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 #define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \
53 | OSC_PCI_ASPM_SUPPORT \
54 | OSC_PCI_CLOCK_PM_SUPPORT \
55 | OSC_PCI_MSI_SUPPORT)
57 static const struct acpi_device_id root_device_ids
[] = {
62 static struct acpi_scan_handler pci_root_handler
= {
63 .ids
= root_device_ids
,
64 .attach
= acpi_pci_root_add
,
65 .detach
= acpi_pci_root_remove
,
68 static DEFINE_MUTEX(osc_lock
);
71 * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
72 * @handle - the ACPI CA node in question.
74 * Note: we could make this API take a struct acpi_device * instead, but
75 * for now, it's more convenient to operate on an acpi_handle.
77 int acpi_is_root_bridge(acpi_handle handle
)
80 struct acpi_device
*device
;
82 ret
= acpi_bus_get_device(handle
, &device
);
86 ret
= acpi_match_device_ids(device
, root_device_ids
);
92 EXPORT_SYMBOL_GPL(acpi_is_root_bridge
);
95 get_root_bridge_busnr_callback(struct acpi_resource
*resource
, void *data
)
97 struct resource
*res
= data
;
98 struct acpi_resource_address64 address
;
101 status
= acpi_resource_to_address64(resource
, &address
);
102 if (ACPI_FAILURE(status
))
105 if ((address
.address_length
> 0) &&
106 (address
.resource_type
== ACPI_BUS_NUMBER_RANGE
)) {
107 res
->start
= address
.minimum
;
108 res
->end
= address
.minimum
+ address
.address_length
- 1;
114 static acpi_status
try_get_root_bridge_busnr(acpi_handle handle
,
115 struct resource
*res
)
121 acpi_walk_resources(handle
, METHOD_NAME__CRS
,
122 get_root_bridge_busnr_callback
, res
);
123 if (ACPI_FAILURE(status
))
125 if (res
->start
== -1)
130 struct pci_osc_bit_struct
{
135 static struct pci_osc_bit_struct pci_osc_support_bit
[] = {
136 { OSC_PCI_EXT_CONFIG_SUPPORT
, "ExtendedConfig" },
137 { OSC_PCI_ASPM_SUPPORT
, "ASPM" },
138 { OSC_PCI_CLOCK_PM_SUPPORT
, "ClockPM" },
139 { OSC_PCI_SEGMENT_GROUPS_SUPPORT
, "Segments" },
140 { OSC_PCI_MSI_SUPPORT
, "MSI" },
143 static struct pci_osc_bit_struct pci_osc_control_bit
[] = {
144 { OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
, "PCIeHotplug" },
145 { OSC_PCI_SHPC_NATIVE_HP_CONTROL
, "SHPCHotplug" },
146 { OSC_PCI_EXPRESS_PME_CONTROL
, "PME" },
147 { OSC_PCI_EXPRESS_AER_CONTROL
, "AER" },
148 { OSC_PCI_EXPRESS_CAPABILITY_CONTROL
, "PCIeCapability" },
151 static void decode_osc_bits(struct acpi_pci_root
*root
, char *msg
, u32 word
,
152 struct pci_osc_bit_struct
*table
, int size
)
156 struct pci_osc_bit_struct
*entry
;
159 for (i
= 0, entry
= table
; i
< size
; i
++, entry
++)
160 if (word
& entry
->bit
)
161 len
+= snprintf(buf
+ len
, sizeof(buf
) - len
, "%s%s",
162 len
? " " : "", entry
->desc
);
164 dev_info(&root
->device
->dev
, "_OSC: %s [%s]\n", msg
, buf
);
167 static void decode_osc_support(struct acpi_pci_root
*root
, char *msg
, u32 word
)
169 decode_osc_bits(root
, msg
, word
, pci_osc_support_bit
,
170 ARRAY_SIZE(pci_osc_support_bit
));
173 static void decode_osc_control(struct acpi_pci_root
*root
, char *msg
, u32 word
)
175 decode_osc_bits(root
, msg
, word
, pci_osc_control_bit
,
176 ARRAY_SIZE(pci_osc_control_bit
));
179 static u8 pci_osc_uuid_str
[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
181 static acpi_status
acpi_pci_run_osc(acpi_handle handle
,
182 const u32
*capbuf
, u32
*retval
)
184 struct acpi_osc_context context
= {
185 .uuid_str
= pci_osc_uuid_str
,
188 .cap
.pointer
= (void *)capbuf
,
192 status
= acpi_run_osc(handle
, &context
);
193 if (ACPI_SUCCESS(status
)) {
194 *retval
= *((u32
*)(context
.ret
.pointer
+ 8));
195 kfree(context
.ret
.pointer
);
200 static acpi_status
acpi_pci_query_osc(struct acpi_pci_root
*root
,
205 u32 result
, capbuf
[3];
207 support
&= OSC_PCI_SUPPORT_MASKS
;
208 support
|= root
->osc_support_set
;
210 capbuf
[OSC_QUERY_DWORD
] = OSC_QUERY_ENABLE
;
211 capbuf
[OSC_SUPPORT_DWORD
] = support
;
213 *control
&= OSC_PCI_CONTROL_MASKS
;
214 capbuf
[OSC_CONTROL_DWORD
] = *control
| root
->osc_control_set
;
216 /* Run _OSC query only with existing controls. */
217 capbuf
[OSC_CONTROL_DWORD
] = root
->osc_control_set
;
220 status
= acpi_pci_run_osc(root
->device
->handle
, capbuf
, &result
);
221 if (ACPI_SUCCESS(status
)) {
222 root
->osc_support_set
= support
;
229 static acpi_status
acpi_pci_osc_support(struct acpi_pci_root
*root
, u32 flags
)
233 mutex_lock(&osc_lock
);
234 status
= acpi_pci_query_osc(root
, flags
, NULL
);
235 mutex_unlock(&osc_lock
);
239 struct acpi_pci_root
*acpi_pci_find_root(acpi_handle handle
)
241 struct acpi_pci_root
*root
;
242 struct acpi_device
*device
;
244 if (acpi_bus_get_device(handle
, &device
) ||
245 acpi_match_device_ids(device
, root_device_ids
))
248 root
= acpi_driver_data(device
);
252 EXPORT_SYMBOL_GPL(acpi_pci_find_root
);
254 struct acpi_handle_node
{
255 struct list_head node
;
260 * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
261 * @handle: the handle in question
263 * Given an ACPI CA handle, the desired PCI device is located in the
264 * list of PCI devices.
266 * If the device is found, its reference count is increased and this
267 * function returns a pointer to its data structure. The caller must
268 * decrement the reference count by calling pci_dev_put().
269 * If no device is found, %NULL is returned.
271 struct pci_dev
*acpi_get_pci_dev(acpi_handle handle
)
274 unsigned long long adr
;
277 struct pci_bus
*pbus
;
278 struct pci_dev
*pdev
= NULL
;
279 struct acpi_handle_node
*node
, *tmp
;
280 struct acpi_pci_root
*root
;
281 LIST_HEAD(device_list
);
284 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
287 while (!acpi_is_root_bridge(phandle
)) {
288 node
= kzalloc(sizeof(struct acpi_handle_node
), GFP_KERNEL
);
292 INIT_LIST_HEAD(&node
->node
);
293 node
->handle
= phandle
;
294 list_add(&node
->node
, &device_list
);
296 status
= acpi_get_parent(phandle
, &phandle
);
297 if (ACPI_FAILURE(status
))
301 root
= acpi_pci_find_root(phandle
);
308 * Now, walk back down the PCI device tree until we return to our
309 * original handle. Assumes that everything between the PCI root
310 * bridge and the device we're looking for must be a P2P bridge.
312 list_for_each_entry(node
, &device_list
, node
) {
313 acpi_handle hnd
= node
->handle
;
314 status
= acpi_evaluate_integer(hnd
, "_ADR", NULL
, &adr
);
315 if (ACPI_FAILURE(status
))
317 dev
= (adr
>> 16) & 0xffff;
320 pdev
= pci_get_slot(pbus
, PCI_DEVFN(dev
, fn
));
321 if (!pdev
|| hnd
== handle
)
324 pbus
= pdev
->subordinate
;
328 * This function may be called for a non-PCI device that has a
329 * PCI parent (eg. a disk under a PCI SATA controller). In that
330 * case pdev->subordinate will be NULL for the parent.
333 dev_dbg(&pdev
->dev
, "Not a PCI-to-PCI bridge\n");
339 list_for_each_entry_safe(node
, tmp
, &device_list
, node
)
344 EXPORT_SYMBOL_GPL(acpi_get_pci_dev
);
347 * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
348 * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
349 * @mask: Mask of _OSC bits to request control of, place to store control mask.
350 * @req: Mask of _OSC bits the control of is essential to the caller.
352 * Run _OSC query for @mask and if that is successful, compare the returned
353 * mask of control bits with @req. If all of the @req bits are set in the
354 * returned mask, run _OSC request for it.
356 * The variable at the @mask address may be modified regardless of whether or
357 * not the function returns success. On success it will contain the mask of
358 * _OSC bits the BIOS has granted control of, but its contents are meaningless
361 acpi_status
acpi_pci_osc_control_set(acpi_handle handle
, u32
*mask
, u32 req
)
363 struct acpi_pci_root
*root
;
364 acpi_status status
= AE_OK
;
368 return AE_BAD_PARAMETER
;
370 ctrl
= *mask
& OSC_PCI_CONTROL_MASKS
;
371 if ((ctrl
& req
) != req
)
374 root
= acpi_pci_find_root(handle
);
378 mutex_lock(&osc_lock
);
380 *mask
= ctrl
| root
->osc_control_set
;
381 /* No need to evaluate _OSC if the control was already granted. */
382 if ((root
->osc_control_set
& ctrl
) == ctrl
)
385 /* Need to check the available controls bits before requesting them. */
387 status
= acpi_pci_query_osc(root
, root
->osc_support_set
, mask
);
388 if (ACPI_FAILURE(status
))
392 decode_osc_control(root
, "platform does not support",
397 if ((ctrl
& req
) != req
) {
398 decode_osc_control(root
, "not requesting control; platform does not support",
404 capbuf
[OSC_QUERY_DWORD
] = 0;
405 capbuf
[OSC_SUPPORT_DWORD
] = root
->osc_support_set
;
406 capbuf
[OSC_CONTROL_DWORD
] = ctrl
;
407 status
= acpi_pci_run_osc(handle
, capbuf
, mask
);
408 if (ACPI_SUCCESS(status
))
409 root
->osc_control_set
= *mask
;
411 mutex_unlock(&osc_lock
);
414 EXPORT_SYMBOL(acpi_pci_osc_control_set
);
416 static void negotiate_os_control(struct acpi_pci_root
*root
, int *no_aspm
,
419 u32 support
, control
, requested
;
421 struct acpi_device
*device
= root
->device
;
422 acpi_handle handle
= device
->handle
;
425 * All supported architectures that use ACPI have support for
426 * PCI domains, so we indicate this in _OSC support capabilities.
428 support
= OSC_PCI_SEGMENT_GROUPS_SUPPORT
;
429 if (pci_ext_cfg_avail())
430 support
|= OSC_PCI_EXT_CONFIG_SUPPORT
;
431 if (pcie_aspm_support_enabled())
432 support
|= OSC_PCI_ASPM_SUPPORT
| OSC_PCI_CLOCK_PM_SUPPORT
;
433 if (pci_msi_enabled())
434 support
|= OSC_PCI_MSI_SUPPORT
;
436 decode_osc_support(root
, "OS supports", support
);
437 status
= acpi_pci_osc_support(root
, support
);
438 if (ACPI_FAILURE(status
)) {
439 dev_info(&device
->dev
, "_OSC failed (%s); disabling ASPM\n",
440 acpi_format_exception(status
));
445 if (pcie_ports_disabled
) {
446 dev_info(&device
->dev
, "PCIe port services disabled; not requesting _OSC control\n");
450 if ((support
& ACPI_PCIE_REQ_SUPPORT
) != ACPI_PCIE_REQ_SUPPORT
) {
451 decode_osc_support(root
, "not requesting OS control; OS requires",
452 ACPI_PCIE_REQ_SUPPORT
);
456 control
= OSC_PCI_EXPRESS_CAPABILITY_CONTROL
457 | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
458 | OSC_PCI_EXPRESS_PME_CONTROL
;
460 if (pci_aer_available()) {
461 if (aer_acpi_firmware_first())
462 dev_info(&device
->dev
,
463 "PCIe AER handled by firmware\n");
465 control
|= OSC_PCI_EXPRESS_AER_CONTROL
;
469 status
= acpi_pci_osc_control_set(handle
, &control
,
470 OSC_PCI_EXPRESS_CAPABILITY_CONTROL
);
471 if (ACPI_SUCCESS(status
)) {
472 decode_osc_control(root
, "OS now controls", control
);
473 if (acpi_gbl_FADT
.boot_flags
& ACPI_FADT_NO_ASPM
) {
475 * We have ASPM control, but the FADT indicates
476 * that it's unsupported. Clear it.
481 decode_osc_control(root
, "OS requested", requested
);
482 decode_osc_control(root
, "platform willing to grant", control
);
483 dev_info(&device
->dev
, "_OSC failed (%s); disabling ASPM\n",
484 acpi_format_exception(status
));
487 * We want to disable ASPM here, but aspm_disabled
488 * needs to remain in its state from boot so that we
489 * properly handle PCIe 1.1 devices. So we set this
490 * flag here, to defer the action until after the ACPI
497 static int acpi_pci_root_add(struct acpi_device
*device
,
498 const struct acpi_device_id
*not_used
)
500 unsigned long long segment
, bus
;
503 struct acpi_pci_root
*root
;
504 acpi_handle handle
= device
->handle
;
505 int no_aspm
= 0, clear_aspm
= 0;
507 root
= kzalloc(sizeof(struct acpi_pci_root
), GFP_KERNEL
);
512 status
= acpi_evaluate_integer(handle
, METHOD_NAME__SEG
, NULL
,
514 if (ACPI_FAILURE(status
) && status
!= AE_NOT_FOUND
) {
515 dev_err(&device
->dev
, "can't evaluate _SEG\n");
520 /* Check _CRS first, then _BBN. If no _BBN, default to zero. */
521 root
->secondary
.flags
= IORESOURCE_BUS
;
522 status
= try_get_root_bridge_busnr(handle
, &root
->secondary
);
523 if (ACPI_FAILURE(status
)) {
525 * We need both the start and end of the downstream bus range
526 * to interpret _CBA (MMCONFIG base address), so it really is
527 * supposed to be in _CRS. If we don't find it there, all we
528 * can do is assume [_BBN-0xFF] or [0-0xFF].
530 root
->secondary
.end
= 0xFF;
531 dev_warn(&device
->dev
,
532 FW_BUG
"no secondary bus range in _CRS\n");
533 status
= acpi_evaluate_integer(handle
, METHOD_NAME__BBN
,
535 if (ACPI_SUCCESS(status
))
536 root
->secondary
.start
= bus
;
537 else if (status
== AE_NOT_FOUND
)
538 root
->secondary
.start
= 0;
540 dev_err(&device
->dev
, "can't evaluate _BBN\n");
546 root
->device
= device
;
547 root
->segment
= segment
& 0xFFFF;
548 strcpy(acpi_device_name(device
), ACPI_PCI_ROOT_DEVICE_NAME
);
549 strcpy(acpi_device_class(device
), ACPI_PCI_ROOT_CLASS
);
550 device
->driver_data
= root
;
552 pr_info(PREFIX
"%s [%s] (domain %04x %pR)\n",
553 acpi_device_name(device
), acpi_device_bid(device
),
554 root
->segment
, &root
->secondary
);
556 root
->mcfg_addr
= acpi_pci_root_get_mcfg_addr(handle
);
558 negotiate_os_control(root
, &no_aspm
, &clear_aspm
);
561 * TBD: Need PCI interface for enumeration/configuration of roots.
565 * Scan the Root Bridge
566 * --------------------
567 * Must do this prior to any attempt to bind the root device, as the
568 * PCI namespace does not get created until this call is made (and
569 * thus the root bridge's pci_dev does not exist).
571 root
->bus
= pci_acpi_scan_root(root
);
573 dev_err(&device
->dev
,
574 "Bus %04x:%02x not present in PCI namespace\n",
575 root
->segment
, (unsigned int)root
->secondary
.start
);
576 device
->driver_data
= NULL
;
582 dev_info(&device
->dev
, "Disabling ASPM (FADT indicates it is unsupported)\n");
583 pcie_clear_aspm(root
->bus
);
588 pci_acpi_add_bus_pm_notifier(device
, root
->bus
);
589 if (device
->wakeup
.flags
.run_wake
)
590 device_set_run_wake(root
->bus
->bridge
, true);
592 if (system_state
!= SYSTEM_BOOTING
) {
593 pcibios_resource_survey_bus(root
->bus
);
594 pci_assign_unassigned_root_bus_resources(root
->bus
);
597 pci_bus_add_devices(root
->bus
);
605 static void acpi_pci_root_remove(struct acpi_device
*device
)
607 struct acpi_pci_root
*root
= acpi_driver_data(device
);
609 pci_stop_root_bus(root
->bus
);
611 device_set_run_wake(root
->bus
->bridge
, false);
612 pci_acpi_remove_bus_pm_notifier(device
);
614 pci_remove_root_bus(root
->bus
);
619 void __init
acpi_pci_root_init(void)
623 if (!acpi_pci_disabled
) {
624 pci_acpi_crs_quirks();
625 acpi_scan_add_handler(&pci_root_handler
);
628 /* Support root bridge hotplug */
630 static void handle_root_bridge_insertion(acpi_handle handle
)
632 struct acpi_device
*device
;
634 if (!acpi_bus_get_device(handle
, &device
)) {
635 dev_printk(KERN_DEBUG
, &device
->dev
,
636 "acpi device already exists; ignoring notify\n");
640 if (acpi_bus_scan(handle
))
641 acpi_handle_err(handle
, "cannot add bridge to acpi list\n");
644 static void hotplug_event_root(void *data
, u32 type
)
646 acpi_handle handle
= data
;
647 struct acpi_pci_root
*root
;
649 acpi_scan_lock_acquire();
651 root
= acpi_pci_find_root(handle
);
654 case ACPI_NOTIFY_BUS_CHECK
:
656 acpi_handle_printk(KERN_DEBUG
, handle
,
657 "Bus check notify on %s\n", __func__
);
659 acpiphp_check_host_bridge(handle
);
661 handle_root_bridge_insertion(handle
);
665 case ACPI_NOTIFY_DEVICE_CHECK
:
667 acpi_handle_printk(KERN_DEBUG
, handle
,
668 "Device check notify on %s\n", __func__
);
670 handle_root_bridge_insertion(handle
);
673 case ACPI_NOTIFY_EJECT_REQUEST
:
674 /* request device eject */
675 acpi_handle_printk(KERN_DEBUG
, handle
,
676 "Device eject notify on %s\n", __func__
);
680 get_device(&root
->device
->dev
);
682 acpi_scan_lock_release();
684 acpi_bus_device_eject(root
->device
, ACPI_NOTIFY_EJECT_REQUEST
);
687 acpi_handle_warn(handle
,
688 "notify_handler: unknown event type 0x%x\n",
693 acpi_scan_lock_release();
696 static void handle_hotplug_event_root(acpi_handle handle
, u32 type
,
699 acpi_hotplug_execute(hotplug_event_root
, handle
, type
);
702 static acpi_status __init
703 find_root_bridges(acpi_handle handle
, u32 lvl
, void *context
, void **rv
)
706 int *count
= (int *)context
;
708 if (!acpi_is_root_bridge(handle
))
713 status
= acpi_install_notify_handler(handle
, ACPI_SYSTEM_NOTIFY
,
714 handle_hotplug_event_root
, NULL
);
715 if (ACPI_FAILURE(status
))
716 acpi_handle_printk(KERN_DEBUG
, handle
,
717 "notify handler is not installed, exit status: %u\n",
718 (unsigned int)status
);
720 acpi_handle_printk(KERN_DEBUG
, handle
,
721 "notify handler is installed\n");
726 void __init
acpi_pci_root_hp_init(void)
730 acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
731 ACPI_UINT32_MAX
, find_root_bridges
, NULL
, &num
, NULL
);
733 printk(KERN_DEBUG
"Found %d acpi root devices\n", num
);