1 /*
2  * Copyright (c) 2016, Wind River Systems, Inc.
3  *
4  * SPDX-License-Identifier: Apache-2.0
5  */
6 
7 #ifndef ZEPHYR_INCLUDE_KERNEL_THREAD_H_
8 #define ZEPHYR_INCLUDE_KERNEL_THREAD_H_
9 
10 #ifdef CONFIG_DEMAND_PAGING_THREAD_STATS
11 #include <zephyr/kernel/mm/demand_paging.h>
12 #endif
13 
14 #include <zephyr/kernel/stats.h>
15 #include <zephyr/sys/arch_interface.h>
16 
17 /**
18  * @typedef k_thread_entry_t
19  * @brief Thread entry point function type.
20  *
21  * A thread's entry point function is invoked when the thread starts executing.
22  * Up to 3 argument values can be passed to the function.
23  *
24  * The thread terminates execution permanently if the entry point function
25  * returns. The thread is responsible for releasing any shared resources
26  * it may own (such as mutexes and dynamically allocated memory), prior to
27  * returning.
28  *
29  * @param p1 First argument.
30  * @param p2 Second argument.
31  * @param p3 Third argument.
32  */
33 
34 #ifdef CONFIG_THREAD_MONITOR
35 struct __thread_entry {
36 	k_thread_entry_t pEntry;
37 	void *parameter1;
38 	void *parameter2;
39 	void *parameter3;
40 };
41 #endif
42 
43 struct k_thread;
44 
45 /*
46  * This _pipe_desc structure is used by the pipes kernel module when
47  * CONFIG_PIPES has been selected.
48  */
49 
50 struct _pipe_desc {
51 	sys_dnode_t      node;
52 	unsigned char   *buffer;         /* Position in src/dest buffer */
53 	size_t           bytes_to_xfer;  /* # bytes left to transfer */
54 	struct k_thread *thread;         /* Back pointer to pended thread */
55 };
56 
57 /* can be used for creating 'dummy' threads, e.g. for pending on objects */
58 struct _thread_base {
59 
60 	/* this thread's entry in a ready/wait queue */
61 	union {
62 		sys_dnode_t qnode_dlist;
63 		struct rbnode qnode_rb;
64 	};
65 
66 	/* wait queue on which the thread is pended (needed only for
67 	 * trees, not dumb lists)
68 	 */
69 	_wait_q_t *pended_on;
70 
71 	/* user facing 'thread options'; values defined in include/kernel.h */
72 	uint8_t user_options;
73 
74 	/* thread state */
75 	uint8_t thread_state;
76 
77 	/*
78 	 * scheduler lock count and thread priority
79 	 *
80 	 * These two fields control the preemptibility of a thread.
81 	 *
82 	 * When the scheduler is locked, sched_locked is decremented, which
83 	 * means that the scheduler is locked for values from 0xff to 0x01. A
84 	 * thread is coop if its prio is negative, thus 0x80 to 0xff when
85 	 * looked at the value as unsigned.
86 	 *
87 	 * By putting them end-to-end, this means that a thread is
88 	 * non-preemptible if the bundled value is greater than or equal to
89 	 * 0x0080.
90 	 */
91 	union {
92 		struct {
93 #ifdef CONFIG_BIG_ENDIAN
94 			uint8_t sched_locked;
95 			int8_t prio;
96 #else /* Little Endian */
97 			int8_t prio;
98 			uint8_t sched_locked;
99 #endif
100 		};
101 		uint16_t preempt;
102 	};
103 
104 #ifdef CONFIG_SCHED_DEADLINE
105 	int prio_deadline;
106 #endif
107 
108 	uint32_t order_key;
109 
110 #ifdef CONFIG_SMP
111 	/* True for the per-CPU idle threads */
112 	uint8_t is_idle;
113 
114 	/* CPU index on which thread was last run */
115 	uint8_t cpu;
116 
117 	/* Recursive count of irq_lock() calls */
118 	uint8_t global_lock_count;
119 
120 #endif
121 
122 #ifdef CONFIG_SCHED_CPU_MASK
123 	/* "May run on" bits for each CPU */
124 #if CONFIG_MP_MAX_NUM_CPUS <= 8
125 	uint8_t cpu_mask;
126 #else
127 	uint16_t cpu_mask;
128 #endif
129 #endif /* CONFIG_SCHED_CPU_MASK */
130 
131 	/* data returned by APIs */
132 	void *swap_data;
133 
134 #ifdef CONFIG_SYS_CLOCK_EXISTS
135 	/* this thread's entry in a timeout queue */
136 	struct _timeout timeout;
137 #endif
138 
139 #ifdef CONFIG_TIMESLICE_PER_THREAD
140 	int32_t slice_ticks;
141 	k_thread_timeslice_fn_t slice_expired;
142 	void *slice_data;
143 #endif
144 
145 #ifdef CONFIG_SCHED_THREAD_USAGE
146 	struct k_cycle_stats  usage;   /* Track thread usage statistics */
147 #endif
148 };
149 
150 typedef struct _thread_base _thread_base_t;
151 
152 #if defined(CONFIG_THREAD_STACK_INFO)
153 /* Contains the stack information of a thread */
154 struct _thread_stack_info {
155 	/* Stack start - Represents the start address of the thread-writable
156 	 * stack area.
157 	 */
158 	uintptr_t start;
159 
160 	/* Thread writable stack buffer size. Represents the size of the actual
161 	 * buffer, starting from the 'start' member, that should be writable by
162 	 * the thread. This comprises of the thread stack area, any area reserved
163 	 * for local thread data storage, as well as any area left-out due to
164 	 * random adjustments applied to the initial thread stack pointer during
165 	 * thread initialization.
166 	 */
167 	size_t size;
168 
169 	/* Adjustment value to the size member, removing any storage
170 	 * used for TLS or random stack base offsets. (start + size - delta)
171 	 * is the initial stack pointer for a thread. May be 0.
172 	 */
173 	size_t delta;
174 };
175 
176 typedef struct _thread_stack_info _thread_stack_info_t;
177 #endif /* CONFIG_THREAD_STACK_INFO */
178 
179 #if defined(CONFIG_USERSPACE)
180 struct _mem_domain_info {
181 	/** memory domain queue node */
182 	sys_dnode_t mem_domain_q_node;
183 	/** memory domain of the thread */
184 	struct k_mem_domain *mem_domain;
185 };
186 
187 #endif /* CONFIG_USERSPACE */
188 
189 #ifdef CONFIG_THREAD_USERSPACE_LOCAL_DATA
190 struct _thread_userspace_local_data {
191 #if defined(CONFIG_ERRNO) && !defined(CONFIG_ERRNO_IN_TLS) && !defined(CONFIG_LIBC_ERRNO)
192 	int errno_var;
193 #endif
194 };
195 #endif
196 
197 typedef struct k_thread_runtime_stats {
198 #ifdef CONFIG_SCHED_THREAD_USAGE
199 	uint64_t execution_cycles;
200 	uint64_t total_cycles;        /* total # of non-idle cycles */
201 	/*
202 	 * In the context of thread statistics, [execution_cycles] is the same
203 	 * as the total # of non-idle cycles. In the context of CPU statistics,
204 	 * it refers to the sum of non-idle + idle cycles.
205 	 */
206 #endif
207 
208 #ifdef CONFIG_SCHED_THREAD_USAGE_ANALYSIS
209 	/*
210 	 * For threads, the following fields refer to the time spent executing
211 	 * as bounded by when the thread was scheduled in and scheduled out.
212 	 * For CPUs, the same fields refer to the time spent executing
213 	 * non-idle threads as bounded by the idle thread(s).
214 	 */
215 
216 	uint64_t current_cycles;      /* current # of non-idle cycles */
217 	uint64_t peak_cycles;         /* peak # of non-idle cycles */
218 	uint64_t average_cycles;      /* average # of non-idle cycles */
219 #endif
220 
221 #ifdef CONFIG_SCHED_THREAD_USAGE_ALL
222 	/*
223 	 * This field is always zero for individual threads. It only comes
224 	 * into play when gathering statistics for the CPU. In that case it
225 	 * represents the total number of cycles spent idling.
226 	 */
227 
228 	uint64_t idle_cycles;
229 #endif
230 
231 #if defined(__cplusplus) && !defined(CONFIG_SCHED_THREAD_USAGE) &&                                 \
232 	!defined(CONFIG_SCHED_THREAD_USAGE_ANALYSIS) && !defined(CONFIG_SCHED_THREAD_USAGE_ALL)
233 	/* If none of the above Kconfig values are defined, this struct will have a size 0 in C
234 	 * which is not allowed in C++ (it'll have a size 1). To prevent this, we add a 1 byte dummy
235 	 * variable when the struct would otherwise be empty.
236 	 */
237 	uint8_t dummy;
238 #endif
239 }  k_thread_runtime_stats_t;
240 
241 struct z_poller {
242 	bool is_polling;
243 	uint8_t mode;
244 };
245 
246 /**
247  * @ingroup thread_apis
248  * Thread Structure
249  */
250 struct k_thread {
251 
252 	struct _thread_base base;
253 
254 	/** defined by the architecture, but all archs need these */
255 	struct _callee_saved callee_saved;
256 
257 	/** static thread init data */
258 	void *init_data;
259 
260 	/** threads waiting in k_thread_join() */
261 	_wait_q_t join_queue;
262 
263 #if defined(CONFIG_POLL)
264 	struct z_poller poller;
265 #endif
266 
267 #if defined(CONFIG_EVENTS)
268 	struct k_thread *next_event_link;
269 
270 	uint32_t   events;
271 	uint32_t   event_options;
272 
273 	/** true if timeout should not wake the thread */
274 	bool no_wake_on_timeout;
275 #endif
276 
277 #if defined(CONFIG_THREAD_MONITOR)
278 	/** thread entry and parameters description */
279 	struct __thread_entry entry;
280 
281 	/** next item in list of all threads */
282 	struct k_thread *next_thread;
283 #endif
284 
285 #if defined(CONFIG_THREAD_NAME)
286 	/** Thread name */
287 	char name[CONFIG_THREAD_MAX_NAME_LEN];
288 #endif
289 
290 #ifdef CONFIG_THREAD_CUSTOM_DATA
291 	/** crude thread-local storage */
292 	void *custom_data;
293 #endif
294 
295 #ifdef CONFIG_THREAD_USERSPACE_LOCAL_DATA
296 	struct _thread_userspace_local_data *userspace_local_data;
297 #endif
298 
299 #if defined(CONFIG_ERRNO) && !defined(CONFIG_ERRNO_IN_TLS) && !defined(CONFIG_LIBC_ERRNO)
300 #ifndef CONFIG_USERSPACE
301 	/** per-thread errno variable */
302 	int errno_var;
303 #endif
304 #endif
305 
306 #if defined(CONFIG_THREAD_STACK_INFO)
307 	/** Stack Info */
308 	struct _thread_stack_info stack_info;
309 #endif /* CONFIG_THREAD_STACK_INFO */
310 
311 #if defined(CONFIG_USERSPACE)
312 	/** memory domain info of the thread */
313 	struct _mem_domain_info mem_domain_info;
314 	/** Base address of thread stack */
315 	k_thread_stack_t *stack_obj;
316 	/** current syscall frame pointer */
317 	void *syscall_frame;
318 #endif /* CONFIG_USERSPACE */
319 
320 
321 #if defined(CONFIG_USE_SWITCH)
322 	/* When using __switch() a few previously arch-specific items
323 	 * become part of the core OS
324 	 */
325 
326 	/** z_swap() return value */
327 	int swap_retval;
328 
329 	/** Context handle returned via arch_switch() */
330 	void *switch_handle;
331 #endif
332 	/** resource pool */
333 	struct k_heap *resource_pool;
334 
335 #if defined(CONFIG_THREAD_LOCAL_STORAGE)
336 	/* Pointer to arch-specific TLS area */
337 	uintptr_t tls;
338 #endif /* CONFIG_THREAD_LOCAL_STORAGE */
339 
340 #ifdef CONFIG_DEMAND_PAGING_THREAD_STATS
341 	/** Paging statistics */
342 	struct k_mem_paging_stats_t paging_stats;
343 #endif
344 
345 #ifdef CONFIG_PIPES
346 	/** Pipe descriptor used with blocking k_pipe operations */
347 	struct _pipe_desc pipe_desc;
348 #endif
349 
350 #ifdef CONFIG_OBJ_CORE_THREAD
351 	struct k_obj_core  obj_core;
352 #endif
353 
354 #ifdef CONFIG_SMP
355 	/** threads waiting in k_thread_suspend() */
356 	_wait_q_t  halt_queue;
357 #endif
358 
359 	/** arch-specifics: must always be at the end */
360 	struct _thread_arch arch;
361 };
362 
363 typedef struct k_thread _thread_t;
364 typedef struct k_thread *k_tid_t;
365 
366 #endif
367