1 /* SPDX-License-Identifier: BSD-3-Clause 2 * Copyright 2016 NXP 3 */ 4 5 #ifndef _RTE_BUS_H_ 6 #define _RTE_BUS_H_ 7 8 /** 9 * @file 10 * 11 * DPDK device bus interface 12 * 13 * This file exposes API and interfaces for bus abstraction 14 * over the devices and drivers in EAL. 15 */ 16 17 #ifdef __cplusplus 18 extern "C" { 19 #endif 20 21 #include <stdio.h> 22 #include <sys/queue.h> 23 24 #include <rte_log.h> 25 #include <rte_dev.h> 26 27 /** Double linked list of buses */ 28 TAILQ_HEAD(rte_bus_list, rte_bus); 29 30 31 /** 32 * IOVA mapping mode. 33 * 34 * IOVA mapping mode is iommu programming mode of a device. 35 * That device (for example: IOMMU backed DMA device) based 36 * on rte_iova_mode will generate physical or virtual address. 37 * 38 */ 39 enum rte_iova_mode { 40 RTE_IOVA_DC = 0, /* Don't care mode */ 41 RTE_IOVA_PA = (1 << 0), /* DMA using physical address */ 42 RTE_IOVA_VA = (1 << 1) /* DMA using virtual address */ 43 }; 44 45 /** 46 * Bus specific scan for devices attached on the bus. 47 * For each bus object, the scan would be responsible for finding devices and 48 * adding them to its private device list. 49 * 50 * A bus should mandatorily implement this method. 51 * 52 * @return 53 * 0 for successful scan 54 * <0 for unsuccessful scan with error value 55 */ 56 typedef int (*rte_bus_scan_t)(void); 57 58 /** 59 * Implementation specific probe function which is responsible for linking 60 * devices on that bus with applicable drivers. 61 * 62 * This is called while iterating over each registered bus. 63 * 64 * @return 65 * 0 for successful probe 66 * !0 for any error while probing 67 */ 68 typedef int (*rte_bus_probe_t)(void); 69 70 /** 71 * Device iterator to find a device on a bus. 72 * 73 * This function returns an rte_device if one of those held by the bus 74 * matches the data passed as parameter. 75 * 76 * If the comparison function returns zero this function should stop iterating 77 * over any more devices. To continue a search the device of a previous search 78 * can be passed via the start parameter. 79 * 80 * @param cmp 81 * Comparison function. 82 * 83 * @param data 84 * Data to compare each device against. 85 * 86 * @param start 87 * starting point for the iteration 88 * 89 * @return 90 * The first device matching the data, NULL if none exists. 91 */ 92 typedef struct rte_device * 93 (*rte_bus_find_device_t)(const struct rte_device *start, rte_dev_cmp_t cmp, 94 const void *data); 95 96 /** 97 * Implementation specific probe function which is responsible for linking 98 * devices on that bus with applicable drivers. 99 * 100 * @param dev 101 * Device pointer that was returned by a previous call to find_device. 102 * 103 * @return 104 * 0 on success. 105 * !0 on error. 106 */ 107 typedef int (*rte_bus_plug_t)(struct rte_device *dev); 108 109 /** 110 * Implementation specific remove function which is responsible for unlinking 111 * devices on that bus from assigned driver. 112 * 113 * @param dev 114 * Device pointer that was returned by a previous call to find_device. 115 * 116 * @return 117 * 0 on success. 118 * !0 on error. 119 */ 120 typedef int (*rte_bus_unplug_t)(struct rte_device *dev); 121 122 /** 123 * Bus specific parsing function. 124 * Validates the syntax used in the textual representation of a device, 125 * If the syntax is valid and ``addr`` is not NULL, writes the bus-specific 126 * device representation to ``addr``. 127 * 128 * @param[in] name 129 * device textual description 130 * 131 * @param[out] addr 132 * device information location address, into which parsed info 133 * should be written. If NULL, nothing should be written, which 134 * is not an error. 135 * 136 * @return 137 * 0 if parsing was successful. 138 * !0 for any error. 139 */ 140 typedef int (*rte_bus_parse_t)(const char *name, void *addr); 141 142 /** 143 * Device level DMA map function. 144 * After a successful call, the memory segment will be mapped to the 145 * given device. 146 * 147 * @param dev 148 * Device pointer. 149 * @param addr 150 * Virtual address to map. 151 * @param iova 152 * IOVA address to map. 153 * @param len 154 * Length of the memory segment being mapped. 155 * 156 * @return 157 * 0 if mapping was successful. 158 * Negative value and rte_errno is set otherwise. 159 */ 160 typedef int (*rte_dev_dma_map_t)(struct rte_device *dev, void *addr, 161 uint64_t iova, size_t len); 162 163 /** 164 * Device level DMA unmap function. 165 * After a successful call, the memory segment will no longer be 166 * accessible by the given device. 167 * 168 * @param dev 169 * Device pointer. 170 * @param addr 171 * Virtual address to unmap. 172 * @param iova 173 * IOVA address to unmap. 174 * @param len 175 * Length of the memory segment being mapped. 176 * 177 * @return 178 * 0 if un-mapping was successful. 179 * Negative value and rte_errno is set otherwise. 180 */ 181 typedef int (*rte_dev_dma_unmap_t)(struct rte_device *dev, void *addr, 182 uint64_t iova, size_t len); 183 184 /** 185 * Implement a specific hot-unplug handler, which is responsible for 186 * handle the failure when device be hot-unplugged. When the event of 187 * hot-unplug be detected, it could call this function to handle 188 * the hot-unplug failure and avoid app crash. 189 * @param dev 190 * Pointer of the device structure. 191 * 192 * @return 193 * 0 on success. 194 * !0 on error. 195 */ 196 typedef int (*rte_bus_hot_unplug_handler_t)(struct rte_device *dev); 197 198 /** 199 * Implement a specific sigbus handler, which is responsible for handling 200 * the sigbus error which is either original memory error, or specific memory 201 * error that caused of device be hot-unplugged. When sigbus error be captured, 202 * it could call this function to handle sigbus error. 203 * @param failure_addr 204 * Pointer of the fault address of the sigbus error. 205 * 206 * @return 207 * 0 for success handle the sigbus for hot-unplug. 208 * 1 for not process it, because it is a generic sigbus error. 209 * -1 for failed to handle the sigbus for hot-unplug. 210 */ 211 typedef int (*rte_bus_sigbus_handler_t)(const void *failure_addr); 212 213 /** 214 * Bus scan policies 215 */ 216 enum rte_bus_scan_mode { 217 RTE_BUS_SCAN_UNDEFINED, 218 RTE_BUS_SCAN_ALLOWLIST, 219 RTE_BUS_SCAN_BLOCKLIST, 220 }; 221 222 /* Backwards compatibility will be removed */ 223 #define RTE_BUS_SCAN_WHITELIST \ 224 RTE_DEPRECATED(RTE_BUS_SCAN_WHITELIST) RTE_BUS_SCAN_ALLOWLIST 225 #define RTE_BUS_SCAN_BLACKLIST \ 226 RTE_DEPRECATED(RTE_BUS_SCAN_BLACKLIST) RTE_BUS_SCAN_BLOCKLIST 227 228 /** 229 * A structure used to configure bus operations. 230 */ 231 struct rte_bus_conf { 232 enum rte_bus_scan_mode scan_mode; /**< Scan policy. */ 233 }; 234 235 236 /** 237 * Get common iommu class of the all the devices on the bus. The bus may 238 * check that those devices are attached to iommu driver. 239 * If no devices are attached to the bus. The bus may return with don't care 240 * (_DC) value. 241 * Otherwise, The bus will return appropriate _pa or _va iova mode. 242 * 243 * @return 244 * enum rte_iova_mode value. 245 */ 246 typedef enum rte_iova_mode (*rte_bus_get_iommu_class_t)(void); 247 248 249 /** 250 * A structure describing a generic bus. 251 */ 252 struct rte_bus { 253 TAILQ_ENTRY(rte_bus) next; /**< Next bus object in linked list */ 254 const char *name; /**< Name of the bus */ 255 rte_bus_scan_t scan; /**< Scan for devices attached to bus */ 256 rte_bus_probe_t probe; /**< Probe devices on bus */ 257 rte_bus_find_device_t find_device; /**< Find a device on the bus */ 258 rte_bus_plug_t plug; /**< Probe single device for drivers */ 259 rte_bus_unplug_t unplug; /**< Remove single device from driver */ 260 rte_bus_parse_t parse; /**< Parse a device name */ 261 rte_dev_dma_map_t dma_map; /**< DMA map for device in the bus */ 262 rte_dev_dma_unmap_t dma_unmap; /**< DMA unmap for device in the bus */ 263 struct rte_bus_conf conf; /**< Bus configuration */ 264 rte_bus_get_iommu_class_t get_iommu_class; /**< Get iommu class */ 265 rte_dev_iterate_t dev_iterate; /**< Device iterator. */ 266 rte_bus_hot_unplug_handler_t hot_unplug_handler; 267 /**< handle hot-unplug failure on the bus */ 268 rte_bus_sigbus_handler_t sigbus_handler; 269 /**< handle sigbus error on the bus */ 270 271 }; 272 273 /** 274 * Register a Bus handler. 275 * 276 * @param bus 277 * A pointer to a rte_bus structure describing the bus 278 * to be registered. 279 */ 280 void rte_bus_register(struct rte_bus *bus); 281 282 /** 283 * Unregister a Bus handler. 284 * 285 * @param bus 286 * A pointer to a rte_bus structure describing the bus 287 * to be unregistered. 288 */ 289 void rte_bus_unregister(struct rte_bus *bus); 290 291 /** 292 * Scan all the buses. 293 * 294 * @return 295 * 0 in case of success in scanning all buses 296 * !0 in case of failure to scan 297 */ 298 int rte_bus_scan(void); 299 300 /** 301 * For each device on the buses, perform a driver 'match' and call the 302 * driver-specific probe for device initialization. 303 * 304 * @return 305 * 0 for successful match/probe 306 * !0 otherwise 307 */ 308 int rte_bus_probe(void); 309 310 /** 311 * Dump information of all the buses registered with EAL. 312 * 313 * @param f 314 * A valid and open output stream handle 315 */ 316 void rte_bus_dump(FILE *f); 317 318 /** 319 * Bus comparison function. 320 * 321 * @param bus 322 * Bus under test. 323 * 324 * @param data 325 * Data to compare against. 326 * 327 * @return 328 * 0 if the bus matches the data. 329 * !0 if the bus does not match. 330 * <0 if ordering is possible and the bus is lower than the data. 331 * >0 if ordering is possible and the bus is greater than the data. 332 */ 333 typedef int (*rte_bus_cmp_t)(const struct rte_bus *bus, const void *data); 334 335 /** 336 * Bus iterator to find a particular bus. 337 * 338 * This function compares each registered bus to find one that matches 339 * the data passed as parameter. 340 * 341 * If the comparison function returns zero this function will stop iterating 342 * over any more buses. To continue a search the bus of a previous search can 343 * be passed via the start parameter. 344 * 345 * @param start 346 * Starting point for the iteration. 347 * 348 * @param cmp 349 * Comparison function. 350 * 351 * @param data 352 * Data to pass to comparison function. 353 * 354 * @return 355 * A pointer to a rte_bus structure or NULL in case no bus matches 356 */ 357 struct rte_bus *rte_bus_find(const struct rte_bus *start, rte_bus_cmp_t cmp, 358 const void *data); 359 360 /** 361 * Find the registered bus for a particular device. 362 */ 363 struct rte_bus *rte_bus_find_by_device(const struct rte_device *dev); 364 365 /** 366 * Find the registered bus for a given name. 367 */ 368 struct rte_bus *rte_bus_find_by_name(const char *busname); 369 370 371 /** 372 * Get the common iommu class of devices bound on to buses available in the 373 * system. RTE_IOVA_DC means that no preference has been expressed. 374 * 375 * @return 376 * enum rte_iova_mode value. 377 */ 378 enum rte_iova_mode rte_bus_get_iommu_class(void); 379 380 /** 381 * Helper for Bus registration. 382 * The constructor has higher priority than PMD constructors. 383 */ 384 #define RTE_REGISTER_BUS(nm, bus) \ 385 RTE_INIT_PRIO(businitfn_ ##nm, BUS) \ 386 {\ 387 (bus).name = RTE_STR(nm);\ 388 rte_bus_register(&bus); \ 389 } 390 391 #ifdef __cplusplus 392 } 393 #endif 394 395 #endif /* _RTE_BUS_H */ 396