1 /* $NetBSD: acpi_pci.c,v 1.14 2010/08/09 09:36:42 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 1.14 2010/08/09 09:36:42 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 < 0 || bus > 0xFFFF) 117 return AE_NOT_EXIST; 118 119 *busp = (uint16_t)bus; 120 121 return rv; 122 } 123 124 static ACPI_STATUS 125 acpi_pcidev_pciroot_bus_callback(ACPI_RESOURCE *res, void *context) 126 { 127 ACPI_RESOURCE_ADDRESS64 addr64; 128 int32_t *bus = context; 129 130 /* Always continue the walk by returning AE_OK. */ 131 if ((res->Type != ACPI_RESOURCE_TYPE_ADDRESS16) && 132 (res->Type != ACPI_RESOURCE_TYPE_ADDRESS32) && 133 (res->Type != ACPI_RESOURCE_TYPE_ADDRESS64)) 134 return AE_OK; 135 136 if (ACPI_FAILURE(AcpiResourceToAddress64(res, &addr64))) 137 return AE_OK; 138 139 if (addr64.ResourceType != ACPI_BUS_NUMBER_RANGE) 140 return AE_OK; 141 142 if (*bus != -1) 143 return AE_ALREADY_EXISTS; 144 145 *bus = addr64.Minimum; 146 147 return AE_OK; 148 } 149 150 /* 151 * acpi_pcidev_scan: 152 * 153 * Scan the ACPI device tree for PCI devices. A node is detected as a 154 * PCI device if it has an ancestor that is a PCI root bridge and such 155 * that all intermediate nodes are PCI-to-PCI bridges. Depth-first 156 * recursive implementation. 157 */ 158 ACPI_STATUS 159 acpi_pcidev_scan(struct acpi_devnode *ad) 160 { 161 struct acpi_devnode *child; 162 struct acpi_pci_info *ap; 163 ACPI_INTEGER val; 164 ACPI_STATUS rv; 165 166 ad->ad_pciinfo = NULL; 167 168 if (ad->ad_devinfo->Type != ACPI_TYPE_DEVICE || 169 !(ad->ad_devinfo->Valid & ACPI_VALID_ADR)) 170 goto rec; 171 172 /* 173 * We attach PCI information only to devices that are present, 174 * enabled, and functioning properly. 175 * Note: there is a possible race condition, because _STA may 176 * have changed since ad->ad_devinfo->CurrentStatus was set. 177 */ 178 if ((ad->ad_devinfo->Valid & ACPI_VALID_STA) != 0 && 179 (ad->ad_devinfo->CurrentStatus & ACPI_STA_OK) != ACPI_STA_OK) 180 goto rec; 181 182 if (ad->ad_devinfo->Flags & ACPI_PCI_ROOT_BRIDGE) { 183 184 ap = kmem_zalloc(sizeof(*ap), KM_SLEEP); 185 186 if (ap == NULL) 187 return AE_NO_MEMORY; 188 189 /* 190 * If no _SEG exist, all PCI bus segments are assumed 191 * to be in the PCI segment group 0 (ACPI 4.0, p. 277). 192 * The segment group number is conveyed in the lower 193 * 16 bits of _SEG (the other bits are all reserved). 194 */ 195 rv = acpi_eval_integer(ad->ad_handle, "_SEG", &val); 196 197 if (ACPI_SUCCESS(rv)) 198 ap->ap_segment = ACPI_LOWORD(val); 199 200 /* Try to get bus number using _CRS first. */ 201 rv = acpi_pcidev_pciroot_bus(ad->ad_handle, &ap->ap_bus); 202 203 if (ACPI_FAILURE(rv)) { 204 rv = acpi_eval_integer(ad->ad_handle, "_BBN", &val); 205 206 if (ACPI_SUCCESS(rv)) 207 ap->ap_bus = ACPI_LOWORD(val); 208 } 209 210 ap->ap_device = ACPI_HILODWORD(ad->ad_devinfo->Address); 211 ap->ap_function = ACPI_LOLODWORD(ad->ad_devinfo->Address); 212 213 if (ap->ap_bus > 255 || ap->ap_device > 31 || 214 ap->ap_function > 7) { 215 aprint_error_dev(ad->ad_root, 216 "invalid PCI address for %s\n", ad->ad_name); 217 kmem_free(ap, sizeof(*ap)); 218 goto rec; 219 } 220 221 ap->ap_bridge = true; 222 ap->ap_downbus = ap->ap_bus; 223 224 ad->ad_pciinfo = ap; 225 226 goto rec; 227 } 228 229 if ((ad->ad_parent != NULL) && 230 (ad->ad_parent->ad_pciinfo != NULL) && 231 (ad->ad_parent->ad_pciinfo->ap_bridge)) { 232 233 /* 234 * Our parent is a PCI root bridge or a PCI-to-PCI 235 * bridge. We have the same PCI segment number, and 236 * our bus number is its downstream bus number. 237 */ 238 ap = kmem_zalloc(sizeof(*ap), KM_SLEEP); 239 240 if (ap == NULL) 241 return AE_NO_MEMORY; 242 243 ap->ap_segment = ad->ad_parent->ad_pciinfo->ap_segment; 244 ap->ap_bus = ad->ad_parent->ad_pciinfo->ap_downbus; 245 246 ap->ap_device = ACPI_HILODWORD(ad->ad_devinfo->Address); 247 ap->ap_function = ACPI_LOLODWORD(ad->ad_devinfo->Address); 248 249 if (ap->ap_device > 31 || ap->ap_function > 7) { 250 aprint_error_dev(ad->ad_root, 251 "invalid PCI address for %s\n", ad->ad_name); 252 kmem_free(ap, sizeof(*ap)); 253 goto rec; 254 } 255 256 /* 257 * Check whether this device is a PCI-to-PCI 258 * bridge and get its secondary bus number. 259 */ 260 rv = acpi_pcidev_ppb_downbus(ap->ap_segment, ap->ap_bus, 261 ap->ap_device, ap->ap_function, &ap->ap_downbus); 262 263 ap->ap_bridge = (rv != AE_OK) ? false : true; 264 ad->ad_pciinfo = ap; 265 266 goto rec; 267 } 268 269 rec: 270 SIMPLEQ_FOREACH(child, &ad->ad_child_head, ad_child_list) { 271 rv = acpi_pcidev_scan(child); 272 273 if (ACPI_FAILURE(rv)) 274 return rv; 275 } 276 277 return AE_OK; 278 } 279 280 /* 281 * acpi_pcidev_ppb_downbus: 282 * 283 * Retrieve the secondary bus number of the PCI-to-PCI bridge having the 284 * given PCI id. If successful, return AE_OK and fill *downbus. 285 * Otherwise, return an exception code and leave *downbus unchanged. 286 * 287 * XXX Need to deal with PCI segment groups (see also acpica/OsdHardware.c). 288 */ 289 ACPI_STATUS 290 acpi_pcidev_ppb_downbus(uint16_t segment, uint16_t bus, uint16_t device, 291 uint16_t function, uint16_t *downbus) 292 { 293 struct acpi_softc *sc = acpi_softc; 294 pci_chipset_tag_t pc; 295 pcitag_t tag; 296 pcireg_t val; 297 298 if (bus > 255 || device > 31 || function > 7) 299 return AE_BAD_PARAMETER; 300 301 pc = sc->sc_pc; 302 303 tag = pci_make_tag(pc, bus, device, function); 304 305 /* Check that this device exists. */ 306 val = pci_conf_read(pc, tag, PCI_ID_REG); 307 308 if (PCI_VENDOR(val) == PCI_VENDOR_INVALID || 309 PCI_VENDOR(val) == 0) 310 return AE_NOT_EXIST; 311 312 /* Check that this device is a PCI-to-PCI bridge. */ 313 val = pci_conf_read(pc, tag, PCI_BHLC_REG); 314 315 if (PCI_HDRTYPE_TYPE(val) != PCI_HDRTYPE_PPB) 316 return AE_TYPE; 317 318 /* This is a PCI-to-PCI bridge. Get its secondary bus#. */ 319 val = pci_conf_read(pc, tag, PPB_REG_BUSINFO); 320 *downbus = PPB_BUSINFO_SECONDARY(val); 321 322 return AE_OK; 323 } 324 325 /* 326 * acpi_pcidev_find: 327 * 328 * Finds a PCI device in the ACPI name space. 329 * 330 * Returns an ACPI device node on success and NULL on failure. 331 */ 332 struct acpi_devnode * 333 acpi_pcidev_find(uint16_t segment, uint16_t bus, 334 uint16_t device, uint16_t function) 335 { 336 struct acpi_softc *sc = acpi_softc; 337 struct acpi_devnode *ad; 338 339 if (sc == NULL) 340 return NULL; 341 342 SIMPLEQ_FOREACH(ad, &sc->ad_head, ad_list) { 343 344 if (ad->ad_pciinfo != NULL && 345 ad->ad_pciinfo->ap_segment == segment && 346 ad->ad_pciinfo->ap_bus == bus && 347 ad->ad_pciinfo->ap_device == device && 348 ad->ad_pciinfo->ap_function == function) 349 return ad; 350 } 351 352 return NULL; 353 } 354