xref: /linux-6.15/include/linux/tee_drv.h (revision bbb03029)
1 /*
2  * Copyright (c) 2015-2016, Linaro Limited
3  *
4  * This software is licensed under the terms of the GNU General Public
5  * License version 2, as published by the Free Software Foundation, and
6  * may be copied, distributed, and modified under those terms.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  */
14 
15 #ifndef __TEE_DRV_H
16 #define __TEE_DRV_H
17 
18 #include <linux/types.h>
19 #include <linux/idr.h>
20 #include <linux/list.h>
21 #include <linux/tee.h>
22 
23 /*
24  * The file describes the API provided by the generic TEE driver to the
25  * specific TEE driver.
26  */
27 
28 #define TEE_SHM_MAPPED		0x1	/* Memory mapped by the kernel */
29 #define TEE_SHM_DMA_BUF		0x2	/* Memory with dma-buf handle */
30 
31 struct tee_device;
32 struct tee_shm;
33 struct tee_shm_pool;
34 
35 /**
36  * struct tee_context - driver specific context on file pointer data
37  * @teedev:	pointer to this drivers struct tee_device
38  * @list_shm:	List of shared memory object owned by this context
39  * @data:	driver specific context data, managed by the driver
40  */
41 struct tee_context {
42 	struct tee_device *teedev;
43 	struct list_head list_shm;
44 	void *data;
45 };
46 
47 struct tee_param_memref {
48 	size_t shm_offs;
49 	size_t size;
50 	struct tee_shm *shm;
51 };
52 
53 struct tee_param_value {
54 	u64 a;
55 	u64 b;
56 	u64 c;
57 };
58 
59 struct tee_param {
60 	u64 attr;
61 	union {
62 		struct tee_param_memref memref;
63 		struct tee_param_value value;
64 	} u;
65 };
66 
67 /**
68  * struct tee_driver_ops - driver operations vtable
69  * @get_version:	returns version of driver
70  * @open:		called when the device file is opened
71  * @release:		release this open file
72  * @open_session:	open a new session
73  * @close_session:	close a session
74  * @invoke_func:	invoke a trusted function
75  * @cancel_req:		request cancel of an ongoing invoke or open
76  * @supp_revc:		called for supplicant to get a command
77  * @supp_send:		called for supplicant to send a response
78  */
79 struct tee_driver_ops {
80 	void (*get_version)(struct tee_device *teedev,
81 			    struct tee_ioctl_version_data *vers);
82 	int (*open)(struct tee_context *ctx);
83 	void (*release)(struct tee_context *ctx);
84 	int (*open_session)(struct tee_context *ctx,
85 			    struct tee_ioctl_open_session_arg *arg,
86 			    struct tee_param *param);
87 	int (*close_session)(struct tee_context *ctx, u32 session);
88 	int (*invoke_func)(struct tee_context *ctx,
89 			   struct tee_ioctl_invoke_arg *arg,
90 			   struct tee_param *param);
91 	int (*cancel_req)(struct tee_context *ctx, u32 cancel_id, u32 session);
92 	int (*supp_recv)(struct tee_context *ctx, u32 *func, u32 *num_params,
93 			 struct tee_param *param);
94 	int (*supp_send)(struct tee_context *ctx, u32 ret, u32 num_params,
95 			 struct tee_param *param);
96 };
97 
98 /**
99  * struct tee_desc - Describes the TEE driver to the subsystem
100  * @name:	name of driver
101  * @ops:	driver operations vtable
102  * @owner:	module providing the driver
103  * @flags:	Extra properties of driver, defined by TEE_DESC_* below
104  */
105 #define TEE_DESC_PRIVILEGED	0x1
106 struct tee_desc {
107 	const char *name;
108 	const struct tee_driver_ops *ops;
109 	struct module *owner;
110 	u32 flags;
111 };
112 
113 /**
114  * tee_device_alloc() - Allocate a new struct tee_device instance
115  * @teedesc:	Descriptor for this driver
116  * @dev:	Parent device for this device
117  * @pool:	Shared memory pool, NULL if not used
118  * @driver_data: Private driver data for this device
119  *
120  * Allocates a new struct tee_device instance. The device is
121  * removed by tee_device_unregister().
122  *
123  * @returns a pointer to a 'struct tee_device' or an ERR_PTR on failure
124  */
125 struct tee_device *tee_device_alloc(const struct tee_desc *teedesc,
126 				    struct device *dev,
127 				    struct tee_shm_pool *pool,
128 				    void *driver_data);
129 
130 /**
131  * tee_device_register() - Registers a TEE device
132  * @teedev:	Device to register
133  *
134  * tee_device_unregister() need to be called to remove the @teedev if
135  * this function fails.
136  *
137  * @returns < 0 on failure
138  */
139 int tee_device_register(struct tee_device *teedev);
140 
141 /**
142  * tee_device_unregister() - Removes a TEE device
143  * @teedev:	Device to unregister
144  *
145  * This function should be called to remove the @teedev even if
146  * tee_device_register() hasn't been called yet. Does nothing if
147  * @teedev is NULL.
148  */
149 void tee_device_unregister(struct tee_device *teedev);
150 
151 /**
152  * struct tee_shm_pool_mem_info - holds information needed to create a shared
153  * memory pool
154  * @vaddr:	Virtual address of start of pool
155  * @paddr:	Physical address of start of pool
156  * @size:	Size in bytes of the pool
157  */
158 struct tee_shm_pool_mem_info {
159 	unsigned long vaddr;
160 	phys_addr_t paddr;
161 	size_t size;
162 };
163 
164 /**
165  * tee_shm_pool_alloc_res_mem() - Create a shared memory pool from reserved
166  * memory range
167  * @priv_info:	 Information for driver private shared memory pool
168  * @dmabuf_info: Information for dma-buf shared memory pool
169  *
170  * Start and end of pools will must be page aligned.
171  *
172  * Allocation with the flag TEE_SHM_DMA_BUF set will use the range supplied
173  * in @dmabuf, others will use the range provided by @priv.
174  *
175  * @returns pointer to a 'struct tee_shm_pool' or an ERR_PTR on failure.
176  */
177 struct tee_shm_pool *
178 tee_shm_pool_alloc_res_mem(struct tee_shm_pool_mem_info *priv_info,
179 			   struct tee_shm_pool_mem_info *dmabuf_info);
180 
181 /**
182  * tee_shm_pool_free() - Free a shared memory pool
183  * @pool:	The shared memory pool to free
184  *
185  * The must be no remaining shared memory allocated from this pool when
186  * this function is called.
187  */
188 void tee_shm_pool_free(struct tee_shm_pool *pool);
189 
190 /**
191  * tee_get_drvdata() - Return driver_data pointer
192  * @returns the driver_data pointer supplied to tee_register().
193  */
194 void *tee_get_drvdata(struct tee_device *teedev);
195 
196 /**
197  * tee_shm_alloc() - Allocate shared memory
198  * @ctx:	Context that allocates the shared memory
199  * @size:	Requested size of shared memory
200  * @flags:	Flags setting properties for the requested shared memory.
201  *
202  * Memory allocated as global shared memory is automatically freed when the
203  * TEE file pointer is closed. The @flags field uses the bits defined by
204  * TEE_SHM_* above. TEE_SHM_MAPPED must currently always be set. If
205  * TEE_SHM_DMA_BUF global shared memory will be allocated and associated
206  * with a dma-buf handle, else driver private memory.
207  *
208  * @returns a pointer to 'struct tee_shm'
209  */
210 struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags);
211 
212 /**
213  * tee_shm_free() - Free shared memory
214  * @shm:	Handle to shared memory to free
215  */
216 void tee_shm_free(struct tee_shm *shm);
217 
218 /**
219  * tee_shm_put() - Decrease reference count on a shared memory handle
220  * @shm:	Shared memory handle
221  */
222 void tee_shm_put(struct tee_shm *shm);
223 
224 /**
225  * tee_shm_va2pa() - Get physical address of a virtual address
226  * @shm:	Shared memory handle
227  * @va:		Virtual address to tranlsate
228  * @pa:		Returned physical address
229  * @returns 0 on success and < 0 on failure
230  */
231 int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa);
232 
233 /**
234  * tee_shm_pa2va() - Get virtual address of a physical address
235  * @shm:	Shared memory handle
236  * @pa:		Physical address to tranlsate
237  * @va:		Returned virtual address
238  * @returns 0 on success and < 0 on failure
239  */
240 int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va);
241 
242 /**
243  * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
244  * @shm:	Shared memory handle
245  * @offs:	Offset from start of this shared memory
246  * @returns virtual address of the shared memory + offs if offs is within
247  *	the bounds of this shared memory, else an ERR_PTR
248  */
249 void *tee_shm_get_va(struct tee_shm *shm, size_t offs);
250 
251 /**
252  * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
253  * @shm:	Shared memory handle
254  * @offs:	Offset from start of this shared memory
255  * @pa:		Physical address to return
256  * @returns 0 if offs is within the bounds of this shared memory, else an
257  *	error code.
258  */
259 int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa);
260 
261 /**
262  * tee_shm_get_id() - Get id of a shared memory object
263  * @shm:	Shared memory handle
264  * @returns id
265  */
266 int tee_shm_get_id(struct tee_shm *shm);
267 
268 /**
269  * tee_shm_get_from_id() - Find shared memory object and increase reference
270  * count
271  * @ctx:	Context owning the shared memory
272  * @id:		Id of shared memory object
273  * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
274  */
275 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id);
276 
277 #endif /*__TEE_DRV_H*/
278