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, set_map = false; 100 int ret; 101 102 if (np == dev->of_node) 103 bus_np = __of_get_dma_parent(np); 104 else 105 bus_np = of_node_get(np); 106 107 ret = of_dma_get_range(bus_np, &map); 108 of_node_put(bus_np); 109 if (ret < 0) { 110 /* 111 * For legacy reasons, we have to assume some devices need 112 * DMA configuration regardless of whether "dma-ranges" is 113 * correctly specified or not. 114 */ 115 if (!force_dma) 116 return ret == -ENODEV ? 0 : ret; 117 } else { 118 /* Determine the overall bounds of all DMA regions */ 119 end = dma_range_map_max(map); 120 set_map = true; 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 (set_map) { 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 ret = of_iommu_configure(dev, np, id); 157 if (ret == -EPROBE_DEFER) { 158 /* Don't touch range map if it wasn't set from a valid dma-ranges */ 159 if (set_map) 160 dev->dma_range_map = NULL; 161 kfree(map); 162 return -EPROBE_DEFER; 163 } 164 /* Take all other IOMMU errors to mean we'll just carry on without it */ 165 dev_dbg(dev, "device is%sbehind an iommu\n", 166 !ret ? " " : " not "); 167 168 arch_setup_dma_ops(dev, coherent); 169 170 if (ret) 171 of_dma_set_restricted_buffer(dev, np); 172 173 return 0; 174 } 175 EXPORT_SYMBOL_GPL(of_dma_configure_id); 176 177 const void *of_device_get_match_data(const struct device *dev) 178 { 179 const struct of_device_id *match; 180 181 match = of_match_device(dev->driver->of_match_table, dev); 182 if (!match) 183 return NULL; 184 185 return match->data; 186 } 187 EXPORT_SYMBOL(of_device_get_match_data); 188 189 /** 190 * of_device_modalias - Fill buffer with newline terminated modalias string 191 * @dev: Calling device 192 * @str: Modalias string 193 * @len: Size of @str 194 */ 195 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) 196 { 197 ssize_t sl; 198 199 if (!dev || !dev->of_node || dev->of_node_reused) 200 return -ENODEV; 201 202 sl = of_modalias(dev->of_node, str, len - 2); 203 if (sl < 0) 204 return sl; 205 if (sl > len - 2) 206 return -ENOMEM; 207 208 str[sl++] = '\n'; 209 str[sl] = 0; 210 return sl; 211 } 212 EXPORT_SYMBOL_GPL(of_device_modalias); 213 214 /** 215 * of_device_uevent - Display OF related uevent information 216 * @dev: Device to display the uevent information for 217 * @env: Kernel object's userspace event reference to fill up 218 */ 219 void of_device_uevent(const struct device *dev, struct kobj_uevent_env *env) 220 { 221 const char *compat, *type; 222 struct alias_prop *app; 223 struct property *p; 224 int seen = 0; 225 226 if ((!dev) || (!dev->of_node)) 227 return; 228 229 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node); 230 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node); 231 type = of_node_get_device_type(dev->of_node); 232 if (type) 233 add_uevent_var(env, "OF_TYPE=%s", type); 234 235 /* Since the compatible field can contain pretty much anything 236 * it's not really legal to split it out with commas. We split it 237 * up using a number of environment variables instead. */ 238 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 239 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 240 seen++; 241 } 242 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 243 244 seen = 0; 245 mutex_lock(&of_mutex); 246 list_for_each_entry(app, &aliases_lookup, link) { 247 if (dev->of_node == app->np) { 248 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 249 app->alias); 250 seen++; 251 } 252 } 253 mutex_unlock(&of_mutex); 254 } 255 EXPORT_SYMBOL_GPL(of_device_uevent); 256 257 int of_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env) 258 { 259 int sl; 260 261 if ((!dev) || (!dev->of_node) || dev->of_node_reused) 262 return -ENODEV; 263 264 /* Devicetree modalias is tricky, we add it in 2 steps */ 265 if (add_uevent_var(env, "MODALIAS=")) 266 return -ENOMEM; 267 268 sl = of_modalias(dev->of_node, &env->buf[env->buflen-1], 269 sizeof(env->buf) - env->buflen); 270 if (sl < 0) 271 return sl; 272 if (sl >= (sizeof(env->buf) - env->buflen)) 273 return -ENOMEM; 274 env->buflen += sl; 275 276 return 0; 277 } 278 EXPORT_SYMBOL_GPL(of_device_uevent_modalias); 279 280 /** 281 * of_device_make_bus_id - Use the device node data to assign a unique name 282 * @dev: pointer to device structure that is linked to a device tree node 283 * 284 * This routine will first try using the translated bus address to 285 * derive a unique name. If it cannot, then it will prepend names from 286 * parent nodes until a unique name can be derived. 287 */ 288 void of_device_make_bus_id(struct device *dev) 289 { 290 struct device_node *node = dev->of_node; 291 const __be32 *reg; 292 u64 addr; 293 u32 mask; 294 295 /* Construct the name, using parent nodes if necessary to ensure uniqueness */ 296 while (node->parent) { 297 /* 298 * If the address can be translated, then that is as much 299 * uniqueness as we need. Make it the first component and return 300 */ 301 reg = of_get_property(node, "reg", NULL); 302 if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) { 303 if (!of_property_read_u32(node, "mask", &mask)) 304 dev_set_name(dev, dev_name(dev) ? "%llx.%x.%pOFn:%s" : "%llx.%x.%pOFn", 305 addr, ffs(mask) - 1, node, dev_name(dev)); 306 307 else 308 dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn", 309 addr, node, dev_name(dev)); 310 return; 311 } 312 313 /* format arguments only used if dev_name() resolves to NULL */ 314 dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s", 315 kbasename(node->full_name), dev_name(dev)); 316 node = node->parent; 317 } 318 } 319 EXPORT_SYMBOL_GPL(of_device_make_bus_id); 320