1 /*
2  * Copyright (c) 2014 Travis Geiselbrecht
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining
5  * a copy of this software and associated documentation files
6  * (the "Software"), to deal in the Software without restriction,
7  * including without limitation the rights to use, copy, modify, merge,
8  * publish, distribute, sublicense, and/or sell copies of the Software,
9  * and to permit persons to whom the Software is furnished to do so,
10  * subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be
13  * included in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
19  * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
20  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
21  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22  */
23 #pragma once
24 
25 #include <compiler.h>
26 #include <limits.h>
27 #include <stdbool.h>
28 #include <stdint.h>
29 #include <kernel/thread.h>
30 
31 __BEGIN_CDECLS;
32 
33 typedef uint32_t mp_cpu_mask_t;
34 
35 #define MP_CPU_ALL_BUT_LOCAL (UINT32_MAX)
36 
37 /* by default, mp_mbx_reschedule does not signal to cpus that are running realtime
38  * threads. Override this behavior.
39  */
40 #define MP_RESCHEDULE_FLAG_REALTIME (0x1)
41 
42 typedef enum {
43     MP_IPI_GENERIC,
44     MP_IPI_RESCHEDULE,
45 } mp_ipi_t;
46 
47 #ifdef WITH_SMP
48 void mp_init(void);
49 
50 void mp_reschedule(mp_cpu_mask_t target, uint flags);
51 void mp_set_curr_cpu_active(bool active);
52 
53 /* called from arch code during reschedule irq */
54 enum handler_return mp_mbx_reschedule_irq(void);
55 
56 /* global mp state to track what the cpus are up to */
57 struct mp_state {
58     volatile mp_cpu_mask_t active_cpus;
59 
60     /* only safely accessible with thread lock held */
61     mp_cpu_mask_t idle_cpus;
62     mp_cpu_mask_t realtime_cpus;
63 };
64 
65 extern struct mp_state mp;
66 
mp_is_cpu_active(uint cpu)67 static inline int mp_is_cpu_active(uint cpu)
68 {
69     return mp.active_cpus & (1 << cpu);
70 }
71 
mp_is_cpu_idle(uint cpu)72 static inline int mp_is_cpu_idle(uint cpu)
73 {
74     return mp.idle_cpus & (1 << cpu);
75 }
76 
77 /* must be called with the thread lock held */
mp_set_cpu_idle(uint cpu)78 static inline void mp_set_cpu_idle(uint cpu)
79 {
80     mp.idle_cpus |= 1UL << cpu;
81 }
82 
mp_set_cpu_busy(uint cpu)83 static inline void mp_set_cpu_busy(uint cpu)
84 {
85     mp.idle_cpus &= ~(1UL << cpu);
86 }
87 
mp_get_idle_mask(void)88 static inline mp_cpu_mask_t mp_get_idle_mask(void)
89 {
90     return mp.idle_cpus;
91 }
92 
mp_set_cpu_realtime(uint cpu)93 static inline void mp_set_cpu_realtime(uint cpu)
94 {
95     mp.realtime_cpus |= 1UL << cpu;
96 }
97 
mp_set_cpu_non_realtime(uint cpu)98 static inline void mp_set_cpu_non_realtime(uint cpu)
99 {
100     mp.realtime_cpus &= ~(1UL << cpu);
101 }
102 
mp_get_realtime_mask(void)103 static inline mp_cpu_mask_t mp_get_realtime_mask(void)
104 {
105     return mp.realtime_cpus;
106 }
107 #else
mp_init(void)108 static inline void mp_init(void) {}
mp_reschedule(mp_cpu_mask_t target,uint flags)109 static inline void mp_reschedule(mp_cpu_mask_t target, uint flags) {}
mp_set_curr_cpu_active(bool active)110 static inline void mp_set_curr_cpu_active(bool active) {}
111 
mp_mbx_reschedule_irq(void)112 static inline enum handler_return mp_mbx_reschedule_irq(void) { return 0; }
113 
114 // only one cpu exists in UP and if you're calling these functions, it's active...
mp_is_cpu_active(uint cpu)115 static inline int mp_is_cpu_active(uint cpu) { return 1; }
mp_is_cpu_idle(uint cpu)116 static inline int mp_is_cpu_idle(uint cpu) { return (get_current_thread()->flags & THREAD_FLAG_IDLE) != 0; }
117 
mp_set_cpu_idle(uint cpu)118 static inline void mp_set_cpu_idle(uint cpu) {}
mp_set_cpu_busy(uint cpu)119 static inline void mp_set_cpu_busy(uint cpu) {}
120 
mp_get_idle_mask(void)121 static inline mp_cpu_mask_t mp_get_idle_mask(void) { return 0; }
122 
mp_set_cpu_realtime(uint cpu)123 static inline void mp_set_cpu_realtime(uint cpu) {}
mp_set_cpu_non_realtime(uint cpu)124 static inline void mp_set_cpu_non_realtime(uint cpu) {}
125 
mp_get_realtime_mask(void)126 static inline mp_cpu_mask_t mp_get_realtime_mask(void) { return 0; }
127 #endif
128 
129 __END_CDECLS;
130