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 */ 26const 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} 33EXPORT_SYMBOL(of_match_device); 34 35static void 36of_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 */ 93int of_dma_configure_id(struct device *dev, struct device_node *np, 94 bool force_dma, const u32 *id) 95{ 96 const struct iommu_ops *iommu; 97 const struct bus_dma_region *map = NULL; 98 struct device_node *bus_np; 99 u64 dma_start = 0; 100 u64 mask, end, size = 0; 101 bool coherent; 102 int ret; 103 104 if (np == dev->of_node) 105 bus_np = __of_get_dma_parent(np); 106 else 107 bus_np = of_node_get(np); 108 109 ret = of_dma_get_range(bus_np, &map); 110 of_node_put(bus_np); 111 if (ret < 0) { 112 /* 113 * For legacy reasons, we have to assume some devices need 114 * DMA configuration regardless of whether "dma-ranges" is 115 * correctly specified or not. 116 */ 117 if (!force_dma) 118 return ret == -ENODEV ? 0 : ret; 119 } else { 120 const struct bus_dma_region *r = map; 121 u64 dma_end = 0; 122 123 /* Determine the overall bounds of all DMA regions */ 124 for (dma_start = ~0; r->size; r++) { 125 /* Take lower and upper limits */ 126 if (r->dma_start < dma_start) 127 dma_start = r->dma_start; 128 if (r->dma_start + r->size > dma_end) 129 dma_end = r->dma_start + r->size; 130 } 131 size = dma_end - dma_start; 132 133 /* 134 * Add a work around to treat the size as mask + 1 in case 135 * it is defined in DT as a mask. 136 */ 137 if (size & 1) { 138 dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n", 139 size); 140 size = size + 1; 141 } 142 143 if (!size) { 144 dev_err(dev, "Adjusted size 0x%llx invalid\n", size); 145 kfree(map); 146 return -EINVAL; 147 } 148 } 149 150 /* 151 * If @dev is expected to be DMA-capable then the bus code that created 152 * it should have initialised its dma_mask pointer by this point. For 153 * now, we'll continue the legacy behaviour of coercing it to the 154 * coherent mask if not, but we'll no longer do so quietly. 155 */ 156 if (!dev->dma_mask) { 157 dev_warn(dev, "DMA mask not set\n"); 158 dev->dma_mask = &dev->coherent_dma_mask; 159 } 160 161 if (!size && dev->coherent_dma_mask) 162 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); 163 else if (!size) 164 size = 1ULL << 32; 165 166 /* 167 * Limit coherent and dma mask based on size and default mask 168 * set by the driver. 169 */ 170 end = dma_start + size - 1; 171 mask = DMA_BIT_MASK(ilog2(end) + 1); 172 dev->coherent_dma_mask &= mask; 173 *dev->dma_mask &= mask; 174 /* ...but only set bus limit and range map if we found valid dma-ranges earlier */ 175 if (!ret) { 176 dev->bus_dma_limit = end; 177 dev->dma_range_map = map; 178 } 179 180 coherent = of_dma_is_coherent(np); 181 dev_dbg(dev, "device is%sdma coherent\n", 182 coherent ? " " : " not "); 183 184 iommu = of_iommu_configure(dev, np, id); 185 if (PTR_ERR(iommu) == -EPROBE_DEFER) { 186 /* Don't touch range map if it wasn't set from a valid dma-ranges */ 187 if (!ret) 188 dev->dma_range_map = NULL; 189 kfree(map); 190 return -EPROBE_DEFER; 191 } 192 193 dev_dbg(dev, "device is%sbehind an iommu\n", 194 iommu ? " " : " not "); 195 196 arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); 197 198 if (!iommu) 199 of_dma_set_restricted_buffer(dev, np); 200 201 return 0; 202} 203EXPORT_SYMBOL_GPL(of_dma_configure_id); 204 205const void *of_device_get_match_data(const struct device *dev) 206{ 207 const struct of_device_id *match; 208 209 match = of_match_device(dev->driver->of_match_table, dev); 210 if (!match) 211 return NULL; 212 213 return match->data; 214} 215EXPORT_SYMBOL(of_device_get_match_data); 216 217/** 218 * of_device_modalias - Fill buffer with newline terminated modalias string 219 * @dev: Calling device 220 * @str: Modalias string 221 * @len: Size of @str 222 */ 223ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) 224{ 225 ssize_t sl; 226 227 if (!dev || !dev->of_node || dev->of_node_reused) 228 return -ENODEV; 229 230 sl = of_modalias(dev->of_node, str, len - 2); 231 if (sl < 0) 232 return sl; 233 if (sl > len - 2) 234 return -ENOMEM; 235 236 str[sl++] = '\n'; 237 str[sl] = 0; 238 return sl; 239} 240EXPORT_SYMBOL_GPL(of_device_modalias); 241 242/** 243 * of_device_uevent - Display OF related uevent information 244 * @dev: Device to display the uevent information for 245 * @env: Kernel object's userspace event reference to fill up 246 */ 247void of_device_uevent(const struct device *dev, struct kobj_uevent_env *env) 248{ 249 const char *compat, *type; 250 struct alias_prop *app; 251 struct property *p; 252 int seen = 0; 253 254 if ((!dev) || (!dev->of_node)) 255 return; 256 257 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node); 258 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node); 259 type = of_node_get_device_type(dev->of_node); 260 if (type) 261 add_uevent_var(env, "OF_TYPE=%s", type); 262 263 /* Since the compatible field can contain pretty much anything 264 * it's not really legal to split it out with commas. We split it 265 * up using a number of environment variables instead. */ 266 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 267 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 268 seen++; 269 } 270 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 271 272 seen = 0; 273 mutex_lock(&of_mutex); 274 list_for_each_entry(app, &aliases_lookup, link) { 275 if (dev->of_node == app->np) { 276 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 277 app->alias); 278 seen++; 279 } 280 } 281 mutex_unlock(&of_mutex); 282} 283EXPORT_SYMBOL_GPL(of_device_uevent); 284 285int of_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env) 286{ 287 int sl; 288 289 if ((!dev) || (!dev->of_node) || dev->of_node_reused) 290 return -ENODEV; 291 292 /* Devicetree modalias is tricky, we add it in 2 steps */ 293 if (add_uevent_var(env, "MODALIAS=")) 294 return -ENOMEM; 295 296 sl = of_modalias(dev->of_node, &env->buf[env->buflen-1], 297 sizeof(env->buf) - env->buflen); 298 if (sl < 0) 299 return sl; 300 if (sl >= (sizeof(env->buf) - env->buflen)) 301 return -ENOMEM; 302 env->buflen += sl; 303 304 return 0; 305} 306EXPORT_SYMBOL_GPL(of_device_uevent_modalias); 307