xref: /linux-6.15/include/linux/thunderbolt.h (revision 5cc0df9c)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Thunderbolt service API
4  *
5  * Copyright (C) 2014 Andreas Noever <[email protected]>
6  * Copyright (C) 2017, Intel Corporation
7  * Authors: Michael Jamet <[email protected]>
8  *          Mika Westerberg <[email protected]>
9  */
10 
11 #ifndef THUNDERBOLT_H_
12 #define THUNDERBOLT_H_
13 
14 #include <linux/device.h>
15 #include <linux/idr.h>
16 #include <linux/list.h>
17 #include <linux/mutex.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/pci.h>
20 #include <linux/uuid.h>
21 #include <linux/workqueue.h>
22 
23 enum tb_cfg_pkg_type {
24 	TB_CFG_PKG_READ = 1,
25 	TB_CFG_PKG_WRITE = 2,
26 	TB_CFG_PKG_ERROR = 3,
27 	TB_CFG_PKG_NOTIFY_ACK = 4,
28 	TB_CFG_PKG_EVENT = 5,
29 	TB_CFG_PKG_XDOMAIN_REQ = 6,
30 	TB_CFG_PKG_XDOMAIN_RESP = 7,
31 	TB_CFG_PKG_OVERRIDE = 8,
32 	TB_CFG_PKG_RESET = 9,
33 	TB_CFG_PKG_ICM_EVENT = 10,
34 	TB_CFG_PKG_ICM_CMD = 11,
35 	TB_CFG_PKG_ICM_RESP = 12,
36 	TB_CFG_PKG_PREPARE_TO_SLEEP = 13,
37 };
38 
39 /**
40  * enum tb_security_level - Thunderbolt security level
41  * @TB_SECURITY_NONE: No security, legacy mode
42  * @TB_SECURITY_USER: User approval required at minimum
43  * @TB_SECURITY_SECURE: One time saved key required at minimum
44  * @TB_SECURITY_DPONLY: Only tunnel Display port (and USB)
45  * @TB_SECURITY_USBONLY: Only tunnel USB controller of the connected
46  *			 Thunderbolt dock (and Display Port). All PCIe
47  *			 links downstream of the dock are removed.
48  */
49 enum tb_security_level {
50 	TB_SECURITY_NONE,
51 	TB_SECURITY_USER,
52 	TB_SECURITY_SECURE,
53 	TB_SECURITY_DPONLY,
54 	TB_SECURITY_USBONLY,
55 };
56 
57 /**
58  * struct tb - main thunderbolt bus structure
59  * @dev: Domain device
60  * @lock: Big lock. Must be held when accessing any struct
61  *	  tb_switch / struct tb_port.
62  * @nhi: Pointer to the NHI structure
63  * @ctl: Control channel for this domain
64  * @wq: Ordered workqueue for all domain specific work
65  * @root_switch: Root switch of this domain
66  * @cm_ops: Connection manager specific operations vector
67  * @index: Linux assigned domain number
68  * @security_level: Current security level
69  * @nboot_acl: Number of boot ACLs the domain supports
70  * @privdata: Private connection manager specific data
71  */
72 struct tb {
73 	struct device dev;
74 	struct mutex lock;
75 	struct tb_nhi *nhi;
76 	struct tb_ctl *ctl;
77 	struct workqueue_struct *wq;
78 	struct tb_switch *root_switch;
79 	const struct tb_cm_ops *cm_ops;
80 	int index;
81 	enum tb_security_level security_level;
82 	size_t nboot_acl;
83 	unsigned long privdata[];
84 };
85 
86 extern struct bus_type tb_bus_type;
87 extern struct device_type tb_service_type;
88 extern struct device_type tb_xdomain_type;
89 
90 #define TB_LINKS_PER_PHY_PORT	2
91 
92 static inline unsigned int tb_phy_port_from_link(unsigned int link)
93 {
94 	return (link - 1) / TB_LINKS_PER_PHY_PORT;
95 }
96 
97 /**
98  * struct tb_property_dir - XDomain property directory
99  * @uuid: Directory UUID or %NULL if root directory
100  * @properties: List of properties in this directory
101  *
102  * User needs to provide serialization if needed.
103  */
104 struct tb_property_dir {
105 	const uuid_t *uuid;
106 	struct list_head properties;
107 };
108 
109 enum tb_property_type {
110 	TB_PROPERTY_TYPE_UNKNOWN = 0x00,
111 	TB_PROPERTY_TYPE_DIRECTORY = 0x44,
112 	TB_PROPERTY_TYPE_DATA = 0x64,
113 	TB_PROPERTY_TYPE_TEXT = 0x74,
114 	TB_PROPERTY_TYPE_VALUE = 0x76,
115 };
116 
117 #define TB_PROPERTY_KEY_SIZE	8
118 
119 /**
120  * struct tb_property - XDomain property
121  * @list: Used to link properties together in a directory
122  * @key: Key for the property (always terminated).
123  * @type: Type of the property
124  * @length: Length of the property data in dwords
125  * @value: Property value
126  *
127  * Users use @type to determine which field in @value is filled.
128  */
129 struct tb_property {
130 	struct list_head list;
131 	char key[TB_PROPERTY_KEY_SIZE + 1];
132 	enum tb_property_type type;
133 	size_t length;
134 	union {
135 		struct tb_property_dir *dir;
136 		u8 *data;
137 		char *text;
138 		u32 immediate;
139 	} value;
140 };
141 
142 struct tb_property_dir *tb_property_parse_dir(const u32 *block,
143 					      size_t block_len);
144 ssize_t tb_property_format_dir(const struct tb_property_dir *dir, u32 *block,
145 			       size_t block_len);
146 struct tb_property_dir *tb_property_create_dir(const uuid_t *uuid);
147 void tb_property_free_dir(struct tb_property_dir *dir);
148 int tb_property_add_immediate(struct tb_property_dir *parent, const char *key,
149 			      u32 value);
150 int tb_property_add_data(struct tb_property_dir *parent, const char *key,
151 			 const void *buf, size_t buflen);
152 int tb_property_add_text(struct tb_property_dir *parent, const char *key,
153 			 const char *text);
154 int tb_property_add_dir(struct tb_property_dir *parent, const char *key,
155 			struct tb_property_dir *dir);
156 void tb_property_remove(struct tb_property *tb_property);
157 struct tb_property *tb_property_find(struct tb_property_dir *dir,
158 			const char *key, enum tb_property_type type);
159 struct tb_property *tb_property_get_next(struct tb_property_dir *dir,
160 					 struct tb_property *prev);
161 
162 #define tb_property_for_each(dir, property)			\
163 	for (property = tb_property_get_next(dir, NULL);	\
164 	     property;						\
165 	     property = tb_property_get_next(dir, property))
166 
167 int tb_register_property_dir(const char *key, struct tb_property_dir *dir);
168 void tb_unregister_property_dir(const char *key, struct tb_property_dir *dir);
169 
170 /**
171  * struct tb_xdomain - Cross-domain (XDomain) connection
172  * @dev: XDomain device
173  * @tb: Pointer to the domain
174  * @remote_uuid: UUID of the remote domain (host)
175  * @local_uuid: Cached local UUID
176  * @route: Route string the other domain can be reached
177  * @vendor: Vendor ID of the remote domain
178  * @device: Device ID of the demote domain
179  * @lock: Lock to serialize access to the following fields of this structure
180  * @vendor_name: Name of the vendor (or %NULL if not known)
181  * @device_name: Name of the device (or %NULL if not known)
182  * @link_speed: Speed of the link in Gb/s
183  * @link_width: Width of the link (1 or 2)
184  * @is_unplugged: The XDomain is unplugged
185  * @resume: The XDomain is being resumed
186  * @needs_uuid: If the XDomain does not have @remote_uuid it will be
187  *		queried first
188  * @transmit_path: HopID which the remote end expects us to transmit
189  * @transmit_ring: Local ring (hop) where outgoing packets are pushed
190  * @receive_path: HopID which we expect the remote end to transmit
191  * @receive_ring: Local ring (hop) where incoming packets arrive
192  * @service_ids: Used to generate IDs for the services
193  * @properties: Properties exported by the remote domain
194  * @property_block_gen: Generation of @properties
195  * @properties_lock: Lock protecting @properties.
196  * @get_uuid_work: Work used to retrieve @remote_uuid
197  * @uuid_retries: Number of times left @remote_uuid is requested before
198  *		  giving up
199  * @get_properties_work: Work used to get remote domain properties
200  * @properties_retries: Number of times left to read properties
201  * @properties_changed_work: Work used to notify the remote domain that
202  *			     our properties have changed
203  * @properties_changed_retries: Number of times left to send properties
204  *				changed notification
205  * @link: Root switch link the remote domain is connected (ICM only)
206  * @depth: Depth in the chain the remote domain is connected (ICM only)
207  *
208  * This structure represents connection across two domains (hosts).
209  * Each XDomain contains zero or more services which are exposed as
210  * &struct tb_service objects.
211  *
212  * Service drivers may access this structure if they need to enumerate
213  * non-standard properties but they need hold @lock when doing so
214  * because properties can be changed asynchronously in response to
215  * changes in the remote domain.
216  */
217 struct tb_xdomain {
218 	struct device dev;
219 	struct tb *tb;
220 	uuid_t *remote_uuid;
221 	const uuid_t *local_uuid;
222 	u64 route;
223 	u16 vendor;
224 	u16 device;
225 	struct mutex lock;
226 	const char *vendor_name;
227 	const char *device_name;
228 	unsigned int link_speed;
229 	unsigned int link_width;
230 	bool is_unplugged;
231 	bool resume;
232 	bool needs_uuid;
233 	u16 transmit_path;
234 	u16 transmit_ring;
235 	u16 receive_path;
236 	u16 receive_ring;
237 	struct ida service_ids;
238 	struct tb_property_dir *properties;
239 	u32 property_block_gen;
240 	struct delayed_work get_uuid_work;
241 	int uuid_retries;
242 	struct delayed_work get_properties_work;
243 	int properties_retries;
244 	struct delayed_work properties_changed_work;
245 	int properties_changed_retries;
246 	u8 link;
247 	u8 depth;
248 };
249 
250 int tb_xdomain_lane_bonding_enable(struct tb_xdomain *xd);
251 void tb_xdomain_lane_bonding_disable(struct tb_xdomain *xd);
252 int tb_xdomain_enable_paths(struct tb_xdomain *xd, u16 transmit_path,
253 			    u16 transmit_ring, u16 receive_path,
254 			    u16 receive_ring);
255 int tb_xdomain_disable_paths(struct tb_xdomain *xd);
256 struct tb_xdomain *tb_xdomain_find_by_uuid(struct tb *tb, const uuid_t *uuid);
257 struct tb_xdomain *tb_xdomain_find_by_route(struct tb *tb, u64 route);
258 
259 static inline struct tb_xdomain *
260 tb_xdomain_find_by_uuid_locked(struct tb *tb, const uuid_t *uuid)
261 {
262 	struct tb_xdomain *xd;
263 
264 	mutex_lock(&tb->lock);
265 	xd = tb_xdomain_find_by_uuid(tb, uuid);
266 	mutex_unlock(&tb->lock);
267 
268 	return xd;
269 }
270 
271 static inline struct tb_xdomain *
272 tb_xdomain_find_by_route_locked(struct tb *tb, u64 route)
273 {
274 	struct tb_xdomain *xd;
275 
276 	mutex_lock(&tb->lock);
277 	xd = tb_xdomain_find_by_route(tb, route);
278 	mutex_unlock(&tb->lock);
279 
280 	return xd;
281 }
282 
283 static inline struct tb_xdomain *tb_xdomain_get(struct tb_xdomain *xd)
284 {
285 	if (xd)
286 		get_device(&xd->dev);
287 	return xd;
288 }
289 
290 static inline void tb_xdomain_put(struct tb_xdomain *xd)
291 {
292 	if (xd)
293 		put_device(&xd->dev);
294 }
295 
296 static inline bool tb_is_xdomain(const struct device *dev)
297 {
298 	return dev->type == &tb_xdomain_type;
299 }
300 
301 static inline struct tb_xdomain *tb_to_xdomain(struct device *dev)
302 {
303 	if (tb_is_xdomain(dev))
304 		return container_of(dev, struct tb_xdomain, dev);
305 	return NULL;
306 }
307 
308 int tb_xdomain_response(struct tb_xdomain *xd, const void *response,
309 			size_t size, enum tb_cfg_pkg_type type);
310 int tb_xdomain_request(struct tb_xdomain *xd, const void *request,
311 		       size_t request_size, enum tb_cfg_pkg_type request_type,
312 		       void *response, size_t response_size,
313 		       enum tb_cfg_pkg_type response_type,
314 		       unsigned int timeout_msec);
315 
316 /**
317  * tb_protocol_handler - Protocol specific handler
318  * @uuid: XDomain messages with this UUID are dispatched to this handler
319  * @callback: Callback called with the XDomain message. Returning %1
320  *	      here tells the XDomain core that the message was handled
321  *	      by this handler and should not be forwared to other
322  *	      handlers.
323  * @data: Data passed with the callback
324  * @list: Handlers are linked using this
325  *
326  * Thunderbolt services can hook into incoming XDomain requests by
327  * registering protocol handler. Only limitation is that the XDomain
328  * discovery protocol UUID cannot be registered since it is handled by
329  * the core XDomain code.
330  *
331  * The @callback must check that the message is really directed to the
332  * service the driver implements.
333  */
334 struct tb_protocol_handler {
335 	const uuid_t *uuid;
336 	int (*callback)(const void *buf, size_t size, void *data);
337 	void *data;
338 	struct list_head list;
339 };
340 
341 int tb_register_protocol_handler(struct tb_protocol_handler *handler);
342 void tb_unregister_protocol_handler(struct tb_protocol_handler *handler);
343 
344 /**
345  * struct tb_service - Thunderbolt service
346  * @dev: XDomain device
347  * @id: ID of the service (shown in sysfs)
348  * @key: Protocol key from the properties directory
349  * @prtcid: Protocol ID from the properties directory
350  * @prtcvers: Protocol version from the properties directory
351  * @prtcrevs: Protocol software revision from the properties directory
352  * @prtcstns: Protocol settings mask from the properties directory
353  *
354  * Each domain exposes set of services it supports as collection of
355  * properties. For each service there will be one corresponding
356  * &struct tb_service. Service drivers are bound to these.
357  */
358 struct tb_service {
359 	struct device dev;
360 	int id;
361 	const char *key;
362 	u32 prtcid;
363 	u32 prtcvers;
364 	u32 prtcrevs;
365 	u32 prtcstns;
366 };
367 
368 static inline struct tb_service *tb_service_get(struct tb_service *svc)
369 {
370 	if (svc)
371 		get_device(&svc->dev);
372 	return svc;
373 }
374 
375 static inline void tb_service_put(struct tb_service *svc)
376 {
377 	if (svc)
378 		put_device(&svc->dev);
379 }
380 
381 static inline bool tb_is_service(const struct device *dev)
382 {
383 	return dev->type == &tb_service_type;
384 }
385 
386 static inline struct tb_service *tb_to_service(struct device *dev)
387 {
388 	if (tb_is_service(dev))
389 		return container_of(dev, struct tb_service, dev);
390 	return NULL;
391 }
392 
393 /**
394  * tb_service_driver - Thunderbolt service driver
395  * @driver: Driver structure
396  * @probe: Called when the driver is probed
397  * @remove: Called when the driver is removed (optional)
398  * @shutdown: Called at shutdown time to stop the service (optional)
399  * @id_table: Table of service identifiers the driver supports
400  */
401 struct tb_service_driver {
402 	struct device_driver driver;
403 	int (*probe)(struct tb_service *svc, const struct tb_service_id *id);
404 	void (*remove)(struct tb_service *svc);
405 	void (*shutdown)(struct tb_service *svc);
406 	const struct tb_service_id *id_table;
407 };
408 
409 #define TB_SERVICE(key, id)				\
410 	.match_flags = TBSVC_MATCH_PROTOCOL_KEY |	\
411 		       TBSVC_MATCH_PROTOCOL_ID,		\
412 	.protocol_key = (key),				\
413 	.protocol_id = (id)
414 
415 int tb_register_service_driver(struct tb_service_driver *drv);
416 void tb_unregister_service_driver(struct tb_service_driver *drv);
417 
418 static inline void *tb_service_get_drvdata(const struct tb_service *svc)
419 {
420 	return dev_get_drvdata(&svc->dev);
421 }
422 
423 static inline void tb_service_set_drvdata(struct tb_service *svc, void *data)
424 {
425 	dev_set_drvdata(&svc->dev, data);
426 }
427 
428 static inline struct tb_xdomain *tb_service_parent(struct tb_service *svc)
429 {
430 	return tb_to_xdomain(svc->dev.parent);
431 }
432 
433 /**
434  * struct tb_nhi - thunderbolt native host interface
435  * @lock: Must be held during ring creation/destruction. Is acquired by
436  *	  interrupt_work when dispatching interrupts to individual rings.
437  * @pdev: Pointer to the PCI device
438  * @ops: NHI specific optional ops
439  * @iobase: MMIO space of the NHI
440  * @tx_rings: All Tx rings available on this host controller
441  * @rx_rings: All Rx rings available on this host controller
442  * @msix_ida: Used to allocate MSI-X vectors for rings
443  * @going_away: The host controller device is about to disappear so when
444  *		this flag is set, avoid touching the hardware anymore.
445  * @interrupt_work: Work scheduled to handle ring interrupt when no
446  *		    MSI-X is used.
447  * @hop_count: Number of rings (end point hops) supported by NHI.
448  */
449 struct tb_nhi {
450 	spinlock_t lock;
451 	struct pci_dev *pdev;
452 	const struct tb_nhi_ops *ops;
453 	void __iomem *iobase;
454 	struct tb_ring **tx_rings;
455 	struct tb_ring **rx_rings;
456 	struct ida msix_ida;
457 	bool going_away;
458 	struct work_struct interrupt_work;
459 	u32 hop_count;
460 };
461 
462 /**
463  * struct tb_ring - thunderbolt TX or RX ring associated with a NHI
464  * @lock: Lock serializing actions to this ring. Must be acquired after
465  *	  nhi->lock.
466  * @nhi: Pointer to the native host controller interface
467  * @size: Size of the ring
468  * @hop: Hop (DMA channel) associated with this ring
469  * @head: Head of the ring (write next descriptor here)
470  * @tail: Tail of the ring (complete next descriptor here)
471  * @descriptors: Allocated descriptors for this ring
472  * @queue: Queue holding frames to be transferred over this ring
473  * @in_flight: Queue holding frames that are currently in flight
474  * @work: Interrupt work structure
475  * @is_tx: Is the ring Tx or Rx
476  * @running: Is the ring running
477  * @irq: MSI-X irq number if the ring uses MSI-X. %0 otherwise.
478  * @vector: MSI-X vector number the ring uses (only set if @irq is > 0)
479  * @flags: Ring specific flags
480  * @sof_mask: Bit mask used to detect start of frame PDF
481  * @eof_mask: Bit mask used to detect end of frame PDF
482  * @start_poll: Called when ring interrupt is triggered to start
483  *		polling. Passing %NULL keeps the ring in interrupt mode.
484  * @poll_data: Data passed to @start_poll
485  */
486 struct tb_ring {
487 	spinlock_t lock;
488 	struct tb_nhi *nhi;
489 	int size;
490 	int hop;
491 	int head;
492 	int tail;
493 	struct ring_desc *descriptors;
494 	dma_addr_t descriptors_dma;
495 	struct list_head queue;
496 	struct list_head in_flight;
497 	struct work_struct work;
498 	bool is_tx:1;
499 	bool running:1;
500 	int irq;
501 	u8 vector;
502 	unsigned int flags;
503 	u16 sof_mask;
504 	u16 eof_mask;
505 	void (*start_poll)(void *data);
506 	void *poll_data;
507 };
508 
509 /* Leave ring interrupt enabled on suspend */
510 #define RING_FLAG_NO_SUSPEND	BIT(0)
511 /* Configure the ring to be in frame mode */
512 #define RING_FLAG_FRAME		BIT(1)
513 
514 struct ring_frame;
515 typedef void (*ring_cb)(struct tb_ring *, struct ring_frame *, bool canceled);
516 
517 /**
518  * enum ring_desc_flags - Flags for DMA ring descriptor
519  * %RING_DESC_ISOCH: Enable isonchronous DMA (Tx only)
520  * %RING_DESC_CRC_ERROR: In frame mode CRC check failed for the frame (Rx only)
521  * %RING_DESC_COMPLETED: Descriptor completed (set by NHI)
522  * %RING_DESC_POSTED: Always set this
523  * %RING_DESC_BUFFER_OVERRUN: RX buffer overrun
524  * %RING_DESC_INTERRUPT: Request an interrupt on completion
525  */
526 enum ring_desc_flags {
527 	RING_DESC_ISOCH = 0x1,
528 	RING_DESC_CRC_ERROR = 0x1,
529 	RING_DESC_COMPLETED = 0x2,
530 	RING_DESC_POSTED = 0x4,
531 	RING_DESC_BUFFER_OVERRUN = 0x04,
532 	RING_DESC_INTERRUPT = 0x8,
533 };
534 
535 /**
536  * struct ring_frame - For use with ring_rx/ring_tx
537  * @buffer_phy: DMA mapped address of the frame
538  * @callback: Callback called when the frame is finished (optional)
539  * @list: Frame is linked to a queue using this
540  * @size: Size of the frame in bytes (%0 means %4096)
541  * @flags: Flags for the frame (see &enum ring_desc_flags)
542  * @eof: End of frame protocol defined field
543  * @sof: Start of frame protocol defined field
544  */
545 struct ring_frame {
546 	dma_addr_t buffer_phy;
547 	ring_cb callback;
548 	struct list_head list;
549 	u32 size:12;
550 	u32 flags:12;
551 	u32 eof:4;
552 	u32 sof:4;
553 };
554 
555 /* Minimum size for ring_rx */
556 #define TB_FRAME_SIZE		0x100
557 
558 struct tb_ring *tb_ring_alloc_tx(struct tb_nhi *nhi, int hop, int size,
559 				 unsigned int flags);
560 struct tb_ring *tb_ring_alloc_rx(struct tb_nhi *nhi, int hop, int size,
561 				 unsigned int flags, u16 sof_mask, u16 eof_mask,
562 				 void (*start_poll)(void *), void *poll_data);
563 void tb_ring_start(struct tb_ring *ring);
564 void tb_ring_stop(struct tb_ring *ring);
565 void tb_ring_free(struct tb_ring *ring);
566 
567 int __tb_ring_enqueue(struct tb_ring *ring, struct ring_frame *frame);
568 
569 /**
570  * tb_ring_rx() - enqueue a frame on an RX ring
571  * @ring: Ring to enqueue the frame
572  * @frame: Frame to enqueue
573  *
574  * @frame->buffer, @frame->buffer_phy have to be set. The buffer must
575  * contain at least %TB_FRAME_SIZE bytes.
576  *
577  * @frame->callback will be invoked with @frame->size, @frame->flags,
578  * @frame->eof, @frame->sof set once the frame has been received.
579  *
580  * If ring_stop() is called after the packet has been enqueued
581  * @frame->callback will be called with canceled set to true.
582  *
583  * Return: Returns %-ESHUTDOWN if ring_stop has been called. Zero otherwise.
584  */
585 static inline int tb_ring_rx(struct tb_ring *ring, struct ring_frame *frame)
586 {
587 	WARN_ON(ring->is_tx);
588 	return __tb_ring_enqueue(ring, frame);
589 }
590 
591 /**
592  * tb_ring_tx() - enqueue a frame on an TX ring
593  * @ring: Ring the enqueue the frame
594  * @frame: Frame to enqueue
595  *
596  * @frame->buffer, @frame->buffer_phy, @frame->size, @frame->eof and
597  * @frame->sof have to be set.
598  *
599  * @frame->callback will be invoked with once the frame has been transmitted.
600  *
601  * If ring_stop() is called after the packet has been enqueued @frame->callback
602  * will be called with canceled set to true.
603  *
604  * Return: Returns %-ESHUTDOWN if ring_stop has been called. Zero otherwise.
605  */
606 static inline int tb_ring_tx(struct tb_ring *ring, struct ring_frame *frame)
607 {
608 	WARN_ON(!ring->is_tx);
609 	return __tb_ring_enqueue(ring, frame);
610 }
611 
612 /* Used only when the ring is in polling mode */
613 struct ring_frame *tb_ring_poll(struct tb_ring *ring);
614 void tb_ring_poll_complete(struct tb_ring *ring);
615 
616 /**
617  * tb_ring_dma_device() - Return device used for DMA mapping
618  * @ring: Ring whose DMA device is retrieved
619  *
620  * Use this function when you are mapping DMA for buffers that are
621  * passed to the ring for sending/receiving.
622  */
623 static inline struct device *tb_ring_dma_device(struct tb_ring *ring)
624 {
625 	return &ring->nhi->pdev->dev;
626 }
627 
628 #endif /* THUNDERBOLT_H_ */
629