +/* Local prototypes */ + +static acpi_status +acpi_hw_build_pci_list(acpi_handle root_pci_device, + acpi_handle pci_region, + struct acpi_pci_device **return_list_head); + +static acpi_status +acpi_hw_process_pci_list(struct acpi_pci_id *pci_id, + struct acpi_pci_device *list_head); + +static void acpi_hw_delete_pci_list(struct acpi_pci_device *list_head); + +static acpi_status +acpi_hw_get_pci_device_info(struct acpi_pci_id *pci_id, + acpi_handle pci_device, + u16 *bus_number, u8 *is_bridge); + +/******************************************************************************* + * + * FUNCTION: acpi_hw_derive_pci_id + * + * PARAMETERS: pci_id - Initial values for the PCI ID. May be + * modified by this function. + * root_pci_device - A handle to a PCI device object. This + * object must be a PCI Root Bridge having a + * _HID value of either PNP0A03 or PNP0A08 + * pci_region - A handle to a PCI configuration space + * Operation Region being initialized + * + * RETURN: Status + * + * DESCRIPTION: This function derives a full PCI ID for a PCI device, + * consisting of a Segment number, Bus number, Device number, + * and function code. + * + * The PCI hardware dynamically configures PCI bus numbers + * depending on the bus topology discovered during system + * initialization. This function is invoked during configuration + * of a PCI_Config Operation Region in order to (possibly) update + * the Bus/Device/Function numbers in the pci_id with the actual + * values as determined by the hardware and operating system + * configuration. + * + * The pci_id parameter is initially populated during the Operation + * Region initialization. This function is then called, and is + * will make any necessary modifications to the Bus, Device, or + * Function number PCI ID subfields as appropriate for the + * current hardware and OS configuration. + * + * NOTE: Created 08/2010. Replaces the previous OSL acpi_os_derive_pci_id + * interface since this feature is OS-independent. This module + * specifically avoids any use of recursion by building a local + * temporary device list. + * + ******************************************************************************/ + +acpi_status +acpi_hw_derive_pci_id(struct acpi_pci_id *pci_id, + acpi_handle root_pci_device, acpi_handle pci_region) +{ + acpi_status status; + struct acpi_pci_device *list_head; + + ACPI_FUNCTION_TRACE(hw_derive_pci_id); + + if (!pci_id) { + return_ACPI_STATUS(AE_BAD_PARAMETER); + } + + /* Build a list of PCI devices, from pci_region up to root_pci_device */ + + status = + acpi_hw_build_pci_list(root_pci_device, pci_region, &list_head); + if (ACPI_SUCCESS(status)) { + + /* Walk the list, updating the PCI device/function/bus numbers */ + + status = acpi_hw_process_pci_list(pci_id, list_head); + + /* Delete the list */ + + acpi_hw_delete_pci_list(list_head); + } + + return_ACPI_STATUS(status); +} + +/******************************************************************************* + * + * FUNCTION: acpi_hw_build_pci_list + * + * PARAMETERS: root_pci_device - A handle to a PCI device object. This + * object is guaranteed to be a PCI Root + * Bridge having a _HID value of either + * PNP0A03 or PNP0A08 + * pci_region - A handle to the PCI configuration space + * Operation Region + * return_list_head - Where the PCI device list is returned + * + * RETURN: Status + * + * DESCRIPTION: Builds a list of devices from the input PCI region up to the + * Root PCI device for this namespace subtree. + * + ******************************************************************************/ + +static acpi_status +acpi_hw_build_pci_list(acpi_handle root_pci_device, + acpi_handle pci_region, + struct acpi_pci_device **return_list_head) +{ + acpi_handle current_device; + acpi_handle parent_device; + acpi_status status; + struct acpi_pci_device *list_element; + + /* + * Ascend namespace branch until the root_pci_device is reached, building + * a list of device nodes. Loop will exit when either the PCI device is + * found, or the root of the namespace is reached. + */ + *return_list_head = NULL; + current_device = pci_region; + while (1) { + status = acpi_get_parent(current_device, &parent_device); + if (ACPI_FAILURE(status)) { + + /* Must delete the list before exit */ + + acpi_hw_delete_pci_list(*return_list_head); + return (status); + } + + /* Finished when we reach the PCI root device (PNP0A03 or PNP0A08) */ + + if (parent_device == root_pci_device) { + return (AE_OK); + } + + list_element = ACPI_ALLOCATE(sizeof(struct acpi_pci_device)); + if (!list_element) { + + /* Must delete the list before exit */ + + acpi_hw_delete_pci_list(*return_list_head); + return (AE_NO_MEMORY); + } + + /* Put new element at the head of the list */ + + list_element->next = *return_list_head; + list_element->device = parent_device; + *return_list_head = list_element; + + current_device = parent_device; + } +} + +/******************************************************************************* + * + * FUNCTION: acpi_hw_process_pci_list + * + * PARAMETERS: pci_id - Initial values for the PCI ID. May be + * modified by this function. + * list_head - Device list created by + * acpi_hw_build_pci_list + * + * RETURN: Status + * + * DESCRIPTION: Walk downward through the PCI device list, getting the device + * info for each, via the PCI configuration space and updating + * the PCI ID as necessary. Deletes the list during traversal. + * + ******************************************************************************/ + +static acpi_status +acpi_hw_process_pci_list(struct acpi_pci_id *pci_id, + struct acpi_pci_device *list_head) +{ + acpi_status status = AE_OK; + struct acpi_pci_device *info; + u16 bus_number; + u8 is_bridge = TRUE; + + ACPI_FUNCTION_NAME(hw_process_pci_list); + + ACPI_DEBUG_PRINT((ACPI_DB_OPREGION, + "Input PciId: Seg %4.4X Bus %4.4X Dev %4.4X Func %4.4X\n", + pci_id->segment, pci_id->bus, pci_id->device, + pci_id->function)); + + bus_number = pci_id->bus; + + /* + * Descend down the namespace tree, collecting PCI device, function, + * and bus numbers. bus_number is only important for PCI bridges. + * Algorithm: As we descend the tree, use the last valid PCI device, + * function, and bus numbers that are discovered, and assign them + * to the PCI ID for the target device. + */ + info = list_head; + while (info) { + status = acpi_hw_get_pci_device_info(pci_id, info->device, + &bus_number, &is_bridge); + if (ACPI_FAILURE(status)) { + return (status); + } + + info = info->next; + } + + ACPI_DEBUG_PRINT((ACPI_DB_OPREGION, + "Output PciId: Seg %4.4X Bus %4.4X Dev %4.4X Func %4.4X " + "Status %X BusNumber %X IsBridge %X\n", + pci_id->segment, pci_id->bus, pci_id->device, + pci_id->function, status, bus_number, is_bridge)); + + return (AE_OK); +} + +/******************************************************************************* + * + * FUNCTION: acpi_hw_delete_pci_list + * + * PARAMETERS: list_head - Device list created by + * acpi_hw_build_pci_list + * + * RETURN: None + * + * DESCRIPTION: Free the entire PCI list. + * + ******************************************************************************/ + +static void acpi_hw_delete_pci_list(struct acpi_pci_device *list_head) +{ + struct acpi_pci_device *next; + struct acpi_pci_device *previous; + + next = list_head; + while (next) { + previous = next; + next = previous->next; + ACPI_FREE(previous); + } +} + +/******************************************************************************* + * + * FUNCTION: acpi_hw_get_pci_device_info + * + * PARAMETERS: pci_id - Initial values for the PCI ID. May be + * modified by this function. + * pci_device - Handle for the PCI device object + * bus_number - Where a PCI bridge bus number is returned + * is_bridge - Return value, indicates if this PCI + * device is a PCI bridge + * + * RETURN: Status + * + * DESCRIPTION: Get the device info for a single PCI device object. Get the + * _ADR (contains PCI device and function numbers), and for PCI + * bridge devices, get the bus number from PCI configuration + * space. + * + ******************************************************************************/ + +static acpi_status +acpi_hw_get_pci_device_info(struct acpi_pci_id *pci_id, + acpi_handle pci_device, + u16 *bus_number, u8 *is_bridge) +{ + acpi_status status; + acpi_object_type object_type; + u64 return_value; + u64 pci_value; + + /* We only care about objects of type Device */ + + status = acpi_get_type(pci_device, &object_type); + if (ACPI_FAILURE(status)) { + return (status); + } + + if (object_type != ACPI_TYPE_DEVICE) { + return (AE_OK); + } + + /* We need an _ADR. Ignore device if not present */ + + status = acpi_ut_evaluate_numeric_object(METHOD_NAME__ADR, + pci_device, &return_value); + if (ACPI_FAILURE(status)) { + return (AE_OK); + } + + /* + * From _ADR, get the PCI Device and Function and + * update the PCI ID. + */ + pci_id->device = ACPI_HIWORD(ACPI_LODWORD(return_value)); + pci_id->function = ACPI_LOWORD(ACPI_LODWORD(return_value)); + + /* + * If the previous device was a bridge, use the previous + * device bus number + */ + if (*is_bridge) { + pci_id->bus = *bus_number; + } + + /* + * Get the bus numbers from PCI Config space: + * + * First, get the PCI header_type + */ + *is_bridge = FALSE; + status = acpi_os_read_pci_configuration(pci_id, + PCI_CFG_HEADER_TYPE_REG, + &pci_value, 8); + if (ACPI_FAILURE(status)) { + return (status); + } + + /* We only care about bridges (1=pci_bridge, 2=card_bus_bridge) */ + + pci_value &= PCI_HEADER_TYPE_MASK; + + if ((pci_value != PCI_TYPE_BRIDGE) && + (pci_value != PCI_TYPE_CARDBUS_BRIDGE)) { + return (AE_OK); + } + + /* Bridge: Get the Primary bus_number */ + + status = acpi_os_read_pci_configuration(pci_id, + PCI_CFG_PRIMARY_BUS_NUMBER_REG, + &pci_value, 8); + if (ACPI_FAILURE(status)) { + return (status); + } + + *is_bridge = TRUE; + pci_id->bus = (u16)pci_value; + + /* Bridge: Get the Secondary bus_number */ + + status = acpi_os_read_pci_configuration(pci_id, + PCI_CFG_SECONDARY_BUS_NUMBER_REG, + &pci_value, 8); + if (ACPI_FAILURE(status)) { + return (status); + } + + *bus_number = (u16)pci_value; + return (AE_OK); +} |