1  /* SPDX-License-Identifier: GPL-2.0-only */
2  /*
3   * Copyright (c) 2024 Linaro Limited
4   */
5  
6  #ifndef __TEE_CORE_H
7  #define __TEE_CORE_H
8  
9  #include <linux/cdev.h>
10  #include <linux/device.h>
11  #include <linux/idr.h>
12  #include <linux/kref.h>
13  #include <linux/list.h>
14  #include <linux/tee.h>
15  #include <linux/tee_drv.h>
16  #include <linux/types.h>
17  #include <linux/uuid.h>
18  
19  /*
20   * The file describes the API provided by the generic TEE driver to the
21   * specific TEE driver.
22   */
23  
24  #define TEE_SHM_DYNAMIC		BIT(0)  /* Dynamic shared memory registered */
25  					/* in secure world */
26  #define TEE_SHM_USER_MAPPED	BIT(1)  /* Memory mapped in user space */
27  #define TEE_SHM_POOL		BIT(2)  /* Memory allocated from pool */
28  #define TEE_SHM_PRIV		BIT(3)  /* Memory private to TEE driver */
29  
30  #define TEE_DEVICE_FLAG_REGISTERED	0x1
31  #define TEE_MAX_DEV_NAME_LEN		32
32  
33  /**
34   * struct tee_device - TEE Device representation
35   * @name:	name of device
36   * @desc:	description of device
37   * @id:		unique id of device
38   * @flags:	represented by TEE_DEVICE_FLAG_REGISTERED above
39   * @dev:	embedded basic device structure
40   * @cdev:	embedded cdev
41   * @num_users:	number of active users of this device
42   * @c_no_user:	completion used when unregistering the device
43   * @mutex:	mutex protecting @num_users and @idr
44   * @idr:	register of user space shared memory objects allocated or
45   *		registered on this device
46   * @pool:	shared memory pool
47   */
48  struct tee_device {
49  	char name[TEE_MAX_DEV_NAME_LEN];
50  	const struct tee_desc *desc;
51  	int id;
52  	unsigned int flags;
53  
54  	struct device dev;
55  	struct cdev cdev;
56  
57  	size_t num_users;
58  	struct completion c_no_users;
59  	struct mutex mutex;	/* protects num_users and idr */
60  
61  	struct idr idr;
62  	struct tee_shm_pool *pool;
63  };
64  
65  /**
66   * struct tee_driver_ops - driver operations vtable
67   * @get_version:	returns version of driver
68   * @open:		called when the device file is opened
69   * @release:		release this open file
70   * @open_session:	open a new session
71   * @close_session:	close a session
72   * @system_session:	declare session as a system session
73   * @invoke_func:	invoke a trusted function
74   * @cancel_req:		request cancel of an ongoing invoke or open
75   * @supp_recv:		called for supplicant to get a command
76   * @supp_send:		called for supplicant to send a response
77   * @shm_register:	register shared memory buffer in TEE
78   * @shm_unregister:	unregister shared memory buffer in TEE
79   */
80  struct tee_driver_ops {
81  	void (*get_version)(struct tee_device *teedev,
82  			    struct tee_ioctl_version_data *vers);
83  	int (*open)(struct tee_context *ctx);
84  	void (*release)(struct tee_context *ctx);
85  	int (*open_session)(struct tee_context *ctx,
86  			    struct tee_ioctl_open_session_arg *arg,
87  			    struct tee_param *param);
88  	int (*close_session)(struct tee_context *ctx, u32 session);
89  	int (*system_session)(struct tee_context *ctx, u32 session);
90  	int (*invoke_func)(struct tee_context *ctx,
91  			   struct tee_ioctl_invoke_arg *arg,
92  			   struct tee_param *param);
93  	int (*cancel_req)(struct tee_context *ctx, u32 cancel_id, u32 session);
94  	int (*supp_recv)(struct tee_context *ctx, u32 *func, u32 *num_params,
95  			 struct tee_param *param);
96  	int (*supp_send)(struct tee_context *ctx, u32 ret, u32 num_params,
97  			 struct tee_param *param);
98  	int (*shm_register)(struct tee_context *ctx, struct tee_shm *shm,
99  			    struct page **pages, size_t num_pages,
100  			    unsigned long start);
101  	int (*shm_unregister)(struct tee_context *ctx, struct tee_shm *shm);
102  };
103  
104  /**
105   * struct tee_desc - Describes the TEE driver to the subsystem
106   * @name:	name of driver
107   * @ops:	driver operations vtable
108   * @owner:	module providing the driver
109   * @flags:	Extra properties of driver, defined by TEE_DESC_* below
110   */
111  #define TEE_DESC_PRIVILEGED	0x1
112  struct tee_desc {
113  	const char *name;
114  	const struct tee_driver_ops *ops;
115  	struct module *owner;
116  	u32 flags;
117  };
118  
119  /**
120   * tee_device_alloc() - Allocate a new struct tee_device instance
121   * @teedesc:	Descriptor for this driver
122   * @dev:	Parent device for this device
123   * @pool:	Shared memory pool, NULL if not used
124   * @driver_data: Private driver data for this device
125   *
126   * Allocates a new struct tee_device instance. The device is
127   * removed by tee_device_unregister().
128   *
129   * @returns a pointer to a 'struct tee_device' or an ERR_PTR on failure
130   */
131  struct tee_device *tee_device_alloc(const struct tee_desc *teedesc,
132  				    struct device *dev,
133  				    struct tee_shm_pool *pool,
134  				    void *driver_data);
135  
136  /**
137   * tee_device_register() - Registers a TEE device
138   * @teedev:	Device to register
139   *
140   * tee_device_unregister() need to be called to remove the @teedev if
141   * this function fails.
142   *
143   * @returns < 0 on failure
144   */
145  int tee_device_register(struct tee_device *teedev);
146  
147  /**
148   * tee_device_unregister() - Removes a TEE device
149   * @teedev:	Device to unregister
150   *
151   * This function should be called to remove the @teedev even if
152   * tee_device_register() hasn't been called yet. Does nothing if
153   * @teedev is NULL.
154   */
155  void tee_device_unregister(struct tee_device *teedev);
156  
157  /**
158   * tee_device_set_dev_groups() - Set device attribute groups
159   * @teedev:	Device to register
160   * @dev_groups: Attribute groups
161   *
162   * Assigns the provided @dev_groups to the @teedev to be registered later
163   * with tee_device_register(). Calling this function is optional, but if
164   * it's called it must be called before tee_device_register().
165   */
166  void tee_device_set_dev_groups(struct tee_device *teedev,
167  			       const struct attribute_group **dev_groups);
168  
169  /**
170   * tee_session_calc_client_uuid() - Calculates client UUID for session
171   * @uuid:		Resulting UUID
172   * @connection_method:	Connection method for session (TEE_IOCTL_LOGIN_*)
173   * @connectuon_data:	Connection data for opening session
174   *
175   * Based on connection method calculates UUIDv5 based client UUID.
176   *
177   * For group based logins verifies that calling process has specified
178   * credentials.
179   *
180   * @return < 0 on failure
181   */
182  int tee_session_calc_client_uuid(uuid_t *uuid, u32 connection_method,
183  				 const u8 connection_data[TEE_IOCTL_UUID_LEN]);
184  
185  /**
186   * struct tee_shm_pool - shared memory pool
187   * @ops:		operations
188   * @private_data:	private data for the shared memory manager
189   */
190  struct tee_shm_pool {
191  	const struct tee_shm_pool_ops *ops;
192  	void *private_data;
193  };
194  
195  /**
196   * struct tee_shm_pool_ops - shared memory pool operations
197   * @alloc:		called when allocating shared memory
198   * @free:		called when freeing shared memory
199   * @destroy_pool:	called when destroying the pool
200   */
201  struct tee_shm_pool_ops {
202  	int (*alloc)(struct tee_shm_pool *pool, struct tee_shm *shm,
203  		     size_t size, size_t align);
204  	void (*free)(struct tee_shm_pool *pool, struct tee_shm *shm);
205  	void (*destroy_pool)(struct tee_shm_pool *pool);
206  };
207  
208  /*
209   * tee_shm_pool_alloc_res_mem() - Create a shm manager for reserved memory
210   * @vaddr:	Virtual address of start of pool
211   * @paddr:	Physical address of start of pool
212   * @size:	Size in bytes of the pool
213   *
214   * @returns pointer to a 'struct tee_shm_pool' or an ERR_PTR on failure.
215   */
216  struct tee_shm_pool *tee_shm_pool_alloc_res_mem(unsigned long vaddr,
217  						phys_addr_t paddr, size_t size,
218  						int min_alloc_order);
219  
220  /**
221   * tee_shm_pool_free() - Free a shared memory pool
222   * @pool:	The shared memory pool to free
223   *
224   * The must be no remaining shared memory allocated from this pool when
225   * this function is called.
226   */
tee_shm_pool_free(struct tee_shm_pool * pool)227  static inline void tee_shm_pool_free(struct tee_shm_pool *pool)
228  {
229  	pool->ops->destroy_pool(pool);
230  }
231  
232  /**
233   * tee_get_drvdata() - Return driver_data pointer
234   * @returns the driver_data pointer supplied to tee_register().
235   */
236  void *tee_get_drvdata(struct tee_device *teedev);
237  
238  /**
239   * tee_shm_alloc_priv_buf() - Allocate shared memory for private use by specific
240   *                            TEE driver
241   * @ctx:	The TEE context for shared memory allocation
242   * @size:	Shared memory allocation size
243   * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
244   */
245  struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size);
246  
247  int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
248  			     int (*shm_register)(struct tee_context *ctx,
249  						 struct tee_shm *shm,
250  						 struct page **pages,
251  						 size_t num_pages,
252  						 unsigned long start));
253  void tee_dyn_shm_free_helper(struct tee_shm *shm,
254  			     int (*shm_unregister)(struct tee_context *ctx,
255  						   struct tee_shm *shm));
256  
257  /**
258   * tee_shm_is_dynamic() - Check if shared memory object is of the dynamic kind
259   * @shm:	Shared memory handle
260   * @returns true if object is dynamic shared memory
261   */
tee_shm_is_dynamic(struct tee_shm * shm)262  static inline bool tee_shm_is_dynamic(struct tee_shm *shm)
263  {
264  	return shm && (shm->flags & TEE_SHM_DYNAMIC);
265  }
266  
267  /**
268   * tee_shm_put() - Decrease reference count on a shared memory handle
269   * @shm:	Shared memory handle
270   */
271  void tee_shm_put(struct tee_shm *shm);
272  
273  /**
274   * tee_shm_get_id() - Get id of a shared memory object
275   * @shm:	Shared memory handle
276   * @returns id
277   */
tee_shm_get_id(struct tee_shm * shm)278  static inline int tee_shm_get_id(struct tee_shm *shm)
279  {
280  	return shm->id;
281  }
282  
283  /**
284   * tee_shm_get_from_id() - Find shared memory object and increase reference
285   * count
286   * @ctx:	Context owning the shared memory
287   * @id:		Id of shared memory object
288   * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
289   */
290  struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id);
291  
tee_param_is_memref(struct tee_param * param)292  static inline bool tee_param_is_memref(struct tee_param *param)
293  {
294  	switch (param->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
295  	case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
296  	case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
297  	case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
298  		return true;
299  	default:
300  		return false;
301  	}
302  }
303  
304  /**
305   * teedev_open() - Open a struct tee_device
306   * @teedev:	Device to open
307   *
308   * @return a pointer to struct tee_context on success or an ERR_PTR on failure.
309   */
310  struct tee_context *teedev_open(struct tee_device *teedev);
311  
312  /**
313   * teedev_close_context() - closes a struct tee_context
314   * @ctx:	The struct tee_context to close
315   */
316  void teedev_close_context(struct tee_context *ctx);
317  
318  #endif /*__TEE_CORE_H*/
319