1/* $NetBSD: acpi_pci.c,v 1.19 2015/04/13 18:32:50 christos Exp $ */
2
3/*
4 * Copyright (c) 2009, 2010 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christoph Egger and Gregoire Sutre.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
23 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
25 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32__KERNEL_RCSID(0, "$NetBSD: acpi_pci.c,v 1.19 2015/04/13 18:32:50 christos Exp $");
33
34#include <sys/param.h>
35#include <sys/device.h>
36#include <sys/kmem.h>
37#include <sys/systm.h>
38
39#include <dev/pci/pcireg.h>
40#include <dev/pci/pcivar.h>
41#include <dev/pci/pcidevs.h>
42#include <dev/pci/ppbreg.h>
43
44#include <dev/acpi/acpireg.h>
45#include <dev/acpi/acpivar.h>
46#include <dev/acpi/acpi_pci.h>
47
48#include "locators.h"
49
50#define _COMPONENT ACPI_BUS_COMPONENT
51ACPI_MODULE_NAME ("acpi_pci")
52
53#define ACPI_HILODWORD(x) ACPI_HIWORD(ACPI_LODWORD((x)))
54#define ACPI_LOLODWORD(x) ACPI_LOWORD(ACPI_LODWORD((x)))
55
56static ACPI_STATUS acpi_pcidev_pciroot_bus(ACPI_HANDLE, uint16_t *);
57static ACPI_STATUS acpi_pcidev_pciroot_bus_callback(ACPI_RESOURCE *,
58 void *);
59
60/*
61 * Regarding PCI Segment Groups (ACPI 4.0, p. 277):
62 *
63 * "The optional _SEG object is located under a PCI host bridge and
64 * evaluates to an integer that describes the PCI Segment Group (see PCI
65 * Firmware Specification v3.0)."
66 *
67 * "PCI Segment Group is purely a software concept managed by system
68 * firmware and used by OSPM. It is a logical collection of PCI buses
69 * (or bus segments). It is a way to logically group the PCI bus segments
70 * and PCI Express Hierarchies. _SEG is a level higher than _BBN."
71 *
72 * "PCI Segment Group supports more than 256 buses in a system by allowing
73 * the reuse of the PCI bus numbers. Within each PCI Segment Group, the bus
74 * numbers for the PCI buses must be unique. PCI buses in different PCI
75 * Segment Group are permitted to have the same bus number."
76 */
77
78/*
79 * Regarding PCI Base Bus Numbers (ACPI 4.0, p. 277):
80 *
81 * "For multi-root PCI platforms, the _BBN object evaluates to the PCI bus
82 * number that the BIOS assigns. This is needed to access a PCI_Config
83 * operation region for the specified bus. The _BBN object is located under
84 * a PCI host bridge and must be unique for every host bridge within a
85 * segment since it is the PCI bus number."
86 *
87 * Moreover, the ACPI FAQ (http://www.acpi.info/acpi_faq.htm) says:
88 *
89 * "For a multiple root bus machine, _BBN is required for each bus. _BBN
90 * should provide the bus number assigned to this bus by the BIOS at boot
91 * time."
92 */
93
94/*
95 * acpi_pcidev_pciroot_bus:
96 *
97 * Derive the PCI bus number of a PCI root bridge from its resources.
98 * If successful, return AE_OK and fill *busp. Otherwise, return an
99 * exception code and leave *busp unchanged.
100 */
101static ACPI_STATUS
102acpi_pcidev_pciroot_bus(ACPI_HANDLE handle, uint16_t *busp)
103{
104 ACPI_STATUS rv;
105 int32_t bus;
106
107 bus = -1;
108
109 /*
110 * XXX: Use the ACPI resource parsing functions (acpi_resource.c)
111 * once bus number ranges have been implemented there.
112 */
113 rv = AcpiWalkResources(handle, "_CRS",
114 acpi_pcidev_pciroot_bus_callback, &bus);
115
116 if (ACPI_FAILURE(rv))
117 return rv;
118
119 if (bus == -1)
120 return AE_NOT_EXIST;
121
122 /* Here it holds that 0 <= bus <= 0xFFFF. */
123 *busp = (uint16_t)bus;
124
125 return rv;
126}
127
128static ACPI_STATUS
129acpi_pcidev_pciroot_bus_callback(ACPI_RESOURCE *res, void *context)
130{
131 ACPI_RESOURCE_ADDRESS64 addr64;
132 int32_t *bus = context;
133
134 /* Always continue the walk by returning AE_OK. */
135 if ((res->Type != ACPI_RESOURCE_TYPE_ADDRESS16) &&
136 (res->Type != ACPI_RESOURCE_TYPE_ADDRESS32) &&
137 (res->Type != ACPI_RESOURCE_TYPE_ADDRESS64))
138 return AE_OK;
139
140 if (ACPI_FAILURE(AcpiResourceToAddress64(res, &addr64)))
141 return AE_OK;
142
143 if (addr64.ResourceType != ACPI_BUS_NUMBER_RANGE)
144 return AE_OK;
145
146 if (*bus != -1)
147 return AE_ALREADY_EXISTS;
148
149 if (addr64.Address.Minimum > 0xFFFF)
150 return AE_BAD_DATA;
151
152 *bus = (int32_t)addr64.Address.Minimum;
153
154 return AE_OK;
155}
156
157/*
158 * acpi_pcidev_scan:
159 *
160 * Scan the ACPI device tree for PCI devices. A node is detected as a
161 * PCI device if it has an ancestor that is a PCI root bridge and such
162 * that all intermediate nodes are PCI-to-PCI bridges. Depth-first
163 * recursive implementation.
164 *
165 * PCI root bridges do not necessarily contain an _ADR, since they already
166 * contain an _HID (ACPI 4.0a, p. 197). However we require an _ADR for
167 * all non-root PCI devices.
168 */
169ACPI_STATUS
170acpi_pcidev_scan(struct acpi_devnode *ad)
171{
172 struct acpi_devnode *child;
173 struct acpi_pci_info *ap;
174 ACPI_INTEGER val;
175 ACPI_STATUS rv;
176
177 ad->ad_pciinfo = NULL;
178
179 /*
180 * We attach PCI information only to devices that are present,
181 * enabled, and functioning properly.
182 * Note: there is a possible race condition, because _STA may
183 * have changed since ad->ad_devinfo->CurrentStatus was set.
184 */
185 if (ad->ad_devinfo->Type != ACPI_TYPE_DEVICE)
186 goto rec;
187 if ((ad->ad_devinfo->Valid & ACPI_VALID_STA) != 0 &&
188 (ad->ad_devinfo->CurrentStatus & ACPI_STA_OK) != ACPI_STA_OK)
189 goto rec;
190
191 if (ad->ad_devinfo->Flags & ACPI_PCI_ROOT_BRIDGE) {
192
193 ap = kmem_zalloc(sizeof(*ap), KM_SLEEP);
194
195 if (ap == NULL)
196 return AE_NO_MEMORY;
197
198 /*
199 * If no _SEG exist, all PCI bus segments are assumed
200 * to be in the PCI segment group 0 (ACPI 4.0, p. 277).
201 * The segment group number is conveyed in the lower
202 * 16 bits of _SEG (the other bits are all reserved).
203 */
204 rv = acpi_eval_integer(ad->ad_handle, "_SEG", &val);
205
206 if (ACPI_SUCCESS(rv))
207 ap->ap_segment = ACPI_LOWORD(val);
208
209 /* Try to get downstream bus number using _CRS first. */
210 rv = acpi_pcidev_pciroot_bus(ad->ad_handle, &ap->ap_downbus);
211
212 if (ACPI_FAILURE(rv)) {
213 rv = acpi_eval_integer(ad->ad_handle, "_BBN", &val);
214
215 if (ACPI_SUCCESS(rv))
216 ap->ap_downbus = ACPI_LOWORD(val);
217 }
218
219 if (ap->ap_downbus > 255) {
220 aprint_error_dev(ad->ad_root,
221 "invalid PCI downstream bus for %s\n", ad->ad_name);
222 kmem_free(ap, sizeof(*ap));
223 goto rec;
224 }
225
226 ap->ap_flags |= ACPI_PCI_INFO_BRIDGE;
227
228 /*
229 * This ACPI node denotes a PCI root bridge, but it may also
230 * denote a PCI device on the bridge's downstream bus segment.
231 */
232 if (ad->ad_devinfo->Valid & ACPI_VALID_ADR) {
233 ap->ap_bus = ap->ap_downbus;
234 ap->ap_device =
235 ACPI_HILODWORD(ad->ad_devinfo->Address);
236 ap->ap_function =
237 ACPI_LOLODWORD(ad->ad_devinfo->Address);
238
239 if (ap->ap_device > 31 ||
240 (ap->ap_function > 7 && ap->ap_function != 0xFFFF))
241 aprint_error_dev(ad->ad_root,
242 "invalid PCI address for %s\n", ad->ad_name);
243 else
244 ap->ap_flags |= ACPI_PCI_INFO_DEVICE;
245 }
246
247 ad->ad_pciinfo = ap;
248
249 goto rec;
250 }
251
252 if ((ad->ad_parent != NULL) &&
253 (ad->ad_parent->ad_pciinfo != NULL) &&
254 (ad->ad_parent->ad_pciinfo->ap_flags & ACPI_PCI_INFO_BRIDGE) &&
255 (ad->ad_devinfo->Valid & ACPI_VALID_ADR)) {
256
257 /*
258 * Our parent is a PCI root bridge or a PCI-to-PCI
259 * bridge. We have the same PCI segment number, and
260 * our bus number is its downstream bus number.
261 */
262 ap = kmem_zalloc(sizeof(*ap), KM_SLEEP);
263
264 if (ap == NULL)
265 return AE_NO_MEMORY;
266
267 ap->ap_segment = ad->ad_parent->ad_pciinfo->ap_segment;
268 ap->ap_bus = ad->ad_parent->ad_pciinfo->ap_downbus;
269
270 ap->ap_device = ACPI_HILODWORD(ad->ad_devinfo->Address);
271 ap->ap_function = ACPI_LOLODWORD(ad->ad_devinfo->Address);
272
273 if (ap->ap_device > 31 ||
274 (ap->ap_function > 7 && ap->ap_function != 0xFFFF)) {
275 aprint_error_dev(ad->ad_root,
276 "invalid PCI address for %s\n", ad->ad_name);
277 kmem_free(ap, sizeof(*ap));
278 goto rec;
279 }
280
281 ap->ap_flags |= ACPI_PCI_INFO_DEVICE;
282
283 if (ap->ap_function == 0xFFFF) {
284 /*
285 * Assume that this device is not a PCI-to-PCI bridge.
286 * XXX: Do we need to be smarter?
287 */
288 } else {
289 /*
290 * Check whether this device is a PCI-to-PCI
291 * bridge and get its secondary bus number.
292 */
293 rv = acpi_pcidev_ppb_downbus(ap->ap_segment, ap->ap_bus,
294 ap->ap_device, ap->ap_function, &ap->ap_downbus);
295
296 if (ACPI_SUCCESS(rv))
297 ap->ap_flags |= ACPI_PCI_INFO_BRIDGE;
298 }
299
300 ad->ad_pciinfo = ap;
301
302 goto rec;
303 }
304
305rec:
306 SIMPLEQ_FOREACH(child, &ad->ad_child_head, ad_child_list) {
307 rv = acpi_pcidev_scan(child);
308
309 if (ACPI_FAILURE(rv))
310 return rv;
311 }
312
313 return AE_OK;
314}
315
316/*
317 * acpi_pcidev_ppb_downbus:
318 *
319 * Retrieve the secondary bus number of the PCI-to-PCI bridge having the
320 * given PCI id. If successful, return AE_OK and fill *downbus.
321 * Otherwise, return an exception code and leave *downbus unchanged.
322 *
323 * XXX Need to deal with PCI segment groups (see also acpica/OsdHardware.c).
324 */
325ACPI_STATUS
326acpi_pcidev_ppb_downbus(uint16_t segment, uint16_t bus, uint16_t device,
327 uint16_t function, uint16_t *downbus)
328{
329 struct acpi_softc *sc = acpi_softc;
330 pci_chipset_tag_t pc;
331 pcitag_t tag;
332 pcireg_t val;
333
334 if (bus > 255 || device > 31 || function > 7)
335 return AE_BAD_PARAMETER;
336
337 pc = sc->sc_pc;
338
339 tag = pci_make_tag(pc, bus, device, function);
340
341 /* Check that this device exists. */
342 val = pci_conf_read(pc, tag, PCI_ID_REG);
343
344 if (PCI_VENDOR(val) == PCI_VENDOR_INVALID ||
345 PCI_VENDOR(val) == 0)
346 return AE_NOT_EXIST;
347
348 /* Check that this device is a PCI-to-PCI bridge. */
349 val = pci_conf_read(pc, tag, PCI_BHLC_REG);
350
351 if (PCI_HDRTYPE_TYPE(val) != PCI_HDRTYPE_PPB)
352 return AE_TYPE;
353
354 /* This is a PCI-to-PCI bridge. Get its secondary bus#. */
355 val = pci_conf_read(pc, tag, PPB_REG_BUSINFO);
356 *downbus = PPB_BUSINFO_SECONDARY(val);
357
358 return AE_OK;
359}
360
361/*
362 * acpi_pcidev_find:
363 *
364 * Finds a PCI device in the ACPI name space.
365 *
366 * Returns an ACPI device node on success and NULL on failure.
367 */
368struct acpi_devnode *
369acpi_pcidev_find(uint16_t segment, uint16_t bus,
370 uint16_t device, uint16_t function)
371{
372 struct acpi_softc *sc = acpi_softc;
373 struct acpi_devnode *ad;
374
375 if (sc == NULL)
376 return NULL;
377
378 SIMPLEQ_FOREACH(ad, &sc->ad_head, ad_list) {
379
380 if (ad->ad_pciinfo != NULL &&
381 (ad->ad_pciinfo->ap_flags & ACPI_PCI_INFO_DEVICE) &&
382 ad->ad_pciinfo->ap_segment == segment &&
383 ad->ad_pciinfo->ap_bus == bus &&
384 ad->ad_pciinfo->ap_device == device &&
385 ad->ad_pciinfo->ap_function == function)
386 return ad;
387 }
388
389 return NULL;
390}
391
392
393/*
394 * acpi_pcidev_find_dev:
395 *
396 * Returns the device corresponding to the given PCI info, or NULL
397 * if it doesn't exist.
398 */
399device_t
400acpi_pcidev_find_dev(struct acpi_devnode *ad)
401{
402 struct acpi_pci_info *ap;
403 struct pci_softc *pci;
404 device_t dv, pr;
405 deviter_t di;
406
407 if (ad == NULL)
408 return NULL;
409
410 if (ad->ad_pciinfo == NULL)
411 return NULL;
412
413 ap = ad->ad_pciinfo;
414
415 if (ap->ap_function == 0xFFFF)
416 return NULL;
417
418 for (dv = deviter_first(&di, DEVITER_F_ROOT_FIRST);
419 dv != NULL; dv = deviter_next(&di)) {
420
421 pr = device_parent(dv);
422
423 if (pr == NULL || device_is_a(pr, "pci") != true)
424 continue;
425
426 if (dv->dv_locators == NULL) /* This should not happen. */
427 continue;
428
429 pci = device_private(pr);
430
431 if (pci->sc_bus == ap->ap_bus &&
432 device_locator(dv, PCICF_DEV) == ap->ap_device &&
433 device_locator(dv, PCICF_FUNCTION) == ap->ap_function)
434 break;
435 }
436
437 deviter_release(&di);
438
439 return dv;
440}
441