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)) 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 break; 86 } 87 88 if (i != count && of_reserved_mem_device_init_by_idx(dev, of_node, i)) 89 dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n"); 90 } 91 92 /** 93 * of_dma_configure_id - Setup DMA configuration 94 * @dev: Device to apply DMA configuration 95 * @np: Pointer to OF node having DMA configuration 96 * @force_dma: Whether device is to be set up by of_dma_configure() even if 97 * DMA capability is not explicitly described by firmware. 98 * @id: Optional const pointer value input id 99 * 100 * Try to get devices's DMA configuration from DT and update it 101 * accordingly. 102 * 103 * If platform code needs to use its own special DMA configuration, it 104 * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events 105 * to fix up DMA configuration. 106 */ 107 int of_dma_configure_id(struct device *dev, struct device_node *np, 108 bool force_dma, const u32 *id) 109 { 110 const struct iommu_ops *iommu; 111 const struct bus_dma_region *map = NULL; 112 u64 dma_start = 0; 113 u64 mask, end, size = 0; 114 bool coherent; 115 int ret; 116 117 ret = of_dma_get_range(np, &map); 118 if (ret < 0) { 119 /* 120 * For legacy reasons, we have to assume some devices need 121 * DMA configuration regardless of whether "dma-ranges" is 122 * correctly specified or not. 123 */ 124 if (!force_dma) 125 return ret == -ENODEV ? 0 : ret; 126 } else { 127 const struct bus_dma_region *r = map; 128 u64 dma_end = 0; 129 130 /* Determine the overall bounds of all DMA regions */ 131 for (dma_start = ~0; r->size; r++) { 132 /* Take lower and upper limits */ 133 if (r->dma_start < dma_start) 134 dma_start = r->dma_start; 135 if (r->dma_start + r->size > dma_end) 136 dma_end = r->dma_start + r->size; 137 } 138 size = dma_end - dma_start; 139 140 /* 141 * Add a work around to treat the size as mask + 1 in case 142 * it is defined in DT as a mask. 143 */ 144 if (size & 1) { 145 dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n", 146 size); 147 size = size + 1; 148 } 149 150 if (!size) { 151 dev_err(dev, "Adjusted size 0x%llx invalid\n", size); 152 kfree(map); 153 return -EINVAL; 154 } 155 } 156 157 /* 158 * If @dev is expected to be DMA-capable then the bus code that created 159 * it should have initialised its dma_mask pointer by this point. For 160 * now, we'll continue the legacy behaviour of coercing it to the 161 * coherent mask if not, but we'll no longer do so quietly. 162 */ 163 if (!dev->dma_mask) { 164 dev_warn(dev, "DMA mask not set\n"); 165 dev->dma_mask = &dev->coherent_dma_mask; 166 } 167 168 if (!size && dev->coherent_dma_mask) 169 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); 170 else if (!size) 171 size = 1ULL << 32; 172 173 /* 174 * Limit coherent and dma mask based on size and default mask 175 * set by the driver. 176 */ 177 end = dma_start + size - 1; 178 mask = DMA_BIT_MASK(ilog2(end) + 1); 179 dev->coherent_dma_mask &= mask; 180 *dev->dma_mask &= mask; 181 /* ...but only set bus limit and range map if we found valid dma-ranges earlier */ 182 if (!ret) { 183 dev->bus_dma_limit = end; 184 dev->dma_range_map = map; 185 } 186 187 coherent = of_dma_is_coherent(np); 188 dev_dbg(dev, "device is%sdma coherent\n", 189 coherent ? " " : " not "); 190 191 iommu = of_iommu_configure(dev, np, id); 192 if (PTR_ERR(iommu) == -EPROBE_DEFER) { 193 /* Don't touch range map if it wasn't set from a valid dma-ranges */ 194 if (!ret) 195 dev->dma_range_map = NULL; 196 kfree(map); 197 return -EPROBE_DEFER; 198 } 199 200 dev_dbg(dev, "device is%sbehind an iommu\n", 201 iommu ? " " : " not "); 202 203 arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); 204 205 if (!iommu) 206 of_dma_set_restricted_buffer(dev, np); 207 208 return 0; 209 } 210 EXPORT_SYMBOL_GPL(of_dma_configure_id); 211 212 int of_device_register(struct platform_device *pdev) 213 { 214 device_initialize(&pdev->dev); 215 return of_device_add(pdev); 216 } 217 EXPORT_SYMBOL(of_device_register); 218 219 void of_device_unregister(struct platform_device *ofdev) 220 { 221 device_unregister(&ofdev->dev); 222 } 223 EXPORT_SYMBOL(of_device_unregister); 224 225 const void *of_device_get_match_data(const struct device *dev) 226 { 227 const struct of_device_id *match; 228 229 match = of_match_device(dev->driver->of_match_table, dev); 230 if (!match) 231 return NULL; 232 233 return match->data; 234 } 235 EXPORT_SYMBOL(of_device_get_match_data); 236 237 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) 238 { 239 const char *compat; 240 char *c; 241 struct property *p; 242 ssize_t csize; 243 ssize_t tsize; 244 245 if ((!dev) || (!dev->of_node)) 246 return -ENODEV; 247 248 /* Name & Type */ 249 /* %p eats all alphanum characters, so %c must be used here */ 250 csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T', 251 of_node_get_device_type(dev->of_node)); 252 tsize = csize; 253 len -= csize; 254 if (str) 255 str += csize; 256 257 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 258 csize = strlen(compat) + 1; 259 tsize += csize; 260 if (csize > len) 261 continue; 262 263 csize = snprintf(str, len, "C%s", compat); 264 for (c = str; c; ) { 265 c = strchr(c, ' '); 266 if (c) 267 *c++ = '_'; 268 } 269 len -= csize; 270 str += csize; 271 } 272 273 return tsize; 274 } 275 276 int of_device_request_module(struct device *dev) 277 { 278 char *str; 279 ssize_t size; 280 int ret; 281 282 size = of_device_get_modalias(dev, NULL, 0); 283 if (size < 0) 284 return size; 285 286 str = kmalloc(size + 1, GFP_KERNEL); 287 if (!str) 288 return -ENOMEM; 289 290 of_device_get_modalias(dev, str, size); 291 str[size] = '\0'; 292 ret = request_module(str); 293 kfree(str); 294 295 return ret; 296 } 297 EXPORT_SYMBOL_GPL(of_device_request_module); 298 299 /** 300 * of_device_modalias - Fill buffer with newline terminated modalias string 301 * @dev: Calling device 302 * @str: Modalias string 303 * @len: Size of @str 304 */ 305 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) 306 { 307 ssize_t sl = of_device_get_modalias(dev, str, len - 2); 308 if (sl < 0) 309 return sl; 310 if (sl > len - 2) 311 return -ENOMEM; 312 313 str[sl++] = '\n'; 314 str[sl] = 0; 315 return sl; 316 } 317 EXPORT_SYMBOL_GPL(of_device_modalias); 318 319 /** 320 * of_device_uevent - Display OF related uevent information 321 * @dev: Device to apply DMA configuration 322 * @env: Kernel object's userspace event reference 323 */ 324 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env) 325 { 326 const char *compat, *type; 327 struct alias_prop *app; 328 struct property *p; 329 int seen = 0; 330 331 if ((!dev) || (!dev->of_node)) 332 return; 333 334 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node); 335 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node); 336 type = of_node_get_device_type(dev->of_node); 337 if (type) 338 add_uevent_var(env, "OF_TYPE=%s", type); 339 340 /* Since the compatible field can contain pretty much anything 341 * it's not really legal to split it out with commas. We split it 342 * up using a number of environment variables instead. */ 343 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 344 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 345 seen++; 346 } 347 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 348 349 seen = 0; 350 mutex_lock(&of_mutex); 351 list_for_each_entry(app, &aliases_lookup, link) { 352 if (dev->of_node == app->np) { 353 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 354 app->alias); 355 seen++; 356 } 357 } 358 mutex_unlock(&of_mutex); 359 } 360 361 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) 362 { 363 int sl; 364 365 if ((!dev) || (!dev->of_node)) 366 return -ENODEV; 367 368 /* Devicetree modalias is tricky, we add it in 2 steps */ 369 if (add_uevent_var(env, "MODALIAS=")) 370 return -ENOMEM; 371 372 sl = of_device_get_modalias(dev, &env->buf[env->buflen-1], 373 sizeof(env->buf) - env->buflen); 374 if (sl >= (sizeof(env->buf) - env->buflen)) 375 return -ENOMEM; 376 env->buflen += sl; 377 378 return 0; 379 } 380 EXPORT_SYMBOL_GPL(of_device_uevent_modalias); 381