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_bus_add_resource(struct pci_bus *bus, struct resource *res, 22 unsigned int flags) 23 { 24 struct pci_bus_resource *bus_res; 25 26 bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL); 27 if (!bus_res) { 28 dev_err(&bus->dev, "can't add %pR resource\n", res); 29 return; 30 } 31 32 bus_res->res = res; 33 bus_res->flags = flags; 34 list_add_tail(&bus_res->list, &bus->resources); 35 } 36 37 struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n) 38 { 39 struct pci_bus_resource *bus_res; 40 41 if (n < PCI_BRIDGE_RESOURCE_NUM) 42 return bus->resource[n]; 43 44 n -= PCI_BRIDGE_RESOURCE_NUM; 45 list_for_each_entry(bus_res, &bus->resources, list) { 46 if (n-- == 0) 47 return bus_res->res; 48 } 49 return NULL; 50 } 51 EXPORT_SYMBOL_GPL(pci_bus_resource_n); 52 53 void pci_bus_remove_resources(struct pci_bus *bus) 54 { 55 struct pci_bus_resource *bus_res, *tmp; 56 int i; 57 58 for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) 59 bus->resource[i] = NULL; 60 61 list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) { 62 list_del(&bus_res->list); 63 kfree(bus_res); 64 } 65 } 66 67 /* 68 * Find the highest-address bus resource below the cursor "res". If the 69 * cursor is NULL, return the highest resource. 70 */ 71 static struct resource *pci_bus_find_resource_prev(struct pci_bus *bus, 72 unsigned int type, 73 struct resource *res) 74 { 75 struct resource *r, *prev = NULL; 76 int i; 77 78 pci_bus_for_each_resource(bus, r, i) { 79 if (!r) 80 continue; 81 82 if ((r->flags & IORESOURCE_TYPE_BITS) != type) 83 continue; 84 85 /* If this resource is at or past the cursor, skip it */ 86 if (res) { 87 if (r == res) 88 continue; 89 if (r->end > res->end) 90 continue; 91 if (r->end == res->end && r->start > res->start) 92 continue; 93 } 94 95 if (!prev) 96 prev = r; 97 98 /* 99 * A small resource is higher than a large one that ends at 100 * the same address. 101 */ 102 if (r->end > prev->end || 103 (r->end == prev->end && r->start > prev->start)) 104 prev = r; 105 } 106 107 return prev; 108 } 109 110 /** 111 * pci_bus_alloc_resource - allocate a resource from a parent bus 112 * @bus: PCI bus 113 * @res: resource to allocate 114 * @size: size of resource to allocate 115 * @align: alignment of resource to allocate 116 * @min: minimum /proc/iomem address to allocate 117 * @type_mask: IORESOURCE_* type flags 118 * @alignf: resource alignment function 119 * @alignf_data: data argument for resource alignment function 120 * 121 * Given the PCI bus a device resides on, the size, minimum address, 122 * alignment and type, try to find an acceptable resource allocation 123 * for a specific device resource. 124 */ 125 int 126 pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res, 127 resource_size_t size, resource_size_t align, 128 resource_size_t min, unsigned int 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 { 135 int ret = -ENOMEM; 136 struct resource *r; 137 resource_size_t max = -1; 138 unsigned int type = res->flags & IORESOURCE_TYPE_BITS; 139 140 type_mask |= IORESOURCE_IO | IORESOURCE_MEM; 141 142 /* don't allocate too high if the pref mem doesn't support 64bit*/ 143 if (!(res->flags & IORESOURCE_MEM_64)) 144 max = PCIBIOS_MAX_MEM_32; 145 146 /* Look for space at highest addresses first */ 147 r = pci_bus_find_resource_prev(bus, type, NULL); 148 for ( ; r; r = pci_bus_find_resource_prev(bus, type, r)) { 149 /* type_mask must match */ 150 if ((res->flags ^ r->flags) & type_mask) 151 continue; 152 153 /* We cannot allocate a non-prefetching resource 154 from a pre-fetching area */ 155 if ((r->flags & IORESOURCE_PREFETCH) && 156 !(res->flags & IORESOURCE_PREFETCH)) 157 continue; 158 159 /* Ok, try it out.. */ 160 ret = allocate_resource(r, res, size, 161 r->start ? : min, 162 max, align, 163 alignf, alignf_data); 164 if (ret == 0) 165 break; 166 } 167 return ret; 168 } 169 170 /** 171 * pci_bus_add_device - add a single device 172 * @dev: device to add 173 * 174 * This adds a single pci device to the global 175 * device list and adds sysfs and procfs entries 176 */ 177 int pci_bus_add_device(struct pci_dev *dev) 178 { 179 int retval; 180 retval = device_add(&dev->dev); 181 if (retval) 182 return retval; 183 184 dev->is_added = 1; 185 pci_proc_attach_device(dev); 186 pci_create_sysfs_dev_files(dev); 187 return 0; 188 } 189 190 /** 191 * pci_bus_add_child - add a child bus 192 * @bus: bus to add 193 * 194 * This adds sysfs entries for a single bus 195 */ 196 int pci_bus_add_child(struct pci_bus *bus) 197 { 198 int retval; 199 200 if (bus->bridge) 201 bus->dev.parent = bus->bridge; 202 203 retval = device_register(&bus->dev); 204 if (retval) 205 return retval; 206 207 bus->is_added = 1; 208 209 retval = device_create_file(&bus->dev, &dev_attr_cpuaffinity); 210 if (retval) 211 return retval; 212 213 retval = device_create_file(&bus->dev, &dev_attr_cpulistaffinity); 214 215 /* Create legacy_io and legacy_mem files for this bus */ 216 pci_create_legacy_files(bus); 217 218 return retval; 219 } 220 221 /** 222 * pci_bus_add_devices - insert newly discovered PCI devices 223 * @bus: bus to check for new devices 224 * 225 * Add newly discovered PCI devices (which are on the bus->devices 226 * list) to the global PCI device list, add the sysfs and procfs 227 * entries. Where a bridge is found, add the discovered bus to 228 * the parents list of child buses, and recurse (breadth-first 229 * to be compatible with 2.4) 230 * 231 * Call hotplug for each new devices. 232 */ 233 void pci_bus_add_devices(const struct pci_bus *bus) 234 { 235 struct pci_dev *dev; 236 struct pci_bus *child; 237 int retval; 238 239 list_for_each_entry(dev, &bus->devices, bus_list) { 240 /* Skip already-added devices */ 241 if (dev->is_added) 242 continue; 243 retval = pci_bus_add_device(dev); 244 if (retval) 245 dev_err(&dev->dev, "Error adding device, continuing\n"); 246 } 247 248 list_for_each_entry(dev, &bus->devices, bus_list) { 249 BUG_ON(!dev->is_added); 250 251 child = dev->subordinate; 252 /* 253 * If there is an unattached subordinate bus, attach 254 * it and then scan for unattached PCI devices. 255 */ 256 if (!child) 257 continue; 258 if (list_empty(&child->node)) { 259 down_write(&pci_bus_sem); 260 list_add_tail(&child->node, &dev->bus->children); 261 up_write(&pci_bus_sem); 262 } 263 pci_bus_add_devices(child); 264 265 /* 266 * register the bus with sysfs as the parent is now 267 * properly registered. 268 */ 269 if (child->is_added) 270 continue; 271 retval = pci_bus_add_child(child); 272 if (retval) 273 dev_err(&dev->dev, "Error adding bus, continuing\n"); 274 } 275 } 276 277 void pci_enable_bridges(struct pci_bus *bus) 278 { 279 struct pci_dev *dev; 280 int retval; 281 282 list_for_each_entry(dev, &bus->devices, bus_list) { 283 if (dev->subordinate) { 284 if (!pci_is_enabled(dev)) { 285 retval = pci_enable_device(dev); 286 if (retval) 287 dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval); 288 pci_set_master(dev); 289 } 290 pci_enable_bridges(dev->subordinate); 291 } 292 } 293 } 294 295 /** pci_walk_bus - walk devices on/under bus, calling callback. 296 * @top bus whose devices should be walked 297 * @cb callback to be called for each device found 298 * @userdata arbitrary pointer to be passed to callback. 299 * 300 * Walk the given bus, including any bridged devices 301 * on buses under this bus. Call the provided callback 302 * on each device found. 303 * 304 * We check the return of @cb each time. If it returns anything 305 * other than 0, we break out. 306 * 307 */ 308 void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *), 309 void *userdata) 310 { 311 struct pci_dev *dev; 312 struct pci_bus *bus; 313 struct list_head *next; 314 int retval; 315 316 bus = top; 317 down_read(&pci_bus_sem); 318 next = top->devices.next; 319 for (;;) { 320 if (next == &bus->devices) { 321 /* end of this bus, go up or finish */ 322 if (bus == top) 323 break; 324 next = bus->self->bus_list.next; 325 bus = bus->self->bus; 326 continue; 327 } 328 dev = list_entry(next, struct pci_dev, bus_list); 329 if (dev->subordinate) { 330 /* this is a pci-pci bridge, do its devices next */ 331 next = dev->subordinate->devices.next; 332 bus = dev->subordinate; 333 } else 334 next = dev->bus_list.next; 335 336 /* Run device routines with the device locked */ 337 device_lock(&dev->dev); 338 retval = cb(dev, userdata); 339 device_unlock(&dev->dev); 340 if (retval) 341 break; 342 } 343 up_read(&pci_bus_sem); 344 } 345 EXPORT_SYMBOL_GPL(pci_walk_bus); 346 347 EXPORT_SYMBOL(pci_bus_alloc_resource); 348 EXPORT_SYMBOL_GPL(pci_bus_add_device); 349 EXPORT_SYMBOL(pci_bus_add_devices); 350 EXPORT_SYMBOL(pci_enable_bridges); 351