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 pci_host_bridge_window *window; 24 25 window = kzalloc(sizeof(struct pci_host_bridge_window), GFP_KERNEL); 26 if (!window) { 27 printk(KERN_ERR "PCI: can't add host bridge window %pR\n", res); 28 return; 29 } 30 31 window->res = res; 32 window->offset = offset; 33 list_add_tail(&window->list, resources); 34 } 35 EXPORT_SYMBOL(pci_add_resource_offset); 36 37 void pci_add_resource(struct list_head *resources, struct resource *res) 38 { 39 pci_add_resource_offset(resources, res, 0); 40 } 41 EXPORT_SYMBOL(pci_add_resource); 42 43 void pci_free_resource_list(struct list_head *resources) 44 { 45 struct pci_host_bridge_window *window, *tmp; 46 47 list_for_each_entry_safe(window, tmp, resources, list) { 48 list_del(&window->list); 49 kfree(window); 50 } 51 } 52 EXPORT_SYMBOL(pci_free_resource_list); 53 54 void pci_bus_add_resource(struct pci_bus *bus, struct resource *res, 55 unsigned int flags) 56 { 57 struct pci_bus_resource *bus_res; 58 59 bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL); 60 if (!bus_res) { 61 dev_err(&bus->dev, "can't add %pR resource\n", res); 62 return; 63 } 64 65 bus_res->res = res; 66 bus_res->flags = flags; 67 list_add_tail(&bus_res->list, &bus->resources); 68 } 69 70 struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n) 71 { 72 struct pci_bus_resource *bus_res; 73 74 if (n < PCI_BRIDGE_RESOURCE_NUM) 75 return bus->resource[n]; 76 77 n -= PCI_BRIDGE_RESOURCE_NUM; 78 list_for_each_entry(bus_res, &bus->resources, list) { 79 if (n-- == 0) 80 return bus_res->res; 81 } 82 return NULL; 83 } 84 EXPORT_SYMBOL_GPL(pci_bus_resource_n); 85 86 void pci_bus_remove_resources(struct pci_bus *bus) 87 { 88 int i; 89 struct pci_bus_resource *bus_res, *tmp; 90 91 for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) 92 bus->resource[i] = NULL; 93 94 list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) { 95 list_del(&bus_res->list); 96 kfree(bus_res); 97 } 98 } 99 100 static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL}; 101 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT 102 static struct pci_bus_region pci_64_bit = {0, 103 (dma_addr_t) 0xffffffffffffffffULL}; 104 static struct pci_bus_region pci_high = {(dma_addr_t) 0x100000000ULL, 105 (dma_addr_t) 0xffffffffffffffffULL}; 106 #endif 107 108 /* 109 * @res contains CPU addresses. Clip it so the corresponding bus addresses 110 * on @bus are entirely within @region. This is used to control the bus 111 * addresses of resources we allocate, e.g., we may need a resource that 112 * can be mapped by a 32-bit BAR. 113 */ 114 static void pci_clip_resource_to_region(struct pci_bus *bus, 115 struct resource *res, 116 struct pci_bus_region *region) 117 { 118 struct pci_bus_region r; 119 120 pcibios_resource_to_bus(bus, &r, res); 121 if (r.start < region->start) 122 r.start = region->start; 123 if (r.end > region->end) 124 r.end = region->end; 125 126 if (r.end < r.start) 127 res->end = res->start - 1; 128 else 129 pcibios_bus_to_resource(bus, res, &r); 130 } 131 132 static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res, 133 resource_size_t size, resource_size_t align, 134 resource_size_t min, unsigned long type_mask, 135 resource_size_t (*alignf)(void *, 136 const struct resource *, 137 resource_size_t, 138 resource_size_t), 139 void *alignf_data, 140 struct pci_bus_region *region) 141 { 142 int i, ret; 143 struct resource *r, avail; 144 resource_size_t max; 145 146 type_mask |= IORESOURCE_TYPE_BITS; 147 148 pci_bus_for_each_resource(bus, r, i) { 149 if (!r) 150 continue; 151 152 /* type_mask must match */ 153 if ((res->flags ^ r->flags) & type_mask) 154 continue; 155 156 /* We cannot allocate a non-prefetching resource 157 from a pre-fetching area */ 158 if ((r->flags & IORESOURCE_PREFETCH) && 159 !(res->flags & IORESOURCE_PREFETCH)) 160 continue; 161 162 avail = *r; 163 pci_clip_resource_to_region(bus, &avail, region); 164 165 /* 166 * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to 167 * protect badly documented motherboard resources, but if 168 * this is an already-configured bridge window, its start 169 * overrides "min". 170 */ 171 if (avail.start) 172 min = avail.start; 173 174 max = avail.end; 175 176 /* Ok, try it out.. */ 177 ret = allocate_resource(r, res, size, min, max, 178 align, alignf, alignf_data); 179 if (ret == 0) 180 return 0; 181 } 182 return -ENOMEM; 183 } 184 185 /** 186 * pci_bus_alloc_resource - allocate a resource from a parent bus 187 * @bus: PCI bus 188 * @res: resource to allocate 189 * @size: size of resource to allocate 190 * @align: alignment of resource to allocate 191 * @min: minimum /proc/iomem address to allocate 192 * @type_mask: IORESOURCE_* type flags 193 * @alignf: resource alignment function 194 * @alignf_data: data argument for resource alignment function 195 * 196 * Given the PCI bus a device resides on, the size, minimum address, 197 * alignment and type, try to find an acceptable resource allocation 198 * for a specific device resource. 199 */ 200 int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res, 201 resource_size_t size, resource_size_t align, 202 resource_size_t min, unsigned long type_mask, 203 resource_size_t (*alignf)(void *, 204 const struct resource *, 205 resource_size_t, 206 resource_size_t), 207 void *alignf_data) 208 { 209 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT 210 int rc; 211 212 if (res->flags & IORESOURCE_MEM_64) { 213 rc = pci_bus_alloc_from_region(bus, res, size, align, min, 214 type_mask, alignf, alignf_data, 215 &pci_high); 216 if (rc == 0) 217 return 0; 218 219 return pci_bus_alloc_from_region(bus, res, size, align, min, 220 type_mask, alignf, alignf_data, 221 &pci_64_bit); 222 } 223 #endif 224 225 return pci_bus_alloc_from_region(bus, res, size, align, min, 226 type_mask, alignf, alignf_data, 227 &pci_32_bit); 228 } 229 EXPORT_SYMBOL(pci_bus_alloc_resource); 230 231 /* 232 * The @idx resource of @dev should be a PCI-PCI bridge window. If this 233 * resource fits inside a window of an upstream bridge, do nothing. If it 234 * overlaps an upstream window but extends outside it, clip the resource so 235 * it fits completely inside. 236 */ 237 bool pci_bus_clip_resource(struct pci_dev *dev, int idx) 238 { 239 struct pci_bus *bus = dev->bus; 240 struct resource *res = &dev->resource[idx]; 241 struct resource orig_res = *res; 242 struct resource *r; 243 int i; 244 245 pci_bus_for_each_resource(bus, r, i) { 246 resource_size_t start, end; 247 248 if (!r) 249 continue; 250 251 if (resource_type(res) != resource_type(r)) 252 continue; 253 254 start = max(r->start, res->start); 255 end = min(r->end, res->end); 256 257 if (start > end) 258 continue; /* no overlap */ 259 260 if (res->start == start && res->end == end) 261 return false; /* no change */ 262 263 res->start = start; 264 res->end = end; 265 dev_printk(KERN_DEBUG, &dev->dev, "%pR clipped to %pR\n", 266 &orig_res, res); 267 268 return true; 269 } 270 271 return false; 272 } 273 274 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { } 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 pci_fixup_device(pci_fixup_final, dev); 291 pci_create_sysfs_dev_files(dev); 292 pci_proc_attach_device(dev); 293 294 dev->match_driver = true; 295 retval = device_attach(&dev->dev); 296 WARN_ON(retval < 0); 297 298 dev->is_added = 1; 299 } 300 EXPORT_SYMBOL_GPL(pci_bus_add_device); 301 302 /** 303 * pci_bus_add_devices - start driver for PCI devices 304 * @bus: bus to check for new devices 305 * 306 * Start driver for PCI devices and add some sysfs entries. 307 */ 308 void pci_bus_add_devices(const struct pci_bus *bus) 309 { 310 struct pci_dev *dev; 311 struct pci_bus *child; 312 313 list_for_each_entry(dev, &bus->devices, bus_list) { 314 /* Skip already-added devices */ 315 if (dev->is_added) 316 continue; 317 pci_bus_add_device(dev); 318 } 319 320 list_for_each_entry(dev, &bus->devices, bus_list) { 321 BUG_ON(!dev->is_added); 322 child = dev->subordinate; 323 if (child) 324 pci_bus_add_devices(child); 325 } 326 } 327 EXPORT_SYMBOL(pci_bus_add_devices); 328 329 /** pci_walk_bus - walk devices on/under bus, calling callback. 330 * @top bus whose devices should be walked 331 * @cb callback to be called for each device found 332 * @userdata arbitrary pointer to be passed to callback. 333 * 334 * Walk the given bus, including any bridged devices 335 * on buses under this bus. Call the provided callback 336 * on each device found. 337 * 338 * We check the return of @cb each time. If it returns anything 339 * other than 0, we break out. 340 * 341 */ 342 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), 343 void *userdata) 344 { 345 struct pci_dev *dev; 346 struct pci_bus *bus; 347 struct list_head *next; 348 int retval; 349 350 bus = top; 351 down_read(&pci_bus_sem); 352 next = top->devices.next; 353 for (;;) { 354 if (next == &bus->devices) { 355 /* end of this bus, go up or finish */ 356 if (bus == top) 357 break; 358 next = bus->self->bus_list.next; 359 bus = bus->self->bus; 360 continue; 361 } 362 dev = list_entry(next, struct pci_dev, bus_list); 363 if (dev->subordinate) { 364 /* this is a pci-pci bridge, do its devices next */ 365 next = dev->subordinate->devices.next; 366 bus = dev->subordinate; 367 } else 368 next = dev->bus_list.next; 369 370 retval = cb(dev, userdata); 371 if (retval) 372 break; 373 } 374 up_read(&pci_bus_sem); 375 } 376 EXPORT_SYMBOL_GPL(pci_walk_bus); 377 378 struct pci_bus *pci_bus_get(struct pci_bus *bus) 379 { 380 if (bus) 381 get_device(&bus->dev); 382 return bus; 383 } 384 EXPORT_SYMBOL(pci_bus_get); 385 386 void pci_bus_put(struct pci_bus *bus) 387 { 388 if (bus) 389 put_device(&bus->dev); 390 } 391 EXPORT_SYMBOL(pci_bus_put); 392 393