2 * pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or (at
12 * your option) any later version.
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
23 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <linux/types.h>
30 #include <linux/mutex.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/pci.h>
34 #include <linux/pci-acpi.h>
35 #include <linux/pci-aspm.h>
36 #include <linux/acpi.h>
37 #include <linux/slab.h>
38 #include <linux/dmi.h>
39 #include <acpi/apei.h> /* for acpi_hest_init() */
43 #define _COMPONENT ACPI_PCI_COMPONENT
44 ACPI_MODULE_NAME("pci_root");
45 #define ACPI_PCI_ROOT_CLASS "pci_bridge"
46 #define ACPI_PCI_ROOT_DEVICE_NAME "PCI Root Bridge"
47 static int acpi_pci_root_add(struct acpi_device
*device
,
48 const struct acpi_device_id
*not_used
);
49 static void acpi_pci_root_remove(struct acpi_device
*device
);
51 static int acpi_pci_root_scan_dependent(struct acpi_device
*adev
)
53 acpiphp_check_host_bridge(adev
);
57 #define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \
58 | OSC_PCI_ASPM_SUPPORT \
59 | OSC_PCI_CLOCK_PM_SUPPORT \
60 | OSC_PCI_MSI_SUPPORT)
62 static const struct acpi_device_id root_device_ids
[] = {
67 static struct acpi_scan_handler pci_root_handler
= {
68 .ids
= root_device_ids
,
69 .attach
= acpi_pci_root_add
,
70 .detach
= acpi_pci_root_remove
,
73 .scan_dependent
= acpi_pci_root_scan_dependent
,
77 static DEFINE_MUTEX(osc_lock
);
80 * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
81 * @handle - the ACPI CA node in question.
83 * Note: we could make this API take a struct acpi_device * instead, but
84 * for now, it's more convenient to operate on an acpi_handle.
86 int acpi_is_root_bridge(acpi_handle handle
)
89 struct acpi_device
*device
;
91 ret
= acpi_bus_get_device(handle
, &device
);
95 ret
= acpi_match_device_ids(device
, root_device_ids
);
101 EXPORT_SYMBOL_GPL(acpi_is_root_bridge
);
104 get_root_bridge_busnr_callback(struct acpi_resource
*resource
, void *data
)
106 struct resource
*res
= data
;
107 struct acpi_resource_address64 address
;
110 status
= acpi_resource_to_address64(resource
, &address
);
111 if (ACPI_FAILURE(status
))
114 if ((address
.address_length
> 0) &&
115 (address
.resource_type
== ACPI_BUS_NUMBER_RANGE
)) {
116 res
->start
= address
.minimum
;
117 res
->end
= address
.minimum
+ address
.address_length
- 1;
123 static acpi_status
try_get_root_bridge_busnr(acpi_handle handle
,
124 struct resource
*res
)
130 acpi_walk_resources(handle
, METHOD_NAME__CRS
,
131 get_root_bridge_busnr_callback
, res
);
132 if (ACPI_FAILURE(status
))
134 if (res
->start
== -1)
139 struct pci_osc_bit_struct
{
144 static struct pci_osc_bit_struct pci_osc_support_bit
[] = {
145 { OSC_PCI_EXT_CONFIG_SUPPORT
, "ExtendedConfig" },
146 { OSC_PCI_ASPM_SUPPORT
, "ASPM" },
147 { OSC_PCI_CLOCK_PM_SUPPORT
, "ClockPM" },
148 { OSC_PCI_SEGMENT_GROUPS_SUPPORT
, "Segments" },
149 { OSC_PCI_MSI_SUPPORT
, "MSI" },
152 static struct pci_osc_bit_struct pci_osc_control_bit
[] = {
153 { OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
, "PCIeHotplug" },
154 { OSC_PCI_SHPC_NATIVE_HP_CONTROL
, "SHPCHotplug" },
155 { OSC_PCI_EXPRESS_PME_CONTROL
, "PME" },
156 { OSC_PCI_EXPRESS_AER_CONTROL
, "AER" },
157 { OSC_PCI_EXPRESS_CAPABILITY_CONTROL
, "PCIeCapability" },
160 static void decode_osc_bits(struct acpi_pci_root
*root
, char *msg
, u32 word
,
161 struct pci_osc_bit_struct
*table
, int size
)
165 struct pci_osc_bit_struct
*entry
;
168 for (i
= 0, entry
= table
; i
< size
; i
++, entry
++)
169 if (word
& entry
->bit
)
170 len
+= snprintf(buf
+ len
, sizeof(buf
) - len
, "%s%s",
171 len
? " " : "", entry
->desc
);
173 dev_info(&root
->device
->dev
, "_OSC: %s [%s]\n", msg
, buf
);
176 static void decode_osc_support(struct acpi_pci_root
*root
, char *msg
, u32 word
)
178 decode_osc_bits(root
, msg
, word
, pci_osc_support_bit
,
179 ARRAY_SIZE(pci_osc_support_bit
));
182 static void decode_osc_control(struct acpi_pci_root
*root
, char *msg
, u32 word
)
184 decode_osc_bits(root
, msg
, word
, pci_osc_control_bit
,
185 ARRAY_SIZE(pci_osc_control_bit
));
188 static u8 pci_osc_uuid_str
[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
190 static acpi_status
acpi_pci_run_osc(acpi_handle handle
,
191 const u32
*capbuf
, u32
*retval
)
193 struct acpi_osc_context context
= {
194 .uuid_str
= pci_osc_uuid_str
,
197 .cap
.pointer
= (void *)capbuf
,
201 status
= acpi_run_osc(handle
, &context
);
202 if (ACPI_SUCCESS(status
)) {
203 *retval
= *((u32
*)(context
.ret
.pointer
+ 8));
204 kfree(context
.ret
.pointer
);
209 static acpi_status
acpi_pci_query_osc(struct acpi_pci_root
*root
,
214 u32 result
, capbuf
[3];
216 support
&= OSC_PCI_SUPPORT_MASKS
;
217 support
|= root
->osc_support_set
;
219 capbuf
[OSC_QUERY_DWORD
] = OSC_QUERY_ENABLE
;
220 capbuf
[OSC_SUPPORT_DWORD
] = support
;
222 *control
&= OSC_PCI_CONTROL_MASKS
;
223 capbuf
[OSC_CONTROL_DWORD
] = *control
| root
->osc_control_set
;
225 /* Run _OSC query only with existing controls. */
226 capbuf
[OSC_CONTROL_DWORD
] = root
->osc_control_set
;
229 status
= acpi_pci_run_osc(root
->device
->handle
, capbuf
, &result
);
230 if (ACPI_SUCCESS(status
)) {
231 root
->osc_support_set
= support
;
238 static acpi_status
acpi_pci_osc_support(struct acpi_pci_root
*root
, u32 flags
)
242 mutex_lock(&osc_lock
);
243 status
= acpi_pci_query_osc(root
, flags
, NULL
);
244 mutex_unlock(&osc_lock
);
248 struct acpi_pci_root
*acpi_pci_find_root(acpi_handle handle
)
250 struct acpi_pci_root
*root
;
251 struct acpi_device
*device
;
253 if (acpi_bus_get_device(handle
, &device
) ||
254 acpi_match_device_ids(device
, root_device_ids
))
257 root
= acpi_driver_data(device
);
261 EXPORT_SYMBOL_GPL(acpi_pci_find_root
);
263 struct acpi_handle_node
{
264 struct list_head node
;
269 * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
270 * @handle: the handle in question
272 * Given an ACPI CA handle, the desired PCI device is located in the
273 * list of PCI devices.
275 * If the device is found, its reference count is increased and this
276 * function returns a pointer to its data structure. The caller must
277 * decrement the reference count by calling pci_dev_put().
278 * If no device is found, %NULL is returned.
280 struct pci_dev
*acpi_get_pci_dev(acpi_handle handle
)
283 unsigned long long adr
;
286 struct pci_bus
*pbus
;
287 struct pci_dev
*pdev
= NULL
;
288 struct acpi_handle_node
*node
, *tmp
;
289 struct acpi_pci_root
*root
;
290 LIST_HEAD(device_list
);
293 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
296 while (!acpi_is_root_bridge(phandle
)) {
297 node
= kzalloc(sizeof(struct acpi_handle_node
), GFP_KERNEL
);
301 INIT_LIST_HEAD(&node
->node
);
302 node
->handle
= phandle
;
303 list_add(&node
->node
, &device_list
);
305 status
= acpi_get_parent(phandle
, &phandle
);
306 if (ACPI_FAILURE(status
))
310 root
= acpi_pci_find_root(phandle
);
317 * Now, walk back down the PCI device tree until we return to our
318 * original handle. Assumes that everything between the PCI root
319 * bridge and the device we're looking for must be a P2P bridge.
321 list_for_each_entry(node
, &device_list
, node
) {
322 acpi_handle hnd
= node
->handle
;
323 status
= acpi_evaluate_integer(hnd
, "_ADR", NULL
, &adr
);
324 if (ACPI_FAILURE(status
))
326 dev
= (adr
>> 16) & 0xffff;
329 pdev
= pci_get_slot(pbus
, PCI_DEVFN(dev
, fn
));
330 if (!pdev
|| hnd
== handle
)
333 pbus
= pdev
->subordinate
;
337 * This function may be called for a non-PCI device that has a
338 * PCI parent (eg. a disk under a PCI SATA controller). In that
339 * case pdev->subordinate will be NULL for the parent.
342 dev_dbg(&pdev
->dev
, "Not a PCI-to-PCI bridge\n");
348 list_for_each_entry_safe(node
, tmp
, &device_list
, node
)
353 EXPORT_SYMBOL_GPL(acpi_get_pci_dev
);
356 * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
357 * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
358 * @mask: Mask of _OSC bits to request control of, place to store control mask.
359 * @req: Mask of _OSC bits the control of is essential to the caller.
361 * Run _OSC query for @mask and if that is successful, compare the returned
362 * mask of control bits with @req. If all of the @req bits are set in the
363 * returned mask, run _OSC request for it.
365 * The variable at the @mask address may be modified regardless of whether or
366 * not the function returns success. On success it will contain the mask of
367 * _OSC bits the BIOS has granted control of, but its contents are meaningless
370 acpi_status
acpi_pci_osc_control_set(acpi_handle handle
, u32
*mask
, u32 req
)
372 struct acpi_pci_root
*root
;
373 acpi_status status
= AE_OK
;
377 return AE_BAD_PARAMETER
;
379 ctrl
= *mask
& OSC_PCI_CONTROL_MASKS
;
380 if ((ctrl
& req
) != req
)
383 root
= acpi_pci_find_root(handle
);
387 mutex_lock(&osc_lock
);
389 *mask
= ctrl
| root
->osc_control_set
;
390 /* No need to evaluate _OSC if the control was already granted. */
391 if ((root
->osc_control_set
& ctrl
) == ctrl
)
394 /* Need to check the available controls bits before requesting them. */
396 status
= acpi_pci_query_osc(root
, root
->osc_support_set
, mask
);
397 if (ACPI_FAILURE(status
))
401 decode_osc_control(root
, "platform does not support",
406 if ((ctrl
& req
) != req
) {
407 decode_osc_control(root
, "not requesting control; platform does not support",
413 capbuf
[OSC_QUERY_DWORD
] = 0;
414 capbuf
[OSC_SUPPORT_DWORD
] = root
->osc_support_set
;
415 capbuf
[OSC_CONTROL_DWORD
] = ctrl
;
416 status
= acpi_pci_run_osc(handle
, capbuf
, mask
);
417 if (ACPI_SUCCESS(status
))
418 root
->osc_control_set
= *mask
;
420 mutex_unlock(&osc_lock
);
423 EXPORT_SYMBOL(acpi_pci_osc_control_set
);
425 static void negotiate_os_control(struct acpi_pci_root
*root
, int *no_aspm
,
428 u32 support
, control
, requested
;
430 struct acpi_device
*device
= root
->device
;
431 acpi_handle handle
= device
->handle
;
434 * Apple always return failure on _OSC calls when _OSI("Darwin") has
435 * been called successfully. We know the feature set supported by the
436 * platform, so avoid calling _OSC at all
439 if (dmi_match(DMI_SYS_VENDOR
, "Apple Inc.")) {
440 root
->osc_control_set
= ~OSC_PCI_EXPRESS_PME_CONTROL
;
441 decode_osc_control(root
, "OS assumes control of",
442 root
->osc_control_set
);
447 * All supported architectures that use ACPI have support for
448 * PCI domains, so we indicate this in _OSC support capabilities.
450 support
= OSC_PCI_SEGMENT_GROUPS_SUPPORT
;
451 if (pci_ext_cfg_avail())
452 support
|= OSC_PCI_EXT_CONFIG_SUPPORT
;
453 if (pcie_aspm_support_enabled())
454 support
|= OSC_PCI_ASPM_SUPPORT
| OSC_PCI_CLOCK_PM_SUPPORT
;
455 if (pci_msi_enabled())
456 support
|= OSC_PCI_MSI_SUPPORT
;
458 decode_osc_support(root
, "OS supports", support
);
459 status
= acpi_pci_osc_support(root
, support
);
460 if (ACPI_FAILURE(status
)) {
461 dev_info(&device
->dev
, "_OSC failed (%s); disabling ASPM\n",
462 acpi_format_exception(status
));
467 if (pcie_ports_disabled
) {
468 dev_info(&device
->dev
, "PCIe port services disabled; not requesting _OSC control\n");
472 if ((support
& ACPI_PCIE_REQ_SUPPORT
) != ACPI_PCIE_REQ_SUPPORT
) {
473 decode_osc_support(root
, "not requesting OS control; OS requires",
474 ACPI_PCIE_REQ_SUPPORT
);
478 control
= OSC_PCI_EXPRESS_CAPABILITY_CONTROL
479 | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
480 | OSC_PCI_EXPRESS_PME_CONTROL
;
482 if (pci_aer_available()) {
483 if (aer_acpi_firmware_first())
484 dev_info(&device
->dev
,
485 "PCIe AER handled by firmware\n");
487 control
|= OSC_PCI_EXPRESS_AER_CONTROL
;
491 status
= acpi_pci_osc_control_set(handle
, &control
,
492 OSC_PCI_EXPRESS_CAPABILITY_CONTROL
);
493 if (ACPI_SUCCESS(status
)) {
494 decode_osc_control(root
, "OS now controls", control
);
495 if (acpi_gbl_FADT
.boot_flags
& ACPI_FADT_NO_ASPM
) {
497 * We have ASPM control, but the FADT indicates
498 * that it's unsupported. Clear it.
503 decode_osc_control(root
, "OS requested", requested
);
504 decode_osc_control(root
, "platform willing to grant", control
);
505 dev_info(&device
->dev
, "_OSC failed (%s); disabling ASPM\n",
506 acpi_format_exception(status
));
509 * We want to disable ASPM here, but aspm_disabled
510 * needs to remain in its state from boot so that we
511 * properly handle PCIe 1.1 devices. So we set this
512 * flag here, to defer the action until after the ACPI
519 static int acpi_pci_root_add(struct acpi_device
*device
,
520 const struct acpi_device_id
*not_used
)
522 unsigned long long segment
, bus
;
525 struct acpi_pci_root
*root
;
526 acpi_handle handle
= device
->handle
;
527 int no_aspm
= 0, clear_aspm
= 0;
529 root
= kzalloc(sizeof(struct acpi_pci_root
), GFP_KERNEL
);
534 status
= acpi_evaluate_integer(handle
, METHOD_NAME__SEG
, NULL
,
536 if (ACPI_FAILURE(status
) && status
!= AE_NOT_FOUND
) {
537 dev_err(&device
->dev
, "can't evaluate _SEG\n");
542 /* Check _CRS first, then _BBN. If no _BBN, default to zero. */
543 root
->secondary
.flags
= IORESOURCE_BUS
;
544 status
= try_get_root_bridge_busnr(handle
, &root
->secondary
);
545 if (ACPI_FAILURE(status
)) {
547 * We need both the start and end of the downstream bus range
548 * to interpret _CBA (MMCONFIG base address), so it really is
549 * supposed to be in _CRS. If we don't find it there, all we
550 * can do is assume [_BBN-0xFF] or [0-0xFF].
552 root
->secondary
.end
= 0xFF;
553 dev_warn(&device
->dev
,
554 FW_BUG
"no secondary bus range in _CRS\n");
555 status
= acpi_evaluate_integer(handle
, METHOD_NAME__BBN
,
557 if (ACPI_SUCCESS(status
))
558 root
->secondary
.start
= bus
;
559 else if (status
== AE_NOT_FOUND
)
560 root
->secondary
.start
= 0;
562 dev_err(&device
->dev
, "can't evaluate _BBN\n");
568 root
->device
= device
;
569 root
->segment
= segment
& 0xFFFF;
570 strcpy(acpi_device_name(device
), ACPI_PCI_ROOT_DEVICE_NAME
);
571 strcpy(acpi_device_class(device
), ACPI_PCI_ROOT_CLASS
);
572 device
->driver_data
= root
;
574 pr_info(PREFIX
"%s [%s] (domain %04x %pR)\n",
575 acpi_device_name(device
), acpi_device_bid(device
),
576 root
->segment
, &root
->secondary
);
578 root
->mcfg_addr
= acpi_pci_root_get_mcfg_addr(handle
);
580 negotiate_os_control(root
, &no_aspm
, &clear_aspm
);
583 * TBD: Need PCI interface for enumeration/configuration of roots.
587 * Scan the Root Bridge
588 * --------------------
589 * Must do this prior to any attempt to bind the root device, as the
590 * PCI namespace does not get created until this call is made (and
591 * thus the root bridge's pci_dev does not exist).
593 root
->bus
= pci_acpi_scan_root(root
);
595 dev_err(&device
->dev
,
596 "Bus %04x:%02x not present in PCI namespace\n",
597 root
->segment
, (unsigned int)root
->secondary
.start
);
598 device
->driver_data
= NULL
;
604 dev_info(&device
->dev
, "Disabling ASPM (FADT indicates it is unsupported)\n");
605 pcie_clear_aspm(root
->bus
);
610 pci_acpi_add_bus_pm_notifier(device
);
611 if (device
->wakeup
.flags
.run_wake
)
612 device_set_run_wake(root
->bus
->bridge
, true);
614 if (system_state
!= SYSTEM_BOOTING
) {
615 pcibios_resource_survey_bus(root
->bus
);
616 pci_assign_unassigned_root_bus_resources(root
->bus
);
619 pci_lock_rescan_remove();
620 pci_bus_add_devices(root
->bus
);
621 pci_unlock_rescan_remove();
629 static void acpi_pci_root_remove(struct acpi_device
*device
)
631 struct acpi_pci_root
*root
= acpi_driver_data(device
);
633 pci_lock_rescan_remove();
635 pci_stop_root_bus(root
->bus
);
637 device_set_run_wake(root
->bus
->bridge
, false);
638 pci_acpi_remove_bus_pm_notifier(device
);
640 pci_remove_root_bus(root
->bus
);
642 pci_unlock_rescan_remove();
647 void __init
acpi_pci_root_init(void)
650 if (acpi_pci_disabled
)
653 pci_acpi_crs_quirks();
654 acpi_scan_add_handler_with_hotplug(&pci_root_handler
, "pci_root");