1 /*
2  * Copyright (c) 2016 Wind River Systems, Inc.
3  *
4  * SPDX-License-Identifier: Apache-2.0
5  */
6 
7 /*
8  * The purpose of this file is to provide essential/minimal kernel structure
9  * definitions, so that they can be used without including kernel.h.
10  *
11  * The following rules must be observed:
12  *  1. kernel_structs.h shall not depend on kernel.h both directly and
13  *    indirectly (i.e. it shall not include any header files that include
14  *    kernel.h in their dependency chain).
15  *  2. kernel.h shall imply kernel_structs.h, such that it shall not be
16  *    necessary to include kernel_structs.h explicitly when kernel.h is
17  *    included.
18  */
19 
20 #ifndef ZEPHYR_KERNEL_INCLUDE_KERNEL_STRUCTS_H_
21 #define ZEPHYR_KERNEL_INCLUDE_KERNEL_STRUCTS_H_
22 
23 #if !defined(_ASMLANGUAGE)
24 #include <sys/atomic.h>
25 #include <zephyr/types.h>
26 #include <kernel/sched_priq.h>
27 #include <sys/dlist.h>
28 #include <sys/util.h>
29 #include <sys/sys_heap.h>
30 #include <arch/structs.h>
31 #endif
32 
33 #ifdef __cplusplus
34 extern "C" {
35 #endif
36 
37 /*
38  * Bitmask definitions for the struct k_thread.thread_state field.
39  *
40  * Must be before kerneL_arch_data.h because it might need them to be already
41  * defined.
42  */
43 
44 /* states: common uses low bits, arch-specific use high bits */
45 
46 /* Not a real thread */
47 #define _THREAD_DUMMY (BIT(0))
48 
49 /* Thread is waiting on an object */
50 #define _THREAD_PENDING (BIT(1))
51 
52 /* Thread has not yet started */
53 #define _THREAD_PRESTART (BIT(2))
54 
55 /* Thread has terminated */
56 #define _THREAD_DEAD (BIT(3))
57 
58 /* Thread is suspended */
59 #define _THREAD_SUSPENDED (BIT(4))
60 
61 /* Thread is being aborted */
62 #define _THREAD_ABORTING (BIT(5))
63 
64 /* Thread is present in the ready queue */
65 #define _THREAD_QUEUED (BIT(7))
66 
67 /* end - states */
68 
69 #ifdef CONFIG_STACK_SENTINEL
70 /* Magic value in lowest bytes of the stack */
71 #define STACK_SENTINEL 0xF0F0F0F0
72 #endif
73 
74 /* lowest value of _thread_base.preempt at which a thread is non-preemptible */
75 #define _NON_PREEMPT_THRESHOLD 0x0080U
76 
77 /* highest value of _thread_base.preempt at which a thread is preemptible */
78 #define _PREEMPT_THRESHOLD (_NON_PREEMPT_THRESHOLD - 1U)
79 
80 #if !defined(_ASMLANGUAGE)
81 
82 struct _ready_q {
83 #ifndef CONFIG_SMP
84 	/* always contains next thread to run: cannot be NULL */
85 	struct k_thread *cache;
86 #endif
87 
88 #if defined(CONFIG_SCHED_DUMB)
89 	sys_dlist_t runq;
90 #elif defined(CONFIG_SCHED_SCALABLE)
91 	struct _priq_rb runq;
92 #elif defined(CONFIG_SCHED_MULTIQ)
93 	struct _priq_mq runq;
94 #endif
95 };
96 
97 typedef struct _ready_q _ready_q_t;
98 
99 struct _cpu {
100 	/* nested interrupt count */
101 	uint32_t nested;
102 
103 	/* interrupt stack pointer base */
104 	char *irq_stack;
105 
106 	/* currently scheduled thread */
107 	struct k_thread *current;
108 
109 	/* one assigned idle thread per CPU */
110 	struct k_thread *idle_thread;
111 
112 #if (CONFIG_NUM_METAIRQ_PRIORITIES > 0) && (CONFIG_NUM_COOP_PRIORITIES > 0)
113 	/* Coop thread preempted by current metairq, or NULL */
114 	struct k_thread *metairq_preempted;
115 #endif
116 
117 #ifdef CONFIG_TIMESLICING
118 	/* number of ticks remaining in current time slice */
119 	int slice_ticks;
120 #endif
121 
122 	uint8_t id;
123 
124 #ifdef CONFIG_SMP
125 	/* True when _current is allowed to context switch */
126 	uint8_t swap_ok;
127 #endif
128 
129 	/* Per CPU architecture specifics */
130 	struct _cpu_arch arch;
131 };
132 
133 typedef struct _cpu _cpu_t;
134 
135 struct z_kernel {
136 	struct _cpu cpus[CONFIG_MP_NUM_CPUS];
137 
138 #ifdef CONFIG_PM
139 	int32_t idle; /* Number of ticks for kernel idling */
140 #endif
141 
142 	/*
143 	 * ready queue: can be big, keep after small fields, since some
144 	 * assembly (e.g. ARC) are limited in the encoding of the offset
145 	 */
146 	struct _ready_q ready_q;
147 
148 #ifdef CONFIG_FPU_SHARING
149 	/*
150 	 * A 'current_sse' field does not exist in addition to the 'current_fp'
151 	 * field since it's not possible to divide the IA-32 non-integer
152 	 * registers into 2 distinct blocks owned by differing threads.  In
153 	 * other words, given that the 'fxnsave/fxrstor' instructions
154 	 * save/restore both the X87 FPU and XMM registers, it's not possible
155 	 * for a thread to only "own" the XMM registers.
156 	 */
157 
158 	/* thread that owns the FP regs */
159 	struct k_thread *current_fp;
160 #endif
161 
162 #if defined(CONFIG_THREAD_MONITOR)
163 	struct k_thread *threads; /* singly linked list of ALL threads */
164 #endif
165 
166 #if defined(CONFIG_SMP) && defined(CONFIG_SCHED_IPI_SUPPORTED)
167 	/* Need to signal an IPI at the next scheduling point */
168 	bool pending_ipi;
169 #endif
170 };
171 
172 typedef struct z_kernel _kernel_t;
173 
174 extern struct z_kernel _kernel;
175 
176 #ifdef CONFIG_SMP
177 
178 /* True if the current context can be preempted and migrated to
179  * another SMP CPU.
180  */
181 bool z_smp_cpu_mobile(void);
182 
183 #define _current_cpu ({ __ASSERT_NO_MSG(!z_smp_cpu_mobile()); \
184 			arch_curr_cpu(); })
185 #define _current z_current_get()
186 
187 #else
188 #define _current_cpu (&_kernel.cpus[0])
189 #define _current _kernel.cpus[0].current
190 #endif
191 
192 /* kernel wait queue record */
193 
194 #ifdef CONFIG_WAITQ_SCALABLE
195 
196 typedef struct {
197 	struct _priq_rb waitq;
198 } _wait_q_t;
199 
200 extern bool z_priq_rb_lessthan(struct rbnode *a, struct rbnode *b);
201 
202 #define Z_WAIT_Q_INIT(wait_q) { { { .lessthan_fn = z_priq_rb_lessthan } } }
203 
204 #else
205 
206 typedef struct {
207 	sys_dlist_t waitq;
208 } _wait_q_t;
209 
210 #define Z_WAIT_Q_INIT(wait_q) { SYS_DLIST_STATIC_INIT(&(wait_q)->waitq) }
211 
212 #endif
213 
214 /* kernel timeout record */
215 
216 struct _timeout;
217 typedef void (*_timeout_func_t)(struct _timeout *t);
218 
219 struct _timeout {
220 	sys_dnode_t node;
221 	_timeout_func_t fn;
222 #ifdef CONFIG_TIMEOUT_64BIT
223 	/* Can't use k_ticks_t for header dependency reasons */
224 	int64_t dticks;
225 #else
226 	int32_t dticks;
227 #endif
228 };
229 
230 #ifdef __cplusplus
231 }
232 #endif
233 
234 #endif /* _ASMLANGUAGE */
235 
236 #endif /* ZEPHYR_KERNEL_INCLUDE_KERNEL_STRUCTS_H_ */
237