xref: /optee_os/core/include/kernel/thread.h (revision 5d9ddca63770b09d096797a3f12c0cb597732464)
1 /* SPDX-License-Identifier: BSD-2-Clause */
2 /*
3  * Copyright (c) 2014, STMicroelectronics International N.V.
4  * Copyright (c) 2016-2017, Linaro Limited
5  * Copyright (c) 2020-2021, Arm Limited
6  */
7 
8 #ifndef KERNEL_THREAD_H
9 #define KERNEL_THREAD_H
10 
11 #ifndef __ASSEMBLER__
12 #include <types_ext.h>
13 #include <compiler.h>
14 #include <mm/pgt_cache.h>
15 #endif
16 #include <kernel/thread_arch.h>
17 
18 #define THREAD_ID_0		0
19 #define THREAD_ID_INVALID	-1
20 
21 #define THREAD_RPC_MAX_NUM_PARAMS	U(4)
22 
23 #ifndef __ASSEMBLER__
24 
25 struct thread_specific_data {
26 	TAILQ_HEAD(, ts_session) sess_stack;
27 	struct ts_ctx *ctx;
28 	struct pgt_cache pgt_cache;
29 #ifdef CFG_CORE_FFA
30 	uint32_t rpc_target_info;
31 #endif
32 	uint32_t abort_type;
33 	uint32_t abort_descr;
34 	vaddr_t abort_va;
35 	unsigned int abort_core;
36 	struct thread_abort_regs abort_regs;
37 #ifdef CFG_CORE_DEBUG_CHECK_STACKS
38 	bool stackcheck_recursion;
39 #endif
40 	unsigned int syscall_recursion;
41 };
42 
43 void thread_init_primary(void);
44 void thread_init_per_cpu(void);
45 
46 struct thread_core_local *thread_get_core_local(void);
47 
48 /*
49  * Sets the stacks to be used by the different threads. Use THREAD_ID_0 for
50  * first stack, THREAD_ID_0 + 1 for the next and so on.
51  *
52  * Returns true on success and false on errors.
53  */
54 bool thread_init_stack(uint32_t stack_id, vaddr_t sp);
55 
56 /*
57  * Initializes thread contexts. Called in thread_init_boot_thread() if
58  * virtualization is disabled. Virtualization subsystem calls it for
59  * every new guest otherwise.
60  */
61 void thread_init_threads(void);
62 
63 /*
64  * Called by the init CPU. Sets temporary stack mode for all CPUs
65  * (curr_thread = -1 and THREAD_CLF_TMP) and sets the temporary stack limit for
66  * the init CPU.
67  */
68 void thread_init_thread_core_local(void);
69 
70 /*
71  * Initializes a thread to be used during boot
72  */
73 void thread_init_boot_thread(void);
74 
75 /*
76  * Clears the current thread id
77  * Only supposed to be used during initialization.
78  */
79 void thread_clr_boot_thread(void);
80 
81 /*
82  * Returns current thread id.
83  */
84 short int thread_get_id(void);
85 
86 /*
87  * Returns current thread id, return -1 on failure.
88  */
89 short int thread_get_id_may_fail(void);
90 
91 /* Returns Thread Specific Data (TSD) pointer. */
92 struct thread_specific_data *thread_get_tsd(void);
93 
94 /*
95  * Sets foreign interrupts status for current thread, must only be called
96  * from an active thread context.
97  *
98  * enable == true  -> enable foreign interrupts
99  * enable == false -> disable foreign interrupts
100  */
101 void thread_set_foreign_intr(bool enable);
102 
103 /*
104  * Restores the foreign interrupts status (in CPSR) for current thread, must
105  * only be called from an active thread context.
106  */
107 void thread_restore_foreign_intr(void);
108 
109 /*
110  * thread_get_exceptions() - return current exception mask
111  */
112 uint32_t thread_get_exceptions(void);
113 
114 /*
115  * thread_set_exceptions() - set exception mask
116  * @exceptions: exception mask to set
117  *
118  * Any previous exception mask is replaced by this exception mask, that is,
119  * old bits are cleared and replaced by these.
120  */
121 void thread_set_exceptions(uint32_t exceptions);
122 
123 /*
124  * thread_mask_exceptions() - Masks (disables) specified asynchronous exceptions
125  * @exceptions	exceptions to mask
126  * @returns old exception state
127  */
128 uint32_t thread_mask_exceptions(uint32_t exceptions);
129 
130 /*
131  * thread_unmask_exceptions() - Unmasks asynchronous exceptions
132  * @state	Old asynchronous exception state to restore (returned by
133  *		thread_mask_exceptions())
134  */
135 void thread_unmask_exceptions(uint32_t state);
136 
137 
138 static inline bool __nostackcheck thread_foreign_intr_disabled(void)
139 {
140 	return !!(thread_get_exceptions() & THREAD_EXCP_FOREIGN_INTR);
141 }
142 
143 /*
144  * thread_enter_user_mode() - Enters user mode
145  * @a0:		Passed in r/x0 for user_func
146  * @a1:		Passed in r/x1 for user_func
147  * @a2:		Passed in r/x2 for user_func
148  * @a3:		Passed in r/x3 for user_func
149  * @user_sp:	Assigned sp value in user mode
150  * @user_func:	Function to execute in user mode
151  * @is_32bit:   True if TA should execute in Aarch32, false if Aarch64
152  * @exit_status0: Pointer to opaque exit staus 0
153  * @exit_status1: Pointer to opaque exit staus 1
154  *
155  * This functions enters user mode with the argument described above,
156  * @exit_status0 and @exit_status1 are filled in by thread_unwind_user_mode()
157  * when returning back to the caller of this function through an exception
158  * handler.
159  *
160  * @Returns what's passed in "ret" to thread_unwind_user_mode()
161  */
162 uint32_t thread_enter_user_mode(unsigned long a0, unsigned long a1,
163 		unsigned long a2, unsigned long a3, unsigned long user_sp,
164 		unsigned long entry_func, bool is_32bit,
165 		uint32_t *exit_status0, uint32_t *exit_status1);
166 
167 /*
168  * thread_unwind_user_mode() - Unwinds kernel stack from user entry
169  * @ret:	Value to return from thread_enter_user_mode()
170  * @exit_status0: Exit status 0
171  * @exit_status1: Exit status 1
172  *
173  * This is the function that exception handlers can return into
174  * to resume execution in kernel mode instead of user mode.
175  *
176  * This function is closely coupled with thread_enter_user_mode() since it
177  * need to restore registers saved by thread_enter_user_mode() and when it
178  * returns make it look like thread_enter_user_mode() just returned. It is
179  * expected that the stack pointer is where thread_enter_user_mode() left
180  * it. The stack will be unwound and the function will return to where
181  * thread_enter_user_mode() was called from.  Exit_status0 and exit_status1
182  * are filled in the corresponding pointers supplied to
183  * thread_enter_user_mode().
184  */
185 void thread_unwind_user_mode(uint32_t ret, uint32_t exit_status0,
186 		uint32_t exit_status1);
187 
188 /*
189  * Returns the start address (bottom) of the stack for the current thread,
190  * zero if there is no current thread.
191  */
192 vaddr_t thread_stack_start(void);
193 
194 
195 /* Returns the stack size for the current thread */
196 size_t thread_stack_size(void);
197 
198 /*
199  * Returns the start (top, lowest address) and end (bottom, highest address) of
200  * the current stack (thread, temporary or abort stack).
201  * When CFG_CORE_DEBUG_CHECK_STACKS=y, the @hard parameter tells if the hard or
202  * soft limits are queried. The difference between soft and hard is that for the
203  * latter, the stack start includes some additional space to let any function
204  * overflow the soft limit and still be able to print a stack dump in this case.
205  */
206 bool get_stack_limits(vaddr_t *start, vaddr_t *end, bool hard);
207 
208 static inline bool __nostackcheck get_stack_soft_limits(vaddr_t *start,
209 							vaddr_t *end)
210 {
211 	return get_stack_limits(start, end, false);
212 }
213 
214 static inline bool __nostackcheck get_stack_hard_limits(vaddr_t *start,
215 							vaddr_t *end)
216 {
217 	return get_stack_limits(start, end, true);
218 }
219 
220 bool thread_is_in_normal_mode(void);
221 
222 /*
223  * Returns true if previous exeception also was in abort mode.
224  *
225  * Note: it's only valid to call this function from an abort exception
226  * handler before interrupts has been re-enabled.
227  */
228 bool thread_is_from_abort_mode(void);
229 
230 /**
231  * Allocates data for payload buffers.
232  *
233  * @size:	size in bytes of payload buffer
234  *
235  * @returns	mobj that describes allocated buffer or NULL on error
236  */
237 struct mobj *thread_rpc_alloc_payload(size_t size);
238 
239 /**
240  * Free physical memory previously allocated with thread_rpc_alloc_payload()
241  *
242  * @mobj:	mobj that describes the buffer
243  */
244 void thread_rpc_free_payload(struct mobj *mobj);
245 
246 /**
247  * Allocate data for payload buffers only shared with the non-secure kernel
248  *
249  * @size:	size in bytes of payload buffer
250  *
251  * @returns	mobj that describes allocated buffer or NULL on error
252  */
253 struct mobj *thread_rpc_alloc_kernel_payload(size_t size);
254 
255 /**
256  * Free physical memory previously allocated with
257  * thread_rpc_alloc_kernel_payload()
258  *
259  * @mobj:	mobj that describes the buffer
260  */
261 void thread_rpc_free_kernel_payload(struct mobj *mobj);
262 
263 struct thread_param_memref {
264 	size_t offs;
265 	size_t size;
266 	struct mobj *mobj;
267 };
268 
269 struct thread_param_value {
270 	uint64_t a;
271 	uint64_t b;
272 	uint64_t c;
273 };
274 
275 /*
276  * Note that there's some arithmetics done on the value so it's important
277  * to keep in IN, OUT, INOUT order.
278  */
279 enum thread_param_attr {
280 	THREAD_PARAM_ATTR_NONE = 0,
281 	THREAD_PARAM_ATTR_VALUE_IN,
282 	THREAD_PARAM_ATTR_VALUE_OUT,
283 	THREAD_PARAM_ATTR_VALUE_INOUT,
284 	THREAD_PARAM_ATTR_MEMREF_IN,
285 	THREAD_PARAM_ATTR_MEMREF_OUT,
286 	THREAD_PARAM_ATTR_MEMREF_INOUT,
287 };
288 
289 struct thread_param {
290 	enum thread_param_attr attr;
291 	union {
292 		struct thread_param_memref memref;
293 		struct thread_param_value value;
294 	} u;
295 };
296 
297 #define THREAD_PARAM_MEMREF(_direction, _mobj, _offs, _size) \
298 	(struct thread_param){ \
299 		.attr = THREAD_PARAM_ATTR_MEMREF_ ## _direction, .u.memref = { \
300 		.mobj = (_mobj), .offs = (_offs), .size = (_size) } \
301 	}
302 
303 #define THREAD_PARAM_VALUE(_direction, _a, _b, _c) \
304 	(struct thread_param){ \
305 		.attr = THREAD_PARAM_ATTR_VALUE_ ## _direction, .u.value = { \
306 		.a = (_a), .b = (_b), .c = (_c) } \
307 	}
308 
309 /**
310  * Does an RPC using a preallocated argument buffer
311  * @cmd: RPC cmd
312  * @num_params: number of parameters
313  * @params: RPC parameters
314  * @returns RPC return value
315  */
316 uint32_t thread_rpc_cmd(uint32_t cmd, size_t num_params,
317 		struct thread_param *params);
318 
319 /**
320  * Allocate data for payload buffers.
321  * Buffer is exported to user mode applications.
322  *
323  * @size:	size in bytes of payload buffer
324  *
325  * @returns	mobj that describes allocated buffer or NULL on error
326  */
327 struct mobj *thread_rpc_alloc_global_payload(size_t size);
328 
329 /**
330  * Free physical memory previously allocated with
331  * thread_rpc_alloc_global_payload()
332  *
333  * @mobj:	mobj that describes the buffer
334  */
335 void thread_rpc_free_global_payload(struct mobj *mobj);
336 
337 /*
338  * enum thread_shm_type - type of non-secure shared memory
339  * @THREAD_SHM_TYPE_APPLICATION - user space application shared memory
340  * @THREAD_SHM_TYPE_KERNEL_PRIVATE - kernel private shared memory
341  * @THREAD_SHM_TYPE_GLOBAL - user space and kernel shared memory
342  */
343 enum thread_shm_type {
344 	THREAD_SHM_TYPE_APPLICATION,
345 	THREAD_SHM_TYPE_KERNEL_PRIVATE,
346 	THREAD_SHM_TYPE_GLOBAL,
347 };
348 
349 /*
350  * enum thread_shm_cache_user - user of a cache allocation
351  * @THREAD_SHM_CACHE_USER_SOCKET - socket communication
352  * @THREAD_SHM_CACHE_USER_FS - filesystem access
353  * @THREAD_SHM_CACHE_USER_I2C - I2C communication
354  *
355  * To ensure that each user of the shared memory cache doesn't interfere
356  * with each other a unique ID per user is used.
357  */
358 enum thread_shm_cache_user {
359 	THREAD_SHM_CACHE_USER_SOCKET,
360 	THREAD_SHM_CACHE_USER_FS,
361 	THREAD_SHM_CACHE_USER_I2C,
362 };
363 
364 /*
365  * Returns a pointer to the cached RPC memory. Each thread and @user tuple
366  * has a unique cache. The pointer is guaranteed to point to a large enough
367  * area or to be NULL.
368  */
369 void *thread_rpc_shm_cache_alloc(enum thread_shm_cache_user user,
370 				 enum thread_shm_type shm_type,
371 				 size_t size, struct mobj **mobj);
372 
373 #endif /*__ASSEMBLER__*/
374 
375 #endif /*KERNEL_THREAD_H*/
376