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