1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * From setup-res.c, by: 4 * Dave Rusling (david.rusling@reo.mts.dec.com) 5 * David Mosberger (davidm@cs.arizona.edu) 6 * David Miller (davem@redhat.com) 7 * Ivan Kokshaysky (ink@jurassic.park.msu.ru) 8 */ 9 #include <linux/module.h> 10 #include <linux/kernel.h> 11 #include <linux/pci.h> 12 #include <linux/errno.h> 13 #include <linux/ioport.h> 14 #include <linux/proc_fs.h> 15 #include <linux/slab.h> 16 17 #include "pci.h" 18 19 void pci_add_resource_offset(struct list_head *resources, struct resource *res, 20 resource_size_t offset) 21 { 22 struct resource_entry *entry; 23 24 entry = resource_list_create_entry(res, 0); 25 if (!entry) { 26 pr_err("PCI: can't add host bridge window %pR\n", res); 27 return; 28 } 29 30 entry->offset = offset; 31 resource_list_add_tail(entry, resources); 32 } 33 EXPORT_SYMBOL(pci_add_resource_offset); 34 35 void pci_add_resource(struct list_head *resources, struct resource *res) 36 { 37 pci_add_resource_offset(resources, res, 0); 38 } 39 EXPORT_SYMBOL(pci_add_resource); 40 41 void pci_free_resource_list(struct list_head *resources) 42 { 43 resource_list_free(resources); 44 } 45 EXPORT_SYMBOL(pci_free_resource_list); 46 47 void pci_bus_add_resource(struct pci_bus *bus, struct resource *res, 48 unsigned int flags) 49 { 50 struct pci_bus_resource *bus_res; 51 52 bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL); 53 if (!bus_res) { 54 dev_err(&bus->dev, "can't add %pR resource\n", res); 55 return; 56 } 57 58 bus_res->res = res; 59 bus_res->flags = flags; 60 list_add_tail(&bus_res->list, &bus->resources); 61 } 62 63 struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n) 64 { 65 struct pci_bus_resource *bus_res; 66 67 if (n < PCI_BRIDGE_RESOURCE_NUM) 68 return bus->resource[n]; 69 70 n -= PCI_BRIDGE_RESOURCE_NUM; 71 list_for_each_entry(bus_res, &bus->resources, list) { 72 if (n-- == 0) 73 return bus_res->res; 74 } 75 return NULL; 76 } 77 EXPORT_SYMBOL_GPL(pci_bus_resource_n); 78 79 void pci_bus_remove_resources(struct pci_bus *bus) 80 { 81 int i; 82 struct pci_bus_resource *bus_res, *tmp; 83 84 for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) 85 bus->resource[i] = NULL; 86 87 list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) { 88 list_del(&bus_res->list); 89 kfree(bus_res); 90 } 91 } 92 93 int devm_request_pci_bus_resources(struct device *dev, 94 struct list_head *resources) 95 { 96 struct resource_entry *win; 97 struct resource *parent, *res; 98 int err; 99 100 resource_list_for_each_entry(win, resources) { 101 res = win->res; 102 switch (resource_type(res)) { 103 case IORESOURCE_IO: 104 parent = &ioport_resource; 105 break; 106 case IORESOURCE_MEM: 107 parent = &iomem_resource; 108 break; 109 default: 110 continue; 111 } 112 113 err = devm_request_resource(dev, parent, res); 114 if (err) 115 return err; 116 } 117 118 return 0; 119 } 120 EXPORT_SYMBOL_GPL(devm_request_pci_bus_resources); 121 122 static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL}; 123 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT 124 static struct pci_bus_region pci_64_bit = {0, 125 (pci_bus_addr_t) 0xffffffffffffffffULL}; 126 static struct pci_bus_region pci_high = {(pci_bus_addr_t) 0x100000000ULL, 127 (pci_bus_addr_t) 0xffffffffffffffffULL}; 128 #endif 129 130 /* 131 * @res contains CPU addresses. Clip it so the corresponding bus addresses 132 * on @bus are entirely within @region. This is used to control the bus 133 * addresses of resources we allocate, e.g., we may need a resource that 134 * can be mapped by a 32-bit BAR. 135 */ 136 static void pci_clip_resource_to_region(struct pci_bus *bus, 137 struct resource *res, 138 struct pci_bus_region *region) 139 { 140 struct pci_bus_region r; 141 142 pcibios_resource_to_bus(bus, &r, res); 143 if (r.start < region->start) 144 r.start = region->start; 145 if (r.end > region->end) 146 r.end = region->end; 147 148 if (r.end < r.start) 149 res->end = res->start - 1; 150 else 151 pcibios_bus_to_resource(bus, res, &r); 152 } 153 154 static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res, 155 resource_size_t size, resource_size_t align, 156 resource_size_t min, unsigned long type_mask, 157 resource_size_t (*alignf)(void *, 158 const struct resource *, 159 resource_size_t, 160 resource_size_t), 161 void *alignf_data, 162 struct pci_bus_region *region) 163 { 164 int i, ret; 165 struct resource *r, avail; 166 resource_size_t max; 167 168 type_mask |= IORESOURCE_TYPE_BITS; 169 170 pci_bus_for_each_resource(bus, r, i) { 171 resource_size_t min_used = min; 172 173 if (!r) 174 continue; 175 176 /* type_mask must match */ 177 if ((res->flags ^ r->flags) & type_mask) 178 continue; 179 180 /* We cannot allocate a non-prefetching resource 181 from a pre-fetching area */ 182 if ((r->flags & IORESOURCE_PREFETCH) && 183 !(res->flags & IORESOURCE_PREFETCH)) 184 continue; 185 186 avail = *r; 187 pci_clip_resource_to_region(bus, &avail, region); 188 189 /* 190 * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to 191 * protect badly documented motherboard resources, but if 192 * this is an already-configured bridge window, its start 193 * overrides "min". 194 */ 195 if (avail.start) 196 min_used = avail.start; 197 198 max = avail.end; 199 200 /* Don't bother if available space isn't large enough */ 201 if (size > max - min_used + 1) 202 continue; 203 204 /* Ok, try it out.. */ 205 ret = allocate_resource(r, res, size, min_used, max, 206 align, alignf, alignf_data); 207 if (ret == 0) 208 return 0; 209 } 210 return -ENOMEM; 211 } 212 213 /** 214 * pci_bus_alloc_resource - allocate a resource from a parent bus 215 * @bus: PCI bus 216 * @res: resource to allocate 217 * @size: size of resource to allocate 218 * @align: alignment of resource to allocate 219 * @min: minimum /proc/iomem address to allocate 220 * @type_mask: IORESOURCE_* type flags 221 * @alignf: resource alignment function 222 * @alignf_data: data argument for resource alignment function 223 * 224 * Given the PCI bus a device resides on, the size, minimum address, 225 * alignment and type, try to find an acceptable resource allocation 226 * for a specific device resource. 227 */ 228 int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res, 229 resource_size_t size, resource_size_t align, 230 resource_size_t min, unsigned long type_mask, 231 resource_size_t (*alignf)(void *, 232 const struct resource *, 233 resource_size_t, 234 resource_size_t), 235 void *alignf_data) 236 { 237 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT 238 int rc; 239 240 if (res->flags & IORESOURCE_MEM_64) { 241 rc = pci_bus_alloc_from_region(bus, res, size, align, min, 242 type_mask, alignf, alignf_data, 243 &pci_high); 244 if (rc == 0) 245 return 0; 246 247 return pci_bus_alloc_from_region(bus, res, size, align, min, 248 type_mask, alignf, alignf_data, 249 &pci_64_bit); 250 } 251 #endif 252 253 return pci_bus_alloc_from_region(bus, res, size, align, min, 254 type_mask, alignf, alignf_data, 255 &pci_32_bit); 256 } 257 EXPORT_SYMBOL(pci_bus_alloc_resource); 258 259 /* 260 * The @idx resource of @dev should be a PCI-PCI bridge window. If this 261 * resource fits inside a window of an upstream bridge, do nothing. If it 262 * overlaps an upstream window but extends outside it, clip the resource so 263 * it fits completely inside. 264 */ 265 bool pci_bus_clip_resource(struct pci_dev *dev, int idx) 266 { 267 struct pci_bus *bus = dev->bus; 268 struct resource *res = &dev->resource[idx]; 269 struct resource orig_res = *res; 270 struct resource *r; 271 int i; 272 273 pci_bus_for_each_resource(bus, r, i) { 274 resource_size_t start, end; 275 276 if (!r) 277 continue; 278 279 if (resource_type(res) != resource_type(r)) 280 continue; 281 282 start = max(r->start, res->start); 283 end = min(r->end, res->end); 284 285 if (start > end) 286 continue; /* no overlap */ 287 288 if (res->start == start && res->end == end) 289 return false; /* no change */ 290 291 res->start = start; 292 res->end = end; 293 res->flags &= ~IORESOURCE_UNSET; 294 orig_res.flags &= ~IORESOURCE_UNSET; 295 pci_info(dev, "%pR clipped to %pR\n", &orig_res, res); 296 297 return true; 298 } 299 300 return false; 301 } 302 303 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { } 304 305 void __weak pcibios_bus_add_device(struct pci_dev *pdev) { } 306 307 /** 308 * pci_bus_add_device - start driver for a single device 309 * @dev: device to add 310 * 311 * This adds add sysfs entries and start device drivers 312 */ 313 void pci_bus_add_device(struct pci_dev *dev) 314 { 315 int retval; 316 317 /* 318 * Can not put in pci_device_add yet because resources 319 * are not assigned yet for some devices. 320 */ 321 pcibios_bus_add_device(dev); 322 pci_fixup_device(pci_fixup_final, dev); 323 pci_create_sysfs_dev_files(dev); 324 pci_proc_attach_device(dev); 325 pci_bridge_d3_update(dev); 326 327 dev->match_driver = true; 328 retval = device_attach(&dev->dev); 329 if (retval < 0 && retval != -EPROBE_DEFER) 330 pci_warn(dev, "device attach failed (%d)\n", retval); 331 332 pci_dev_assign_added(dev, true); 333 } 334 EXPORT_SYMBOL_GPL(pci_bus_add_device); 335 336 /** 337 * pci_bus_add_devices - start driver for PCI devices 338 * @bus: bus to check for new devices 339 * 340 * Start driver for PCI devices and add some sysfs entries. 341 */ 342 void pci_bus_add_devices(const struct pci_bus *bus) 343 { 344 struct pci_dev *dev; 345 struct pci_bus *child; 346 347 list_for_each_entry(dev, &bus->devices, bus_list) { 348 /* Skip already-added devices */ 349 if (pci_dev_is_added(dev)) 350 continue; 351 pci_bus_add_device(dev); 352 } 353 354 list_for_each_entry(dev, &bus->devices, bus_list) { 355 /* Skip if device attach failed */ 356 if (!pci_dev_is_added(dev)) 357 continue; 358 child = dev->subordinate; 359 if (child) 360 pci_bus_add_devices(child); 361 } 362 } 363 EXPORT_SYMBOL(pci_bus_add_devices); 364 365 /** pci_walk_bus - walk devices on/under bus, calling callback. 366 * @top bus whose devices should be walked 367 * @cb callback to be called for each device found 368 * @userdata arbitrary pointer to be passed to callback. 369 * 370 * Walk the given bus, including any bridged devices 371 * on buses under this bus. Call the provided callback 372 * on each device found. 373 * 374 * We check the return of @cb each time. If it returns anything 375 * other than 0, we break out. 376 * 377 */ 378 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), 379 void *userdata) 380 { 381 struct pci_dev *dev; 382 struct pci_bus *bus; 383 struct list_head *next; 384 int retval; 385 386 bus = top; 387 down_read(&pci_bus_sem); 388 next = top->devices.next; 389 for (;;) { 390 if (next == &bus->devices) { 391 /* end of this bus, go up or finish */ 392 if (bus == top) 393 break; 394 next = bus->self->bus_list.next; 395 bus = bus->self->bus; 396 continue; 397 } 398 dev = list_entry(next, struct pci_dev, bus_list); 399 if (dev->subordinate) { 400 /* this is a pci-pci bridge, do its devices next */ 401 next = dev->subordinate->devices.next; 402 bus = dev->subordinate; 403 } else 404 next = dev->bus_list.next; 405 406 retval = cb(dev, userdata); 407 if (retval) 408 break; 409 } 410 up_read(&pci_bus_sem); 411 } 412 EXPORT_SYMBOL_GPL(pci_walk_bus); 413 414 struct pci_bus *pci_bus_get(struct pci_bus *bus) 415 { 416 if (bus) 417 get_device(&bus->dev); 418 return bus; 419 } 420 421 void pci_bus_put(struct pci_bus *bus) 422 { 423 if (bus) 424 put_device(&bus->dev); 425 } 426