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 long 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_TYPE_BITS; 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); 165 166 /* 167 * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to 168 * protect badly documented motherboard resources, but if 169 * this is an already-configured bridge window, its start 170 * overrides "min". 171 */ 172 if (avail.start) 173 min = avail.start; 174 175 max = avail.end; 176 177 /* Ok, try it out.. */ 178 ret = allocate_resource(r, res, size, min, max, 179 align, alignf, alignf_data); 180 if (ret == 0) 181 return 0; 182 } 183 return -ENOMEM; 184 } 185 186 /** 187 * pci_bus_alloc_resource - allocate a resource from a parent bus 188 * @bus: PCI bus 189 * @res: resource to allocate 190 * @size: size of resource to allocate 191 * @align: alignment of resource to allocate 192 * @min: minimum /proc/iomem address to allocate 193 * @type_mask: IORESOURCE_* type flags 194 * @alignf: resource alignment function 195 * @alignf_data: data argument for resource alignment function 196 * 197 * Given the PCI bus a device resides on, the size, minimum address, 198 * alignment and type, try to find an acceptable resource allocation 199 * for a specific device resource. 200 */ 201 int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res, 202 resource_size_t size, resource_size_t align, 203 resource_size_t min, unsigned long type_mask, 204 resource_size_t (*alignf)(void *, 205 const struct resource *, 206 resource_size_t, 207 resource_size_t), 208 void *alignf_data) 209 { 210 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT 211 int rc; 212 213 if (res->flags & IORESOURCE_MEM_64) { 214 rc = pci_bus_alloc_from_region(bus, res, size, align, min, 215 type_mask, alignf, alignf_data, 216 &pci_high); 217 if (rc == 0) 218 return 0; 219 220 return pci_bus_alloc_from_region(bus, res, size, align, min, 221 type_mask, alignf, alignf_data, 222 &pci_64_bit); 223 } 224 #endif 225 226 return pci_bus_alloc_from_region(bus, res, size, align, min, 227 type_mask, alignf, alignf_data, 228 &pci_32_bit); 229 } 230 231 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { } 232 233 /** 234 * pci_bus_add_device - start driver for a single device 235 * @dev: device to add 236 * 237 * This adds add sysfs entries and start device drivers 238 */ 239 int pci_bus_add_device(struct pci_dev *dev) 240 { 241 int retval; 242 243 /* 244 * Can not put in pci_device_add yet because resources 245 * are not assigned yet for some devices. 246 */ 247 pci_fixup_device(pci_fixup_final, dev); 248 pci_create_sysfs_dev_files(dev); 249 pci_proc_attach_device(dev); 250 251 dev->match_driver = true; 252 retval = device_attach(&dev->dev); 253 WARN_ON(retval < 0); 254 255 dev->is_added = 1; 256 257 return 0; 258 } 259 260 /** 261 * pci_bus_add_devices - start driver for PCI devices 262 * @bus: bus to check for new devices 263 * 264 * Start driver for PCI devices and add some sysfs entries. 265 */ 266 void pci_bus_add_devices(const struct pci_bus *bus) 267 { 268 struct pci_dev *dev; 269 struct pci_bus *child; 270 int retval; 271 272 list_for_each_entry(dev, &bus->devices, bus_list) { 273 /* Skip already-added devices */ 274 if (dev->is_added) 275 continue; 276 retval = pci_bus_add_device(dev); 277 if (retval) 278 dev_err(&dev->dev, "Error adding device (%d)\n", 279 retval); 280 } 281 282 list_for_each_entry(dev, &bus->devices, bus_list) { 283 BUG_ON(!dev->is_added); 284 child = dev->subordinate; 285 if (child) 286 pci_bus_add_devices(child); 287 } 288 } 289 290 /** pci_walk_bus - walk devices on/under bus, calling callback. 291 * @top bus whose devices should be walked 292 * @cb callback to be called for each device found 293 * @userdata arbitrary pointer to be passed to callback. 294 * 295 * Walk the given bus, including any bridged devices 296 * on buses under this bus. Call the provided callback 297 * on each device found. 298 * 299 * We check the return of @cb each time. If it returns anything 300 * other than 0, we break out. 301 * 302 */ 303 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), 304 void *userdata) 305 { 306 struct pci_dev *dev; 307 struct pci_bus *bus; 308 struct list_head *next; 309 int retval; 310 311 bus = top; 312 down_read(&pci_bus_sem); 313 next = top->devices.next; 314 for (;;) { 315 if (next == &bus->devices) { 316 /* end of this bus, go up or finish */ 317 if (bus == top) 318 break; 319 next = bus->self->bus_list.next; 320 bus = bus->self->bus; 321 continue; 322 } 323 dev = list_entry(next, struct pci_dev, bus_list); 324 if (dev->subordinate) { 325 /* this is a pci-pci bridge, do its devices next */ 326 next = dev->subordinate->devices.next; 327 bus = dev->subordinate; 328 } else 329 next = dev->bus_list.next; 330 331 retval = cb(dev, userdata); 332 if (retval) 333 break; 334 } 335 up_read(&pci_bus_sem); 336 } 337 EXPORT_SYMBOL_GPL(pci_walk_bus); 338 339 struct pci_bus *pci_bus_get(struct pci_bus *bus) 340 { 341 if (bus) 342 get_device(&bus->dev); 343 return bus; 344 } 345 EXPORT_SYMBOL(pci_bus_get); 346 347 void pci_bus_put(struct pci_bus *bus) 348 { 349 if (bus) 350 put_device(&bus->dev); 351 } 352 EXPORT_SYMBOL(pci_bus_put); 353 354 EXPORT_SYMBOL(pci_bus_alloc_resource); 355 EXPORT_SYMBOL_GPL(pci_bus_add_device); 356 EXPORT_SYMBOL(pci_bus_add_devices); 357