1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/string.h> 3 #include <linux/kernel.h> 4 #include <linux/of.h> 5 #include <linux/of_device.h> 6 #include <linux/of_address.h> 7 #include <linux/of_iommu.h> 8 #include <linux/of_reserved_mem.h> 9 #include <linux/dma-direct.h> /* for bus_dma_region */ 10 #include <linux/dma-map-ops.h> 11 #include <linux/init.h> 12 #include <linux/module.h> 13 #include <linux/mod_devicetable.h> 14 #include <linux/slab.h> 15 #include <linux/platform_device.h> 16 17 #include <asm/errno.h> 18 #include "of_private.h" 19 20 /** 21 * of_match_device - Tell if a struct device matches an of_device_id list 22 * @matches: array of of device match structures to search in 23 * @dev: the of device structure to match against 24 * 25 * Used by a driver to check whether an platform_device present in the 26 * system is in its list of supported devices. 27 */ 28 const struct of_device_id *of_match_device(const struct of_device_id *matches, 29 const struct device *dev) 30 { 31 if (!matches || !dev->of_node || dev->of_node_reused) 32 return NULL; 33 return of_match_node(matches, dev->of_node); 34 } 35 EXPORT_SYMBOL(of_match_device); 36 37 int of_device_add(struct platform_device *ofdev) 38 { 39 BUG_ON(ofdev->dev.of_node == NULL); 40 41 /* name and id have to be set so that the platform bus doesn't get 42 * confused on matching */ 43 ofdev->name = dev_name(&ofdev->dev); 44 ofdev->id = PLATFORM_DEVID_NONE; 45 46 /* 47 * If this device has not binding numa node in devicetree, that is 48 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this 49 * device is on the same node as the parent. 50 */ 51 set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node)); 52 53 return device_add(&ofdev->dev); 54 } 55 56 static void 57 of_dma_set_restricted_buffer(struct device *dev, struct device_node *np) 58 { 59 struct device_node *node, *of_node = dev->of_node; 60 int count, i; 61 62 if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL)) 63 return; 64 65 count = of_property_count_elems_of_size(of_node, "memory-region", 66 sizeof(u32)); 67 /* 68 * If dev->of_node doesn't exist or doesn't contain memory-region, try 69 * the OF node having DMA configuration. 70 */ 71 if (count <= 0) { 72 of_node = np; 73 count = of_property_count_elems_of_size( 74 of_node, "memory-region", sizeof(u32)); 75 } 76 77 for (i = 0; i < count; i++) { 78 node = of_parse_phandle(of_node, "memory-region", i); 79 /* 80 * There might be multiple memory regions, but only one 81 * restricted-dma-pool region is allowed. 82 */ 83 if (of_device_is_compatible(node, "restricted-dma-pool") && 84 of_device_is_available(node)) { 85 of_node_put(node); 86 break; 87 } 88 of_node_put(node); 89 } 90 91 /* 92 * Attempt to initialize a restricted-dma-pool region if one was found. 93 * Note that count can hold a negative error code. 94 */ 95 if (i < count && of_reserved_mem_device_init_by_idx(dev, of_node, i)) 96 dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n"); 97 } 98 99 /** 100 * of_dma_configure_id - Setup DMA configuration 101 * @dev: Device to apply DMA configuration 102 * @np: Pointer to OF node having DMA configuration 103 * @force_dma: Whether device is to be set up by of_dma_configure() even if 104 * DMA capability is not explicitly described by firmware. 105 * @id: Optional const pointer value input id 106 * 107 * Try to get devices's DMA configuration from DT and update it 108 * accordingly. 109 * 110 * If platform code needs to use its own special DMA configuration, it 111 * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events 112 * to fix up DMA configuration. 113 */ 114 int of_dma_configure_id(struct device *dev, struct device_node *np, 115 bool force_dma, const u32 *id) 116 { 117 const struct iommu_ops *iommu; 118 const struct bus_dma_region *map = NULL; 119 struct device_node *bus_np; 120 u64 dma_start = 0; 121 u64 mask, end, size = 0; 122 bool coherent; 123 int ret; 124 125 if (np == dev->of_node) 126 bus_np = __of_get_dma_parent(np); 127 else 128 bus_np = of_node_get(np); 129 130 ret = of_dma_get_range(bus_np, &map); 131 of_node_put(bus_np); 132 if (ret < 0) { 133 /* 134 * For legacy reasons, we have to assume some devices need 135 * DMA configuration regardless of whether "dma-ranges" is 136 * correctly specified or not. 137 */ 138 if (!force_dma) 139 return ret == -ENODEV ? 0 : ret; 140 } else { 141 const struct bus_dma_region *r = map; 142 u64 dma_end = 0; 143 144 /* Determine the overall bounds of all DMA regions */ 145 for (dma_start = ~0; r->size; r++) { 146 /* Take lower and upper limits */ 147 if (r->dma_start < dma_start) 148 dma_start = r->dma_start; 149 if (r->dma_start + r->size > dma_end) 150 dma_end = r->dma_start + r->size; 151 } 152 size = dma_end - dma_start; 153 154 /* 155 * Add a work around to treat the size as mask + 1 in case 156 * it is defined in DT as a mask. 157 */ 158 if (size & 1) { 159 dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n", 160 size); 161 size = size + 1; 162 } 163 164 if (!size) { 165 dev_err(dev, "Adjusted size 0x%llx invalid\n", size); 166 kfree(map); 167 return -EINVAL; 168 } 169 } 170 171 /* 172 * If @dev is expected to be DMA-capable then the bus code that created 173 * it should have initialised its dma_mask pointer by this point. For 174 * now, we'll continue the legacy behaviour of coercing it to the 175 * coherent mask if not, but we'll no longer do so quietly. 176 */ 177 if (!dev->dma_mask) { 178 dev_warn(dev, "DMA mask not set\n"); 179 dev->dma_mask = &dev->coherent_dma_mask; 180 } 181 182 if (!size && dev->coherent_dma_mask) 183 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); 184 else if (!size) 185 size = 1ULL << 32; 186 187 /* 188 * Limit coherent and dma mask based on size and default mask 189 * set by the driver. 190 */ 191 end = dma_start + size - 1; 192 mask = DMA_BIT_MASK(ilog2(end) + 1); 193 dev->coherent_dma_mask &= mask; 194 *dev->dma_mask &= mask; 195 /* ...but only set bus limit and range map if we found valid dma-ranges earlier */ 196 if (!ret) { 197 dev->bus_dma_limit = end; 198 dev->dma_range_map = map; 199 } 200 201 coherent = of_dma_is_coherent(np); 202 dev_dbg(dev, "device is%sdma coherent\n", 203 coherent ? " " : " not "); 204 205 iommu = of_iommu_configure(dev, np, id); 206 if (PTR_ERR(iommu) == -EPROBE_DEFER) { 207 /* Don't touch range map if it wasn't set from a valid dma-ranges */ 208 if (!ret) 209 dev->dma_range_map = NULL; 210 kfree(map); 211 return -EPROBE_DEFER; 212 } 213 214 dev_dbg(dev, "device is%sbehind an iommu\n", 215 iommu ? " " : " not "); 216 217 arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); 218 219 if (!iommu) 220 of_dma_set_restricted_buffer(dev, np); 221 222 return 0; 223 } 224 EXPORT_SYMBOL_GPL(of_dma_configure_id); 225 226 int of_device_register(struct platform_device *pdev) 227 { 228 device_initialize(&pdev->dev); 229 return of_device_add(pdev); 230 } 231 EXPORT_SYMBOL(of_device_register); 232 233 void of_device_unregister(struct platform_device *ofdev) 234 { 235 device_unregister(&ofdev->dev); 236 } 237 EXPORT_SYMBOL(of_device_unregister); 238 239 const void *of_device_get_match_data(const struct device *dev) 240 { 241 const struct of_device_id *match; 242 243 match = of_match_device(dev->driver->of_match_table, dev); 244 if (!match) 245 return NULL; 246 247 return match->data; 248 } 249 EXPORT_SYMBOL(of_device_get_match_data); 250 251 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) 252 { 253 const char *compat; 254 char *c; 255 struct property *p; 256 ssize_t csize; 257 ssize_t tsize; 258 259 if ((!dev) || (!dev->of_node)) 260 return -ENODEV; 261 262 /* Name & Type */ 263 /* %p eats all alphanum characters, so %c must be used here */ 264 csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T', 265 of_node_get_device_type(dev->of_node)); 266 tsize = csize; 267 len -= csize; 268 if (str) 269 str += csize; 270 271 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 272 csize = strlen(compat) + 1; 273 tsize += csize; 274 if (csize > len) 275 continue; 276 277 csize = snprintf(str, len, "C%s", compat); 278 for (c = str; c; ) { 279 c = strchr(c, ' '); 280 if (c) 281 *c++ = '_'; 282 } 283 len -= csize; 284 str += csize; 285 } 286 287 return tsize; 288 } 289 290 int of_device_request_module(struct device *dev) 291 { 292 char *str; 293 ssize_t size; 294 int ret; 295 296 size = of_device_get_modalias(dev, NULL, 0); 297 if (size < 0) 298 return size; 299 300 str = kmalloc(size + 1, GFP_KERNEL); 301 if (!str) 302 return -ENOMEM; 303 304 of_device_get_modalias(dev, str, size); 305 str[size] = '\0'; 306 ret = request_module(str); 307 kfree(str); 308 309 return ret; 310 } 311 EXPORT_SYMBOL_GPL(of_device_request_module); 312 313 /** 314 * of_device_modalias - Fill buffer with newline terminated modalias string 315 * @dev: Calling device 316 * @str: Modalias string 317 * @len: Size of @str 318 */ 319 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) 320 { 321 ssize_t sl = of_device_get_modalias(dev, str, len - 2); 322 if (sl < 0) 323 return sl; 324 if (sl > len - 2) 325 return -ENOMEM; 326 327 str[sl++] = '\n'; 328 str[sl] = 0; 329 return sl; 330 } 331 EXPORT_SYMBOL_GPL(of_device_modalias); 332 333 /** 334 * of_device_uevent - Display OF related uevent information 335 * @dev: Device to display the uevent information for 336 * @env: Kernel object's userspace event reference to fill up 337 */ 338 void of_device_uevent(const struct device *dev, struct kobj_uevent_env *env) 339 { 340 const char *compat, *type; 341 struct alias_prop *app; 342 struct property *p; 343 int seen = 0; 344 345 if ((!dev) || (!dev->of_node)) 346 return; 347 348 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node); 349 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node); 350 type = of_node_get_device_type(dev->of_node); 351 if (type) 352 add_uevent_var(env, "OF_TYPE=%s", type); 353 354 /* Since the compatible field can contain pretty much anything 355 * it's not really legal to split it out with commas. We split it 356 * up using a number of environment variables instead. */ 357 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 358 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 359 seen++; 360 } 361 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 362 363 seen = 0; 364 mutex_lock(&of_mutex); 365 list_for_each_entry(app, &aliases_lookup, link) { 366 if (dev->of_node == app->np) { 367 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 368 app->alias); 369 seen++; 370 } 371 } 372 mutex_unlock(&of_mutex); 373 } 374 375 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) 376 { 377 int sl; 378 379 if ((!dev) || (!dev->of_node)) 380 return -ENODEV; 381 382 /* Devicetree modalias is tricky, we add it in 2 steps */ 383 if (add_uevent_var(env, "MODALIAS=")) 384 return -ENOMEM; 385 386 sl = of_device_get_modalias(dev, &env->buf[env->buflen-1], 387 sizeof(env->buf) - env->buflen); 388 if (sl >= (sizeof(env->buf) - env->buflen)) 389 return -ENOMEM; 390 env->buflen += sl; 391 392 return 0; 393 } 394 EXPORT_SYMBOL_GPL(of_device_uevent_modalias); 395