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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 time |
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 <config.h> |
44 | #include <config.h> |
45 | #include <synch/spinlock.h> |
45 | #include <synch/spinlock.h> |
46 | #include <synch/waitq.h> |
46 | #include <synch/waitq.h> |
47 | #include <func.h> |
47 | #include <func.h> |
48 | #include <proc/scheduler.h> |
48 | #include <proc/scheduler.h> |
49 | #include <cpu.h> |
49 | #include <cpu.h> |
50 | #include <arch.h> |
50 | #include <arch.h> |
51 | #include <adt/list.h> |
51 | #include <adt/list.h> |
52 | #include <atomic.h> |
52 | #include <atomic.h> |
53 | #include <proc/thread.h> |
53 | #include <proc/thread.h> |
54 | #include <sysinfo/sysinfo.h> |
54 | #include <sysinfo/sysinfo.h> |
55 | #include <arch/barrier.h> |
55 | #include <arch/barrier.h> |
56 | #include <mm/frame.h> |
56 | #include <mm/frame.h> |
57 | #include <ddi/ddi.h> |
57 | #include <ddi/ddi.h> |
58 | 58 | ||
59 | /* Pointer to variable with uptime */ |
59 | /* Pointer to variable with uptime */ |
60 | uptime_t *uptime; |
60 | uptime_t *uptime; |
61 | 61 | ||
62 | /** Physical memory area of the real time clock */ |
62 | /** Physical memory area of the real time clock */ |
63 | static parea_t clock_parea; |
63 | static parea_t clock_parea; |
64 | 64 | ||
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 unative_t secfrag = 0; |
68 | static unative_t 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 | void clock_counter_init(void) |
76 | void clock_counter_init(void) |
77 | { |
77 | { |
78 | void *faddr; |
78 | void *faddr; |
79 | 79 | ||
80 | faddr = frame_alloc(ONE_FRAME, FRAME_ATOMIC); |
80 | faddr = frame_alloc(ONE_FRAME, FRAME_ATOMIC); |
81 | if (!faddr) |
81 | if (!faddr) |
82 | panic("Cannot allocate page for clock."); |
82 | panic("Cannot allocate page for clock."); |
83 | 83 | ||
84 | uptime = (uptime_t *) PA2KA(faddr); |
84 | uptime = (uptime_t *) PA2KA(faddr); |
85 | 85 | ||
86 | uptime->seconds1 = 0; |
86 | uptime->seconds1 = 0; |
87 | uptime->seconds2 = 0; |
87 | uptime->seconds2 = 0; |
88 | uptime->useconds = 0; |
88 | uptime->useconds = 0; |
89 | 89 | ||
90 | clock_parea.pbase = (uintptr_t) faddr; |
90 | clock_parea.pbase = (uintptr_t) faddr; |
91 | clock_parea.frames = 1; |
91 | clock_parea.frames = 1; |
92 | ddi_parea_register(&clock_parea); |
92 | ddi_parea_register(&clock_parea); |
93 | 93 | ||
94 | /* |
94 | /* |
95 | * Prepare information for the userspace so that it can successfully |
95 | * Prepare information for the userspace so that it can successfully |
96 | * physmem_map() the clock_parea. |
96 | * physmem_map() the clock_parea. |
97 | */ |
97 | */ |
98 | sysinfo_set_item_val("clock.cacheable", NULL, (unative_t) true); |
98 | sysinfo_set_item_val("clock.cacheable", NULL, (unative_t) true); |
99 | sysinfo_set_item_val("clock.faddr", NULL, (unative_t) faddr); |
99 | sysinfo_set_item_val("clock.faddr", NULL, (unative_t) faddr); |
100 | } |
100 | } |
101 | 101 | ||
102 | 102 | ||
103 | /** Update public counters |
103 | /** Update public counters |
104 | * |
104 | * |
105 | * Update it only on first processor |
105 | * Update it only on first processor |
106 | * TODO: Do we really need so many write barriers? |
106 | * TODO: Do we really need so many write barriers? |
107 | */ |
107 | */ |
108 | static void clock_update_counters(void) |
108 | static void clock_update_counters(void) |
109 | { |
109 | { |
110 | if (CPU->id == 0) { |
110 | if (CPU->id == 0) { |
111 | secfrag += 1000000 / HZ; |
111 | secfrag += 1000000 / HZ; |
112 | if (secfrag >= 1000000) { |
112 | if (secfrag >= 1000000) { |
113 | secfrag -= 1000000; |
113 | secfrag -= 1000000; |
114 | uptime->seconds1++; |
114 | uptime->seconds1++; |
115 | write_barrier(); |
115 | write_barrier(); |
116 | uptime->useconds = secfrag; |
116 | uptime->useconds = secfrag; |
117 | write_barrier(); |
117 | write_barrier(); |
118 | uptime->seconds2 = uptime->seconds1; |
118 | uptime->seconds2 = uptime->seconds1; |
119 | } else |
119 | } else |
120 | uptime->useconds += 1000000 / HZ; |
120 | uptime->useconds += 1000000 / HZ; |
121 | } |
121 | } |
122 | } |
122 | } |
123 | 123 | ||
124 | /** Clock routine |
124 | /** Clock routine |
125 | * |
125 | * |
126 | * Clock routine executed from clock interrupt handler |
126 | * Clock routine executed from clock interrupt handler |
127 | * (assuming interrupts_disable()'d). Runs expired timeouts |
127 | * (assuming interrupts_disable()'d). Runs expired timeouts |
128 | * and preemptive scheduling. |
128 | * and preemptive scheduling. |
129 | * |
129 | * |
130 | */ |
130 | */ |
131 | void clock(void) |
131 | void clock(void) |
132 | { |
132 | { |
133 | link_t *l; |
133 | link_t *l; |
134 | timeout_t *h; |
134 | timeout_t *h; |
135 | timeout_handler_t f; |
135 | timeout_handler_t f; |
136 | void *arg; |
136 | void *arg; |
137 | count_t missed_clock_ticks = CPU->missed_clock_ticks; |
137 | size_t missed_clock_ticks = CPU->missed_clock_ticks; |
138 | unsigned int i; |
138 | unsigned int i; |
139 | 139 | ||
140 | /* |
140 | /* |
141 | * To avoid lock ordering problems, |
141 | * To avoid lock ordering problems, |
142 | * run all expired timeouts as you visit them. |
142 | * run all expired timeouts as you visit them. |
143 | */ |
143 | */ |
144 | for (i = 0; i <= missed_clock_ticks; i++) { |
144 | for (i = 0; i <= missed_clock_ticks; i++) { |
145 | clock_update_counters(); |
145 | clock_update_counters(); |
146 | spinlock_lock(&CPU->timeoutlock); |
146 | spinlock_lock(&CPU->timeoutlock); |
147 | while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) { |
147 | while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) { |
148 | h = list_get_instance(l, timeout_t, link); |
148 | h = list_get_instance(l, timeout_t, link); |
149 | spinlock_lock(&h->lock); |
149 | spinlock_lock(&h->lock); |
150 | if (h->ticks-- != 0) { |
150 | if (h->ticks-- != 0) { |
151 | spinlock_unlock(&h->lock); |
151 | spinlock_unlock(&h->lock); |
152 | break; |
152 | break; |
153 | } |
153 | } |
154 | list_remove(l); |
154 | list_remove(l); |
155 | f = h->handler; |
155 | f = h->handler; |
156 | arg = h->arg; |
156 | arg = h->arg; |
157 | timeout_reinitialize(h); |
157 | timeout_reinitialize(h); |
158 | spinlock_unlock(&h->lock); |
158 | spinlock_unlock(&h->lock); |
159 | spinlock_unlock(&CPU->timeoutlock); |
159 | spinlock_unlock(&CPU->timeoutlock); |
160 | 160 | ||
161 | f(arg); |
161 | f(arg); |
162 | 162 | ||
163 | spinlock_lock(&CPU->timeoutlock); |
163 | spinlock_lock(&CPU->timeoutlock); |
164 | } |
164 | } |
165 | spinlock_unlock(&CPU->timeoutlock); |
165 | spinlock_unlock(&CPU->timeoutlock); |
166 | } |
166 | } |
167 | CPU->missed_clock_ticks = 0; |
167 | CPU->missed_clock_ticks = 0; |
168 | 168 | ||
169 | /* |
169 | /* |
170 | * Do CPU usage accounting and find out whether to preempt THREAD. |
170 | * Do CPU usage accounting and find out whether to preempt THREAD. |
171 | */ |
171 | */ |
172 | 172 | ||
173 | if (THREAD) { |
173 | if (THREAD) { |
174 | uint64_t ticks; |
174 | uint64_t ticks; |
175 | 175 | ||
176 | spinlock_lock(&CPU->lock); |
176 | spinlock_lock(&CPU->lock); |
177 | CPU->needs_relink += 1 + missed_clock_ticks; |
177 | CPU->needs_relink += 1 + missed_clock_ticks; |
178 | spinlock_unlock(&CPU->lock); |
178 | spinlock_unlock(&CPU->lock); |
179 | 179 | ||
180 | spinlock_lock(&THREAD->lock); |
180 | spinlock_lock(&THREAD->lock); |
181 | if ((ticks = THREAD->ticks)) { |
181 | if ((ticks = THREAD->ticks)) { |
182 | if (ticks >= 1 + missed_clock_ticks) |
182 | if (ticks >= 1 + missed_clock_ticks) |
183 | THREAD->ticks -= 1 + missed_clock_ticks; |
183 | THREAD->ticks -= 1 + missed_clock_ticks; |
184 | else |
184 | else |
185 | THREAD->ticks = 0; |
185 | THREAD->ticks = 0; |
186 | } |
186 | } |
187 | spinlock_unlock(&THREAD->lock); |
187 | spinlock_unlock(&THREAD->lock); |
188 | 188 | ||
189 | if (!ticks && !PREEMPTION_DISABLED) { |
189 | if (!ticks && !PREEMPTION_DISABLED) { |
190 | #ifdef CONFIG_UDEBUG |
190 | #ifdef CONFIG_UDEBUG |
191 | istate_t *istate; |
191 | istate_t *istate; |
192 | #endif |
192 | #endif |
193 | scheduler(); |
193 | scheduler(); |
194 | #ifdef CONFIG_UDEBUG |
194 | #ifdef CONFIG_UDEBUG |
195 | /* |
195 | /* |
196 | * Give udebug chance to stop the thread |
196 | * Give udebug chance to stop the thread |
197 | * before it begins executing userspace code. |
197 | * before it begins executing userspace code. |
198 | */ |
198 | */ |
199 | istate = THREAD->udebug.uspace_state; |
199 | istate = THREAD->udebug.uspace_state; |
200 | if (istate && istate_from_uspace(istate)) |
200 | if (istate && istate_from_uspace(istate)) |
201 | udebug_before_thread_runs(); |
201 | udebug_before_thread_runs(); |
202 | #endif |
202 | #endif |
203 | } |
203 | } |
204 | } |
204 | } |
205 | 205 | ||
206 | } |
206 | } |
207 | 207 | ||
208 | /** @} |
208 | /** @} |
209 | */ |
209 | */ |
210 | 210 |