1 /* 2 * drivers/pci/bus.c 3 * 4 * From setup-res.c, by: 5 * Dave Rusling (david.rusling@reo.mts.dec.com) 6 * David Mosberger (davidm@cs.arizona.edu) 7 * David Miller (davem@redhat.com) 8 * Ivan Kokshaysky (ink@jurassic.park.msu.ru) 9 */ 10 #include <linux/module.h> 11 #include <linux/kernel.h> 12 #include <linux/pci.h> 13 #include <linux/errno.h> 14 #include <linux/ioport.h> 15 #include <linux/proc_fs.h> 16 #include <linux/slab.h> 17 18 #include "pci.h" 19 20 void pci_add_resource_offset(struct list_head *resources, struct resource *res, 21 resource_size_t offset) 22 { 23 struct resource_entry *entry; 24 25 entry = resource_list_create_entry(res, 0); 26 if (!entry) { 27 printk(KERN_ERR "PCI: can't add host bridge window %pR\n", res); 28 return; 29 } 30 31 entry->offset = offset; 32 resource_list_add_tail(entry, resources); 33 } 34 EXPORT_SYMBOL(pci_add_resource_offset); 35 36 void pci_add_resource(struct list_head *resources, struct resource *res) 37 { 38 pci_add_resource_offset(resources, res, 0); 39 } 40 EXPORT_SYMBOL(pci_add_resource); 41 42 void pci_free_resource_list(struct list_head *resources) 43 { 44 resource_list_free(resources); 45 } 46 EXPORT_SYMBOL(pci_free_resource_list); 47 48 void pci_bus_add_resource(struct pci_bus *bus, struct resource *res, 49 unsigned int flags) 50 { 51 struct pci_bus_resource *bus_res; 52 53 bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL); 54 if (!bus_res) { 55 dev_err(&bus->dev, "can't add %pR resource\n", res); 56 return; 57 } 58 59 bus_res->res = res; 60 bus_res->flags = flags; 61 list_add_tail(&bus_res->list, &bus->resources); 62 } 63 64 struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n) 65 { 66 struct pci_bus_resource *bus_res; 67 68 if (n < PCI_BRIDGE_RESOURCE_NUM) 69 return bus->resource[n]; 70 71 n -= PCI_BRIDGE_RESOURCE_NUM; 72 list_for_each_entry(bus_res, &bus->resources, list) { 73 if (n-- == 0) 74 return bus_res->res; 75 } 76 return NULL; 77 } 78 EXPORT_SYMBOL_GPL(pci_bus_resource_n); 79 80 void pci_bus_remove_resources(struct pci_bus *bus) 81 { 82 int i; 83 struct pci_bus_resource *bus_res, *tmp; 84 85 for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) 86 bus->resource[i] = NULL; 87 88 list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) { 89 list_del(&bus_res->list); 90 kfree(bus_res); 91 } 92 } 93 94 static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL}; 95 #ifdef CONFIG_PCI_BUS_ADDR_T_64BIT 96 static struct pci_bus_region pci_64_bit = {0, 97 (pci_bus_addr_t) 0xffffffffffffffffULL}; 98 static struct pci_bus_region pci_high = {(pci_bus_addr_t) 0x100000000ULL, 99 (pci_bus_addr_t) 0xffffffffffffffffULL}; 100 #endif 101 102 /* 103 * @res contains CPU addresses. Clip it so the corresponding bus addresses 104 * on @bus are entirely within @region. This is used to control the bus 105 * addresses of resources we allocate, e.g., we may need a resource that 106 * can be mapped by a 32-bit BAR. 107 */ 108 static void pci_clip_resource_to_region(struct pci_bus *bus, 109 struct resource *res, 110 struct pci_bus_region *region) 111 { 112 struct pci_bus_region r; 113 114 pcibios_resource_to_bus(bus, &r, res); 115 if (r.start < region->start) 116 r.start = region->start; 117 if (r.end > region->end) 118 r.end = region->end; 119 120 if (r.end < r.start) 121 res->end = res->start - 1; 122 else 123 pcibios_bus_to_resource(bus, res, &r); 124 } 125 126 static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res, 127 resource_size_t size, resource_size_t align, 128 resource_size_t min, unsigned long type_mask, 129 resource_size_t (*alignf)(void *, 130 const struct resource *, 131 resource_size_t, 132 resource_size_t), 133 void *alignf_data, 134 struct pci_bus_region *region) 135 { 136 int i, ret; 137 struct resource *r, avail; 138 resource_size_t max; 139 140 type_mask |= IORESOURCE_TYPE_BITS; 141 142 pci_bus_for_each_resource(bus, r, i) { 143 resource_size_t min_used = min; 144 145 if (!r) 146 continue; 147 148 /* type_mask must match */ 149 if ((res->flags ^ r->flags) & type_mask) 150 continue; 151 152 /* We cannot allocate a non-prefetching resource 153 from a pre-fetching area */ 154 if ((r->flags & IORESOURCE_PREFETCH) && 155 !(res->flags & IORESOURCE_PREFETCH)) 156 continue; 157 158 avail = *r; 159 pci_clip_resource_to_region(bus, &avail, region); 160 161 /* 162 * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to 163 * protect badly documented motherboard resources, but if 164 * this is an already-configured bridge window, its start 165 * overrides "min". 166 */ 167 if (avail.start) 168 min_used = avail.start; 169 170 max = avail.end; 171 172 /* Ok, try it out.. */ 173 ret = allocate_resource(r, res, size, min_used, max, 174 align, alignf, alignf_data); 175 if (ret == 0) 176 return 0; 177 } 178 return -ENOMEM; 179 } 180 181 /** 182 * pci_bus_alloc_resource - allocate a resource from a parent bus 183 * @bus: PCI bus 184 * @res: resource to allocate 185 * @size: size of resource to allocate 186 * @align: alignment of resource to allocate 187 * @min: minimum /proc/iomem address to allocate 188 * @type_mask: IORESOURCE_* type flags 189 * @alignf: resource alignment function 190 * @alignf_data: data argument for resource alignment function 191 * 192 * Given the PCI bus a device resides on, the size, minimum address, 193 * alignment and type, try to find an acceptable resource allocation 194 * for a specific device resource. 195 */ 196 int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res, 197 resource_size_t size, resource_size_t align, 198 resource_size_t min, unsigned long type_mask, 199 resource_size_t (*alignf)(void *, 200 const struct resource *, 201 resource_size_t, 202 resource_size_t), 203 void *alignf_data) 204 { 205 #ifdef CONFIG_PCI_BUS_ADDR_T_64BIT 206 int rc; 207 208 if (res->flags & IORESOURCE_MEM_64) { 209 rc = pci_bus_alloc_from_region(bus, res, size, align, min, 210 type_mask, alignf, alignf_data, 211 &pci_high); 212 if (rc == 0) 213 return 0; 214 215 return pci_bus_alloc_from_region(bus, res, size, align, min, 216 type_mask, alignf, alignf_data, 217 &pci_64_bit); 218 } 219 #endif 220 221 return pci_bus_alloc_from_region(bus, res, size, align, min, 222 type_mask, alignf, alignf_data, 223 &pci_32_bit); 224 } 225 EXPORT_SYMBOL(pci_bus_alloc_resource); 226 227 /* 228 * The @idx resource of @dev should be a PCI-PCI bridge window. If this 229 * resource fits inside a window of an upstream bridge, do nothing. If it 230 * overlaps an upstream window but extends outside it, clip the resource so 231 * it fits completely inside. 232 */ 233 bool pci_bus_clip_resource(struct pci_dev *dev, int idx) 234 { 235 struct pci_bus *bus = dev->bus; 236 struct resource *res = &dev->resource[idx]; 237 struct resource orig_res = *res; 238 struct resource *r; 239 int i; 240 241 pci_bus_for_each_resource(bus, r, i) { 242 resource_size_t start, end; 243 244 if (!r) 245 continue; 246 247 if (resource_type(res) != resource_type(r)) 248 continue; 249 250 start = max(r->start, res->start); 251 end = min(r->end, res->end); 252 253 if (start > end) 254 continue; /* no overlap */ 255 256 if (res->start == start && res->end == end) 257 return false; /* no change */ 258 259 res->start = start; 260 res->end = end; 261 res->flags &= ~IORESOURCE_UNSET; 262 orig_res.flags &= ~IORESOURCE_UNSET; 263 dev_printk(KERN_DEBUG, &dev->dev, "%pR clipped to %pR\n", 264 &orig_res, res); 265 266 return true; 267 } 268 269 return false; 270 } 271 272 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { } 273 274 void __weak pcibios_bus_add_device(struct pci_dev *pdev) { } 275 276 /** 277 * pci_bus_add_device - start driver for a single device 278 * @dev: device to add 279 * 280 * This adds add sysfs entries and start device drivers 281 */ 282 void pci_bus_add_device(struct pci_dev *dev) 283 { 284 int retval; 285 286 /* 287 * Can not put in pci_device_add yet because resources 288 * are not assigned yet for some devices. 289 */ 290 pcibios_bus_add_device(dev); 291 pci_fixup_device(pci_fixup_final, dev); 292 pci_create_sysfs_dev_files(dev); 293 pci_proc_attach_device(dev); 294 295 dev->match_driver = true; 296 retval = device_attach(&dev->dev); 297 if (retval < 0 && retval != -EPROBE_DEFER) { 298 dev_warn(&dev->dev, "device attach failed (%d)\n", retval); 299 pci_proc_detach_device(dev); 300 pci_remove_sysfs_dev_files(dev); 301 return; 302 } 303 304 dev->is_added = 1; 305 } 306 EXPORT_SYMBOL_GPL(pci_bus_add_device); 307 308 /** 309 * pci_bus_add_devices - start driver for PCI devices 310 * @bus: bus to check for new devices 311 * 312 * Start driver for PCI devices and add some sysfs entries. 313 */ 314 void pci_bus_add_devices(const struct pci_bus *bus) 315 { 316 struct pci_dev *dev; 317 struct pci_bus *child; 318 319 list_for_each_entry(dev, &bus->devices, bus_list) { 320 /* Skip already-added devices */ 321 if (dev->is_added) 322 continue; 323 pci_bus_add_device(dev); 324 } 325 326 list_for_each_entry(dev, &bus->devices, bus_list) { 327 /* Skip if device attach failed */ 328 if (!dev->is_added) 329 continue; 330 child = dev->subordinate; 331 if (child) 332 pci_bus_add_devices(child); 333 } 334 } 335 EXPORT_SYMBOL(pci_bus_add_devices); 336 337 /** pci_walk_bus - walk devices on/under bus, calling callback. 338 * @top bus whose devices should be walked 339 * @cb callback to be called for each device found 340 * @userdata arbitrary pointer to be passed to callback. 341 * 342 * Walk the given bus, including any bridged devices 343 * on buses under this bus. Call the provided callback 344 * on each device found. 345 * 346 * We check the return of @cb each time. If it returns anything 347 * other than 0, we break out. 348 * 349 */ 350 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), 351 void *userdata) 352 { 353 struct pci_dev *dev; 354 struct pci_bus *bus; 355 struct list_head *next; 356 int retval; 357 358 bus = top; 359 down_read(&pci_bus_sem); 360 next = top->devices.next; 361 for (;;) { 362 if (next == &bus->devices) { 363 /* end of this bus, go up or finish */ 364 if (bus == top) 365 break; 366 next = bus->self->bus_list.next; 367 bus = bus->self->bus; 368 continue; 369 } 370 dev = list_entry(next, struct pci_dev, bus_list); 371 if (dev->subordinate) { 372 /* this is a pci-pci bridge, do its devices next */ 373 next = dev->subordinate->devices.next; 374 bus = dev->subordinate; 375 } else 376 next = dev->bus_list.next; 377 378 retval = cb(dev, userdata); 379 if (retval) 380 break; 381 } 382 up_read(&pci_bus_sem); 383 } 384 EXPORT_SYMBOL_GPL(pci_walk_bus); 385 386 struct pci_bus *pci_bus_get(struct pci_bus *bus) 387 { 388 if (bus) 389 get_device(&bus->dev); 390 return bus; 391 } 392 EXPORT_SYMBOL(pci_bus_get); 393 394 void pci_bus_put(struct pci_bus *bus) 395 { 396 if (bus) 397 put_device(&bus->dev); 398 } 399 EXPORT_SYMBOL(pci_bus_put); 400 401