1/*
2 *  pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
3 *
4 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 *
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8 *
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.
13 *
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.
18 *
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.
22 *
23 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
24 */
25
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/init.h>
29#include <linux/types.h>
30#include <linux/spinlock.h>
31#include <linux/pm.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/acpi_bus.h>
39#include <acpi/acpi_drivers.h>
40#include <acpi/apei.h>
41
42#define PREFIX "ACPI: "
43
44#define _COMPONENT		ACPI_PCI_COMPONENT
45ACPI_MODULE_NAME("pci_root");
46#define ACPI_PCI_ROOT_CLASS		"pci_bridge"
47#define ACPI_PCI_ROOT_DEVICE_NAME	"PCI Root Bridge"
48static int acpi_pci_root_add(struct acpi_device *device);
49static int acpi_pci_root_remove(struct acpi_device *device, int type);
50static int acpi_pci_root_start(struct acpi_device *device);
51
52#define ACPI_PCIE_REQ_SUPPORT (OSC_EXT_PCI_CONFIG_SUPPORT \
53				| OSC_ACTIVE_STATE_PWR_SUPPORT \
54				| OSC_CLOCK_PWR_CAPABILITY_SUPPORT \
55				| OSC_MSI_SUPPORT)
56
57static const struct acpi_device_id root_device_ids[] = {
58	{"PNP0A03", 0},
59	{"", 0},
60};
61MODULE_DEVICE_TABLE(acpi, root_device_ids);
62
63static struct acpi_driver acpi_pci_root_driver = {
64	.name = "pci_root",
65	.class = ACPI_PCI_ROOT_CLASS,
66	.ids = root_device_ids,
67	.ops = {
68		.add = acpi_pci_root_add,
69		.remove = acpi_pci_root_remove,
70		.start = acpi_pci_root_start,
71		},
72};
73
74static LIST_HEAD(acpi_pci_roots);
75
76static struct acpi_pci_driver *sub_driver;
77static DEFINE_MUTEX(osc_lock);
78
79int acpi_pci_register_driver(struct acpi_pci_driver *driver)
80{
81	int n = 0;
82	struct acpi_pci_root *root;
83
84	struct acpi_pci_driver **pptr = &sub_driver;
85	while (*pptr)
86		pptr = &(*pptr)->next;
87	*pptr = driver;
88
89	if (!driver->add)
90		return 0;
91
92	list_for_each_entry(root, &acpi_pci_roots, node) {
93		driver->add(root->device->handle);
94		n++;
95	}
96
97	return n;
98}
99
100EXPORT_SYMBOL(acpi_pci_register_driver);
101
102void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
103{
104	struct acpi_pci_root *root;
105
106	struct acpi_pci_driver **pptr = &sub_driver;
107	while (*pptr) {
108		if (*pptr == driver)
109			break;
110		pptr = &(*pptr)->next;
111	}
112	BUG_ON(!*pptr);
113	*pptr = (*pptr)->next;
114
115	if (!driver->remove)
116		return;
117
118	list_for_each_entry(root, &acpi_pci_roots, node)
119		driver->remove(root->device->handle);
120}
121
122EXPORT_SYMBOL(acpi_pci_unregister_driver);
123
124acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
125{
126	struct acpi_pci_root *root;
127
128	list_for_each_entry(root, &acpi_pci_roots, node)
129		if ((root->segment == (u16) seg) &&
130		    (root->secondary.start == (u16) bus))
131			return root->device->handle;
132	return NULL;
133}
134
135EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
136
137/**
138 * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
139 * @handle - the ACPI CA node in question.
140 *
141 * Note: we could make this API take a struct acpi_device * instead, but
142 * for now, it's more convenient to operate on an acpi_handle.
143 */
144int acpi_is_root_bridge(acpi_handle handle)
145{
146	int ret;
147	struct acpi_device *device;
148
149	ret = acpi_bus_get_device(handle, &device);
150	if (ret)
151		return 0;
152
153	ret = acpi_match_device_ids(device, root_device_ids);
154	if (ret)
155		return 0;
156	else
157		return 1;
158}
159EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
160
161static acpi_status
162get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
163{
164	struct resource *res = data;
165	struct acpi_resource_address64 address;
166
167	if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
168	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
169	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
170		return AE_OK;
171
172	acpi_resource_to_address64(resource, &address);
173	if ((address.address_length > 0) &&
174	    (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
175		res->start = address.minimum;
176		res->end = address.minimum + address.address_length - 1;
177	}
178
179	return AE_OK;
180}
181
182static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
183					     struct resource *res)
184{
185	acpi_status status;
186
187	res->start = -1;
188	status =
189	    acpi_walk_resources(handle, METHOD_NAME__CRS,
190				get_root_bridge_busnr_callback, res);
191	if (ACPI_FAILURE(status))
192		return status;
193	if (res->start == -1)
194		return AE_ERROR;
195	return AE_OK;
196}
197
198static void acpi_pci_bridge_scan(struct acpi_device *device)
199{
200	int status;
201	struct acpi_device *child = NULL;
202
203	if (device->flags.bus_address)
204		if (device->parent && device->parent->ops.bind) {
205			status = device->parent->ops.bind(device);
206			if (!status) {
207				list_for_each_entry(child, &device->children, node)
208					acpi_pci_bridge_scan(child);
209			}
210		}
211}
212
213static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
214
215static acpi_status acpi_pci_run_osc(acpi_handle handle,
216				    const u32 *capbuf, u32 *retval)
217{
218	struct acpi_osc_context context = {
219		.uuid_str = pci_osc_uuid_str,
220		.rev = 1,
221		.cap.length = 12,
222		.cap.pointer = (void *)capbuf,
223	};
224	acpi_status status;
225
226	status = acpi_run_osc(handle, &context);
227	if (ACPI_SUCCESS(status)) {
228		*retval = *((u32 *)(context.ret.pointer + 8));
229		kfree(context.ret.pointer);
230	}
231	return status;
232}
233
234static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
235					u32 support,
236					u32 *control)
237{
238	acpi_status status;
239	u32 result, capbuf[3];
240
241	support &= OSC_PCI_SUPPORT_MASKS;
242	support |= root->osc_support_set;
243
244	capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
245	capbuf[OSC_SUPPORT_TYPE] = support;
246	if (control) {
247		*control &= OSC_PCI_CONTROL_MASKS;
248		capbuf[OSC_CONTROL_TYPE] = *control | root->osc_control_set;
249	} else {
250		/* Run _OSC query for all possible controls. */
251		capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS;
252	}
253
254	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
255	if (ACPI_SUCCESS(status)) {
256		root->osc_support_set = support;
257		if (control)
258			*control = result;
259	}
260	return status;
261}
262
263static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
264{
265	acpi_status status;
266	acpi_handle tmp;
267
268	status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
269	if (ACPI_FAILURE(status))
270		return status;
271	mutex_lock(&osc_lock);
272	status = acpi_pci_query_osc(root, flags, NULL);
273	mutex_unlock(&osc_lock);
274	return status;
275}
276
277struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
278{
279	struct acpi_pci_root *root;
280
281	list_for_each_entry(root, &acpi_pci_roots, node) {
282		if (root->device->handle == handle)
283			return root;
284	}
285	return NULL;
286}
287EXPORT_SYMBOL_GPL(acpi_pci_find_root);
288
289struct acpi_handle_node {
290	struct list_head node;
291	acpi_handle handle;
292};
293
294/**
295 * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
296 * @handle: the handle in question
297 *
298 * Given an ACPI CA handle, the desired PCI device is located in the
299 * list of PCI devices.
300 *
301 * If the device is found, its reference count is increased and this
302 * function returns a pointer to its data structure.  The caller must
303 * decrement the reference count by calling pci_dev_put().
304 * If no device is found, %NULL is returned.
305 */
306struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
307{
308	int dev, fn;
309	unsigned long long adr;
310	acpi_status status;
311	acpi_handle phandle;
312	struct pci_bus *pbus;
313	struct pci_dev *pdev = NULL;
314	struct acpi_handle_node *node, *tmp;
315	struct acpi_pci_root *root;
316	LIST_HEAD(device_list);
317
318	/*
319	 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
320	 */
321	phandle = handle;
322	while (!acpi_is_root_bridge(phandle)) {
323		node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
324		if (!node)
325			goto out;
326
327		INIT_LIST_HEAD(&node->node);
328		node->handle = phandle;
329		list_add(&node->node, &device_list);
330
331		status = acpi_get_parent(phandle, &phandle);
332		if (ACPI_FAILURE(status))
333			goto out;
334	}
335
336	root = acpi_pci_find_root(phandle);
337	if (!root)
338		goto out;
339
340	pbus = root->bus;
341
342	/*
343	 * Now, walk back down the PCI device tree until we return to our
344	 * original handle. Assumes that everything between the PCI root
345	 * bridge and the device we're looking for must be a P2P bridge.
346	 */
347	list_for_each_entry(node, &device_list, node) {
348		acpi_handle hnd = node->handle;
349		status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
350		if (ACPI_FAILURE(status))
351			goto out;
352		dev = (adr >> 16) & 0xffff;
353		fn  = adr & 0xffff;
354
355		pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
356		if (!pdev || hnd == handle)
357			break;
358
359		pbus = pdev->subordinate;
360		pci_dev_put(pdev);
361
362		/*
363		 * This function may be called for a non-PCI device that has a
364		 * PCI parent (eg. a disk under a PCI SATA controller).  In that
365		 * case pdev->subordinate will be NULL for the parent.
366		 */
367		if (!pbus) {
368			dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
369			pdev = NULL;
370			break;
371		}
372	}
373out:
374	list_for_each_entry_safe(node, tmp, &device_list, node)
375		kfree(node);
376
377	return pdev;
378}
379EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
380
381/**
382 * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
383 * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
384 * @mask: Mask of _OSC bits to request control of, place to store control mask.
385 * @req: Mask of _OSC bits the control of is essential to the caller.
386 *
387 * Run _OSC query for @mask and if that is successful, compare the returned
388 * mask of control bits with @req.  If all of the @req bits are set in the
389 * returned mask, run _OSC request for it.
390 *
391 * The variable at the @mask address may be modified regardless of whether or
392 * not the function returns success.  On success it will contain the mask of
393 * _OSC bits the BIOS has granted control of, but its contents are meaningless
394 * on failure.
395 **/
396acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
397{
398	struct acpi_pci_root *root;
399	acpi_status status;
400	u32 ctrl, capbuf[3];
401	acpi_handle tmp;
402
403	if (!mask)
404		return AE_BAD_PARAMETER;
405
406	ctrl = *mask & OSC_PCI_CONTROL_MASKS;
407	if ((ctrl & req) != req)
408		return AE_TYPE;
409
410	root = acpi_pci_find_root(handle);
411	if (!root)
412		return AE_NOT_EXIST;
413
414	status = acpi_get_handle(handle, "_OSC", &tmp);
415	if (ACPI_FAILURE(status))
416		return status;
417
418	mutex_lock(&osc_lock);
419
420	*mask = ctrl | root->osc_control_set;
421	/* No need to evaluate _OSC if the control was already granted. */
422	if ((root->osc_control_set & ctrl) == ctrl)
423		goto out;
424
425	/* Need to check the available controls bits before requesting them. */
426	while (*mask) {
427		status = acpi_pci_query_osc(root, root->osc_support_set, mask);
428		if (ACPI_FAILURE(status))
429			goto out;
430		if (ctrl == *mask)
431			break;
432		ctrl = *mask;
433	}
434
435	if ((ctrl & req) != req) {
436		status = AE_SUPPORT;
437		goto out;
438	}
439
440	capbuf[OSC_QUERY_TYPE] = 0;
441	capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
442	capbuf[OSC_CONTROL_TYPE] = ctrl;
443	status = acpi_pci_run_osc(handle, capbuf, mask);
444	if (ACPI_SUCCESS(status))
445		root->osc_control_set = *mask;
446out:
447	mutex_unlock(&osc_lock);
448	return status;
449}
450EXPORT_SYMBOL(acpi_pci_osc_control_set);
451
452static int __devinit acpi_pci_root_add(struct acpi_device *device)
453{
454	unsigned long long segment, bus;
455	acpi_status status;
456	int result;
457	struct acpi_pci_root *root;
458	acpi_handle handle;
459	struct acpi_device *child;
460	u32 flags, base_flags;
461
462	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
463	if (!root)
464		return -ENOMEM;
465
466	segment = 0;
467	status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
468				       &segment);
469	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
470		printk(KERN_ERR PREFIX "can't evaluate _SEG\n");
471		result = -ENODEV;
472		goto end;
473	}
474
475	/* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
476	root->secondary.flags = IORESOURCE_BUS;
477	status = try_get_root_bridge_busnr(device->handle, &root->secondary);
478	if (ACPI_FAILURE(status)) {
479		/*
480		 * We need both the start and end of the downstream bus range
481		 * to interpret _CBA (MMCONFIG base address), so it really is
482		 * supposed to be in _CRS.  If we don't find it there, all we
483		 * can do is assume [_BBN-0xFF] or [0-0xFF].
484		 */
485		root->secondary.end = 0xFF;
486		printk(KERN_WARNING FW_BUG PREFIX
487		       "no secondary bus range in _CRS\n");
488		status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN,
489					       NULL, &bus);
490		if (ACPI_SUCCESS(status))
491			root->secondary.start = bus;
492		else if (status == AE_NOT_FOUND)
493			root->secondary.start = 0;
494		else {
495			printk(KERN_ERR PREFIX "can't evaluate _BBN\n");
496			result = -ENODEV;
497			goto end;
498		}
499	}
500
501	INIT_LIST_HEAD(&root->node);
502	root->device = device;
503	root->segment = segment & 0xFFFF;
504	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
505	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
506	device->driver_data = root;
507
508	/*
509	 * All supported architectures that use ACPI have support for
510	 * PCI domains, so we indicate this in _OSC support capabilities.
511	 */
512	flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
513	acpi_pci_osc_support(root, flags);
514
515	/*
516	 * TBD: Need PCI interface for enumeration/configuration of roots.
517	 */
518
519	/* TBD: Locking */
520	list_add_tail(&root->node, &acpi_pci_roots);
521
522	printk(KERN_INFO PREFIX "%s [%s] (domain %04x %pR)\n",
523	       acpi_device_name(device), acpi_device_bid(device),
524	       root->segment, &root->secondary);
525
526	/*
527	 * Scan the Root Bridge
528	 * --------------------
529	 * Must do this prior to any attempt to bind the root device, as the
530	 * PCI namespace does not get created until this call is made (and
531	 * thus the root bridge's pci_dev does not exist).
532	 */
533	root->bus = pci_acpi_scan_root(root);
534	if (!root->bus) {
535		printk(KERN_ERR PREFIX
536			    "Bus %04x:%02x not present in PCI namespace\n",
537			    root->segment, (unsigned int)root->secondary.start);
538		result = -ENODEV;
539		goto end;
540	}
541
542	/*
543	 * Attach ACPI-PCI Context
544	 * -----------------------
545	 * Thus binding the ACPI and PCI devices.
546	 */
547	result = acpi_pci_bind_root(device);
548	if (result)
549		goto end;
550
551	/*
552	 * PCI Routing Table
553	 * -----------------
554	 * Evaluate and parse _PRT, if exists.
555	 */
556	status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
557	if (ACPI_SUCCESS(status))
558		result = acpi_pci_irq_add_prt(device->handle, root->bus);
559
560	/*
561	 * Scan and bind all _ADR-Based Devices
562	 */
563	list_for_each_entry(child, &device->children, node)
564		acpi_pci_bridge_scan(child);
565
566	/* Indicate support for various _OSC capabilities. */
567	if (pci_ext_cfg_avail(root->bus->self))
568		flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
569	if (pcie_aspm_support_enabled())
570		flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
571			OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
572	if (pci_msi_enabled())
573		flags |= OSC_MSI_SUPPORT;
574	if (flags != base_flags)
575		acpi_pci_osc_support(root, flags);
576
577	if (!pcie_ports_disabled
578	    && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) {
579		flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL
580			| OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
581			| OSC_PCI_EXPRESS_PME_CONTROL;
582
583		if (pci_aer_available()) {
584			if (aer_acpi_firmware_first())
585				dev_dbg(root->bus->bridge,
586					"PCIe errors handled by BIOS.\n");
587			else
588				flags |= OSC_PCI_EXPRESS_AER_CONTROL;
589		}
590
591		dev_info(root->bus->bridge,
592			"Requesting ACPI _OSC control (0x%02x)\n", flags);
593
594		status = acpi_pci_osc_control_set(device->handle, &flags,
595					OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
596		if (ACPI_SUCCESS(status)) {
597			dev_info(root->bus->bridge,
598				"ACPI _OSC control (0x%02x) granted\n", flags);
599			if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
600				/*
601				 * We have ASPM control, but the FADT indicates
602				 * that it's unsupported. Clear it.
603				 */
604				pcie_clear_aspm(root->bus);
605			}
606		} else {
607			dev_info(root->bus->bridge,
608				"ACPI _OSC request failed (%s), "
609				"returned control mask: 0x%02x\n",
610				acpi_format_exception(status), flags);
611			pr_info("ACPI _OSC control for PCIe not granted, "
612				"disabling ASPM\n");
613			pcie_no_aspm();
614		}
615	} else {
616		dev_info(root->bus->bridge,
617			 "Unable to request _OSC control "
618			 "(_OSC support mask: 0x%02x)\n", flags);
619	}
620
621	pci_acpi_add_bus_pm_notifier(device, root->bus);
622	if (device->wakeup.flags.run_wake)
623		device_set_run_wake(root->bus->bridge, true);
624
625	return 0;
626
627end:
628	if (!list_empty(&root->node))
629		list_del(&root->node);
630	kfree(root);
631	return result;
632}
633
634static int acpi_pci_root_start(struct acpi_device *device)
635{
636	struct acpi_pci_root *root = acpi_driver_data(device);
637
638	pci_bus_add_devices(root->bus);
639	return 0;
640}
641
642static int acpi_pci_root_remove(struct acpi_device *device, int type)
643{
644	struct acpi_pci_root *root = acpi_driver_data(device);
645
646	device_set_run_wake(root->bus->bridge, false);
647	pci_acpi_remove_bus_pm_notifier(device);
648
649	kfree(root);
650	return 0;
651}
652
653static int __init acpi_pci_root_init(void)
654{
655	acpi_hest_init();
656
657	if (acpi_pci_disabled)
658		return 0;
659
660	pci_acpi_crs_quirks();
661	if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
662		return -ENODEV;
663
664	return 0;
665}
666
667subsys_initcall(acpi_pci_root_init);
668