1 /* SPDX-License-Identifier: BSD-3-Clause
11 * DPDK device bus interface
13 * This file exposes API and interfaces for bus abstraction
14 * over the devices and drivers in EAL.
26 /** Double linked list of buses */
27 RTE_TAILQ_HEAD(rte_bus_list, rte_bus);
33 * IOVA mapping mode is iommu programming mode of a device.
34 * That device (for example: IOMMU backed DMA device) based
35 * on rte_iova_mode will generate physical or virtual address.
39 RTE_IOVA_DC = 0, /* Don't care mode */
40 RTE_IOVA_PA = (1 << 0), /* DMA using physical address */
41 RTE_IOVA_VA = (1 << 1) /* DMA using virtual address */
45 * Bus specific scan for devices attached on the bus.
46 * For each bus object, the scan would be responsible for finding devices and
47 * adding them to its private device list.
49 * A bus should mandatorily implement this method.
52 * 0 for successful scan
53 * <0 for unsuccessful scan with error value
55 typedef int (*rte_bus_scan_t)(void);
58 * Implementation specific probe function which is responsible for linking
59 * devices on that bus with applicable drivers.
61 * This is called while iterating over each registered bus.
64 * 0 for successful probe
65 * !0 for any error while probing
67 typedef int (*rte_bus_probe_t)(void);
70 * Device iterator to find a device on a bus.
72 * This function returns an rte_device if one of those held by the bus
73 * matches the data passed as parameter.
75 * If the comparison function returns zero this function should stop iterating
76 * over any more devices. To continue a search the device of a previous search
77 * can be passed via the start parameter.
80 * Comparison function.
83 * Data to compare each device against.
86 * starting point for the iteration
89 * The first device matching the data, NULL if none exists.
91 typedef struct rte_device *
92 (*rte_bus_find_device_t)(const struct rte_device *start, rte_dev_cmp_t cmp,
96 * Implementation specific probe function which is responsible for linking
97 * devices on that bus with applicable drivers.
100 * Device pointer that was returned by a previous call to find_device.
106 typedef int (*rte_bus_plug_t)(struct rte_device *dev);
109 * Implementation specific remove function which is responsible for unlinking
110 * devices on that bus from assigned driver.
113 * Device pointer that was returned by a previous call to find_device.
119 typedef int (*rte_bus_unplug_t)(struct rte_device *dev);
122 * Bus specific parsing function.
123 * Validates the syntax used in the textual representation of a device,
124 * If the syntax is valid and ``addr`` is not NULL, writes the bus-specific
125 * device representation to ``addr``.
128 * device textual description
131 * device information location address, into which parsed info
132 * should be written. If NULL, nothing should be written, which
136 * 0 if parsing was successful.
139 typedef int (*rte_bus_parse_t)(const char *name, void *addr);
142 * Parse bus part of the device arguments.
144 * The field name of the struct rte_devargs will be set.
147 * Pointer to the devargs to parse.
150 * 0 on successful parsing, otherwise rte_errno is set.
151 * -EINVAL: on parsing error.
152 * -ENODEV: if no key matching a device argument is specified.
153 * -E2BIG: device name is too long.
155 typedef int (*rte_bus_devargs_parse_t)(struct rte_devargs *da);
158 * Device level DMA map function.
159 * After a successful call, the memory segment will be mapped to the
165 * Virtual address to map.
167 * IOVA address to map.
169 * Length of the memory segment being mapped.
172 * 0 if mapping was successful.
173 * Negative value and rte_errno is set otherwise.
175 typedef int (*rte_dev_dma_map_t)(struct rte_device *dev, void *addr,
176 uint64_t iova, size_t len);
179 * Device level DMA unmap function.
180 * After a successful call, the memory segment will no longer be
181 * accessible by the given device.
186 * Virtual address to unmap.
188 * IOVA address to unmap.
190 * Length of the memory segment being mapped.
193 * 0 if un-mapping was successful.
194 * Negative value and rte_errno is set otherwise.
196 typedef int (*rte_dev_dma_unmap_t)(struct rte_device *dev, void *addr,
197 uint64_t iova, size_t len);
200 * Implement a specific hot-unplug handler, which is responsible for
201 * handle the failure when device be hot-unplugged. When the event of
202 * hot-unplug be detected, it could call this function to handle
203 * the hot-unplug failure and avoid app crash.
205 * Pointer of the device structure.
211 typedef int (*rte_bus_hot_unplug_handler_t)(struct rte_device *dev);
214 * Implement a specific sigbus handler, which is responsible for handling
215 * the sigbus error which is either original memory error, or specific memory
216 * error that caused of device be hot-unplugged. When sigbus error be captured,
217 * it could call this function to handle sigbus error.
218 * @param failure_addr
219 * Pointer of the fault address of the sigbus error.
222 * 0 for success handle the sigbus for hot-unplug.
223 * 1 for not process it, because it is a generic sigbus error.
224 * -1 for failed to handle the sigbus for hot-unplug.
226 typedef int (*rte_bus_sigbus_handler_t)(const void *failure_addr);
231 enum rte_bus_scan_mode {
232 RTE_BUS_SCAN_UNDEFINED,
233 RTE_BUS_SCAN_ALLOWLIST,
234 RTE_BUS_SCAN_BLOCKLIST,
238 * A structure used to configure bus operations.
240 struct rte_bus_conf {
241 enum rte_bus_scan_mode scan_mode; /**< Scan policy. */
246 * Get common iommu class of the all the devices on the bus. The bus may
247 * check that those devices are attached to iommu driver.
248 * If no devices are attached to the bus. The bus may return with don't care
250 * Otherwise, The bus will return appropriate _pa or _va iova mode.
253 * enum rte_iova_mode value.
255 typedef enum rte_iova_mode (*rte_bus_get_iommu_class_t)(void);
259 * A structure describing a generic bus.
262 RTE_TAILQ_ENTRY(rte_bus) next; /**< Next bus object in linked list */
263 const char *name; /**< Name of the bus */
264 rte_bus_scan_t scan; /**< Scan for devices attached to bus */
265 rte_bus_probe_t probe; /**< Probe devices on bus */
266 rte_bus_find_device_t find_device; /**< Find a device on the bus */
267 rte_bus_plug_t plug; /**< Probe single device for drivers */
268 rte_bus_unplug_t unplug; /**< Remove single device from driver */
269 rte_bus_parse_t parse; /**< Parse a device name */
270 rte_bus_devargs_parse_t devargs_parse; /**< Parse bus devargs */
271 rte_dev_dma_map_t dma_map; /**< DMA map for device in the bus */
272 rte_dev_dma_unmap_t dma_unmap; /**< DMA unmap for device in the bus */
273 struct rte_bus_conf conf; /**< Bus configuration */
274 rte_bus_get_iommu_class_t get_iommu_class; /**< Get iommu class */
275 rte_dev_iterate_t dev_iterate; /**< Device iterator. */
276 rte_bus_hot_unplug_handler_t hot_unplug_handler;
277 /**< handle hot-unplug failure on the bus */
278 rte_bus_sigbus_handler_t sigbus_handler;
279 /**< handle sigbus error on the bus */
284 * Register a Bus handler.
287 * A pointer to a rte_bus structure describing the bus
290 void rte_bus_register(struct rte_bus *bus);
293 * Unregister a Bus handler.
296 * A pointer to a rte_bus structure describing the bus
297 * to be unregistered.
299 void rte_bus_unregister(struct rte_bus *bus);
302 * Scan all the buses.
305 * 0 in case of success in scanning all buses
306 * !0 in case of failure to scan
308 int rte_bus_scan(void);
311 * For each device on the buses, perform a driver 'match' and call the
312 * driver-specific probe for device initialization.
315 * 0 for successful match/probe
318 int rte_bus_probe(void);
321 * Dump information of all the buses registered with EAL.
324 * A valid and open output stream handle
326 void rte_bus_dump(FILE *f);
329 * Bus comparison function.
335 * Data to compare against.
338 * 0 if the bus matches the data.
339 * !0 if the bus does not match.
340 * <0 if ordering is possible and the bus is lower than the data.
341 * >0 if ordering is possible and the bus is greater than the data.
343 typedef int (*rte_bus_cmp_t)(const struct rte_bus *bus, const void *data);
346 * Bus iterator to find a particular bus.
348 * This function compares each registered bus to find one that matches
349 * the data passed as parameter.
351 * If the comparison function returns zero this function will stop iterating
352 * over any more buses. To continue a search the bus of a previous search can
353 * be passed via the start parameter.
356 * Starting point for the iteration.
359 * Comparison function.
362 * Data to pass to comparison function.
365 * A pointer to a rte_bus structure or NULL in case no bus matches
367 struct rte_bus *rte_bus_find(const struct rte_bus *start, rte_bus_cmp_t cmp,
371 * Find the registered bus for a particular device.
373 struct rte_bus *rte_bus_find_by_device(const struct rte_device *dev);
376 * Find the registered bus for a given name.
378 struct rte_bus *rte_bus_find_by_name(const char *busname);
382 * Get the common iommu class of devices bound on to buses available in the
383 * system. RTE_IOVA_DC means that no preference has been expressed.
386 * enum rte_iova_mode value.
388 enum rte_iova_mode rte_bus_get_iommu_class(void);
391 * Helper for Bus registration.
392 * The constructor has higher priority than PMD constructors.
394 #define RTE_REGISTER_BUS(nm, bus) \
395 RTE_INIT_PRIO(businitfn_ ##nm, BUS) \
397 (bus).name = RTE_STR(nm);\
398 rte_bus_register(&bus); \
405 #endif /* _RTE_BUS_H */