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 static void 36 of_dma_set_restricted_buffer(struct device *dev, struct device_node *np) 37 { 38 struct device_node *node, *of_node = dev->of_node; 39 int count, i; 40 41 if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL)) 42 return; 43 44 count = of_property_count_elems_of_size(of_node, "memory-region", 45 sizeof(u32)); 46 /* 47 * If dev->of_node doesn't exist or doesn't contain memory-region, try 48 * the OF node having DMA configuration. 49 */ 50 if (count <= 0) { 51 of_node = np; 52 count = of_property_count_elems_of_size( 53 of_node, "memory-region", sizeof(u32)); 54 } 55 56 for (i = 0; i < count; i++) { 57 node = of_parse_phandle(of_node, "memory-region", i); 58 /* 59 * There might be multiple memory regions, but only one 60 * restricted-dma-pool region is allowed. 61 */ 62 if (of_device_is_compatible(node, "restricted-dma-pool") && 63 of_device_is_available(node)) { 64 of_node_put(node); 65 break; 66 } 67 of_node_put(node); 68 } 69 70 /* 71 * Attempt to initialize a restricted-dma-pool region if one was found. 72 * Note that count can hold a negative error code. 73 */ 74 if (i < count && of_reserved_mem_device_init_by_idx(dev, of_node, i)) 75 dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n"); 76 } 77 78 /** 79 * of_dma_configure_id - Setup DMA configuration 80 * @dev: Device to apply DMA configuration 81 * @np: Pointer to OF node having DMA configuration 82 * @force_dma: Whether device is to be set up by of_dma_configure() even if 83 * DMA capability is not explicitly described by firmware. 84 * @id: Optional const pointer value input id 85 * 86 * Try to get devices's DMA configuration from DT and update it 87 * accordingly. 88 * 89 * If platform code needs to use its own special DMA configuration, it 90 * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events 91 * to fix up DMA configuration. 92 */ 93 int of_dma_configure_id(struct device *dev, struct device_node *np, 94 bool force_dma, const u32 *id) 95 { 96 const struct bus_dma_region *map = NULL; 97 struct device_node *bus_np; 98 u64 mask, end = 0; 99 bool coherent; 100 int iommu_ret; 101 int ret; 102 103 if (np == dev->of_node) 104 bus_np = __of_get_dma_parent(np); 105 else 106 bus_np = of_node_get(np); 107 108 ret = of_dma_get_range(bus_np, &map); 109 of_node_put(bus_np); 110 if (ret < 0) { 111 /* 112 * For legacy reasons, we have to assume some devices need 113 * DMA configuration regardless of whether "dma-ranges" is 114 * correctly specified or not. 115 */ 116 if (!force_dma) 117 return ret == -ENODEV ? 0 : ret; 118 } else { 119 /* Determine the overall bounds of all DMA regions */ 120 end = dma_range_map_max(map); 121 } 122 123 /* 124 * If @dev is expected to be DMA-capable then the bus code that created 125 * it should have initialised its dma_mask pointer by this point. For 126 * now, we'll continue the legacy behaviour of coercing it to the 127 * coherent mask if not, but we'll no longer do so quietly. 128 */ 129 if (!dev->dma_mask) { 130 dev_warn(dev, "DMA mask not set\n"); 131 dev->dma_mask = &dev->coherent_dma_mask; 132 } 133 134 if (!end && dev->coherent_dma_mask) 135 end = dev->coherent_dma_mask; 136 else if (!end) 137 end = (1ULL << 32) - 1; 138 139 /* 140 * Limit coherent and dma mask based on size and default mask 141 * set by the driver. 142 */ 143 mask = DMA_BIT_MASK(ilog2(end) + 1); 144 dev->coherent_dma_mask &= mask; 145 *dev->dma_mask &= mask; 146 /* ...but only set bus limit and range map if we found valid dma-ranges earlier */ 147 if (!ret) { 148 dev->bus_dma_limit = end; 149 dev->dma_range_map = map; 150 } 151 152 coherent = of_dma_is_coherent(np); 153 dev_dbg(dev, "device is%sdma coherent\n", 154 coherent ? " " : " not "); 155 156 iommu_ret = of_iommu_configure(dev, np, id); 157 if (iommu_ret == -EPROBE_DEFER) { 158 /* Don't touch range map if it wasn't set from a valid dma-ranges */ 159 if (!ret) 160 dev->dma_range_map = NULL; 161 kfree(map); 162 return -EPROBE_DEFER; 163 } else if (iommu_ret == -ENODEV) { 164 dev_dbg(dev, "device is not behind an iommu\n"); 165 } else if (iommu_ret) { 166 dev_err(dev, "iommu configuration for device failed with %pe\n", 167 ERR_PTR(iommu_ret)); 168 169 /* 170 * Historically this routine doesn't fail driver probing 171 * due to errors in of_iommu_configure() 172 */ 173 } else 174 dev_dbg(dev, "device is behind an iommu\n"); 175 176 arch_setup_dma_ops(dev, coherent); 177 178 if (iommu_ret) 179 of_dma_set_restricted_buffer(dev, np); 180 181 return 0; 182 } 183 EXPORT_SYMBOL_GPL(of_dma_configure_id); 184 185 const void *of_device_get_match_data(const struct device *dev) 186 { 187 const struct of_device_id *match; 188 189 match = of_match_device(dev->driver->of_match_table, dev); 190 if (!match) 191 return NULL; 192 193 return match->data; 194 } 195 EXPORT_SYMBOL(of_device_get_match_data); 196 197 /** 198 * of_device_modalias - Fill buffer with newline terminated modalias string 199 * @dev: Calling device 200 * @str: Modalias string 201 * @len: Size of @str 202 */ 203 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) 204 { 205 ssize_t sl; 206 207 if (!dev || !dev->of_node || dev->of_node_reused) 208 return -ENODEV; 209 210 sl = of_modalias(dev->of_node, str, len - 2); 211 if (sl < 0) 212 return sl; 213 if (sl > len - 2) 214 return -ENOMEM; 215 216 str[sl++] = '\n'; 217 str[sl] = 0; 218 return sl; 219 } 220 EXPORT_SYMBOL_GPL(of_device_modalias); 221 222 /** 223 * of_device_uevent - Display OF related uevent information 224 * @dev: Device to display the uevent information for 225 * @env: Kernel object's userspace event reference to fill up 226 */ 227 void of_device_uevent(const struct device *dev, struct kobj_uevent_env *env) 228 { 229 const char *compat, *type; 230 struct alias_prop *app; 231 struct property *p; 232 int seen = 0; 233 234 if ((!dev) || (!dev->of_node)) 235 return; 236 237 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node); 238 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node); 239 type = of_node_get_device_type(dev->of_node); 240 if (type) 241 add_uevent_var(env, "OF_TYPE=%s", type); 242 243 /* Since the compatible field can contain pretty much anything 244 * it's not really legal to split it out with commas. We split it 245 * up using a number of environment variables instead. */ 246 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 247 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 248 seen++; 249 } 250 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 251 252 seen = 0; 253 mutex_lock(&of_mutex); 254 list_for_each_entry(app, &aliases_lookup, link) { 255 if (dev->of_node == app->np) { 256 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 257 app->alias); 258 seen++; 259 } 260 } 261 mutex_unlock(&of_mutex); 262 } 263 EXPORT_SYMBOL_GPL(of_device_uevent); 264 265 int of_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env) 266 { 267 int sl; 268 269 if ((!dev) || (!dev->of_node) || dev->of_node_reused) 270 return -ENODEV; 271 272 /* Devicetree modalias is tricky, we add it in 2 steps */ 273 if (add_uevent_var(env, "MODALIAS=")) 274 return -ENOMEM; 275 276 sl = of_modalias(dev->of_node, &env->buf[env->buflen-1], 277 sizeof(env->buf) - env->buflen); 278 if (sl < 0) 279 return sl; 280 if (sl >= (sizeof(env->buf) - env->buflen)) 281 return -ENOMEM; 282 env->buflen += sl; 283 284 return 0; 285 } 286 EXPORT_SYMBOL_GPL(of_device_uevent_modalias); 287 288 /** 289 * of_device_make_bus_id - Use the device node data to assign a unique name 290 * @dev: pointer to device structure that is linked to a device tree node 291 * 292 * This routine will first try using the translated bus address to 293 * derive a unique name. If it cannot, then it will prepend names from 294 * parent nodes until a unique name can be derived. 295 */ 296 void of_device_make_bus_id(struct device *dev) 297 { 298 struct device_node *node = dev->of_node; 299 const __be32 *reg; 300 u64 addr; 301 u32 mask; 302 303 /* Construct the name, using parent nodes if necessary to ensure uniqueness */ 304 while (node->parent) { 305 /* 306 * If the address can be translated, then that is as much 307 * uniqueness as we need. Make it the first component and return 308 */ 309 reg = of_get_property(node, "reg", NULL); 310 if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) { 311 if (!of_property_read_u32(node, "mask", &mask)) 312 dev_set_name(dev, dev_name(dev) ? "%llx.%x.%pOFn:%s" : "%llx.%x.%pOFn", 313 addr, ffs(mask) - 1, node, dev_name(dev)); 314 315 else 316 dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn", 317 addr, node, dev_name(dev)); 318 return; 319 } 320 321 /* format arguments only used if dev_name() resolves to NULL */ 322 dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s", 323 kbasename(node->full_name), dev_name(dev)); 324 node = node->parent; 325 } 326 } 327 EXPORT_SYMBOL_GPL(of_device_make_bus_id); 328