1 /*
2  * Thunderbolt service API
3  *
4  * Copyright (C) 2014 Andreas Noever <andreas.noever@gmail.com>
5  * Copyright (C) 2017, Intel Corporation
6  * Authors: Michael Jamet <michael.jamet@intel.com>
7  *          Mika Westerberg <mika.westerberg@linux.intel.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 
14 #ifndef THUNDERBOLT_H_
15 #define THUNDERBOLT_H_
16 
17 #include <linux/device.h>
18 #include <linux/idr.h>
19 #include <linux/list.h>
20 #include <linux/mutex.h>
21 #include <linux/mod_devicetable.h>
22 #include <linux/pci.h>
23 #include <linux/uuid.h>
24 #include <linux/workqueue.h>
25 
26 enum tb_cfg_pkg_type {
27 	TB_CFG_PKG_READ = 1,
28 	TB_CFG_PKG_WRITE = 2,
29 	TB_CFG_PKG_ERROR = 3,
30 	TB_CFG_PKG_NOTIFY_ACK = 4,
31 	TB_CFG_PKG_EVENT = 5,
32 	TB_CFG_PKG_XDOMAIN_REQ = 6,
33 	TB_CFG_PKG_XDOMAIN_RESP = 7,
34 	TB_CFG_PKG_OVERRIDE = 8,
35 	TB_CFG_PKG_RESET = 9,
36 	TB_CFG_PKG_ICM_EVENT = 10,
37 	TB_CFG_PKG_ICM_CMD = 11,
38 	TB_CFG_PKG_ICM_RESP = 12,
39 	TB_CFG_PKG_PREPARE_TO_SLEEP = 13,
40 };
41 
42 /**
43  * enum tb_security_level - Thunderbolt security level
44  * @TB_SECURITY_NONE: No security, legacy mode
45  * @TB_SECURITY_USER: User approval required at minimum
46  * @TB_SECURITY_SECURE: One time saved key required at minimum
47  * @TB_SECURITY_DPONLY: Only tunnel Display port (and USB)
48  * @TB_SECURITY_USBONLY: Only tunnel USB controller of the connected
49  *			 Thunderbolt dock (and Display Port). All PCIe
50  *			 links downstream of the dock are removed.
51  */
52 enum tb_security_level {
53 	TB_SECURITY_NONE,
54 	TB_SECURITY_USER,
55 	TB_SECURITY_SECURE,
56 	TB_SECURITY_DPONLY,
57 	TB_SECURITY_USBONLY,
58 };
59 
60 /**
61  * struct tb - main thunderbolt bus structure
62  * @dev: Domain device
63  * @lock: Big lock. Must be held when accessing any struct
64  *	  tb_switch / struct tb_port.
65  * @nhi: Pointer to the NHI structure
66  * @ctl: Control channel for this domain
67  * @wq: Ordered workqueue for all domain specific work
68  * @root_switch: Root switch of this domain
69  * @cm_ops: Connection manager specific operations vector
70  * @index: Linux assigned domain number
71  * @security_level: Current security level
72  * @nboot_acl: Number of boot ACLs the domain supports
73  * @privdata: Private connection manager specific data
74  */
75 struct tb {
76 	struct device dev;
77 	struct mutex lock;
78 	struct tb_nhi *nhi;
79 	struct tb_ctl *ctl;
80 	struct workqueue_struct *wq;
81 	struct tb_switch *root_switch;
82 	const struct tb_cm_ops *cm_ops;
83 	int index;
84 	enum tb_security_level security_level;
85 	size_t nboot_acl;
86 	unsigned long privdata[0];
87 };
88 
89 extern struct bus_type tb_bus_type;
90 extern struct device_type tb_service_type;
91 extern struct device_type tb_xdomain_type;
92 
93 #define TB_LINKS_PER_PHY_PORT	2
94 
tb_phy_port_from_link(unsigned int link)95 static inline unsigned int tb_phy_port_from_link(unsigned int link)
96 {
97 	return (link - 1) / TB_LINKS_PER_PHY_PORT;
98 }
99 
100 /**
101  * struct tb_property_dir - XDomain property directory
102  * @uuid: Directory UUID or %NULL if root directory
103  * @properties: List of properties in this directory
104  *
105  * User needs to provide serialization if needed.
106  */
107 struct tb_property_dir {
108 	const uuid_t *uuid;
109 	struct list_head properties;
110 };
111 
112 enum tb_property_type {
113 	TB_PROPERTY_TYPE_UNKNOWN = 0x00,
114 	TB_PROPERTY_TYPE_DIRECTORY = 0x44,
115 	TB_PROPERTY_TYPE_DATA = 0x64,
116 	TB_PROPERTY_TYPE_TEXT = 0x74,
117 	TB_PROPERTY_TYPE_VALUE = 0x76,
118 };
119 
120 #define TB_PROPERTY_KEY_SIZE	8
121 
122 /**
123  * struct tb_property - XDomain property
124  * @list: Used to link properties together in a directory
125  * @key: Key for the property (always terminated).
126  * @type: Type of the property
127  * @length: Length of the property data in dwords
128  * @value: Property value
129  *
130  * Users use @type to determine which field in @value is filled.
131  */
132 struct tb_property {
133 	struct list_head list;
134 	char key[TB_PROPERTY_KEY_SIZE + 1];
135 	enum tb_property_type type;
136 	size_t length;
137 	union {
138 		struct tb_property_dir *dir;
139 		u8 *data;
140 		char *text;
141 		u32 immediate;
142 	} value;
143 };
144 
145 struct tb_property_dir *tb_property_parse_dir(const u32 *block,
146 					      size_t block_len);
147 ssize_t tb_property_format_dir(const struct tb_property_dir *dir, u32 *block,
148 			       size_t block_len);
149 struct tb_property_dir *tb_property_create_dir(const uuid_t *uuid);
150 void tb_property_free_dir(struct tb_property_dir *dir);
151 int tb_property_add_immediate(struct tb_property_dir *parent, const char *key,
152 			      u32 value);
153 int tb_property_add_data(struct tb_property_dir *parent, const char *key,
154 			 const void *buf, size_t buflen);
155 int tb_property_add_text(struct tb_property_dir *parent, const char *key,
156 			 const char *text);
157 int tb_property_add_dir(struct tb_property_dir *parent, const char *key,
158 			struct tb_property_dir *dir);
159 void tb_property_remove(struct tb_property *tb_property);
160 struct tb_property *tb_property_find(struct tb_property_dir *dir,
161 			const char *key, enum tb_property_type type);
162 struct tb_property *tb_property_get_next(struct tb_property_dir *dir,
163 					 struct tb_property *prev);
164 
165 #define tb_property_for_each(dir, property)			\
166 	for (property = tb_property_get_next(dir, NULL);	\
167 	     property;						\
168 	     property = tb_property_get_next(dir, property))
169 
170 int tb_register_property_dir(const char *key, struct tb_property_dir *dir);
171 void tb_unregister_property_dir(const char *key, struct tb_property_dir *dir);
172 
173 /**
174  * struct tb_xdomain - Cross-domain (XDomain) connection
175  * @dev: XDomain device
176  * @tb: Pointer to the domain
177  * @remote_uuid: UUID of the remote domain (host)
178  * @local_uuid: Cached local UUID
179  * @route: Route string the other domain can be reached
180  * @vendor: Vendor ID of the remote domain
181  * @device: Device ID of the demote domain
182  * @lock: Lock to serialize access to the following fields of this structure
183  * @vendor_name: Name of the vendor (or %NULL if not known)
184  * @device_name: Name of the device (or %NULL if not known)
185  * @is_unplugged: The XDomain is unplugged
186  * @resume: The XDomain is being resumed
187  * @transmit_path: HopID which the remote end expects us to transmit
188  * @transmit_ring: Local ring (hop) where outgoing packets are pushed
189  * @receive_path: HopID which we expect the remote end to transmit
190  * @receive_ring: Local ring (hop) where incoming packets arrive
191  * @service_ids: Used to generate IDs for the services
192  * @properties: Properties exported by the remote domain
193  * @property_block_gen: Generation of @properties
194  * @properties_lock: Lock protecting @properties.
195  * @get_properties_work: Work used to get remote domain properties
196  * @properties_retries: Number of times left to read properties
197  * @properties_changed_work: Work used to notify the remote domain that
198  *			     our properties have changed
199  * @properties_changed_retries: Number of times left to send properties
200  *				changed notification
201  * @link: Root switch link the remote domain is connected (ICM only)
202  * @depth: Depth in the chain the remote domain is connected (ICM only)
203  *
204  * This structure represents connection across two domains (hosts).
205  * Each XDomain contains zero or more services which are exposed as
206  * &struct tb_service objects.
207  *
208  * Service drivers may access this structure if they need to enumerate
209  * non-standard properties but they need hold @lock when doing so
210  * because properties can be changed asynchronously in response to
211  * changes in the remote domain.
212  */
213 struct tb_xdomain {
214 	struct device dev;
215 	struct tb *tb;
216 	uuid_t *remote_uuid;
217 	const uuid_t *local_uuid;
218 	u64 route;
219 	u16 vendor;
220 	u16 device;
221 	struct mutex lock;
222 	const char *vendor_name;
223 	const char *device_name;
224 	bool is_unplugged;
225 	bool resume;
226 	u16 transmit_path;
227 	u16 transmit_ring;
228 	u16 receive_path;
229 	u16 receive_ring;
230 	struct ida service_ids;
231 	struct tb_property_dir *properties;
232 	u32 property_block_gen;
233 	struct delayed_work get_properties_work;
234 	int properties_retries;
235 	struct delayed_work properties_changed_work;
236 	int properties_changed_retries;
237 	u8 link;
238 	u8 depth;
239 };
240 
241 int tb_xdomain_enable_paths(struct tb_xdomain *xd, u16 transmit_path,
242 			    u16 transmit_ring, u16 receive_path,
243 			    u16 receive_ring);
244 int tb_xdomain_disable_paths(struct tb_xdomain *xd);
245 struct tb_xdomain *tb_xdomain_find_by_uuid(struct tb *tb, const uuid_t *uuid);
246 struct tb_xdomain *tb_xdomain_find_by_route(struct tb *tb, u64 route);
247 
248 static inline struct tb_xdomain *
tb_xdomain_find_by_uuid_locked(struct tb * tb,const uuid_t * uuid)249 tb_xdomain_find_by_uuid_locked(struct tb *tb, const uuid_t *uuid)
250 {
251 	struct tb_xdomain *xd;
252 
253 	mutex_lock(&tb->lock);
254 	xd = tb_xdomain_find_by_uuid(tb, uuid);
255 	mutex_unlock(&tb->lock);
256 
257 	return xd;
258 }
259 
260 static inline struct tb_xdomain *
tb_xdomain_find_by_route_locked(struct tb * tb,u64 route)261 tb_xdomain_find_by_route_locked(struct tb *tb, u64 route)
262 {
263 	struct tb_xdomain *xd;
264 
265 	mutex_lock(&tb->lock);
266 	xd = tb_xdomain_find_by_route(tb, route);
267 	mutex_unlock(&tb->lock);
268 
269 	return xd;
270 }
271 
tb_xdomain_get(struct tb_xdomain * xd)272 static inline struct tb_xdomain *tb_xdomain_get(struct tb_xdomain *xd)
273 {
274 	if (xd)
275 		get_device(&xd->dev);
276 	return xd;
277 }
278 
tb_xdomain_put(struct tb_xdomain * xd)279 static inline void tb_xdomain_put(struct tb_xdomain *xd)
280 {
281 	if (xd)
282 		put_device(&xd->dev);
283 }
284 
tb_is_xdomain(const struct device * dev)285 static inline bool tb_is_xdomain(const struct device *dev)
286 {
287 	return dev->type == &tb_xdomain_type;
288 }
289 
tb_to_xdomain(struct device * dev)290 static inline struct tb_xdomain *tb_to_xdomain(struct device *dev)
291 {
292 	if (tb_is_xdomain(dev))
293 		return container_of(dev, struct tb_xdomain, dev);
294 	return NULL;
295 }
296 
297 int tb_xdomain_response(struct tb_xdomain *xd, const void *response,
298 			size_t size, enum tb_cfg_pkg_type type);
299 int tb_xdomain_request(struct tb_xdomain *xd, const void *request,
300 		       size_t request_size, enum tb_cfg_pkg_type request_type,
301 		       void *response, size_t response_size,
302 		       enum tb_cfg_pkg_type response_type,
303 		       unsigned int timeout_msec);
304 
305 /**
306  * tb_protocol_handler - Protocol specific handler
307  * @uuid: XDomain messages with this UUID are dispatched to this handler
308  * @callback: Callback called with the XDomain message. Returning %1
309  *	      here tells the XDomain core that the message was handled
310  *	      by this handler and should not be forwared to other
311  *	      handlers.
312  * @data: Data passed with the callback
313  * @list: Handlers are linked using this
314  *
315  * Thunderbolt services can hook into incoming XDomain requests by
316  * registering protocol handler. Only limitation is that the XDomain
317  * discovery protocol UUID cannot be registered since it is handled by
318  * the core XDomain code.
319  *
320  * The @callback must check that the message is really directed to the
321  * service the driver implements.
322  */
323 struct tb_protocol_handler {
324 	const uuid_t *uuid;
325 	int (*callback)(const void *buf, size_t size, void *data);
326 	void *data;
327 	struct list_head list;
328 };
329 
330 int tb_register_protocol_handler(struct tb_protocol_handler *handler);
331 void tb_unregister_protocol_handler(struct tb_protocol_handler *handler);
332 
333 /**
334  * struct tb_service - Thunderbolt service
335  * @dev: XDomain device
336  * @id: ID of the service (shown in sysfs)
337  * @key: Protocol key from the properties directory
338  * @prtcid: Protocol ID from the properties directory
339  * @prtcvers: Protocol version from the properties directory
340  * @prtcrevs: Protocol software revision from the properties directory
341  * @prtcstns: Protocol settings mask from the properties directory
342  *
343  * Each domain exposes set of services it supports as collection of
344  * properties. For each service there will be one corresponding
345  * &struct tb_service. Service drivers are bound to these.
346  */
347 struct tb_service {
348 	struct device dev;
349 	int id;
350 	const char *key;
351 	u32 prtcid;
352 	u32 prtcvers;
353 	u32 prtcrevs;
354 	u32 prtcstns;
355 };
356 
tb_service_get(struct tb_service * svc)357 static inline struct tb_service *tb_service_get(struct tb_service *svc)
358 {
359 	if (svc)
360 		get_device(&svc->dev);
361 	return svc;
362 }
363 
tb_service_put(struct tb_service * svc)364 static inline void tb_service_put(struct tb_service *svc)
365 {
366 	if (svc)
367 		put_device(&svc->dev);
368 }
369 
tb_is_service(const struct device * dev)370 static inline bool tb_is_service(const struct device *dev)
371 {
372 	return dev->type == &tb_service_type;
373 }
374 
tb_to_service(struct device * dev)375 static inline struct tb_service *tb_to_service(struct device *dev)
376 {
377 	if (tb_is_service(dev))
378 		return container_of(dev, struct tb_service, dev);
379 	return NULL;
380 }
381 
382 /**
383  * tb_service_driver - Thunderbolt service driver
384  * @driver: Driver structure
385  * @probe: Called when the driver is probed
386  * @remove: Called when the driver is removed (optional)
387  * @shutdown: Called at shutdown time to stop the service (optional)
388  * @id_table: Table of service identifiers the driver supports
389  */
390 struct tb_service_driver {
391 	struct device_driver driver;
392 	int (*probe)(struct tb_service *svc, const struct tb_service_id *id);
393 	void (*remove)(struct tb_service *svc);
394 	void (*shutdown)(struct tb_service *svc);
395 	const struct tb_service_id *id_table;
396 };
397 
398 #define TB_SERVICE(key, id)				\
399 	.match_flags = TBSVC_MATCH_PROTOCOL_KEY |	\
400 		       TBSVC_MATCH_PROTOCOL_ID,		\
401 	.protocol_key = (key),				\
402 	.protocol_id = (id)
403 
404 int tb_register_service_driver(struct tb_service_driver *drv);
405 void tb_unregister_service_driver(struct tb_service_driver *drv);
406 
tb_service_get_drvdata(const struct tb_service * svc)407 static inline void *tb_service_get_drvdata(const struct tb_service *svc)
408 {
409 	return dev_get_drvdata(&svc->dev);
410 }
411 
tb_service_set_drvdata(struct tb_service * svc,void * data)412 static inline void tb_service_set_drvdata(struct tb_service *svc, void *data)
413 {
414 	dev_set_drvdata(&svc->dev, data);
415 }
416 
tb_service_parent(struct tb_service * svc)417 static inline struct tb_xdomain *tb_service_parent(struct tb_service *svc)
418 {
419 	return tb_to_xdomain(svc->dev.parent);
420 }
421 
422 /**
423  * struct tb_nhi - thunderbolt native host interface
424  * @lock: Must be held during ring creation/destruction. Is acquired by
425  *	  interrupt_work when dispatching interrupts to individual rings.
426  * @pdev: Pointer to the PCI device
427  * @iobase: MMIO space of the NHI
428  * @tx_rings: All Tx rings available on this host controller
429  * @rx_rings: All Rx rings available on this host controller
430  * @msix_ida: Used to allocate MSI-X vectors for rings
431  * @going_away: The host controller device is about to disappear so when
432  *		this flag is set, avoid touching the hardware anymore.
433  * @interrupt_work: Work scheduled to handle ring interrupt when no
434  *		    MSI-X is used.
435  * @hop_count: Number of rings (end point hops) supported by NHI.
436  */
437 struct tb_nhi {
438 	spinlock_t lock;
439 	struct pci_dev *pdev;
440 	void __iomem *iobase;
441 	struct tb_ring **tx_rings;
442 	struct tb_ring **rx_rings;
443 	struct ida msix_ida;
444 	bool going_away;
445 	struct work_struct interrupt_work;
446 	u32 hop_count;
447 };
448 
449 /**
450  * struct tb_ring - thunderbolt TX or RX ring associated with a NHI
451  * @lock: Lock serializing actions to this ring. Must be acquired after
452  *	  nhi->lock.
453  * @nhi: Pointer to the native host controller interface
454  * @size: Size of the ring
455  * @hop: Hop (DMA channel) associated with this ring
456  * @head: Head of the ring (write next descriptor here)
457  * @tail: Tail of the ring (complete next descriptor here)
458  * @descriptors: Allocated descriptors for this ring
459  * @queue: Queue holding frames to be transferred over this ring
460  * @in_flight: Queue holding frames that are currently in flight
461  * @work: Interrupt work structure
462  * @is_tx: Is the ring Tx or Rx
463  * @running: Is the ring running
464  * @irq: MSI-X irq number if the ring uses MSI-X. %0 otherwise.
465  * @vector: MSI-X vector number the ring uses (only set if @irq is > 0)
466  * @flags: Ring specific flags
467  * @sof_mask: Bit mask used to detect start of frame PDF
468  * @eof_mask: Bit mask used to detect end of frame PDF
469  * @start_poll: Called when ring interrupt is triggered to start
470  *		polling. Passing %NULL keeps the ring in interrupt mode.
471  * @poll_data: Data passed to @start_poll
472  */
473 struct tb_ring {
474 	spinlock_t lock;
475 	struct tb_nhi *nhi;
476 	int size;
477 	int hop;
478 	int head;
479 	int tail;
480 	struct ring_desc *descriptors;
481 	dma_addr_t descriptors_dma;
482 	struct list_head queue;
483 	struct list_head in_flight;
484 	struct work_struct work;
485 	bool is_tx:1;
486 	bool running:1;
487 	int irq;
488 	u8 vector;
489 	unsigned int flags;
490 	u16 sof_mask;
491 	u16 eof_mask;
492 	void (*start_poll)(void *data);
493 	void *poll_data;
494 };
495 
496 /* Leave ring interrupt enabled on suspend */
497 #define RING_FLAG_NO_SUSPEND	BIT(0)
498 /* Configure the ring to be in frame mode */
499 #define RING_FLAG_FRAME		BIT(1)
500 /* Enable end-to-end flow control */
501 #define RING_FLAG_E2E		BIT(2)
502 
503 struct ring_frame;
504 typedef void (*ring_cb)(struct tb_ring *, struct ring_frame *, bool canceled);
505 
506 /**
507  * enum ring_desc_flags - Flags for DMA ring descriptor
508  * %RING_DESC_ISOCH: Enable isonchronous DMA (Tx only)
509  * %RING_DESC_CRC_ERROR: In frame mode CRC check failed for the frame (Rx only)
510  * %RING_DESC_COMPLETED: Descriptor completed (set by NHI)
511  * %RING_DESC_POSTED: Always set this
512  * %RING_DESC_BUFFER_OVERRUN: RX buffer overrun
513  * %RING_DESC_INTERRUPT: Request an interrupt on completion
514  */
515 enum ring_desc_flags {
516 	RING_DESC_ISOCH = 0x1,
517 	RING_DESC_CRC_ERROR = 0x1,
518 	RING_DESC_COMPLETED = 0x2,
519 	RING_DESC_POSTED = 0x4,
520 	RING_DESC_BUFFER_OVERRUN = 0x04,
521 	RING_DESC_INTERRUPT = 0x8,
522 };
523 
524 /**
525  * struct ring_frame - For use with ring_rx/ring_tx
526  * @buffer_phy: DMA mapped address of the frame
527  * @callback: Callback called when the frame is finished (optional)
528  * @list: Frame is linked to a queue using this
529  * @size: Size of the frame in bytes (%0 means %4096)
530  * @flags: Flags for the frame (see &enum ring_desc_flags)
531  * @eof: End of frame protocol defined field
532  * @sof: Start of frame protocol defined field
533  */
534 struct ring_frame {
535 	dma_addr_t buffer_phy;
536 	ring_cb callback;
537 	struct list_head list;
538 	u32 size:12;
539 	u32 flags:12;
540 	u32 eof:4;
541 	u32 sof:4;
542 };
543 
544 /* Minimum size for ring_rx */
545 #define TB_FRAME_SIZE		0x100
546 
547 struct tb_ring *tb_ring_alloc_tx(struct tb_nhi *nhi, int hop, int size,
548 				 unsigned int flags);
549 struct tb_ring *tb_ring_alloc_rx(struct tb_nhi *nhi, int hop, int size,
550 				 unsigned int flags, u16 sof_mask, u16 eof_mask,
551 				 void (*start_poll)(void *), void *poll_data);
552 void tb_ring_start(struct tb_ring *ring);
553 void tb_ring_stop(struct tb_ring *ring);
554 void tb_ring_free(struct tb_ring *ring);
555 
556 int __tb_ring_enqueue(struct tb_ring *ring, struct ring_frame *frame);
557 
558 /**
559  * tb_ring_rx() - enqueue a frame on an RX ring
560  * @ring: Ring to enqueue the frame
561  * @frame: Frame to enqueue
562  *
563  * @frame->buffer, @frame->buffer_phy have to be set. The buffer must
564  * contain at least %TB_FRAME_SIZE bytes.
565  *
566  * @frame->callback will be invoked with @frame->size, @frame->flags,
567  * @frame->eof, @frame->sof set once the frame has been received.
568  *
569  * If ring_stop() is called after the packet has been enqueued
570  * @frame->callback will be called with canceled set to true.
571  *
572  * Return: Returns %-ESHUTDOWN if ring_stop has been called. Zero otherwise.
573  */
tb_ring_rx(struct tb_ring * ring,struct ring_frame * frame)574 static inline int tb_ring_rx(struct tb_ring *ring, struct ring_frame *frame)
575 {
576 	WARN_ON(ring->is_tx);
577 	return __tb_ring_enqueue(ring, frame);
578 }
579 
580 /**
581  * tb_ring_tx() - enqueue a frame on an TX ring
582  * @ring: Ring the enqueue the frame
583  * @frame: Frame to enqueue
584  *
585  * @frame->buffer, @frame->buffer_phy, @frame->size, @frame->eof and
586  * @frame->sof have to be set.
587  *
588  * @frame->callback will be invoked with once the frame has been transmitted.
589  *
590  * If ring_stop() is called after the packet has been enqueued @frame->callback
591  * will be called with canceled set to true.
592  *
593  * Return: Returns %-ESHUTDOWN if ring_stop has been called. Zero otherwise.
594  */
tb_ring_tx(struct tb_ring * ring,struct ring_frame * frame)595 static inline int tb_ring_tx(struct tb_ring *ring, struct ring_frame *frame)
596 {
597 	WARN_ON(!ring->is_tx);
598 	return __tb_ring_enqueue(ring, frame);
599 }
600 
601 /* Used only when the ring is in polling mode */
602 struct ring_frame *tb_ring_poll(struct tb_ring *ring);
603 void tb_ring_poll_complete(struct tb_ring *ring);
604 
605 /**
606  * tb_ring_dma_device() - Return device used for DMA mapping
607  * @ring: Ring whose DMA device is retrieved
608  *
609  * Use this function when you are mapping DMA for buffers that are
610  * passed to the ring for sending/receiving.
611  */
tb_ring_dma_device(struct tb_ring * ring)612 static inline struct device *tb_ring_dma_device(struct tb_ring *ring)
613 {
614 	return &ring->nhi->pdev->dev;
615 }
616 
617 #endif /* THUNDERBOLT_H_ */
618