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 u64 dma_start = 0; 120 u64 mask, end, size = 0; 121 bool coherent; 122 int ret; 123 124 ret = of_dma_get_range(np, &map); 125 if (ret < 0) { 126 /* 127 * For legacy reasons, we have to assume some devices need 128 * DMA configuration regardless of whether "dma-ranges" is 129 * correctly specified or not. 130 */ 131 if (!force_dma) 132 return ret == -ENODEV ? 0 : ret; 133 } else { 134 const struct bus_dma_region *r = map; 135 u64 dma_end = 0; 136 137 /* Determine the overall bounds of all DMA regions */ 138 for (dma_start = ~0; r->size; r++) { 139 /* Take lower and upper limits */ 140 if (r->dma_start < dma_start) 141 dma_start = r->dma_start; 142 if (r->dma_start + r->size > dma_end) 143 dma_end = r->dma_start + r->size; 144 } 145 size = dma_end - dma_start; 146 147 /* 148 * Add a work around to treat the size as mask + 1 in case 149 * it is defined in DT as a mask. 150 */ 151 if (size & 1) { 152 dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n", 153 size); 154 size = size + 1; 155 } 156 157 if (!size) { 158 dev_err(dev, "Adjusted size 0x%llx invalid\n", size); 159 kfree(map); 160 return -EINVAL; 161 } 162 } 163 164 /* 165 * If @dev is expected to be DMA-capable then the bus code that created 166 * it should have initialised its dma_mask pointer by this point. For 167 * now, we'll continue the legacy behaviour of coercing it to the 168 * coherent mask if not, but we'll no longer do so quietly. 169 */ 170 if (!dev->dma_mask) { 171 dev_warn(dev, "DMA mask not set\n"); 172 dev->dma_mask = &dev->coherent_dma_mask; 173 } 174 175 if (!size && dev->coherent_dma_mask) 176 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); 177 else if (!size) 178 size = 1ULL << 32; 179 180 /* 181 * Limit coherent and dma mask based on size and default mask 182 * set by the driver. 183 */ 184 end = dma_start + size - 1; 185 mask = DMA_BIT_MASK(ilog2(end) + 1); 186 dev->coherent_dma_mask &= mask; 187 *dev->dma_mask &= mask; 188 /* ...but only set bus limit and range map if we found valid dma-ranges earlier */ 189 if (!ret) { 190 dev->bus_dma_limit = end; 191 dev->dma_range_map = map; 192 } 193 194 coherent = of_dma_is_coherent(np); 195 dev_dbg(dev, "device is%sdma coherent\n", 196 coherent ? " " : " not "); 197 198 iommu = of_iommu_configure(dev, np, id); 199 if (PTR_ERR(iommu) == -EPROBE_DEFER) { 200 /* Don't touch range map if it wasn't set from a valid dma-ranges */ 201 if (!ret) 202 dev->dma_range_map = NULL; 203 kfree(map); 204 return -EPROBE_DEFER; 205 } 206 207 dev_dbg(dev, "device is%sbehind an iommu\n", 208 iommu ? " " : " not "); 209 210 arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); 211 212 if (!iommu) 213 of_dma_set_restricted_buffer(dev, np); 214 215 return 0; 216 } 217 EXPORT_SYMBOL_GPL(of_dma_configure_id); 218 219 int of_device_register(struct platform_device *pdev) 220 { 221 device_initialize(&pdev->dev); 222 return of_device_add(pdev); 223 } 224 EXPORT_SYMBOL(of_device_register); 225 226 void of_device_unregister(struct platform_device *ofdev) 227 { 228 device_unregister(&ofdev->dev); 229 } 230 EXPORT_SYMBOL(of_device_unregister); 231 232 const void *of_device_get_match_data(const struct device *dev) 233 { 234 const struct of_device_id *match; 235 236 match = of_match_device(dev->driver->of_match_table, dev); 237 if (!match) 238 return NULL; 239 240 return match->data; 241 } 242 EXPORT_SYMBOL(of_device_get_match_data); 243 244 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) 245 { 246 const char *compat; 247 char *c; 248 struct property *p; 249 ssize_t csize; 250 ssize_t tsize; 251 252 if ((!dev) || (!dev->of_node)) 253 return -ENODEV; 254 255 /* Name & Type */ 256 /* %p eats all alphanum characters, so %c must be used here */ 257 csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T', 258 of_node_get_device_type(dev->of_node)); 259 tsize = csize; 260 len -= csize; 261 if (str) 262 str += csize; 263 264 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 265 csize = strlen(compat) + 1; 266 tsize += csize; 267 if (csize > len) 268 continue; 269 270 csize = snprintf(str, len, "C%s", compat); 271 for (c = str; c; ) { 272 c = strchr(c, ' '); 273 if (c) 274 *c++ = '_'; 275 } 276 len -= csize; 277 str += csize; 278 } 279 280 return tsize; 281 } 282 283 int of_device_request_module(struct device *dev) 284 { 285 char *str; 286 ssize_t size; 287 int ret; 288 289 size = of_device_get_modalias(dev, NULL, 0); 290 if (size < 0) 291 return size; 292 293 str = kmalloc(size + 1, GFP_KERNEL); 294 if (!str) 295 return -ENOMEM; 296 297 of_device_get_modalias(dev, str, size); 298 str[size] = '\0'; 299 ret = request_module(str); 300 kfree(str); 301 302 return ret; 303 } 304 EXPORT_SYMBOL_GPL(of_device_request_module); 305 306 /** 307 * of_device_modalias - Fill buffer with newline terminated modalias string 308 * @dev: Calling device 309 * @str: Modalias string 310 * @len: Size of @str 311 */ 312 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) 313 { 314 ssize_t sl = of_device_get_modalias(dev, str, len - 2); 315 if (sl < 0) 316 return sl; 317 if (sl > len - 2) 318 return -ENOMEM; 319 320 str[sl++] = '\n'; 321 str[sl] = 0; 322 return sl; 323 } 324 EXPORT_SYMBOL_GPL(of_device_modalias); 325 326 /** 327 * of_device_uevent - Display OF related uevent information 328 * @dev: Device to apply DMA configuration 329 * @env: Kernel object's userspace event reference 330 */ 331 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env) 332 { 333 const char *compat, *type; 334 struct alias_prop *app; 335 struct property *p; 336 int seen = 0; 337 338 if ((!dev) || (!dev->of_node)) 339 return; 340 341 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node); 342 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node); 343 type = of_node_get_device_type(dev->of_node); 344 if (type) 345 add_uevent_var(env, "OF_TYPE=%s", type); 346 347 /* Since the compatible field can contain pretty much anything 348 * it's not really legal to split it out with commas. We split it 349 * up using a number of environment variables instead. */ 350 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 351 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 352 seen++; 353 } 354 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 355 356 seen = 0; 357 mutex_lock(&of_mutex); 358 list_for_each_entry(app, &aliases_lookup, link) { 359 if (dev->of_node == app->np) { 360 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 361 app->alias); 362 seen++; 363 } 364 } 365 mutex_unlock(&of_mutex); 366 } 367 368 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) 369 { 370 int sl; 371 372 if ((!dev) || (!dev->of_node)) 373 return -ENODEV; 374 375 /* Devicetree modalias is tricky, we add it in 2 steps */ 376 if (add_uevent_var(env, "MODALIAS=")) 377 return -ENOMEM; 378 379 sl = of_device_get_modalias(dev, &env->buf[env->buflen-1], 380 sizeof(env->buf) - env->buflen); 381 if (sl >= (sizeof(env->buf) - env->buflen)) 382 return -ENOMEM; 383 env->buflen += sl; 384 385 return 0; 386 } 387 EXPORT_SYMBOL_GPL(of_device_uevent_modalias); 388