1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (c) 2015-2022 Linaro Limited
4  */
5 
6 #ifndef __TEE_DRV_H
7 #define __TEE_DRV_H
8 
9 #include <linux/device.h>
10 #include <linux/idr.h>
11 #include <linux/kref.h>
12 #include <linux/list.h>
13 #include <linux/mod_devicetable.h>
14 #include <linux/tee.h>
15 #include <linux/types.h>
16 #include <linux/uuid.h>
17 
18 /*
19  * The file describes the API provided by the generic TEE driver to the
20  * specific TEE driver.
21  */
22 
23 #define TEE_SHM_DYNAMIC		BIT(0)  /* Dynamic shared memory registered */
24 					/* in secure world */
25 #define TEE_SHM_USER_MAPPED	BIT(1)  /* Memory mapped in user space */
26 #define TEE_SHM_POOL		BIT(2)  /* Memory allocated from pool */
27 #define TEE_SHM_PRIV		BIT(3)  /* Memory private to TEE driver */
28 
29 struct device;
30 struct tee_device;
31 struct tee_shm;
32 struct tee_shm_pool;
33 
34 /**
35  * struct tee_context - driver specific context on file pointer data
36  * @teedev:	pointer to this drivers struct tee_device
37  * @list_shm:	List of shared memory object owned by this context
38  * @data:	driver specific context data, managed by the driver
39  * @refcount:	reference counter for this structure
40  * @releasing:  flag that indicates if context is being released right now.
41  *		It is needed to break circular dependency on context during
42  *              shared memory release.
43  * @supp_nowait: flag that indicates that requests in this context should not
44  *              wait for tee-supplicant daemon to be started if not present
45  *              and just return with an error code. It is needed for requests
46  *              that arises from TEE based kernel drivers that should be
47  *              non-blocking in nature.
48  * @cap_memref_null: flag indicating if the TEE Client support shared
49  *                   memory buffer with a NULL pointer.
50  */
51 struct tee_context {
52 	struct tee_device *teedev;
53 	void *data;
54 	struct kref refcount;
55 	bool releasing;
56 	bool supp_nowait;
57 	bool cap_memref_null;
58 };
59 
60 struct tee_param_memref {
61 	size_t shm_offs;
62 	size_t size;
63 	struct tee_shm *shm;
64 };
65 
66 struct tee_param_value {
67 	u64 a;
68 	u64 b;
69 	u64 c;
70 };
71 
72 struct tee_param {
73 	u64 attr;
74 	union {
75 		struct tee_param_memref memref;
76 		struct tee_param_value value;
77 	} u;
78 };
79 
80 /**
81  * struct tee_driver_ops - driver operations vtable
82  * @get_version:	returns version of driver
83  * @open:		called when the device file is opened
84  * @release:		release this open file
85  * @open_session:	open a new session
86  * @close_session:	close a session
87  * @invoke_func:	invoke a trusted function
88  * @cancel_req:		request cancel of an ongoing invoke or open
89  * @supp_recv:		called for supplicant to get a command
90  * @supp_send:		called for supplicant to send a response
91  * @shm_register:	register shared memory buffer in TEE
92  * @shm_unregister:	unregister shared memory buffer in TEE
93  */
94 struct tee_driver_ops {
95 	void (*get_version)(struct tee_device *teedev,
96 			    struct tee_ioctl_version_data *vers);
97 	int (*open)(struct tee_context *ctx);
98 	void (*release)(struct tee_context *ctx);
99 	int (*open_session)(struct tee_context *ctx,
100 			    struct tee_ioctl_open_session_arg *arg,
101 			    struct tee_param *param);
102 	int (*close_session)(struct tee_context *ctx, u32 session);
103 	int (*invoke_func)(struct tee_context *ctx,
104 			   struct tee_ioctl_invoke_arg *arg,
105 			   struct tee_param *param);
106 	int (*cancel_req)(struct tee_context *ctx, u32 cancel_id, u32 session);
107 	int (*supp_recv)(struct tee_context *ctx, u32 *func, u32 *num_params,
108 			 struct tee_param *param);
109 	int (*supp_send)(struct tee_context *ctx, u32 ret, u32 num_params,
110 			 struct tee_param *param);
111 	int (*shm_register)(struct tee_context *ctx, struct tee_shm *shm,
112 			    struct page **pages, size_t num_pages,
113 			    unsigned long start);
114 	int (*shm_unregister)(struct tee_context *ctx, struct tee_shm *shm);
115 };
116 
117 /**
118  * struct tee_desc - Describes the TEE driver to the subsystem
119  * @name:	name of driver
120  * @ops:	driver operations vtable
121  * @owner:	module providing the driver
122  * @flags:	Extra properties of driver, defined by TEE_DESC_* below
123  */
124 #define TEE_DESC_PRIVILEGED	0x1
125 struct tee_desc {
126 	const char *name;
127 	const struct tee_driver_ops *ops;
128 	struct module *owner;
129 	u32 flags;
130 };
131 
132 /**
133  * tee_device_alloc() - Allocate a new struct tee_device instance
134  * @teedesc:	Descriptor for this driver
135  * @dev:	Parent device for this device
136  * @pool:	Shared memory pool, NULL if not used
137  * @driver_data: Private driver data for this device
138  *
139  * Allocates a new struct tee_device instance. The device is
140  * removed by tee_device_unregister().
141  *
142  * @returns a pointer to a 'struct tee_device' or an ERR_PTR on failure
143  */
144 struct tee_device *tee_device_alloc(const struct tee_desc *teedesc,
145 				    struct device *dev,
146 				    struct tee_shm_pool *pool,
147 				    void *driver_data);
148 
149 /**
150  * tee_device_register() - Registers a TEE device
151  * @teedev:	Device to register
152  *
153  * tee_device_unregister() need to be called to remove the @teedev if
154  * this function fails.
155  *
156  * @returns < 0 on failure
157  */
158 int tee_device_register(struct tee_device *teedev);
159 
160 /**
161  * tee_device_unregister() - Removes a TEE device
162  * @teedev:	Device to unregister
163  *
164  * This function should be called to remove the @teedev even if
165  * tee_device_register() hasn't been called yet. Does nothing if
166  * @teedev is NULL.
167  */
168 void tee_device_unregister(struct tee_device *teedev);
169 
170 /**
171  * tee_session_calc_client_uuid() - Calculates client UUID for session
172  * @uuid:		Resulting UUID
173  * @connection_method:	Connection method for session (TEE_IOCTL_LOGIN_*)
174  * @connectuon_data:	Connection data for opening session
175  *
176  * Based on connection method calculates UUIDv5 based client UUID.
177  *
178  * For group based logins verifies that calling process has specified
179  * credentials.
180  *
181  * @return < 0 on failure
182  */
183 int tee_session_calc_client_uuid(uuid_t *uuid, u32 connection_method,
184 				 const u8 connection_data[TEE_IOCTL_UUID_LEN]);
185 
186 /**
187  * struct tee_shm - shared memory object
188  * @ctx:	context using the object
189  * @paddr:	physical address of the shared memory
190  * @kaddr:	virtual address of the shared memory
191  * @size:	size of shared memory
192  * @offset:	offset of buffer in user space
193  * @pages:	locked pages from userspace
194  * @num_pages:	number of locked pages
195  * @refcount:	reference counter
196  * @flags:	defined by TEE_SHM_* in tee_drv.h
197  * @id:		unique id of a shared memory object on this device, shared
198  *		with user space
199  * @sec_world_id:
200  *		secure world assigned id of this shared memory object, not
201  *		used by all drivers
202  *
203  * This pool is only supposed to be accessed directly from the TEE
204  * subsystem and from drivers that implements their own shm pool manager.
205  */
206 struct tee_shm {
207 	struct tee_context *ctx;
208 	phys_addr_t paddr;
209 	void *kaddr;
210 	size_t size;
211 	unsigned int offset;
212 	struct page **pages;
213 	size_t num_pages;
214 	refcount_t refcount;
215 	u32 flags;
216 	int id;
217 	u64 sec_world_id;
218 };
219 
220 /**
221  * struct tee_shm_pool - shared memory pool
222  * @ops:		operations
223  * @private_data:	private data for the shared memory manager
224  */
225 struct tee_shm_pool {
226 	const struct tee_shm_pool_ops *ops;
227 	void *private_data;
228 };
229 
230 /**
231  * struct tee_shm_pool_ops - shared memory pool operations
232  * @alloc:		called when allocating shared memory
233  * @free:		called when freeing shared memory
234  * @destroy_pool:	called when destroying the pool
235  */
236 struct tee_shm_pool_ops {
237 	int (*alloc)(struct tee_shm_pool *pool, struct tee_shm *shm,
238 		     size_t size, size_t align);
239 	void (*free)(struct tee_shm_pool *pool, struct tee_shm *shm);
240 	void (*destroy_pool)(struct tee_shm_pool *pool);
241 };
242 
243 /*
244  * tee_shm_pool_alloc_res_mem() - Create a shm manager for reserved memory
245  * @vaddr:	Virtual address of start of pool
246  * @paddr:	Physical address of start of pool
247  * @size:	Size in bytes of the pool
248  *
249  * @returns pointer to a 'struct tee_shm_pool' or an ERR_PTR on failure.
250  */
251 struct tee_shm_pool *tee_shm_pool_alloc_res_mem(unsigned long vaddr,
252 						phys_addr_t paddr, size_t size,
253 						int min_alloc_order);
254 
255 /**
256  * tee_shm_pool_free() - Free a shared memory pool
257  * @pool:	The shared memory pool to free
258  *
259  * The must be no remaining shared memory allocated from this pool when
260  * this function is called.
261  */
tee_shm_pool_free(struct tee_shm_pool * pool)262 static inline void tee_shm_pool_free(struct tee_shm_pool *pool)
263 {
264 	pool->ops->destroy_pool(pool);
265 }
266 
267 /**
268  * tee_get_drvdata() - Return driver_data pointer
269  * @returns the driver_data pointer supplied to tee_register().
270  */
271 void *tee_get_drvdata(struct tee_device *teedev);
272 
273 struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size);
274 struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size);
275 
276 struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
277 					    void *addr, size_t length);
278 
279 /**
280  * tee_shm_is_dynamic() - Check if shared memory object is of the dynamic kind
281  * @shm:	Shared memory handle
282  * @returns true if object is dynamic shared memory
283  */
tee_shm_is_dynamic(struct tee_shm * shm)284 static inline bool tee_shm_is_dynamic(struct tee_shm *shm)
285 {
286 	return shm && (shm->flags & TEE_SHM_DYNAMIC);
287 }
288 
289 /**
290  * tee_shm_free() - Free shared memory
291  * @shm:	Handle to shared memory to free
292  */
293 void tee_shm_free(struct tee_shm *shm);
294 
295 /**
296  * tee_shm_put() - Decrease reference count on a shared memory handle
297  * @shm:	Shared memory handle
298  */
299 void tee_shm_put(struct tee_shm *shm);
300 
301 /**
302  * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
303  * @shm:	Shared memory handle
304  * @offs:	Offset from start of this shared memory
305  * @returns virtual address of the shared memory + offs if offs is within
306  *	the bounds of this shared memory, else an ERR_PTR
307  */
308 void *tee_shm_get_va(struct tee_shm *shm, size_t offs);
309 
310 /**
311  * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
312  * @shm:	Shared memory handle
313  * @offs:	Offset from start of this shared memory
314  * @pa:		Physical address to return
315  * @returns 0 if offs is within the bounds of this shared memory, else an
316  *	error code.
317  */
318 int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa);
319 
320 /**
321  * tee_shm_get_size() - Get size of shared memory buffer
322  * @shm:	Shared memory handle
323  * @returns size of shared memory
324  */
tee_shm_get_size(struct tee_shm * shm)325 static inline size_t tee_shm_get_size(struct tee_shm *shm)
326 {
327 	return shm->size;
328 }
329 
330 /**
331  * tee_shm_get_pages() - Get list of pages that hold shared buffer
332  * @shm:	Shared memory handle
333  * @num_pages:	Number of pages will be stored there
334  * @returns pointer to pages array
335  */
tee_shm_get_pages(struct tee_shm * shm,size_t * num_pages)336 static inline struct page **tee_shm_get_pages(struct tee_shm *shm,
337 					      size_t *num_pages)
338 {
339 	*num_pages = shm->num_pages;
340 	return shm->pages;
341 }
342 
343 /**
344  * tee_shm_get_page_offset() - Get shared buffer offset from page start
345  * @shm:	Shared memory handle
346  * @returns page offset of shared buffer
347  */
tee_shm_get_page_offset(struct tee_shm * shm)348 static inline size_t tee_shm_get_page_offset(struct tee_shm *shm)
349 {
350 	return shm->offset;
351 }
352 
353 /**
354  * tee_shm_get_id() - Get id of a shared memory object
355  * @shm:	Shared memory handle
356  * @returns id
357  */
tee_shm_get_id(struct tee_shm * shm)358 static inline int tee_shm_get_id(struct tee_shm *shm)
359 {
360 	return shm->id;
361 }
362 
363 /**
364  * tee_shm_get_from_id() - Find shared memory object and increase reference
365  * count
366  * @ctx:	Context owning the shared memory
367  * @id:		Id of shared memory object
368  * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
369  */
370 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id);
371 
372 /**
373  * tee_client_open_context() - Open a TEE context
374  * @start:	if not NULL, continue search after this context
375  * @match:	function to check TEE device
376  * @data:	data for match function
377  * @vers:	if not NULL, version data of TEE device of the context returned
378  *
379  * This function does an operation similar to open("/dev/teeX") in user space.
380  * A returned context must be released with tee_client_close_context().
381  *
382  * Returns a TEE context of the first TEE device matched by the match()
383  * callback or an ERR_PTR.
384  */
385 struct tee_context *
386 tee_client_open_context(struct tee_context *start,
387 			int (*match)(struct tee_ioctl_version_data *,
388 				     const void *),
389 			const void *data, struct tee_ioctl_version_data *vers);
390 
391 /**
392  * tee_client_close_context() - Close a TEE context
393  * @ctx:	TEE context to close
394  *
395  * Note that all sessions previously opened with this context will be
396  * closed when this function is called.
397  */
398 void tee_client_close_context(struct tee_context *ctx);
399 
400 /**
401  * tee_client_get_version() - Query version of TEE
402  * @ctx:	TEE context to TEE to query
403  * @vers:	Pointer to version data
404  */
405 void tee_client_get_version(struct tee_context *ctx,
406 			    struct tee_ioctl_version_data *vers);
407 
408 /**
409  * tee_client_open_session() - Open a session to a Trusted Application
410  * @ctx:	TEE context
411  * @arg:	Open session arguments, see description of
412  *		struct tee_ioctl_open_session_arg
413  * @param:	Parameters passed to the Trusted Application
414  *
415  * Returns < 0 on error else see @arg->ret for result. If @arg->ret
416  * is TEEC_SUCCESS the session identifier is available in @arg->session.
417  */
418 int tee_client_open_session(struct tee_context *ctx,
419 			    struct tee_ioctl_open_session_arg *arg,
420 			    struct tee_param *param);
421 
422 /**
423  * tee_client_close_session() - Close a session to a Trusted Application
424  * @ctx:	TEE Context
425  * @session:	Session id
426  *
427  * Return < 0 on error else 0, regardless the session will not be
428  * valid after this function has returned.
429  */
430 int tee_client_close_session(struct tee_context *ctx, u32 session);
431 
432 /**
433  * tee_client_invoke_func() - Invoke a function in a Trusted Application
434  * @ctx:	TEE Context
435  * @arg:	Invoke arguments, see description of
436  *		struct tee_ioctl_invoke_arg
437  * @param:	Parameters passed to the Trusted Application
438  *
439  * Returns < 0 on error else see @arg->ret for result.
440  */
441 int tee_client_invoke_func(struct tee_context *ctx,
442 			   struct tee_ioctl_invoke_arg *arg,
443 			   struct tee_param *param);
444 
445 /**
446  * tee_client_cancel_req() - Request cancellation of the previous open-session
447  * or invoke-command operations in a Trusted Application
448  * @ctx:       TEE Context
449  * @arg:       Cancellation arguments, see description of
450  *             struct tee_ioctl_cancel_arg
451  *
452  * Returns < 0 on error else 0 if the cancellation was successfully requested.
453  */
454 int tee_client_cancel_req(struct tee_context *ctx,
455 			  struct tee_ioctl_cancel_arg *arg);
456 
tee_param_is_memref(struct tee_param * param)457 static inline bool tee_param_is_memref(struct tee_param *param)
458 {
459 	switch (param->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
460 	case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
461 	case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
462 	case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
463 		return true;
464 	default:
465 		return false;
466 	}
467 }
468 
469 extern struct bus_type tee_bus_type;
470 
471 /**
472  * struct tee_client_device - tee based device
473  * @id:			device identifier
474  * @dev:		device structure
475  */
476 struct tee_client_device {
477 	struct tee_client_device_id id;
478 	struct device dev;
479 };
480 
481 #define to_tee_client_device(d) container_of(d, struct tee_client_device, dev)
482 
483 /**
484  * struct tee_client_driver - tee client driver
485  * @id_table:		device id table supported by this driver
486  * @driver:		driver structure
487  */
488 struct tee_client_driver {
489 	const struct tee_client_device_id *id_table;
490 	struct device_driver driver;
491 };
492 
493 #define to_tee_client_driver(d) \
494 		container_of(d, struct tee_client_driver, driver)
495 
496 /**
497  * teedev_open() - Open a struct tee_device
498  * @teedev:	Device to open
499  *
500  * @return a pointer to struct tee_context on success or an ERR_PTR on failure.
501  */
502 struct tee_context *teedev_open(struct tee_device *teedev);
503 
504 /**
505  * teedev_close_context() - closes a struct tee_context
506  * @ctx:	The struct tee_context to close
507  */
508 void teedev_close_context(struct tee_context *ctx);
509 
510 #endif /*__TEE_DRV_H*/
511