1 /* $NetBSD: acpi_pci.c,v 1.16 2010/10/26 22:27:44 gsutre 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 1.16 2010/10/26 22:27:44 gsutre 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/pcidevs.h> 41 #include <dev/pci/ppbreg.h> 42 43 #include <dev/acpi/acpireg.h> 44 #include <dev/acpi/acpivar.h> 45 #include <dev/acpi/acpi_pci.h> 46 47 #define _COMPONENT ACPI_BUS_COMPONENT 48 ACPI_MODULE_NAME ("acpi_pci") 49 50 #define ACPI_HILODWORD(x) ACPI_HIWORD(ACPI_LODWORD((x))) 51 #define ACPI_LOLODWORD(x) ACPI_LOWORD(ACPI_LODWORD((x))) 52 53 static ACPI_STATUS acpi_pcidev_pciroot_bus(ACPI_HANDLE, uint16_t *); 54 static ACPI_STATUS acpi_pcidev_pciroot_bus_callback(ACPI_RESOURCE *, 55 void *); 56 57 /* 58 * Regarding PCI Segment Groups (ACPI 4.0, p. 277): 59 * 60 * "The optional _SEG object is located under a PCI host bridge and 61 * evaluates to an integer that describes the PCI Segment Group (see PCI 62 * Firmware Specification v3.0)." 63 * 64 * "PCI Segment Group is purely a software concept managed by system 65 * firmware and used by OSPM. It is a logical collection of PCI buses 66 * (or bus segments). It is a way to logically group the PCI bus segments 67 * and PCI Express Hierarchies. _SEG is a level higher than _BBN." 68 * 69 * "PCI Segment Group supports more than 256 buses in a system by allowing 70 * the reuse of the PCI bus numbers. Within each PCI Segment Group, the bus 71 * numbers for the PCI buses must be unique. PCI buses in different PCI 72 * Segment Group are permitted to have the same bus number." 73 */ 74 75 /* 76 * Regarding PCI Base Bus Numbers (ACPI 4.0, p. 277): 77 * 78 * "For multi-root PCI platforms, the _BBN object evaluates to the PCI bus 79 * number that the BIOS assigns. This is needed to access a PCI_Config 80 * operation region for the specified bus. The _BBN object is located under 81 * a PCI host bridge and must be unique for every host bridge within a 82 * segment since it is the PCI bus number." 83 * 84 * Moreover, the ACPI FAQ (http://www.acpi.info/acpi_faq.htm) says: 85 * 86 * "For a multiple root bus machine, _BBN is required for each bus. _BBN 87 * should provide the bus number assigned to this bus by the BIOS at boot 88 * time." 89 */ 90 91 /* 92 * acpi_pcidev_pciroot_bus: 93 * 94 * Derive the PCI bus number of a PCI root bridge from its resources. 95 * If successful, return AE_OK and fill *busp. Otherwise, return an 96 * exception code and leave *busp unchanged. 97 */ 98 static ACPI_STATUS 99 acpi_pcidev_pciroot_bus(ACPI_HANDLE handle, uint16_t *busp) 100 { 101 ACPI_STATUS rv; 102 int32_t bus; 103 104 bus = -1; 105 106 /* 107 * XXX: Use the ACPI resource parsing functions (acpi_resource.c) 108 * once bus number ranges have been implemented there. 109 */ 110 rv = AcpiWalkResources(handle, "_CRS", 111 acpi_pcidev_pciroot_bus_callback, &bus); 112 113 if (ACPI_FAILURE(rv)) 114 return rv; 115 116 if (bus == -1) 117 return AE_NOT_EXIST; 118 119 /* Here it holds that 0 <= bus <= 0xFFFF. */ 120 *busp = (uint16_t)bus; 121 122 return rv; 123 } 124 125 static ACPI_STATUS 126 acpi_pcidev_pciroot_bus_callback(ACPI_RESOURCE *res, void *context) 127 { 128 ACPI_RESOURCE_ADDRESS64 addr64; 129 int32_t *bus = context; 130 131 /* Always continue the walk by returning AE_OK. */ 132 if ((res->Type != ACPI_RESOURCE_TYPE_ADDRESS16) && 133 (res->Type != ACPI_RESOURCE_TYPE_ADDRESS32) && 134 (res->Type != ACPI_RESOURCE_TYPE_ADDRESS64)) 135 return AE_OK; 136 137 if (ACPI_FAILURE(AcpiResourceToAddress64(res, &addr64))) 138 return AE_OK; 139 140 if (addr64.ResourceType != ACPI_BUS_NUMBER_RANGE) 141 return AE_OK; 142 143 if (*bus != -1) 144 return AE_ALREADY_EXISTS; 145 146 if (addr64.Minimum > 0xFFFF) 147 return AE_BAD_DATA; 148 149 *bus = (int32_t)addr64.Minimum; 150 151 return AE_OK; 152 } 153 154 /* 155 * acpi_pcidev_scan: 156 * 157 * Scan the ACPI device tree for PCI devices. A node is detected as a 158 * PCI device if it has an ancestor that is a PCI root bridge and such 159 * that all intermediate nodes are PCI-to-PCI bridges. Depth-first 160 * recursive implementation. 161 * 162 * PCI root bridges do not necessarily contain an _ADR, since they already 163 * contain an _HID (ACPI 4.0a, p. 197). However we require an _ADR for 164 * all non-root PCI devices. 165 */ 166 ACPI_STATUS 167 acpi_pcidev_scan(struct acpi_devnode *ad) 168 { 169 struct acpi_devnode *child; 170 struct acpi_pci_info *ap; 171 ACPI_INTEGER val; 172 ACPI_STATUS rv; 173 174 ad->ad_pciinfo = NULL; 175 176 /* 177 * We attach PCI information only to devices that are present, 178 * enabled, and functioning properly. 179 * Note: there is a possible race condition, because _STA may 180 * have changed since ad->ad_devinfo->CurrentStatus was set. 181 */ 182 if (ad->ad_devinfo->Type != ACPI_TYPE_DEVICE) 183 goto rec; 184 if ((ad->ad_devinfo->Valid & ACPI_VALID_STA) != 0 && 185 (ad->ad_devinfo->CurrentStatus & ACPI_STA_OK) != ACPI_STA_OK) 186 goto rec; 187 188 if (ad->ad_devinfo->Flags & ACPI_PCI_ROOT_BRIDGE) { 189 190 ap = kmem_zalloc(sizeof(*ap), KM_SLEEP); 191 192 if (ap == NULL) 193 return AE_NO_MEMORY; 194 195 /* 196 * If no _SEG exist, all PCI bus segments are assumed 197 * to be in the PCI segment group 0 (ACPI 4.0, p. 277). 198 * The segment group number is conveyed in the lower 199 * 16 bits of _SEG (the other bits are all reserved). 200 */ 201 rv = acpi_eval_integer(ad->ad_handle, "_SEG", &val); 202 203 if (ACPI_SUCCESS(rv)) 204 ap->ap_segment = ACPI_LOWORD(val); 205 206 /* Try to get downstream bus number using _CRS first. */ 207 rv = acpi_pcidev_pciroot_bus(ad->ad_handle, &ap->ap_downbus); 208 209 if (ACPI_FAILURE(rv)) { 210 rv = acpi_eval_integer(ad->ad_handle, "_BBN", &val); 211 212 if (ACPI_SUCCESS(rv)) 213 ap->ap_downbus = ACPI_LOWORD(val); 214 } 215 216 if (ap->ap_downbus > 255) { 217 aprint_error_dev(ad->ad_root, 218 "invalid PCI downstream bus for %s\n", ad->ad_name); 219 kmem_free(ap, sizeof(*ap)); 220 goto rec; 221 } 222 223 ap->ap_flags |= ACPI_PCI_INFO_BRIDGE; 224 225 /* 226 * This ACPI node denotes a PCI root bridge, but it may also 227 * denote a PCI device on the bridge's downstream bus segment. 228 */ 229 if (ad->ad_devinfo->Valid & ACPI_VALID_ADR) { 230 ap->ap_bus = ap->ap_downbus; 231 ap->ap_device = 232 ACPI_HILODWORD(ad->ad_devinfo->Address); 233 ap->ap_function = 234 ACPI_LOLODWORD(ad->ad_devinfo->Address); 235 236 if (ap->ap_device > 31 || 237 (ap->ap_function > 7 && ap->ap_function != 0xFFFF)) 238 aprint_error_dev(ad->ad_root, 239 "invalid PCI address for %s\n", ad->ad_name); 240 else 241 ap->ap_flags |= ACPI_PCI_INFO_DEVICE; 242 } 243 244 ad->ad_pciinfo = ap; 245 246 goto rec; 247 } 248 249 if ((ad->ad_parent != NULL) && 250 (ad->ad_parent->ad_pciinfo != NULL) && 251 (ad->ad_parent->ad_pciinfo->ap_flags & ACPI_PCI_INFO_BRIDGE) && 252 (ad->ad_devinfo->Valid & ACPI_VALID_ADR)) { 253 254 /* 255 * Our parent is a PCI root bridge or a PCI-to-PCI 256 * bridge. We have the same PCI segment number, and 257 * our bus number is its downstream bus number. 258 */ 259 ap = kmem_zalloc(sizeof(*ap), KM_SLEEP); 260 261 if (ap == NULL) 262 return AE_NO_MEMORY; 263 264 ap->ap_segment = ad->ad_parent->ad_pciinfo->ap_segment; 265 ap->ap_bus = ad->ad_parent->ad_pciinfo->ap_downbus; 266 267 ap->ap_device = ACPI_HILODWORD(ad->ad_devinfo->Address); 268 ap->ap_function = ACPI_LOLODWORD(ad->ad_devinfo->Address); 269 270 if (ap->ap_device > 31 || 271 (ap->ap_function > 7 && ap->ap_function != 0xFFFF)) { 272 aprint_error_dev(ad->ad_root, 273 "invalid PCI address for %s\n", ad->ad_name); 274 kmem_free(ap, sizeof(*ap)); 275 goto rec; 276 } 277 278 ap->ap_flags |= ACPI_PCI_INFO_DEVICE; 279 280 if (ap->ap_function == 0xFFFF) { 281 /* 282 * Assume that this device is not a PCI-to-PCI bridge. 283 * XXX: Do we need to be smarter? 284 */ 285 } else { 286 /* 287 * Check whether this device is a PCI-to-PCI 288 * bridge and get its secondary bus number. 289 */ 290 rv = acpi_pcidev_ppb_downbus(ap->ap_segment, ap->ap_bus, 291 ap->ap_device, ap->ap_function, &ap->ap_downbus); 292 293 if (ACPI_SUCCESS(rv)) 294 ap->ap_flags |= ACPI_PCI_INFO_BRIDGE; 295 } 296 297 ad->ad_pciinfo = ap; 298 299 goto rec; 300 } 301 302 rec: 303 SIMPLEQ_FOREACH(child, &ad->ad_child_head, ad_child_list) { 304 rv = acpi_pcidev_scan(child); 305 306 if (ACPI_FAILURE(rv)) 307 return rv; 308 } 309 310 return AE_OK; 311 } 312 313 /* 314 * acpi_pcidev_ppb_downbus: 315 * 316 * Retrieve the secondary bus number of the PCI-to-PCI bridge having the 317 * given PCI id. If successful, return AE_OK and fill *downbus. 318 * Otherwise, return an exception code and leave *downbus unchanged. 319 * 320 * XXX Need to deal with PCI segment groups (see also acpica/OsdHardware.c). 321 */ 322 ACPI_STATUS 323 acpi_pcidev_ppb_downbus(uint16_t segment, uint16_t bus, uint16_t device, 324 uint16_t function, uint16_t *downbus) 325 { 326 struct acpi_softc *sc = acpi_softc; 327 pci_chipset_tag_t pc; 328 pcitag_t tag; 329 pcireg_t val; 330 331 if (bus > 255 || device > 31 || function > 7) 332 return AE_BAD_PARAMETER; 333 334 pc = sc->sc_pc; 335 336 tag = pci_make_tag(pc, bus, device, function); 337 338 /* Check that this device exists. */ 339 val = pci_conf_read(pc, tag, PCI_ID_REG); 340 341 if (PCI_VENDOR(val) == PCI_VENDOR_INVALID || 342 PCI_VENDOR(val) == 0) 343 return AE_NOT_EXIST; 344 345 /* Check that this device is a PCI-to-PCI bridge. */ 346 val = pci_conf_read(pc, tag, PCI_BHLC_REG); 347 348 if (PCI_HDRTYPE_TYPE(val) != PCI_HDRTYPE_PPB) 349 return AE_TYPE; 350 351 /* This is a PCI-to-PCI bridge. Get its secondary bus#. */ 352 val = pci_conf_read(pc, tag, PPB_REG_BUSINFO); 353 *downbus = PPB_BUSINFO_SECONDARY(val); 354 355 return AE_OK; 356 } 357 358 /* 359 * acpi_pcidev_find: 360 * 361 * Finds a PCI device in the ACPI name space. 362 * 363 * Returns an ACPI device node on success and NULL on failure. 364 */ 365 struct acpi_devnode * 366 acpi_pcidev_find(uint16_t segment, uint16_t bus, 367 uint16_t device, uint16_t function) 368 { 369 struct acpi_softc *sc = acpi_softc; 370 struct acpi_devnode *ad; 371 372 if (sc == NULL) 373 return NULL; 374 375 SIMPLEQ_FOREACH(ad, &sc->ad_head, ad_list) { 376 377 if (ad->ad_pciinfo != NULL && 378 (ad->ad_pciinfo->ap_flags & ACPI_PCI_INFO_DEVICE) && 379 ad->ad_pciinfo->ap_segment == segment && 380 ad->ad_pciinfo->ap_bus == bus && 381 ad->ad_pciinfo->ap_device == device && 382 ad->ad_pciinfo->ap_function == function) 383 return ad; 384 } 385 386 return NULL; 387 } 388