1 /*******************************************************************************
3 * Module Name: hwpci - Obtain PCI bus, device, and function numbers
5 ******************************************************************************/
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44 #include <acpi/acpi.h>
47 #define _COMPONENT ACPI_NAMESPACE
48 ACPI_MODULE_NAME("hwpci")
50 /* PCI configuration space values */
51 #define PCI_CFG_HEADER_TYPE_REG 0x0E
52 #define PCI_CFG_PRIMARY_BUS_NUMBER_REG 0x18
53 #define PCI_CFG_SECONDARY_BUS_NUMBER_REG 0x19
54 /* PCI header values */
55 #define PCI_HEADER_TYPE_MASK 0x7F
56 #define PCI_TYPE_BRIDGE 0x01
57 #define PCI_TYPE_CARDBUS_BRIDGE 0x02
58 typedef struct acpi_pci_device
{
60 struct acpi_pci_device
*next
;
64 /* Local prototypes */
67 acpi_hw_build_pci_list(acpi_handle root_pci_device
,
68 acpi_handle pci_region
,
69 struct acpi_pci_device
**return_list_head
);
72 acpi_hw_process_pci_list(struct acpi_pci_id
*pci_id
,
73 struct acpi_pci_device
*list_head
);
75 static void acpi_hw_delete_pci_list(struct acpi_pci_device
*list_head
);
78 acpi_hw_get_pci_device_info(struct acpi_pci_id
*pci_id
,
79 acpi_handle pci_device
,
80 u16
*bus_number
, u8
*is_bridge
);
82 /*******************************************************************************
84 * FUNCTION: acpi_hw_derive_pci_id
86 * PARAMETERS: pci_id - Initial values for the PCI ID. May be
87 * modified by this function.
88 * root_pci_device - A handle to a PCI device object. This
89 * object must be a PCI Root Bridge having a
90 * _HID value of either PNP0A03 or PNP0A08
91 * pci_region - A handle to a PCI configuration space
92 * Operation Region being initialized
96 * DESCRIPTION: This function derives a full PCI ID for a PCI device,
97 * consisting of a Segment number, Bus number, Device number,
100 * The PCI hardware dynamically configures PCI bus numbers
101 * depending on the bus topology discovered during system
102 * initialization. This function is invoked during configuration
103 * of a PCI_Config Operation Region in order to (possibly) update
104 * the Bus/Device/Function numbers in the pci_id with the actual
105 * values as determined by the hardware and operating system
108 * The pci_id parameter is initially populated during the Operation
109 * Region initialization. This function is then called, and is
110 * will make any necessary modifications to the Bus, Device, or
111 * Function number PCI ID subfields as appropriate for the
112 * current hardware and OS configuration.
114 * NOTE: Created 08/2010. Replaces the previous OSL acpi_os_derive_pci_id
115 * interface since this feature is OS-independent. This module
116 * specifically avoids any use of recursion by building a local
117 * temporary device list.
119 ******************************************************************************/
122 acpi_hw_derive_pci_id(struct acpi_pci_id
*pci_id
,
123 acpi_handle root_pci_device
, acpi_handle pci_region
)
126 struct acpi_pci_device
*list_head
;
128 ACPI_FUNCTION_TRACE(hw_derive_pci_id
);
131 return_ACPI_STATUS(AE_BAD_PARAMETER
);
134 /* Build a list of PCI devices, from pci_region up to root_pci_device */
137 acpi_hw_build_pci_list(root_pci_device
, pci_region
, &list_head
);
138 if (ACPI_SUCCESS(status
)) {
140 /* Walk the list, updating the PCI device/function/bus numbers */
142 status
= acpi_hw_process_pci_list(pci_id
, list_head
);
144 /* Delete the list */
146 acpi_hw_delete_pci_list(list_head
);
149 return_ACPI_STATUS(status
);
152 /*******************************************************************************
154 * FUNCTION: acpi_hw_build_pci_list
156 * PARAMETERS: root_pci_device - A handle to a PCI device object. This
157 * object is guaranteed to be a PCI Root
158 * Bridge having a _HID value of either
160 * pci_region - A handle to the PCI configuration space
162 * return_list_head - Where the PCI device list is returned
166 * DESCRIPTION: Builds a list of devices from the input PCI region up to the
167 * Root PCI device for this namespace subtree.
169 ******************************************************************************/
172 acpi_hw_build_pci_list(acpi_handle root_pci_device
,
173 acpi_handle pci_region
,
174 struct acpi_pci_device
**return_list_head
)
176 acpi_handle current_device
;
177 acpi_handle parent_device
;
179 struct acpi_pci_device
*list_element
;
182 * Ascend namespace branch until the root_pci_device is reached, building
183 * a list of device nodes. Loop will exit when either the PCI device is
184 * found, or the root of the namespace is reached.
186 *return_list_head
= NULL
;
187 current_device
= pci_region
;
189 status
= acpi_get_parent(current_device
, &parent_device
);
190 if (ACPI_FAILURE(status
)) {
192 /* Must delete the list before exit */
194 acpi_hw_delete_pci_list(*return_list_head
);
198 /* Finished when we reach the PCI root device (PNP0A03 or PNP0A08) */
200 if (parent_device
== root_pci_device
) {
204 list_element
= ACPI_ALLOCATE(sizeof(struct acpi_pci_device
));
207 /* Must delete the list before exit */
209 acpi_hw_delete_pci_list(*return_list_head
);
210 return (AE_NO_MEMORY
);
213 /* Put new element at the head of the list */
215 list_element
->next
= *return_list_head
;
216 list_element
->device
= parent_device
;
217 *return_list_head
= list_element
;
219 current_device
= parent_device
;
223 /*******************************************************************************
225 * FUNCTION: acpi_hw_process_pci_list
227 * PARAMETERS: pci_id - Initial values for the PCI ID. May be
228 * modified by this function.
229 * list_head - Device list created by
230 * acpi_hw_build_pci_list
234 * DESCRIPTION: Walk downward through the PCI device list, getting the device
235 * info for each, via the PCI configuration space and updating
236 * the PCI ID as necessary. Deletes the list during traversal.
238 ******************************************************************************/
241 acpi_hw_process_pci_list(struct acpi_pci_id
*pci_id
,
242 struct acpi_pci_device
*list_head
)
244 acpi_status status
= AE_OK
;
245 struct acpi_pci_device
*info
;
249 ACPI_FUNCTION_NAME(hw_process_pci_list
);
251 ACPI_DEBUG_PRINT((ACPI_DB_OPREGION
,
252 "Input PciId: Seg %4.4X Bus %4.4X Dev %4.4X Func %4.4X\n",
253 pci_id
->segment
, pci_id
->bus
, pci_id
->device
,
256 bus_number
= pci_id
->bus
;
259 * Descend down the namespace tree, collecting PCI device, function,
260 * and bus numbers. bus_number is only important for PCI bridges.
261 * Algorithm: As we descend the tree, use the last valid PCI device,
262 * function, and bus numbers that are discovered, and assign them
263 * to the PCI ID for the target device.
267 status
= acpi_hw_get_pci_device_info(pci_id
, info
->device
,
268 &bus_number
, &is_bridge
);
269 if (ACPI_FAILURE(status
)) {
276 ACPI_DEBUG_PRINT((ACPI_DB_OPREGION
,
277 "Output PciId: Seg %4.4X Bus %4.4X Dev %4.4X Func %4.4X "
278 "Status %X BusNumber %X IsBridge %X\n",
279 pci_id
->segment
, pci_id
->bus
, pci_id
->device
,
280 pci_id
->function
, status
, bus_number
, is_bridge
));
285 /*******************************************************************************
287 * FUNCTION: acpi_hw_delete_pci_list
289 * PARAMETERS: list_head - Device list created by
290 * acpi_hw_build_pci_list
294 * DESCRIPTION: Free the entire PCI list.
296 ******************************************************************************/
298 static void acpi_hw_delete_pci_list(struct acpi_pci_device
*list_head
)
300 struct acpi_pci_device
*next
;
301 struct acpi_pci_device
*previous
;
306 next
= previous
->next
;
311 /*******************************************************************************
313 * FUNCTION: acpi_hw_get_pci_device_info
315 * PARAMETERS: pci_id - Initial values for the PCI ID. May be
316 * modified by this function.
317 * pci_device - Handle for the PCI device object
318 * bus_number - Where a PCI bridge bus number is returned
319 * is_bridge - Return value, indicates if this PCI
320 * device is a PCI bridge
324 * DESCRIPTION: Get the device info for a single PCI device object. Get the
325 * _ADR (contains PCI device and function numbers), and for PCI
326 * bridge devices, get the bus number from PCI configuration
329 ******************************************************************************/
332 acpi_hw_get_pci_device_info(struct acpi_pci_id
*pci_id
,
333 acpi_handle pci_device
,
334 u16
*bus_number
, u8
*is_bridge
)
337 acpi_object_type object_type
;
341 /* We only care about objects of type Device */
343 status
= acpi_get_type(pci_device
, &object_type
);
344 if (ACPI_FAILURE(status
)) {
348 if (object_type
!= ACPI_TYPE_DEVICE
) {
352 /* We need an _ADR. Ignore device if not present */
354 status
= acpi_ut_evaluate_numeric_object(METHOD_NAME__ADR
,
355 pci_device
, &return_value
);
356 if (ACPI_FAILURE(status
)) {
361 * From _ADR, get the PCI Device and Function and
364 pci_id
->device
= ACPI_HIWORD(ACPI_LODWORD(return_value
));
365 pci_id
->function
= ACPI_LOWORD(ACPI_LODWORD(return_value
));
368 * If the previous device was a bridge, use the previous
372 pci_id
->bus
= *bus_number
;
376 * Get the bus numbers from PCI Config space:
378 * First, get the PCI header_type
381 status
= acpi_os_read_pci_configuration(pci_id
,
382 PCI_CFG_HEADER_TYPE_REG
,
384 if (ACPI_FAILURE(status
)) {
388 /* We only care about bridges (1=pci_bridge, 2=card_bus_bridge) */
390 pci_value
&= PCI_HEADER_TYPE_MASK
;
392 if ((pci_value
!= PCI_TYPE_BRIDGE
) &&
393 (pci_value
!= PCI_TYPE_CARDBUS_BRIDGE
)) {
397 /* Bridge: Get the Primary bus_number */
399 status
= acpi_os_read_pci_configuration(pci_id
,
400 PCI_CFG_PRIMARY_BUS_NUMBER_REG
,
402 if (ACPI_FAILURE(status
)) {
407 pci_id
->bus
= (u16
)pci_value
;
409 /* Bridge: Get the Secondary bus_number */
411 status
= acpi_os_read_pci_configuration(pci_id
,
412 PCI_CFG_SECONDARY_BUS_NUMBER_REG
,
414 if (ACPI_FAILURE(status
)) {
418 *bus_number
= (u16
)pci_value
;