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/init.h> 17 #include <linux/slab.h> 18 19 #include "pci.h" 20 21 void pci_add_resource_offset(struct list_head *resources, struct resource *res, 22 resource_size_t offset) 23 { 24 struct pci_host_bridge_window *window; 25 26 window = kzalloc(sizeof(struct pci_host_bridge_window), GFP_KERNEL); 27 if (!window) { 28 printk(KERN_ERR "PCI: can't add host bridge window %pR\n", res); 29 return; 30 } 31 32 window->res = res; 33 window->offset = offset; 34 list_add_tail(&window->list, resources); 35 } 36 EXPORT_SYMBOL(pci_add_resource_offset); 37 38 void pci_add_resource(struct list_head *resources, struct resource *res) 39 { 40 pci_add_resource_offset(resources, res, 0); 41 } 42 EXPORT_SYMBOL(pci_add_resource); 43 44 void pci_free_resource_list(struct list_head *resources) 45 { 46 struct pci_host_bridge_window *window, *tmp; 47 48 list_for_each_entry_safe(window, tmp, resources, list) { 49 list_del(&window->list); 50 kfree(window); 51 } 52 } 53 EXPORT_SYMBOL(pci_free_resource_list); 54 55 void pci_bus_add_resource(struct pci_bus *bus, struct resource *res, 56 unsigned int flags) 57 { 58 struct pci_bus_resource *bus_res; 59 60 bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL); 61 if (!bus_res) { 62 dev_err(&bus->dev, "can't add %pR resource\n", res); 63 return; 64 } 65 66 bus_res->res = res; 67 bus_res->flags = flags; 68 list_add_tail(&bus_res->list, &bus->resources); 69 } 70 71 struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n) 72 { 73 struct pci_bus_resource *bus_res; 74 75 if (n < PCI_BRIDGE_RESOURCE_NUM) 76 return bus->resource[n]; 77 78 n -= PCI_BRIDGE_RESOURCE_NUM; 79 list_for_each_entry(bus_res, &bus->resources, list) { 80 if (n-- == 0) 81 return bus_res->res; 82 } 83 return NULL; 84 } 85 EXPORT_SYMBOL_GPL(pci_bus_resource_n); 86 87 void pci_bus_remove_resources(struct pci_bus *bus) 88 { 89 int i; 90 struct pci_bus_resource *bus_res, *tmp; 91 92 for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) 93 bus->resource[i] = NULL; 94 95 list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) { 96 list_del(&bus_res->list); 97 kfree(bus_res); 98 } 99 } 100 101 static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL}; 102 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT 103 static struct pci_bus_region pci_64_bit = {0, 104 (dma_addr_t) 0xffffffffffffffffULL}; 105 static struct pci_bus_region pci_high = {(dma_addr_t) 0x100000000ULL, 106 (dma_addr_t) 0xffffffffffffffffULL}; 107 #endif 108 109 /* 110 * @res contains CPU addresses. Clip it so the corresponding bus addresses 111 * on @bus are entirely within @region. This is used to control the bus 112 * addresses of resources we allocate, e.g., we may need a resource that 113 * can be mapped by a 32-bit BAR. 114 */ 115 static void pci_clip_resource_to_region(struct pci_bus *bus, 116 struct resource *res, 117 struct pci_bus_region *region) 118 { 119 struct pci_bus_region r; 120 121 pcibios_resource_to_bus(bus, &r, res); 122 if (r.start < region->start) 123 r.start = region->start; 124 if (r.end > region->end) 125 r.end = region->end; 126 127 if (r.end < r.start) 128 res->end = res->start - 1; 129 else 130 pcibios_bus_to_resource(bus, res, &r); 131 } 132 133 static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res, 134 resource_size_t size, resource_size_t align, 135 resource_size_t min, unsigned int type_mask, 136 resource_size_t (*alignf)(void *, 137 const struct resource *, 138 resource_size_t, 139 resource_size_t), 140 void *alignf_data, 141 struct pci_bus_region *region) 142 { 143 int i, ret; 144 struct resource *r, avail; 145 resource_size_t max; 146 147 type_mask |= IORESOURCE_IO | IORESOURCE_MEM; 148 149 pci_bus_for_each_resource(bus, r, i) { 150 if (!r) 151 continue; 152 153 /* type_mask must match */ 154 if ((res->flags ^ r->flags) & type_mask) 155 continue; 156 157 /* We cannot allocate a non-prefetching resource 158 from a pre-fetching area */ 159 if ((r->flags & IORESOURCE_PREFETCH) && 160 !(res->flags & IORESOURCE_PREFETCH)) 161 continue; 162 163 avail = *r; 164 pci_clip_resource_to_region(bus, &avail, region); 165 if (!resource_size(&avail)) 166 continue; 167 168 /* 169 * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to 170 * protect badly documented motherboard resources, but if 171 * this is an already-configured bridge window, its start 172 * overrides "min". 173 */ 174 if (avail.start) 175 min = avail.start; 176 177 max = avail.end; 178 179 /* Ok, try it out.. */ 180 ret = allocate_resource(r, res, size, min, max, 181 align, alignf, alignf_data); 182 if (ret == 0) 183 return 0; 184 } 185 return -ENOMEM; 186 } 187 188 /** 189 * pci_bus_alloc_resource - allocate a resource from a parent bus 190 * @bus: PCI bus 191 * @res: resource to allocate 192 * @size: size of resource to allocate 193 * @align: alignment of resource to allocate 194 * @min: minimum /proc/iomem address to allocate 195 * @type_mask: IORESOURCE_* type flags 196 * @alignf: resource alignment function 197 * @alignf_data: data argument for resource alignment function 198 * 199 * Given the PCI bus a device resides on, the size, minimum address, 200 * alignment and type, try to find an acceptable resource allocation 201 * for a specific device resource. 202 */ 203 int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res, 204 resource_size_t size, resource_size_t align, 205 resource_size_t min, unsigned int type_mask, 206 resource_size_t (*alignf)(void *, 207 const struct resource *, 208 resource_size_t, 209 resource_size_t), 210 void *alignf_data) 211 { 212 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT 213 int rc; 214 215 if (res->flags & IORESOURCE_MEM_64) { 216 rc = pci_bus_alloc_from_region(bus, res, size, align, min, 217 type_mask, alignf, alignf_data, 218 &pci_high); 219 if (rc == 0) 220 return 0; 221 222 return pci_bus_alloc_from_region(bus, res, size, align, min, 223 type_mask, alignf, alignf_data, 224 &pci_64_bit); 225 } 226 #endif 227 228 return pci_bus_alloc_from_region(bus, res, size, align, min, 229 type_mask, alignf, alignf_data, 230 &pci_32_bit); 231 } 232 233 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { } 234 235 /** 236 * pci_bus_add_device - start driver for a single device 237 * @dev: device to add 238 * 239 * This adds add sysfs entries and start device drivers 240 */ 241 int pci_bus_add_device(struct pci_dev *dev) 242 { 243 int retval; 244 245 /* 246 * Can not put in pci_device_add yet because resources 247 * are not assigned yet for some devices. 248 */ 249 pci_fixup_device(pci_fixup_final, dev); 250 pci_create_sysfs_dev_files(dev); 251 pci_proc_attach_device(dev); 252 253 dev->match_driver = true; 254 retval = device_attach(&dev->dev); 255 WARN_ON(retval < 0); 256 257 dev->is_added = 1; 258 259 return 0; 260 } 261 262 /** 263 * pci_bus_add_devices - start driver for PCI devices 264 * @bus: bus to check for new devices 265 * 266 * Start driver for PCI devices and add some sysfs entries. 267 */ 268 void pci_bus_add_devices(const struct pci_bus *bus) 269 { 270 struct pci_dev *dev; 271 struct pci_bus *child; 272 int retval; 273 274 list_for_each_entry(dev, &bus->devices, bus_list) { 275 /* Skip already-added devices */ 276 if (dev->is_added) 277 continue; 278 retval = pci_bus_add_device(dev); 279 if (retval) 280 dev_err(&dev->dev, "Error adding device (%d)\n", 281 retval); 282 } 283 284 list_for_each_entry(dev, &bus->devices, bus_list) { 285 BUG_ON(!dev->is_added); 286 child = dev->subordinate; 287 if (child) 288 pci_bus_add_devices(child); 289 } 290 } 291 292 /** pci_walk_bus - walk devices on/under bus, calling callback. 293 * @top bus whose devices should be walked 294 * @cb callback to be called for each device found 295 * @userdata arbitrary pointer to be passed to callback. 296 * 297 * Walk the given bus, including any bridged devices 298 * on buses under this bus. Call the provided callback 299 * on each device found. 300 * 301 * We check the return of @cb each time. If it returns anything 302 * other than 0, we break out. 303 * 304 */ 305 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), 306 void *userdata) 307 { 308 struct pci_dev *dev; 309 struct pci_bus *bus; 310 struct list_head *next; 311 int retval; 312 313 bus = top; 314 down_read(&pci_bus_sem); 315 next = top->devices.next; 316 for (;;) { 317 if (next == &bus->devices) { 318 /* end of this bus, go up or finish */ 319 if (bus == top) 320 break; 321 next = bus->self->bus_list.next; 322 bus = bus->self->bus; 323 continue; 324 } 325 dev = list_entry(next, struct pci_dev, bus_list); 326 if (dev->subordinate) { 327 /* this is a pci-pci bridge, do its devices next */ 328 next = dev->subordinate->devices.next; 329 bus = dev->subordinate; 330 } else 331 next = dev->bus_list.next; 332 333 retval = cb(dev, userdata); 334 if (retval) 335 break; 336 } 337 up_read(&pci_bus_sem); 338 } 339 EXPORT_SYMBOL_GPL(pci_walk_bus); 340 341 struct pci_bus *pci_bus_get(struct pci_bus *bus) 342 { 343 if (bus) 344 get_device(&bus->dev); 345 return bus; 346 } 347 EXPORT_SYMBOL(pci_bus_get); 348 349 void pci_bus_put(struct pci_bus *bus) 350 { 351 if (bus) 352 put_device(&bus->dev); 353 } 354 EXPORT_SYMBOL(pci_bus_put); 355 356 EXPORT_SYMBOL(pci_bus_alloc_resource); 357 EXPORT_SYMBOL_GPL(pci_bus_add_device); 358 EXPORT_SYMBOL(pci_bus_add_devices); 359