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 <acpi/apei.h> /* for acpi_hest_init() */
42 #define PREFIX "ACPI: "
44 #define _COMPONENT ACPI_PCI_COMPONENT
45 ACPI_MODULE_NAME("pci_root");
46 #define ACPI_PCI_ROOT_CLASS "pci_bridge"
47 #define ACPI_PCI_ROOT_DEVICE_NAME "PCI Root Bridge"
48 static int acpi_pci_root_add(struct acpi_device
*device
,
49 const struct acpi_device_id
*not_used
);
50 static void acpi_pci_root_remove(struct acpi_device
*device
);
52 static int acpi_pci_root_scan_dependent(struct acpi_device
*adev
)
54 acpiphp_check_host_bridge(adev
->handle
);
58 #define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \
59 | OSC_PCI_ASPM_SUPPORT \
60 | OSC_PCI_CLOCK_PM_SUPPORT \
61 | OSC_PCI_MSI_SUPPORT)
63 static const struct acpi_device_id root_device_ids
[] = {
68 static struct acpi_scan_handler pci_root_handler
= {
69 .ids
= root_device_ids
,
70 .attach
= acpi_pci_root_add
,
71 .detach
= acpi_pci_root_remove
,
74 .scan_dependent
= acpi_pci_root_scan_dependent
,
78 static DEFINE_MUTEX(osc_lock
);
81 * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
82 * @handle - the ACPI CA node in question.
84 * Note: we could make this API take a struct acpi_device * instead, but
85 * for now, it's more convenient to operate on an acpi_handle.
87 int acpi_is_root_bridge(acpi_handle handle
)
90 struct acpi_device
*device
;
92 ret
= acpi_bus_get_device(handle
, &device
);
96 ret
= acpi_match_device_ids(device
, root_device_ids
);
102 EXPORT_SYMBOL_GPL(acpi_is_root_bridge
);
105 get_root_bridge_busnr_callback(struct acpi_resource
*resource
, void *data
)
107 struct resource
*res
= data
;
108 struct acpi_resource_address64 address
;
111 status
= acpi_resource_to_address64(resource
, &address
);
112 if (ACPI_FAILURE(status
))
115 if ((address
.address_length
> 0) &&
116 (address
.resource_type
== ACPI_BUS_NUMBER_RANGE
)) {
117 res
->start
= address
.minimum
;
118 res
->end
= address
.minimum
+ address
.address_length
- 1;
124 static acpi_status
try_get_root_bridge_busnr(acpi_handle handle
,
125 struct resource
*res
)
131 acpi_walk_resources(handle
, METHOD_NAME__CRS
,
132 get_root_bridge_busnr_callback
, res
);
133 if (ACPI_FAILURE(status
))
135 if (res
->start
== -1)
140 struct pci_osc_bit_struct
{
145 static struct pci_osc_bit_struct pci_osc_support_bit
[] = {
146 { OSC_PCI_EXT_CONFIG_SUPPORT
, "ExtendedConfig" },
147 { OSC_PCI_ASPM_SUPPORT
, "ASPM" },
148 { OSC_PCI_CLOCK_PM_SUPPORT
, "ClockPM" },
149 { OSC_PCI_SEGMENT_GROUPS_SUPPORT
, "Segments" },
150 { OSC_PCI_MSI_SUPPORT
, "MSI" },
153 static struct pci_osc_bit_struct pci_osc_control_bit
[] = {
154 { OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
, "PCIeHotplug" },
155 { OSC_PCI_SHPC_NATIVE_HP_CONTROL
, "SHPCHotplug" },
156 { OSC_PCI_EXPRESS_PME_CONTROL
, "PME" },
157 { OSC_PCI_EXPRESS_AER_CONTROL
, "AER" },
158 { OSC_PCI_EXPRESS_CAPABILITY_CONTROL
, "PCIeCapability" },
161 static void decode_osc_bits(struct acpi_pci_root
*root
, char *msg
, u32 word
,
162 struct pci_osc_bit_struct
*table
, int size
)
166 struct pci_osc_bit_struct
*entry
;
169 for (i
= 0, entry
= table
; i
< size
; i
++, entry
++)
170 if (word
& entry
->bit
)
171 len
+= snprintf(buf
+ len
, sizeof(buf
) - len
, "%s%s",
172 len
? " " : "", entry
->desc
);
174 dev_info(&root
->device
->dev
, "_OSC: %s [%s]\n", msg
, buf
);
177 static void decode_osc_support(struct acpi_pci_root
*root
, char *msg
, u32 word
)
179 decode_osc_bits(root
, msg
, word
, pci_osc_support_bit
,
180 ARRAY_SIZE(pci_osc_support_bit
));
183 static void decode_osc_control(struct acpi_pci_root
*root
, char *msg
, u32 word
)
185 decode_osc_bits(root
, msg
, word
, pci_osc_control_bit
,
186 ARRAY_SIZE(pci_osc_control_bit
));
189 static u8 pci_osc_uuid_str
[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
191 static acpi_status
acpi_pci_run_osc(acpi_handle handle
,
192 const u32
*capbuf
, u32
*retval
)
194 struct acpi_osc_context context
= {
195 .uuid_str
= pci_osc_uuid_str
,
198 .cap
.pointer
= (void *)capbuf
,
202 status
= acpi_run_osc(handle
, &context
);
203 if (ACPI_SUCCESS(status
)) {
204 *retval
= *((u32
*)(context
.ret
.pointer
+ 8));
205 kfree(context
.ret
.pointer
);
210 static acpi_status
acpi_pci_query_osc(struct acpi_pci_root
*root
,
215 u32 result
, capbuf
[3];
217 support
&= OSC_PCI_SUPPORT_MASKS
;
218 support
|= root
->osc_support_set
;
220 capbuf
[OSC_QUERY_DWORD
] = OSC_QUERY_ENABLE
;
221 capbuf
[OSC_SUPPORT_DWORD
] = support
;
223 *control
&= OSC_PCI_CONTROL_MASKS
;
224 capbuf
[OSC_CONTROL_DWORD
] = *control
| root
->osc_control_set
;
226 /* Run _OSC query only with existing controls. */
227 capbuf
[OSC_CONTROL_DWORD
] = root
->osc_control_set
;
230 status
= acpi_pci_run_osc(root
->device
->handle
, capbuf
, &result
);
231 if (ACPI_SUCCESS(status
)) {
232 root
->osc_support_set
= support
;
239 static acpi_status
acpi_pci_osc_support(struct acpi_pci_root
*root
, u32 flags
)
243 mutex_lock(&osc_lock
);
244 status
= acpi_pci_query_osc(root
, flags
, NULL
);
245 mutex_unlock(&osc_lock
);
249 struct acpi_pci_root
*acpi_pci_find_root(acpi_handle handle
)
251 struct acpi_pci_root
*root
;
252 struct acpi_device
*device
;
254 if (acpi_bus_get_device(handle
, &device
) ||
255 acpi_match_device_ids(device
, root_device_ids
))
258 root
= acpi_driver_data(device
);
262 EXPORT_SYMBOL_GPL(acpi_pci_find_root
);
264 struct acpi_handle_node
{
265 struct list_head node
;
270 * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
271 * @handle: the handle in question
273 * Given an ACPI CA handle, the desired PCI device is located in the
274 * list of PCI devices.
276 * If the device is found, its reference count is increased and this
277 * function returns a pointer to its data structure. The caller must
278 * decrement the reference count by calling pci_dev_put().
279 * If no device is found, %NULL is returned.
281 struct pci_dev
*acpi_get_pci_dev(acpi_handle handle
)
284 unsigned long long adr
;
287 struct pci_bus
*pbus
;
288 struct pci_dev
*pdev
= NULL
;
289 struct acpi_handle_node
*node
, *tmp
;
290 struct acpi_pci_root
*root
;
291 LIST_HEAD(device_list
);
294 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
297 while (!acpi_is_root_bridge(phandle
)) {
298 node
= kzalloc(sizeof(struct acpi_handle_node
), GFP_KERNEL
);
302 INIT_LIST_HEAD(&node
->node
);
303 node
->handle
= phandle
;
304 list_add(&node
->node
, &device_list
);
306 status
= acpi_get_parent(phandle
, &phandle
);
307 if (ACPI_FAILURE(status
))
311 root
= acpi_pci_find_root(phandle
);
318 * Now, walk back down the PCI device tree until we return to our
319 * original handle. Assumes that everything between the PCI root
320 * bridge and the device we're looking for must be a P2P bridge.
322 list_for_each_entry(node
, &device_list
, node
) {
323 acpi_handle hnd
= node
->handle
;
324 status
= acpi_evaluate_integer(hnd
, "_ADR", NULL
, &adr
);
325 if (ACPI_FAILURE(status
))
327 dev
= (adr
>> 16) & 0xffff;
330 pdev
= pci_get_slot(pbus
, PCI_DEVFN(dev
, fn
));
331 if (!pdev
|| hnd
== handle
)
334 pbus
= pdev
->subordinate
;
338 * This function may be called for a non-PCI device that has a
339 * PCI parent (eg. a disk under a PCI SATA controller). In that
340 * case pdev->subordinate will be NULL for the parent.
343 dev_dbg(&pdev
->dev
, "Not a PCI-to-PCI bridge\n");
349 list_for_each_entry_safe(node
, tmp
, &device_list
, node
)
354 EXPORT_SYMBOL_GPL(acpi_get_pci_dev
);
357 * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
358 * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
359 * @mask: Mask of _OSC bits to request control of, place to store control mask.
360 * @req: Mask of _OSC bits the control of is essential to the caller.
362 * Run _OSC query for @mask and if that is successful, compare the returned
363 * mask of control bits with @req. If all of the @req bits are set in the
364 * returned mask, run _OSC request for it.
366 * The variable at the @mask address may be modified regardless of whether or
367 * not the function returns success. On success it will contain the mask of
368 * _OSC bits the BIOS has granted control of, but its contents are meaningless
371 acpi_status
acpi_pci_osc_control_set(acpi_handle handle
, u32
*mask
, u32 req
)
373 struct acpi_pci_root
*root
;
374 acpi_status status
= AE_OK
;
378 return AE_BAD_PARAMETER
;
380 ctrl
= *mask
& OSC_PCI_CONTROL_MASKS
;
381 if ((ctrl
& req
) != req
)
384 root
= acpi_pci_find_root(handle
);
388 mutex_lock(&osc_lock
);
390 *mask
= ctrl
| root
->osc_control_set
;
391 /* No need to evaluate _OSC if the control was already granted. */
392 if ((root
->osc_control_set
& ctrl
) == ctrl
)
395 /* Need to check the available controls bits before requesting them. */
397 status
= acpi_pci_query_osc(root
, root
->osc_support_set
, mask
);
398 if (ACPI_FAILURE(status
))
402 decode_osc_control(root
, "platform does not support",
407 if ((ctrl
& req
) != req
) {
408 decode_osc_control(root
, "not requesting control; platform does not support",
414 capbuf
[OSC_QUERY_DWORD
] = 0;
415 capbuf
[OSC_SUPPORT_DWORD
] = root
->osc_support_set
;
416 capbuf
[OSC_CONTROL_DWORD
] = ctrl
;
417 status
= acpi_pci_run_osc(handle
, capbuf
, mask
);
418 if (ACPI_SUCCESS(status
))
419 root
->osc_control_set
= *mask
;
421 mutex_unlock(&osc_lock
);
424 EXPORT_SYMBOL(acpi_pci_osc_control_set
);
426 static void negotiate_os_control(struct acpi_pci_root
*root
, int *no_aspm
,
429 u32 support
, control
, requested
;
431 struct acpi_device
*device
= root
->device
;
432 acpi_handle handle
= device
->handle
;
435 * All supported architectures that use ACPI have support for
436 * PCI domains, so we indicate this in _OSC support capabilities.
438 support
= OSC_PCI_SEGMENT_GROUPS_SUPPORT
;
439 if (pci_ext_cfg_avail())
440 support
|= OSC_PCI_EXT_CONFIG_SUPPORT
;
441 if (pcie_aspm_support_enabled())
442 support
|= OSC_PCI_ASPM_SUPPORT
| OSC_PCI_CLOCK_PM_SUPPORT
;
443 if (pci_msi_enabled())
444 support
|= OSC_PCI_MSI_SUPPORT
;
446 decode_osc_support(root
, "OS supports", support
);
447 status
= acpi_pci_osc_support(root
, support
);
448 if (ACPI_FAILURE(status
)) {
449 dev_info(&device
->dev
, "_OSC failed (%s); disabling ASPM\n",
450 acpi_format_exception(status
));
455 if (pcie_ports_disabled
) {
456 dev_info(&device
->dev
, "PCIe port services disabled; not requesting _OSC control\n");
460 if ((support
& ACPI_PCIE_REQ_SUPPORT
) != ACPI_PCIE_REQ_SUPPORT
) {
461 decode_osc_support(root
, "not requesting OS control; OS requires",
462 ACPI_PCIE_REQ_SUPPORT
);
466 control
= OSC_PCI_EXPRESS_CAPABILITY_CONTROL
467 | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
468 | OSC_PCI_EXPRESS_PME_CONTROL
;
470 if (pci_aer_available()) {
471 if (aer_acpi_firmware_first())
472 dev_info(&device
->dev
,
473 "PCIe AER handled by firmware\n");
475 control
|= OSC_PCI_EXPRESS_AER_CONTROL
;
479 status
= acpi_pci_osc_control_set(handle
, &control
,
480 OSC_PCI_EXPRESS_CAPABILITY_CONTROL
);
481 if (ACPI_SUCCESS(status
)) {
482 decode_osc_control(root
, "OS now controls", control
);
483 if (acpi_gbl_FADT
.boot_flags
& ACPI_FADT_NO_ASPM
) {
485 * We have ASPM control, but the FADT indicates
486 * that it's unsupported. Clear it.
491 decode_osc_control(root
, "OS requested", requested
);
492 decode_osc_control(root
, "platform willing to grant", control
);
493 dev_info(&device
->dev
, "_OSC failed (%s); disabling ASPM\n",
494 acpi_format_exception(status
));
497 * We want to disable ASPM here, but aspm_disabled
498 * needs to remain in its state from boot so that we
499 * properly handle PCIe 1.1 devices. So we set this
500 * flag here, to defer the action until after the ACPI
507 static int acpi_pci_root_add(struct acpi_device
*device
,
508 const struct acpi_device_id
*not_used
)
510 unsigned long long segment
, bus
;
513 struct acpi_pci_root
*root
;
514 acpi_handle handle
= device
->handle
;
515 int no_aspm
= 0, clear_aspm
= 0;
517 root
= kzalloc(sizeof(struct acpi_pci_root
), GFP_KERNEL
);
522 status
= acpi_evaluate_integer(handle
, METHOD_NAME__SEG
, NULL
,
524 if (ACPI_FAILURE(status
) && status
!= AE_NOT_FOUND
) {
525 dev_err(&device
->dev
, "can't evaluate _SEG\n");
530 /* Check _CRS first, then _BBN. If no _BBN, default to zero. */
531 root
->secondary
.flags
= IORESOURCE_BUS
;
532 status
= try_get_root_bridge_busnr(handle
, &root
->secondary
);
533 if (ACPI_FAILURE(status
)) {
535 * We need both the start and end of the downstream bus range
536 * to interpret _CBA (MMCONFIG base address), so it really is
537 * supposed to be in _CRS. If we don't find it there, all we
538 * can do is assume [_BBN-0xFF] or [0-0xFF].
540 root
->secondary
.end
= 0xFF;
541 dev_warn(&device
->dev
,
542 FW_BUG
"no secondary bus range in _CRS\n");
543 status
= acpi_evaluate_integer(handle
, METHOD_NAME__BBN
,
545 if (ACPI_SUCCESS(status
))
546 root
->secondary
.start
= bus
;
547 else if (status
== AE_NOT_FOUND
)
548 root
->secondary
.start
= 0;
550 dev_err(&device
->dev
, "can't evaluate _BBN\n");
556 root
->device
= device
;
557 root
->segment
= segment
& 0xFFFF;
558 strcpy(acpi_device_name(device
), ACPI_PCI_ROOT_DEVICE_NAME
);
559 strcpy(acpi_device_class(device
), ACPI_PCI_ROOT_CLASS
);
560 device
->driver_data
= root
;
562 pr_info(PREFIX
"%s [%s] (domain %04x %pR)\n",
563 acpi_device_name(device
), acpi_device_bid(device
),
564 root
->segment
, &root
->secondary
);
566 root
->mcfg_addr
= acpi_pci_root_get_mcfg_addr(handle
);
568 negotiate_os_control(root
, &no_aspm
, &clear_aspm
);
571 * TBD: Need PCI interface for enumeration/configuration of roots.
575 * Scan the Root Bridge
576 * --------------------
577 * Must do this prior to any attempt to bind the root device, as the
578 * PCI namespace does not get created until this call is made (and
579 * thus the root bridge's pci_dev does not exist).
581 root
->bus
= pci_acpi_scan_root(root
);
583 dev_err(&device
->dev
,
584 "Bus %04x:%02x not present in PCI namespace\n",
585 root
->segment
, (unsigned int)root
->secondary
.start
);
586 device
->driver_data
= NULL
;
592 dev_info(&device
->dev
, "Disabling ASPM (FADT indicates it is unsupported)\n");
593 pcie_clear_aspm(root
->bus
);
598 pci_acpi_add_bus_pm_notifier(device
, root
->bus
);
599 if (device
->wakeup
.flags
.run_wake
)
600 device_set_run_wake(root
->bus
->bridge
, true);
602 if (system_state
!= SYSTEM_BOOTING
) {
603 pcibios_resource_survey_bus(root
->bus
);
604 pci_assign_unassigned_root_bus_resources(root
->bus
);
607 pci_lock_rescan_remove();
608 pci_bus_add_devices(root
->bus
);
609 pci_unlock_rescan_remove();
617 static void acpi_pci_root_remove(struct acpi_device
*device
)
619 struct acpi_pci_root
*root
= acpi_driver_data(device
);
621 pci_lock_rescan_remove();
623 pci_stop_root_bus(root
->bus
);
625 device_set_run_wake(root
->bus
->bridge
, false);
626 pci_acpi_remove_bus_pm_notifier(device
);
628 pci_remove_root_bus(root
->bus
);
630 pci_unlock_rescan_remove();
635 void __init
acpi_pci_root_init(void)
638 if (acpi_pci_disabled
)
641 pci_acpi_crs_quirks();
642 acpi_scan_add_handler_with_hotplug(&pci_root_handler
, "pci_root");