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1 | /* |
1 | /* |
2 | * Copyright (C) 2001-2004 Jakub Jermar |
2 | * Copyright (C) 2001-2004 Jakub Jermar |
3 | * All rights reserved. |
3 | * All rights reserved. |
4 | * |
4 | * |
5 | * Redistribution and use in source and binary forms, with or without |
5 | * Redistribution and use in source and binary forms, with or without |
6 | * modification, are permitted provided that the following conditions |
6 | * modification, are permitted provided that the following conditions |
7 | * are met: |
7 | * are met: |
8 | * |
8 | * |
9 | * - Redistributions of source code must retain the above copyright |
9 | * - Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * - Redistributions in binary form must reproduce the above copyright |
11 | * - Redistributions in binary form must reproduce the above copyright |
12 | * notice, this list of conditions and the following disclaimer in the |
12 | * notice, this list of conditions and the following disclaimer in the |
13 | * documentation and/or other materials provided with the distribution. |
13 | * documentation and/or other materials provided with the distribution. |
14 | * - The name of the author may not be used to endorse or promote products |
14 | * - The name of the author may not be used to endorse or promote products |
15 | * derived from this software without specific prior written permission. |
15 | * derived from this software without specific prior written permission. |
16 | * |
16 | * |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
27 | */ |
27 | */ |
28 | 28 | ||
- | 29 | /** @defgroup others Others |
|
- | 30 | * @ingroup kernel |
|
- | 31 | * @{ |
|
- | 32 | * @} |
|
- | 33 | */ |
|
- | 34 | ||
- | 35 | /** @addtogroup generic |
|
- | 36 | * @{ |
|
- | 37 | */ |
|
- | 38 | ||
29 | /** |
39 | /** |
30 | * @file clock.c |
40 | * @file |
31 | * @brief High-level clock interrupt handler. |
41 | * @brief High-level clock interrupt handler. |
32 | * |
42 | * |
33 | * This file contains the clock() function which is the source |
43 | * This file contains the clock() function which is the source |
34 | * of preemption. It is also responsible for executing expired |
44 | * of preemption. It is also responsible for executing expired |
35 | * timeouts. |
45 | * timeouts. |
36 | */ |
46 | */ |
37 | 47 | ||
38 | #include <time/clock.h> |
48 | #include <time/clock.h> |
39 | #include <time/timeout.h> |
49 | #include <time/timeout.h> |
40 | #include <arch/types.h> |
50 | #include <arch/types.h> |
41 | #include <config.h> |
51 | #include <config.h> |
42 | #include <synch/spinlock.h> |
52 | #include <synch/spinlock.h> |
43 | #include <synch/waitq.h> |
53 | #include <synch/waitq.h> |
44 | #include <func.h> |
54 | #include <func.h> |
45 | #include <proc/scheduler.h> |
55 | #include <proc/scheduler.h> |
46 | #include <cpu.h> |
56 | #include <cpu.h> |
47 | #include <arch.h> |
57 | #include <arch.h> |
48 | #include <adt/list.h> |
58 | #include <adt/list.h> |
49 | #include <atomic.h> |
59 | #include <atomic.h> |
50 | #include <proc/thread.h> |
60 | #include <proc/thread.h> |
51 | #include <sysinfo/sysinfo.h> |
61 | #include <sysinfo/sysinfo.h> |
52 | #include <arch/barrier.h> |
62 | #include <arch/barrier.h> |
53 | 63 | ||
54 | /* Pointers to public variables with time */ |
64 | /* Pointers to public variables with time */ |
55 | struct ptime { |
65 | struct ptime { |
56 | __native seconds1; |
66 | __native seconds1; |
57 | __native useconds; |
67 | __native useconds; |
58 | __native seconds2; |
68 | __native seconds2; |
59 | }; |
69 | }; |
60 | struct ptime *public_time; |
70 | struct ptime *public_time; |
61 | /* Variable holding fragment of second, so that we would update |
71 | /* Variable holding fragment of second, so that we would update |
62 | * seconds correctly |
72 | * seconds correctly |
63 | */ |
73 | */ |
64 | static __native secfrag = 0; |
74 | static __native secfrag = 0; |
65 | 75 | ||
66 | /** Initialize realtime clock counter |
76 | /** Initialize realtime clock counter |
67 | * |
77 | * |
68 | * The applications (and sometimes kernel) need to access accurate |
78 | * The applications (and sometimes kernel) need to access accurate |
69 | * information about realtime data. We allocate 1 page with these |
79 | * information about realtime data. We allocate 1 page with these |
70 | * data and update it periodically. |
80 | * data and update it periodically. |
71 | * |
81 | * |
72 | * |
82 | * |
73 | */ |
83 | */ |
74 | void clock_counter_init(void) |
84 | void clock_counter_init(void) |
75 | { |
85 | { |
76 | void *faddr; |
86 | void *faddr; |
77 | 87 | ||
78 | faddr = (void *)PFN2ADDR(frame_alloc(0, FRAME_ATOMIC)); |
88 | faddr = (void *)PFN2ADDR(frame_alloc(0, FRAME_ATOMIC)); |
79 | if (!faddr) |
89 | if (!faddr) |
80 | panic("Cannot allocate page for clock"); |
90 | panic("Cannot allocate page for clock"); |
81 | 91 | ||
82 | public_time = (struct ptime *)PA2KA(faddr); |
92 | public_time = (struct ptime *)PA2KA(faddr); |
83 | 93 | ||
84 | /* TODO: We would need some arch dependent settings here */ |
94 | /* TODO: We would need some arch dependent settings here */ |
85 | public_time->seconds1 = 0; |
95 | public_time->seconds1 = 0; |
86 | public_time->seconds2 = 0; |
96 | public_time->seconds2 = 0; |
87 | public_time->useconds = 0; |
97 | public_time->useconds = 0; |
88 | 98 | ||
89 | sysinfo_set_item_val("clock.faddr", NULL, (__native)faddr); |
99 | sysinfo_set_item_val("clock.faddr", NULL, (__native)faddr); |
90 | } |
100 | } |
91 | 101 | ||
92 | 102 | ||
93 | /** Update public counters |
103 | /** Update public counters |
94 | * |
104 | * |
95 | * Update it only on first processor |
105 | * Update it only on first processor |
96 | * TODO: Do we really need so many write barriers? |
106 | * TODO: Do we really need so many write barriers? |
97 | */ |
107 | */ |
98 | static void clock_update_counters(void) |
108 | static void clock_update_counters(void) |
99 | { |
109 | { |
100 | if (CPU->id == 0) { |
110 | if (CPU->id == 0) { |
101 | secfrag += 1000000/HZ; |
111 | secfrag += 1000000/HZ; |
102 | if (secfrag >= 1000000) { |
112 | if (secfrag >= 1000000) { |
103 | secfrag -= 1000000; |
113 | secfrag -= 1000000; |
104 | public_time->seconds1++; |
114 | public_time->seconds1++; |
105 | write_barrier(); |
115 | write_barrier(); |
106 | public_time->useconds = secfrag; |
116 | public_time->useconds = secfrag; |
107 | write_barrier(); |
117 | write_barrier(); |
108 | public_time->seconds2 = public_time->seconds1; |
118 | public_time->seconds2 = public_time->seconds1; |
109 | } else |
119 | } else |
110 | public_time->useconds += 1000000/HZ; |
120 | public_time->useconds += 1000000/HZ; |
111 | } |
121 | } |
112 | } |
122 | } |
113 | 123 | ||
114 | /** Clock routine |
124 | /** Clock routine |
115 | * |
125 | * |
116 | * Clock routine executed from clock interrupt handler |
126 | * Clock routine executed from clock interrupt handler |
117 | * (assuming interrupts_disable()'d). Runs expired timeouts |
127 | * (assuming interrupts_disable()'d). Runs expired timeouts |
118 | * and preemptive scheduling. |
128 | * and preemptive scheduling. |
119 | * |
129 | * |
120 | */ |
130 | */ |
121 | void clock(void) |
131 | void clock(void) |
122 | { |
132 | { |
123 | link_t *l; |
133 | link_t *l; |
124 | timeout_t *h; |
134 | timeout_t *h; |
125 | timeout_handler_t f; |
135 | timeout_handler_t f; |
126 | void *arg; |
136 | void *arg; |
127 | count_t missed_clock_ticks = CPU->missed_clock_ticks; |
137 | count_t missed_clock_ticks = CPU->missed_clock_ticks; |
128 | int i; |
138 | int i; |
129 | 139 | ||
130 | /* |
140 | /* |
131 | * To avoid lock ordering problems, |
141 | * To avoid lock ordering problems, |
132 | * run all expired timeouts as you visit them. |
142 | * run all expired timeouts as you visit them. |
133 | */ |
143 | */ |
134 | for (i = 0; i <= missed_clock_ticks; i++) { |
144 | for (i = 0; i <= missed_clock_ticks; i++) { |
135 | clock_update_counters(); |
145 | clock_update_counters(); |
136 | spinlock_lock(&CPU->timeoutlock); |
146 | spinlock_lock(&CPU->timeoutlock); |
137 | while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) { |
147 | while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) { |
138 | h = list_get_instance(l, timeout_t, link); |
148 | h = list_get_instance(l, timeout_t, link); |
139 | spinlock_lock(&h->lock); |
149 | spinlock_lock(&h->lock); |
140 | if (h->ticks-- != 0) { |
150 | if (h->ticks-- != 0) { |
141 | spinlock_unlock(&h->lock); |
151 | spinlock_unlock(&h->lock); |
142 | break; |
152 | break; |
143 | } |
153 | } |
144 | list_remove(l); |
154 | list_remove(l); |
145 | f = h->handler; |
155 | f = h->handler; |
146 | arg = h->arg; |
156 | arg = h->arg; |
147 | timeout_reinitialize(h); |
157 | timeout_reinitialize(h); |
148 | spinlock_unlock(&h->lock); |
158 | spinlock_unlock(&h->lock); |
149 | spinlock_unlock(&CPU->timeoutlock); |
159 | spinlock_unlock(&CPU->timeoutlock); |
150 | 160 | ||
151 | f(arg); |
161 | f(arg); |
152 | 162 | ||
153 | spinlock_lock(&CPU->timeoutlock); |
163 | spinlock_lock(&CPU->timeoutlock); |
154 | } |
164 | } |
155 | spinlock_unlock(&CPU->timeoutlock); |
165 | spinlock_unlock(&CPU->timeoutlock); |
156 | } |
166 | } |
157 | CPU->missed_clock_ticks = 0; |
167 | CPU->missed_clock_ticks = 0; |
158 | 168 | ||
159 | /* |
169 | /* |
160 | * Do CPU usage accounting and find out whether to preempt THREAD. |
170 | * Do CPU usage accounting and find out whether to preempt THREAD. |
161 | */ |
171 | */ |
162 | 172 | ||
163 | if (THREAD) { |
173 | if (THREAD) { |
164 | __u64 ticks; |
174 | __u64 ticks; |
165 | 175 | ||
166 | spinlock_lock(&CPU->lock); |
176 | spinlock_lock(&CPU->lock); |
167 | CPU->needs_relink += 1 + missed_clock_ticks; |
177 | CPU->needs_relink += 1 + missed_clock_ticks; |
168 | spinlock_unlock(&CPU->lock); |
178 | spinlock_unlock(&CPU->lock); |
169 | 179 | ||
170 | spinlock_lock(&THREAD->lock); |
180 | spinlock_lock(&THREAD->lock); |
171 | if ((ticks = THREAD->ticks)) { |
181 | if ((ticks = THREAD->ticks)) { |
172 | if (ticks >= 1 + missed_clock_ticks) |
182 | if (ticks >= 1 + missed_clock_ticks) |
173 | THREAD->ticks -= 1 + missed_clock_ticks; |
183 | THREAD->ticks -= 1 + missed_clock_ticks; |
174 | else |
184 | else |
175 | THREAD->ticks = 0; |
185 | THREAD->ticks = 0; |
176 | } |
186 | } |
177 | spinlock_unlock(&THREAD->lock); |
187 | spinlock_unlock(&THREAD->lock); |
178 | 188 | ||
179 | if (!ticks && !PREEMPTION_DISABLED) { |
189 | if (!ticks && !PREEMPTION_DISABLED) { |
180 | scheduler(); |
190 | scheduler(); |
181 | } |
191 | } |
182 | } |
192 | } |
183 | 193 | ||
184 | } |
194 | } |
- | 195 | ||
- | 196 | /** @} |
|
- | 197 | */ |
|
- | 198 | ||
185 | 199 |