1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Thunderbolt service API
4  *
5  * Copyright (C) 2014 Andreas Noever <andreas.noever@gmail.com>
6  * Copyright (C) 2017, Intel Corporation
7  * Authors: Michael Jamet <michael.jamet@intel.com>
8  *          Mika Westerberg <mika.westerberg@linux.intel.com>
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 };
37 
38 /**
39  * enum tb_security_level - Thunderbolt security level
40  * @TB_SECURITY_NONE: No security, legacy mode
41  * @TB_SECURITY_USER: User approval required at minimum
42  * @TB_SECURITY_SECURE: One time saved key required at minimum
43  * @TB_SECURITY_DPONLY: Only tunnel Display port (and USB)
44  * @TB_SECURITY_USBONLY: Only tunnel USB controller of the connected
45  *			 Thunderbolt dock (and Display Port). All PCIe
46  *			 links downstream of the dock are removed.
47  * @TB_SECURITY_NOPCIE: For USB4 systems this level is used when the
48  *			PCIe tunneling is disabled from the BIOS.
49  */
50 enum tb_security_level {
51 	TB_SECURITY_NONE,
52 	TB_SECURITY_USER,
53 	TB_SECURITY_SECURE,
54 	TB_SECURITY_DPONLY,
55 	TB_SECURITY_USBONLY,
56 	TB_SECURITY_NOPCIE,
57 };
58 
59 /**
60  * struct tb - main thunderbolt bus structure
61  * @dev: Domain device
62  * @lock: Big lock. Must be held when accessing any struct
63  *	  tb_switch / struct tb_port.
64  * @nhi: Pointer to the NHI structure
65  * @ctl: Control channel for this domain
66  * @wq: Ordered workqueue for all domain specific work
67  * @root_switch: Root switch of this domain
68  * @cm_ops: Connection manager specific operations vector
69  * @index: Linux assigned domain number
70  * @security_level: Current security level
71  * @nboot_acl: Number of boot ACLs the domain supports
72  * @privdata: Private connection manager specific data
73  */
74 struct tb {
75 	struct device dev;
76 	struct mutex lock;
77 	struct tb_nhi *nhi;
78 	struct tb_ctl *ctl;
79 	struct workqueue_struct *wq;
80 	struct tb_switch *root_switch;
81 	const struct tb_cm_ops *cm_ops;
82 	int index;
83 	enum tb_security_level security_level;
84 	size_t nboot_acl;
85 	unsigned long privdata[];
86 };
87 
88 extern const struct bus_type tb_bus_type;
89 extern const struct device_type tb_service_type;
90 extern const struct device_type tb_xdomain_type;
91 
92 #define TB_LINKS_PER_PHY_PORT	2
93 
tb_phy_port_from_link(unsigned int link)94 static inline unsigned int tb_phy_port_from_link(unsigned int link)
95 {
96 	return (link - 1) / TB_LINKS_PER_PHY_PORT;
97 }
98 
99 /**
100  * struct tb_property_dir - XDomain property directory
101  * @uuid: Directory UUID or %NULL if root directory
102  * @properties: List of properties in this directory
103  *
104  * User needs to provide serialization if needed.
105  */
106 struct tb_property_dir {
107 	const uuid_t *uuid;
108 	struct list_head properties;
109 };
110 
111 enum tb_property_type {
112 	TB_PROPERTY_TYPE_UNKNOWN = 0x00,
113 	TB_PROPERTY_TYPE_DIRECTORY = 0x44,
114 	TB_PROPERTY_TYPE_DATA = 0x64,
115 	TB_PROPERTY_TYPE_TEXT = 0x74,
116 	TB_PROPERTY_TYPE_VALUE = 0x76,
117 };
118 
119 #define TB_PROPERTY_KEY_SIZE	8
120 
121 /**
122  * struct tb_property - XDomain property
123  * @list: Used to link properties together in a directory
124  * @key: Key for the property (always terminated).
125  * @type: Type of the property
126  * @length: Length of the property data in dwords
127  * @value: Property value
128  *
129  * Users use @type to determine which field in @value is filled.
130  */
131 struct tb_property {
132 	struct list_head list;
133 	char key[TB_PROPERTY_KEY_SIZE + 1];
134 	enum tb_property_type type;
135 	size_t length;
136 	union {
137 		struct tb_property_dir *dir;
138 		u8 *data;
139 		char *text;
140 		u32 immediate;
141 	} value;
142 };
143 
144 struct tb_property_dir *tb_property_parse_dir(const u32 *block,
145 					      size_t block_len);
146 ssize_t tb_property_format_dir(const struct tb_property_dir *dir, u32 *block,
147 			       size_t block_len);
148 struct tb_property_dir *tb_property_copy_dir(const struct tb_property_dir *dir);
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  * enum tb_link_width - Thunderbolt/USB4 link width
175  * @TB_LINK_WIDTH_SINGLE: Single lane link
176  * @TB_LINK_WIDTH_DUAL: Dual lane symmetric link
177  * @TB_LINK_WIDTH_ASYM_TX: Dual lane asymmetric Gen 4 link with 3 transmitters
178  * @TB_LINK_WIDTH_ASYM_RX: Dual lane asymmetric Gen 4 link with 3 receivers
179  */
180 enum tb_link_width {
181 	TB_LINK_WIDTH_SINGLE = BIT(0),
182 	TB_LINK_WIDTH_DUAL = BIT(1),
183 	TB_LINK_WIDTH_ASYM_TX = BIT(2),
184 	TB_LINK_WIDTH_ASYM_RX = BIT(3),
185 };
186 
187 /**
188  * struct tb_xdomain - Cross-domain (XDomain) connection
189  * @dev: XDomain device
190  * @tb: Pointer to the domain
191  * @remote_uuid: UUID of the remote domain (host)
192  * @local_uuid: Cached local UUID
193  * @route: Route string the other domain can be reached
194  * @vendor: Vendor ID of the remote domain
195  * @device: Device ID of the demote domain
196  * @local_max_hopid: Maximum input HopID of this host
197  * @remote_max_hopid: Maximum input HopID of the remote host
198  * @lock: Lock to serialize access to the following fields of this structure
199  * @vendor_name: Name of the vendor (or %NULL if not known)
200  * @device_name: Name of the device (or %NULL if not known)
201  * @link_speed: Speed of the link in Gb/s
202  * @link_width: Width of the downstream facing link
203  * @link_usb4: Downstream link is USB4
204  * @is_unplugged: The XDomain is unplugged
205  * @needs_uuid: If the XDomain does not have @remote_uuid it will be
206  *		queried first
207  * @service_ids: Used to generate IDs for the services
208  * @in_hopids: Input HopIDs for DMA tunneling
209  * @out_hopids; Output HopIDs for DMA tunneling
210  * @local_property_block: Local block of properties
211  * @local_property_block_gen: Generation of @local_property_block
212  * @local_property_block_len: Length of the @local_property_block in dwords
213  * @remote_properties: Properties exported by the remote domain
214  * @remote_property_block_gen: Generation of @remote_properties
215  * @state: Next XDomain discovery state to run
216  * @state_work: Work used to run the next state
217  * @state_retries: Number of retries remain for the state
218  * @properties_changed_work: Work used to notify the remote domain that
219  *			     our properties have changed
220  * @properties_changed_retries: Number of times left to send properties
221  *				changed notification
222  * @bonding_possible: True if lane bonding is possible on local side
223  * @target_link_width: Target link width from the remote host
224  * @link: Root switch link the remote domain is connected (ICM only)
225  * @depth: Depth in the chain the remote domain is connected (ICM only)
226  *
227  * This structure represents connection across two domains (hosts).
228  * Each XDomain contains zero or more services which are exposed as
229  * &struct tb_service objects.
230  *
231  * Service drivers may access this structure if they need to enumerate
232  * non-standard properties but they need hold @lock when doing so
233  * because properties can be changed asynchronously in response to
234  * changes in the remote domain.
235  */
236 struct tb_xdomain {
237 	struct device dev;
238 	struct tb *tb;
239 	uuid_t *remote_uuid;
240 	const uuid_t *local_uuid;
241 	u64 route;
242 	u16 vendor;
243 	u16 device;
244 	unsigned int local_max_hopid;
245 	unsigned int remote_max_hopid;
246 	struct mutex lock;
247 	const char *vendor_name;
248 	const char *device_name;
249 	unsigned int link_speed;
250 	enum tb_link_width link_width;
251 	bool link_usb4;
252 	bool is_unplugged;
253 	bool needs_uuid;
254 	struct ida service_ids;
255 	struct ida in_hopids;
256 	struct ida out_hopids;
257 	u32 *local_property_block;
258 	u32 local_property_block_gen;
259 	u32 local_property_block_len;
260 	struct tb_property_dir *remote_properties;
261 	u32 remote_property_block_gen;
262 	int state;
263 	struct delayed_work state_work;
264 	int state_retries;
265 	struct delayed_work properties_changed_work;
266 	int properties_changed_retries;
267 	bool bonding_possible;
268 	u8 target_link_width;
269 	u8 link;
270 	u8 depth;
271 };
272 
273 int tb_xdomain_lane_bonding_enable(struct tb_xdomain *xd);
274 void tb_xdomain_lane_bonding_disable(struct tb_xdomain *xd);
275 int tb_xdomain_alloc_in_hopid(struct tb_xdomain *xd, int hopid);
276 void tb_xdomain_release_in_hopid(struct tb_xdomain *xd, int hopid);
277 int tb_xdomain_alloc_out_hopid(struct tb_xdomain *xd, int hopid);
278 void tb_xdomain_release_out_hopid(struct tb_xdomain *xd, int hopid);
279 int tb_xdomain_enable_paths(struct tb_xdomain *xd, int transmit_path,
280 			    int transmit_ring, int receive_path,
281 			    int receive_ring);
282 int tb_xdomain_disable_paths(struct tb_xdomain *xd, int transmit_path,
283 			     int transmit_ring, int receive_path,
284 			     int receive_ring);
285 
tb_xdomain_disable_all_paths(struct tb_xdomain * xd)286 static inline int tb_xdomain_disable_all_paths(struct tb_xdomain *xd)
287 {
288 	return tb_xdomain_disable_paths(xd, -1, -1, -1, -1);
289 }
290 
291 struct tb_xdomain *tb_xdomain_find_by_uuid(struct tb *tb, const uuid_t *uuid);
292 struct tb_xdomain *tb_xdomain_find_by_route(struct tb *tb, u64 route);
293 
294 static inline struct tb_xdomain *
tb_xdomain_find_by_uuid_locked(struct tb * tb,const uuid_t * uuid)295 tb_xdomain_find_by_uuid_locked(struct tb *tb, const uuid_t *uuid)
296 {
297 	struct tb_xdomain *xd;
298 
299 	mutex_lock(&tb->lock);
300 	xd = tb_xdomain_find_by_uuid(tb, uuid);
301 	mutex_unlock(&tb->lock);
302 
303 	return xd;
304 }
305 
306 static inline struct tb_xdomain *
tb_xdomain_find_by_route_locked(struct tb * tb,u64 route)307 tb_xdomain_find_by_route_locked(struct tb *tb, u64 route)
308 {
309 	struct tb_xdomain *xd;
310 
311 	mutex_lock(&tb->lock);
312 	xd = tb_xdomain_find_by_route(tb, route);
313 	mutex_unlock(&tb->lock);
314 
315 	return xd;
316 }
317 
tb_xdomain_get(struct tb_xdomain * xd)318 static inline struct tb_xdomain *tb_xdomain_get(struct tb_xdomain *xd)
319 {
320 	if (xd)
321 		get_device(&xd->dev);
322 	return xd;
323 }
324 
tb_xdomain_put(struct tb_xdomain * xd)325 static inline void tb_xdomain_put(struct tb_xdomain *xd)
326 {
327 	if (xd)
328 		put_device(&xd->dev);
329 }
330 
tb_is_xdomain(const struct device * dev)331 static inline bool tb_is_xdomain(const struct device *dev)
332 {
333 	return dev->type == &tb_xdomain_type;
334 }
335 
tb_to_xdomain(struct device * dev)336 static inline struct tb_xdomain *tb_to_xdomain(struct device *dev)
337 {
338 	if (tb_is_xdomain(dev))
339 		return container_of(dev, struct tb_xdomain, dev);
340 	return NULL;
341 }
342 
343 int tb_xdomain_response(struct tb_xdomain *xd, const void *response,
344 			size_t size, enum tb_cfg_pkg_type type);
345 int tb_xdomain_request(struct tb_xdomain *xd, const void *request,
346 		       size_t request_size, enum tb_cfg_pkg_type request_type,
347 		       void *response, size_t response_size,
348 		       enum tb_cfg_pkg_type response_type,
349 		       unsigned int timeout_msec);
350 
351 /**
352  * tb_protocol_handler - Protocol specific handler
353  * @uuid: XDomain messages with this UUID are dispatched to this handler
354  * @callback: Callback called with the XDomain message. Returning %1
355  *	      here tells the XDomain core that the message was handled
356  *	      by this handler and should not be forwared to other
357  *	      handlers.
358  * @data: Data passed with the callback
359  * @list: Handlers are linked using this
360  *
361  * Thunderbolt services can hook into incoming XDomain requests by
362  * registering protocol handler. Only limitation is that the XDomain
363  * discovery protocol UUID cannot be registered since it is handled by
364  * the core XDomain code.
365  *
366  * The @callback must check that the message is really directed to the
367  * service the driver implements.
368  */
369 struct tb_protocol_handler {
370 	const uuid_t *uuid;
371 	int (*callback)(const void *buf, size_t size, void *data);
372 	void *data;
373 	struct list_head list;
374 };
375 
376 int tb_register_protocol_handler(struct tb_protocol_handler *handler);
377 void tb_unregister_protocol_handler(struct tb_protocol_handler *handler);
378 
379 /**
380  * struct tb_service - Thunderbolt service
381  * @dev: XDomain device
382  * @id: ID of the service (shown in sysfs)
383  * @key: Protocol key from the properties directory
384  * @prtcid: Protocol ID from the properties directory
385  * @prtcvers: Protocol version from the properties directory
386  * @prtcrevs: Protocol software revision from the properties directory
387  * @prtcstns: Protocol settings mask from the properties directory
388  * @debugfs_dir: Pointer to the service debugfs directory. Always created
389  *		 when debugfs is enabled. Can be used by service drivers to
390  *		 add their own entries under the service.
391  *
392  * Each domain exposes set of services it supports as collection of
393  * properties. For each service there will be one corresponding
394  * &struct tb_service. Service drivers are bound to these.
395  */
396 struct tb_service {
397 	struct device dev;
398 	int id;
399 	const char *key;
400 	u32 prtcid;
401 	u32 prtcvers;
402 	u32 prtcrevs;
403 	u32 prtcstns;
404 	struct dentry *debugfs_dir;
405 };
406 
tb_service_get(struct tb_service * svc)407 static inline struct tb_service *tb_service_get(struct tb_service *svc)
408 {
409 	if (svc)
410 		get_device(&svc->dev);
411 	return svc;
412 }
413 
tb_service_put(struct tb_service * svc)414 static inline void tb_service_put(struct tb_service *svc)
415 {
416 	if (svc)
417 		put_device(&svc->dev);
418 }
419 
tb_is_service(const struct device * dev)420 static inline bool tb_is_service(const struct device *dev)
421 {
422 	return dev->type == &tb_service_type;
423 }
424 
tb_to_service(struct device * dev)425 static inline struct tb_service *tb_to_service(struct device *dev)
426 {
427 	if (tb_is_service(dev))
428 		return container_of(dev, struct tb_service, dev);
429 	return NULL;
430 }
431 
432 /**
433  * tb_service_driver - Thunderbolt service driver
434  * @driver: Driver structure
435  * @probe: Called when the driver is probed
436  * @remove: Called when the driver is removed (optional)
437  * @shutdown: Called at shutdown time to stop the service (optional)
438  * @id_table: Table of service identifiers the driver supports
439  */
440 struct tb_service_driver {
441 	struct device_driver driver;
442 	int (*probe)(struct tb_service *svc, const struct tb_service_id *id);
443 	void (*remove)(struct tb_service *svc);
444 	void (*shutdown)(struct tb_service *svc);
445 	const struct tb_service_id *id_table;
446 };
447 
448 #define TB_SERVICE(key, id)				\
449 	.match_flags = TBSVC_MATCH_PROTOCOL_KEY |	\
450 		       TBSVC_MATCH_PROTOCOL_ID,		\
451 	.protocol_key = (key),				\
452 	.protocol_id = (id)
453 
454 int tb_register_service_driver(struct tb_service_driver *drv);
455 void tb_unregister_service_driver(struct tb_service_driver *drv);
456 
tb_service_get_drvdata(const struct tb_service * svc)457 static inline void *tb_service_get_drvdata(const struct tb_service *svc)
458 {
459 	return dev_get_drvdata(&svc->dev);
460 }
461 
tb_service_set_drvdata(struct tb_service * svc,void * data)462 static inline void tb_service_set_drvdata(struct tb_service *svc, void *data)
463 {
464 	dev_set_drvdata(&svc->dev, data);
465 }
466 
tb_service_parent(struct tb_service * svc)467 static inline struct tb_xdomain *tb_service_parent(struct tb_service *svc)
468 {
469 	return tb_to_xdomain(svc->dev.parent);
470 }
471 
472 /**
473  * struct tb_nhi - thunderbolt native host interface
474  * @lock: Must be held during ring creation/destruction. Is acquired by
475  *	  interrupt_work when dispatching interrupts to individual rings.
476  * @pdev: Pointer to the PCI device
477  * @ops: NHI specific optional ops
478  * @iobase: MMIO space of the NHI
479  * @tx_rings: All Tx rings available on this host controller
480  * @rx_rings: All Rx rings available on this host controller
481  * @msix_ida: Used to allocate MSI-X vectors for rings
482  * @going_away: The host controller device is about to disappear so when
483  *		this flag is set, avoid touching the hardware anymore.
484  * @iommu_dma_protection: An IOMMU will isolate external-facing ports.
485  * @interrupt_work: Work scheduled to handle ring interrupt when no
486  *		    MSI-X is used.
487  * @hop_count: Number of rings (end point hops) supported by NHI.
488  * @quirks: NHI specific quirks if any
489  */
490 struct tb_nhi {
491 	spinlock_t lock;
492 	struct pci_dev *pdev;
493 	const struct tb_nhi_ops *ops;
494 	void __iomem *iobase;
495 	struct tb_ring **tx_rings;
496 	struct tb_ring **rx_rings;
497 	struct ida msix_ida;
498 	bool going_away;
499 	bool iommu_dma_protection;
500 	struct work_struct interrupt_work;
501 	u32 hop_count;
502 	unsigned long quirks;
503 };
504 
505 /**
506  * struct tb_ring - thunderbolt TX or RX ring associated with a NHI
507  * @lock: Lock serializing actions to this ring. Must be acquired after
508  *	  nhi->lock.
509  * @nhi: Pointer to the native host controller interface
510  * @size: Size of the ring
511  * @hop: Hop (DMA channel) associated with this ring
512  * @head: Head of the ring (write next descriptor here)
513  * @tail: Tail of the ring (complete next descriptor here)
514  * @descriptors: Allocated descriptors for this ring
515  * @queue: Queue holding frames to be transferred over this ring
516  * @in_flight: Queue holding frames that are currently in flight
517  * @work: Interrupt work structure
518  * @is_tx: Is the ring Tx or Rx
519  * @running: Is the ring running
520  * @irq: MSI-X irq number if the ring uses MSI-X. %0 otherwise.
521  * @vector: MSI-X vector number the ring uses (only set if @irq is > 0)
522  * @flags: Ring specific flags
523  * @e2e_tx_hop: Transmit HopID when E2E is enabled. Only applicable to
524  *		RX ring. For TX ring this should be set to %0.
525  * @sof_mask: Bit mask used to detect start of frame PDF
526  * @eof_mask: Bit mask used to detect end of frame PDF
527  * @start_poll: Called when ring interrupt is triggered to start
528  *		polling. Passing %NULL keeps the ring in interrupt mode.
529  * @poll_data: Data passed to @start_poll
530  */
531 struct tb_ring {
532 	spinlock_t lock;
533 	struct tb_nhi *nhi;
534 	int size;
535 	int hop;
536 	int head;
537 	int tail;
538 	struct ring_desc *descriptors;
539 	dma_addr_t descriptors_dma;
540 	struct list_head queue;
541 	struct list_head in_flight;
542 	struct work_struct work;
543 	bool is_tx:1;
544 	bool running:1;
545 	int irq;
546 	u8 vector;
547 	unsigned int flags;
548 	int e2e_tx_hop;
549 	u16 sof_mask;
550 	u16 eof_mask;
551 	void (*start_poll)(void *data);
552 	void *poll_data;
553 };
554 
555 /* Leave ring interrupt enabled on suspend */
556 #define RING_FLAG_NO_SUSPEND	BIT(0)
557 /* Configure the ring to be in frame mode */
558 #define RING_FLAG_FRAME		BIT(1)
559 /* Enable end-to-end flow control */
560 #define RING_FLAG_E2E		BIT(2)
561 
562 struct ring_frame;
563 typedef void (*ring_cb)(struct tb_ring *, struct ring_frame *, bool canceled);
564 
565 /**
566  * enum ring_desc_flags - Flags for DMA ring descriptor
567  * %RING_DESC_ISOCH: Enable isonchronous DMA (Tx only)
568  * %RING_DESC_CRC_ERROR: In frame mode CRC check failed for the frame (Rx only)
569  * %RING_DESC_COMPLETED: Descriptor completed (set by NHI)
570  * %RING_DESC_POSTED: Always set this
571  * %RING_DESC_BUFFER_OVERRUN: RX buffer overrun
572  * %RING_DESC_INTERRUPT: Request an interrupt on completion
573  */
574 enum ring_desc_flags {
575 	RING_DESC_ISOCH = 0x1,
576 	RING_DESC_CRC_ERROR = 0x1,
577 	RING_DESC_COMPLETED = 0x2,
578 	RING_DESC_POSTED = 0x4,
579 	RING_DESC_BUFFER_OVERRUN = 0x04,
580 	RING_DESC_INTERRUPT = 0x8,
581 };
582 
583 /**
584  * struct ring_frame - For use with ring_rx/ring_tx
585  * @buffer_phy: DMA mapped address of the frame
586  * @callback: Callback called when the frame is finished (optional)
587  * @list: Frame is linked to a queue using this
588  * @size: Size of the frame in bytes (%0 means %4096)
589  * @flags: Flags for the frame (see &enum ring_desc_flags)
590  * @eof: End of frame protocol defined field
591  * @sof: Start of frame protocol defined field
592  */
593 struct ring_frame {
594 	dma_addr_t buffer_phy;
595 	ring_cb callback;
596 	struct list_head list;
597 	u32 size:12;
598 	u32 flags:12;
599 	u32 eof:4;
600 	u32 sof:4;
601 };
602 
603 /* Minimum size for ring_rx */
604 #define TB_FRAME_SIZE		0x100
605 
606 struct tb_ring *tb_ring_alloc_tx(struct tb_nhi *nhi, int hop, int size,
607 				 unsigned int flags);
608 struct tb_ring *tb_ring_alloc_rx(struct tb_nhi *nhi, int hop, int size,
609 				 unsigned int flags, int e2e_tx_hop,
610 				 u16 sof_mask, u16 eof_mask,
611 				 void (*start_poll)(void *), void *poll_data);
612 void tb_ring_start(struct tb_ring *ring);
613 void tb_ring_stop(struct tb_ring *ring);
614 void tb_ring_free(struct tb_ring *ring);
615 
616 int __tb_ring_enqueue(struct tb_ring *ring, struct ring_frame *frame);
617 
618 /**
619  * tb_ring_rx() - enqueue a frame on an RX ring
620  * @ring: Ring to enqueue the frame
621  * @frame: Frame to enqueue
622  *
623  * @frame->buffer, @frame->buffer_phy have to be set. The buffer must
624  * contain at least %TB_FRAME_SIZE bytes.
625  *
626  * @frame->callback will be invoked with @frame->size, @frame->flags,
627  * @frame->eof, @frame->sof set once the frame has been received.
628  *
629  * If ring_stop() is called after the packet has been enqueued
630  * @frame->callback will be called with canceled set to true.
631  *
632  * Return: Returns %-ESHUTDOWN if ring_stop has been called. Zero otherwise.
633  */
tb_ring_rx(struct tb_ring * ring,struct ring_frame * frame)634 static inline int tb_ring_rx(struct tb_ring *ring, struct ring_frame *frame)
635 {
636 	WARN_ON(ring->is_tx);
637 	return __tb_ring_enqueue(ring, frame);
638 }
639 
640 /**
641  * tb_ring_tx() - enqueue a frame on an TX ring
642  * @ring: Ring the enqueue the frame
643  * @frame: Frame to enqueue
644  *
645  * @frame->buffer, @frame->buffer_phy, @frame->size, @frame->eof and
646  * @frame->sof have to be set.
647  *
648  * @frame->callback will be invoked with once the frame has been transmitted.
649  *
650  * If ring_stop() is called after the packet has been enqueued @frame->callback
651  * will be called with canceled set to true.
652  *
653  * Return: Returns %-ESHUTDOWN if ring_stop has been called. Zero otherwise.
654  */
tb_ring_tx(struct tb_ring * ring,struct ring_frame * frame)655 static inline int tb_ring_tx(struct tb_ring *ring, struct ring_frame *frame)
656 {
657 	WARN_ON(!ring->is_tx);
658 	return __tb_ring_enqueue(ring, frame);
659 }
660 
661 /* Used only when the ring is in polling mode */
662 struct ring_frame *tb_ring_poll(struct tb_ring *ring);
663 void tb_ring_poll_complete(struct tb_ring *ring);
664 
665 /**
666  * tb_ring_dma_device() - Return device used for DMA mapping
667  * @ring: Ring whose DMA device is retrieved
668  *
669  * Use this function when you are mapping DMA for buffers that are
670  * passed to the ring for sending/receiving.
671  */
tb_ring_dma_device(struct tb_ring * ring)672 static inline struct device *tb_ring_dma_device(struct tb_ring *ring)
673 {
674 	return &ring->nhi->pdev->dev;
675 }
676 
677 #endif /* THUNDERBOLT_H_ */
678