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 *of_node = dev->of_node; 39 struct of_phandle_iterator it; 40 int rc, i = 0; 41 42 if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL)) 43 return; 44 45 /* 46 * If dev->of_node doesn't exist or doesn't contain memory-region, try 47 * the OF node having DMA configuration. 48 */ 49 if (!of_property_present(of_node, "memory-region")) 50 of_node = np; 51 52 of_for_each_phandle(&it, rc, of_node, "memory-region", NULL, 0) { 53 /* 54 * There might be multiple memory regions, but only one 55 * restricted-dma-pool region is allowed. 56 */ 57 if (of_device_is_compatible(it.node, "restricted-dma-pool") && 58 of_device_is_available(it.node)) { 59 if (of_reserved_mem_device_init_by_idx(dev, of_node, i)) 60 dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n"); 61 of_node_put(it.node); 62 break; 63 } 64 i++; 65 } 66 67 } 68 69 /** 70 * of_dma_configure_id - Setup DMA configuration 71 * @dev: Device to apply DMA configuration 72 * @np: Pointer to OF node having DMA configuration 73 * @force_dma: Whether device is to be set up by of_dma_configure() even if 74 * DMA capability is not explicitly described by firmware. 75 * @id: Optional const pointer value input id 76 * 77 * Try to get devices's DMA configuration from DT and update it 78 * accordingly. 79 * 80 * If platform code needs to use its own special DMA configuration, it 81 * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events 82 * to fix up DMA configuration. 83 */ 84 int of_dma_configure_id(struct device *dev, struct device_node *np, 85 bool force_dma, const u32 *id) 86 { 87 const struct bus_dma_region *map = NULL; 88 struct device_node *bus_np; 89 u64 mask, end = 0; 90 bool coherent, set_map = false; 91 int ret; 92 93 if (dev->dma_range_map) { 94 dev_dbg(dev, "dma_range_map already set\n"); 95 goto skip_map; 96 } 97 98 if (np == dev->of_node) 99 bus_np = __of_get_dma_parent(np); 100 else 101 bus_np = of_node_get(np); 102 103 ret = of_dma_get_range(bus_np, &map); 104 of_node_put(bus_np); 105 if (ret < 0) { 106 /* 107 * For legacy reasons, we have to assume some devices need 108 * DMA configuration regardless of whether "dma-ranges" is 109 * correctly specified or not. 110 */ 111 if (!force_dma) 112 return ret == -ENODEV ? 0 : ret; 113 } else { 114 /* Determine the overall bounds of all DMA regions */ 115 end = dma_range_map_max(map); 116 set_map = true; 117 } 118 skip_map: 119 /* 120 * If @dev is expected to be DMA-capable then the bus code that created 121 * it should have initialised its dma_mask pointer by this point. For 122 * now, we'll continue the legacy behaviour of coercing it to the 123 * coherent mask if not, but we'll no longer do so quietly. 124 */ 125 if (!dev->dma_mask) { 126 dev_warn(dev, "DMA mask not set\n"); 127 dev->dma_mask = &dev->coherent_dma_mask; 128 } 129 130 if (!end && dev->coherent_dma_mask) 131 end = dev->coherent_dma_mask; 132 else if (!end) 133 end = (1ULL << 32) - 1; 134 135 /* 136 * Limit coherent and dma mask based on size and default mask 137 * set by the driver. 138 */ 139 mask = DMA_BIT_MASK(ilog2(end) + 1); 140 dev->coherent_dma_mask &= mask; 141 *dev->dma_mask &= mask; 142 /* ...but only set bus limit and range map if we found valid dma-ranges earlier */ 143 if (set_map) { 144 dev->bus_dma_limit = end; 145 dev->dma_range_map = map; 146 } 147 148 coherent = of_dma_is_coherent(np); 149 dev_dbg(dev, "device is%sdma coherent\n", 150 coherent ? " " : " not "); 151 152 ret = of_iommu_configure(dev, np, id); 153 if (ret == -EPROBE_DEFER) { 154 /* Don't touch range map if it wasn't set from a valid dma-ranges */ 155 if (set_map) 156 dev->dma_range_map = NULL; 157 kfree(map); 158 return -EPROBE_DEFER; 159 } 160 /* Take all other IOMMU errors to mean we'll just carry on without it */ 161 dev_dbg(dev, "device is%sbehind an iommu\n", 162 !ret ? " " : " not "); 163 164 arch_setup_dma_ops(dev, coherent); 165 166 if (ret) 167 of_dma_set_restricted_buffer(dev, np); 168 169 return 0; 170 } 171 EXPORT_SYMBOL_GPL(of_dma_configure_id); 172 173 const void *of_device_get_match_data(const struct device *dev) 174 { 175 const struct of_device_id *match; 176 177 match = of_match_device(dev->driver->of_match_table, dev); 178 if (!match) 179 return NULL; 180 181 return match->data; 182 } 183 EXPORT_SYMBOL(of_device_get_match_data); 184 185 /** 186 * of_device_modalias - Fill buffer with newline terminated modalias string 187 * @dev: Calling device 188 * @str: Modalias string 189 * @len: Size of @str 190 */ 191 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) 192 { 193 ssize_t sl; 194 195 if (!dev || !dev->of_node || dev->of_node_reused) 196 return -ENODEV; 197 198 sl = of_modalias(dev->of_node, str, len - 2); 199 if (sl < 0) 200 return sl; 201 if (sl > len - 2) 202 return -ENOMEM; 203 204 str[sl++] = '\n'; 205 str[sl] = 0; 206 return sl; 207 } 208 EXPORT_SYMBOL_GPL(of_device_modalias); 209 210 /** 211 * of_device_uevent - Display OF related uevent information 212 * @dev: Device to display the uevent information for 213 * @env: Kernel object's userspace event reference to fill up 214 */ 215 void of_device_uevent(const struct device *dev, struct kobj_uevent_env *env) 216 { 217 const char *compat, *type; 218 struct alias_prop *app; 219 struct property *p; 220 int seen = 0; 221 222 if ((!dev) || (!dev->of_node)) 223 return; 224 225 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node); 226 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node); 227 type = of_node_get_device_type(dev->of_node); 228 if (type) 229 add_uevent_var(env, "OF_TYPE=%s", type); 230 231 /* Since the compatible field can contain pretty much anything 232 * it's not really legal to split it out with commas. We split it 233 * up using a number of environment variables instead. */ 234 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 235 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 236 seen++; 237 } 238 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 239 240 seen = 0; 241 mutex_lock(&of_mutex); 242 list_for_each_entry(app, &aliases_lookup, link) { 243 if (dev->of_node == app->np) { 244 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 245 app->alias); 246 seen++; 247 } 248 } 249 mutex_unlock(&of_mutex); 250 } 251 EXPORT_SYMBOL_GPL(of_device_uevent); 252 253 int of_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env) 254 { 255 int sl; 256 257 if ((!dev) || (!dev->of_node) || dev->of_node_reused) 258 return -ENODEV; 259 260 /* Devicetree modalias is tricky, we add it in 2 steps */ 261 if (add_uevent_var(env, "MODALIAS=")) 262 return -ENOMEM; 263 264 sl = of_modalias(dev->of_node, &env->buf[env->buflen-1], 265 sizeof(env->buf) - env->buflen); 266 if (sl < 0) 267 return sl; 268 if (sl >= (sizeof(env->buf) - env->buflen)) 269 return -ENOMEM; 270 env->buflen += sl; 271 272 return 0; 273 } 274 EXPORT_SYMBOL_GPL(of_device_uevent_modalias); 275 276 /** 277 * of_device_make_bus_id - Use the device node data to assign a unique name 278 * @dev: pointer to device structure that is linked to a device tree node 279 * 280 * This routine will first try using the translated bus address to 281 * derive a unique name. If it cannot, then it will prepend names from 282 * parent nodes until a unique name can be derived. 283 */ 284 void of_device_make_bus_id(struct device *dev) 285 { 286 struct device_node *node = dev->of_node; 287 const __be32 *reg; 288 u64 addr; 289 u32 mask; 290 291 /* Construct the name, using parent nodes if necessary to ensure uniqueness */ 292 while (node->parent) { 293 /* 294 * If the address can be translated, then that is as much 295 * uniqueness as we need. Make it the first component and return 296 */ 297 reg = of_get_property(node, "reg", NULL); 298 if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) { 299 if (!of_property_read_u32(node, "mask", &mask)) 300 dev_set_name(dev, dev_name(dev) ? "%llx.%x.%pOFn:%s" : "%llx.%x.%pOFn", 301 addr, ffs(mask) - 1, node, dev_name(dev)); 302 303 else 304 dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn", 305 addr, node, dev_name(dev)); 306 return; 307 } 308 309 /* format arguments only used if dev_name() resolves to NULL */ 310 dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s", 311 kbasename(node->full_name), dev_name(dev)); 312 node = node->parent; 313 } 314 } 315 EXPORT_SYMBOL_GPL(of_device_make_bus_id); 316