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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 | /** @addtogroup generic |
29 | /** @addtogroup time |
30 | * @{ |
30 | * @{ |
31 | */ |
31 | */ |
32 | 32 | ||
33 | /** |
33 | /** |
34 | * @file |
34 | * @file |
35 | * @brief High-level clock interrupt handler. |
35 | * @brief High-level clock interrupt handler. |
36 | * |
36 | * |
37 | * This file contains the clock() function which is the source |
37 | * This file contains the clock() function which is the source |
38 | * of preemption. It is also responsible for executing expired |
38 | * of preemption. It is also responsible for executing expired |
39 | * timeouts. |
39 | * timeouts. |
40 | */ |
40 | */ |
41 | 41 | ||
42 | #include <time/clock.h> |
42 | #include <time/clock.h> |
43 | #include <time/timeout.h> |
43 | #include <time/timeout.h> |
44 | #include <arch/types.h> |
44 | #include <arch/types.h> |
45 | #include <config.h> |
45 | #include <config.h> |
46 | #include <synch/spinlock.h> |
46 | #include <synch/spinlock.h> |
47 | #include <synch/waitq.h> |
47 | #include <synch/waitq.h> |
48 | #include <func.h> |
48 | #include <func.h> |
49 | #include <proc/scheduler.h> |
49 | #include <proc/scheduler.h> |
50 | #include <cpu.h> |
50 | #include <cpu.h> |
51 | #include <arch.h> |
51 | #include <arch.h> |
52 | #include <adt/list.h> |
52 | #include <adt/list.h> |
53 | #include <atomic.h> |
53 | #include <atomic.h> |
54 | #include <proc/thread.h> |
54 | #include <proc/thread.h> |
55 | #include <sysinfo/sysinfo.h> |
55 | #include <sysinfo/sysinfo.h> |
56 | #include <arch/barrier.h> |
56 | #include <arch/barrier.h> |
57 | 57 | ||
58 | /* Pointers to public variables with time */ |
58 | /* Pointers to public variables with time */ |
59 | struct ptime { |
59 | struct ptime { |
60 | __native seconds1; |
60 | __native seconds1; |
61 | __native useconds; |
61 | __native useconds; |
62 | __native seconds2; |
62 | __native seconds2; |
63 | }; |
63 | }; |
64 | struct ptime *public_time; |
64 | struct ptime *public_time; |
65 | /* Variable holding fragment of second, so that we would update |
65 | /* Variable holding fragment of second, so that we would update |
66 | * seconds correctly |
66 | * seconds correctly |
67 | */ |
67 | */ |
68 | static __native secfrag = 0; |
68 | static __native secfrag = 0; |
69 | 69 | ||
70 | /** Initialize realtime clock counter |
70 | /** Initialize realtime clock counter |
71 | * |
71 | * |
72 | * The applications (and sometimes kernel) need to access accurate |
72 | * The applications (and sometimes kernel) need to access accurate |
73 | * information about realtime data. We allocate 1 page with these |
73 | * information about realtime data. We allocate 1 page with these |
74 | * data and update it periodically. |
74 | * data and update it periodically. |
75 | * |
75 | * |
76 | * |
76 | * |
77 | */ |
77 | */ |
78 | void clock_counter_init(void) |
78 | void clock_counter_init(void) |
79 | { |
79 | { |
80 | void *faddr; |
80 | void *faddr; |
81 | 81 | ||
82 | faddr = (void *)PFN2ADDR(frame_alloc(0, FRAME_ATOMIC)); |
82 | faddr = (void *)PFN2ADDR(frame_alloc(0, FRAME_ATOMIC)); |
83 | if (!faddr) |
83 | if (!faddr) |
84 | panic("Cannot allocate page for clock"); |
84 | panic("Cannot allocate page for clock"); |
85 | 85 | ||
86 | public_time = (struct ptime *)PA2KA(faddr); |
86 | public_time = (struct ptime *)PA2KA(faddr); |
87 | 87 | ||
88 | /* TODO: We would need some arch dependent settings here */ |
88 | /* TODO: We would need some arch dependent settings here */ |
89 | public_time->seconds1 = 0; |
89 | public_time->seconds1 = 0; |
90 | public_time->seconds2 = 0; |
90 | public_time->seconds2 = 0; |
91 | public_time->useconds = 0; |
91 | public_time->useconds = 0; |
92 | 92 | ||
93 | sysinfo_set_item_val("clock.faddr", NULL, (__native)faddr); |
93 | sysinfo_set_item_val("clock.faddr", NULL, (__native)faddr); |
94 | } |
94 | } |
95 | 95 | ||
96 | 96 | ||
97 | /** Update public counters |
97 | /** Update public counters |
98 | * |
98 | * |
99 | * Update it only on first processor |
99 | * Update it only on first processor |
100 | * TODO: Do we really need so many write barriers? |
100 | * TODO: Do we really need so many write barriers? |
101 | */ |
101 | */ |
102 | static void clock_update_counters(void) |
102 | static void clock_update_counters(void) |
103 | { |
103 | { |
104 | if (CPU->id == 0) { |
104 | if (CPU->id == 0) { |
105 | secfrag += 1000000/HZ; |
105 | secfrag += 1000000/HZ; |
106 | if (secfrag >= 1000000) { |
106 | if (secfrag >= 1000000) { |
107 | secfrag -= 1000000; |
107 | secfrag -= 1000000; |
108 | public_time->seconds1++; |
108 | public_time->seconds1++; |
109 | write_barrier(); |
109 | write_barrier(); |
110 | public_time->useconds = secfrag; |
110 | public_time->useconds = secfrag; |
111 | write_barrier(); |
111 | write_barrier(); |
112 | public_time->seconds2 = public_time->seconds1; |
112 | public_time->seconds2 = public_time->seconds1; |
113 | } else |
113 | } else |
114 | public_time->useconds += 1000000/HZ; |
114 | public_time->useconds += 1000000/HZ; |
115 | } |
115 | } |
116 | } |
116 | } |
117 | 117 | ||
118 | /** Clock routine |
118 | /** Clock routine |
119 | * |
119 | * |
120 | * Clock routine executed from clock interrupt handler |
120 | * Clock routine executed from clock interrupt handler |
121 | * (assuming interrupts_disable()'d). Runs expired timeouts |
121 | * (assuming interrupts_disable()'d). Runs expired timeouts |
122 | * and preemptive scheduling. |
122 | * and preemptive scheduling. |
123 | * |
123 | * |
124 | */ |
124 | */ |
125 | void clock(void) |
125 | void clock(void) |
126 | { |
126 | { |
127 | link_t *l; |
127 | link_t *l; |
128 | timeout_t *h; |
128 | timeout_t *h; |
129 | timeout_handler_t f; |
129 | timeout_handler_t f; |
130 | void *arg; |
130 | void *arg; |
131 | count_t missed_clock_ticks = CPU->missed_clock_ticks; |
131 | count_t missed_clock_ticks = CPU->missed_clock_ticks; |
132 | int i; |
132 | int i; |
133 | 133 | ||
134 | /* |
134 | /* |
135 | * To avoid lock ordering problems, |
135 | * To avoid lock ordering problems, |
136 | * run all expired timeouts as you visit them. |
136 | * run all expired timeouts as you visit them. |
137 | */ |
137 | */ |
138 | for (i = 0; i <= missed_clock_ticks; i++) { |
138 | for (i = 0; i <= missed_clock_ticks; i++) { |
139 | clock_update_counters(); |
139 | clock_update_counters(); |
140 | spinlock_lock(&CPU->timeoutlock); |
140 | spinlock_lock(&CPU->timeoutlock); |
141 | while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) { |
141 | while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) { |
142 | h = list_get_instance(l, timeout_t, link); |
142 | h = list_get_instance(l, timeout_t, link); |
143 | spinlock_lock(&h->lock); |
143 | spinlock_lock(&h->lock); |
144 | if (h->ticks-- != 0) { |
144 | if (h->ticks-- != 0) { |
145 | spinlock_unlock(&h->lock); |
145 | spinlock_unlock(&h->lock); |
146 | break; |
146 | break; |
147 | } |
147 | } |
148 | list_remove(l); |
148 | list_remove(l); |
149 | f = h->handler; |
149 | f = h->handler; |
150 | arg = h->arg; |
150 | arg = h->arg; |
151 | timeout_reinitialize(h); |
151 | timeout_reinitialize(h); |
152 | spinlock_unlock(&h->lock); |
152 | spinlock_unlock(&h->lock); |
153 | spinlock_unlock(&CPU->timeoutlock); |
153 | spinlock_unlock(&CPU->timeoutlock); |
154 | 154 | ||
155 | f(arg); |
155 | f(arg); |
156 | 156 | ||
157 | spinlock_lock(&CPU->timeoutlock); |
157 | spinlock_lock(&CPU->timeoutlock); |
158 | } |
158 | } |
159 | spinlock_unlock(&CPU->timeoutlock); |
159 | spinlock_unlock(&CPU->timeoutlock); |
160 | } |
160 | } |
161 | CPU->missed_clock_ticks = 0; |
161 | CPU->missed_clock_ticks = 0; |
162 | 162 | ||
163 | /* |
163 | /* |
164 | * Do CPU usage accounting and find out whether to preempt THREAD. |
164 | * Do CPU usage accounting and find out whether to preempt THREAD. |
165 | */ |
165 | */ |
166 | 166 | ||
167 | if (THREAD) { |
167 | if (THREAD) { |
168 | __u64 ticks; |
168 | __u64 ticks; |
169 | 169 | ||
170 | spinlock_lock(&CPU->lock); |
170 | spinlock_lock(&CPU->lock); |
171 | CPU->needs_relink += 1 + missed_clock_ticks; |
171 | CPU->needs_relink += 1 + missed_clock_ticks; |
172 | spinlock_unlock(&CPU->lock); |
172 | spinlock_unlock(&CPU->lock); |
173 | 173 | ||
174 | spinlock_lock(&THREAD->lock); |
174 | spinlock_lock(&THREAD->lock); |
175 | if ((ticks = THREAD->ticks)) { |
175 | if ((ticks = THREAD->ticks)) { |
176 | if (ticks >= 1 + missed_clock_ticks) |
176 | if (ticks >= 1 + missed_clock_ticks) |
177 | THREAD->ticks -= 1 + missed_clock_ticks; |
177 | THREAD->ticks -= 1 + missed_clock_ticks; |
178 | else |
178 | else |
179 | THREAD->ticks = 0; |
179 | THREAD->ticks = 0; |
180 | } |
180 | } |
181 | spinlock_unlock(&THREAD->lock); |
181 | spinlock_unlock(&THREAD->lock); |
182 | 182 | ||
183 | if (!ticks && !PREEMPTION_DISABLED) { |
183 | if (!ticks && !PREEMPTION_DISABLED) { |
184 | scheduler(); |
184 | scheduler(); |
185 | } |
185 | } |
186 | } |
186 | } |
187 | 187 | ||
188 | } |
188 | } |
189 | 189 | ||
190 | /** @} |
190 | /** @} |
191 | */ |
191 | */ |
192 | 192 | ||
193 | 193 |