WebSVN – HelenOS – Diff – /branches/network/kernel/generic/src/time/clock.c


/*
 * Copyright (c) 2001-2004 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/** @addtogroup time
 * @{
 */
 
/**
 * @file
 * @brief   High-level clock interrupt handler.
 *
 * This file contains the clock() function which is the source
 * of preemption. It is also responsible for executing expired
 * timeouts.
 */
 
#include <time/clock.h>
#include <time/timeout.h>
#include <config.h>
#include <synch/spinlock.h>
#include <synch/waitq.h>
#include <func.h>
#include <proc/scheduler.h>
#include <cpu.h>
#include <arch.h>
#include <adt/list.h>
#include <atomic.h>
#include <proc/thread.h>
#include <sysinfo/sysinfo.h>
#include <arch/barrier.h>
#include <mm/frame.h>
#include <ddi/ddi.h>
 
/* Pointer to variable with uptime */
uptime_t *uptime;
 
/** Physical memory area of the real time clock */
static parea_t clock_parea;
 
/* Variable holding fragment of second, so that we would update
 * seconds correctly
 */
static unative_t secfrag = 0;
 
/** Initialize realtime clock counter
 *
 * The applications (and sometimes kernel) need to access accurate
 * information about realtime data. We allocate 1 page with these
 * data and update it periodically.
 */
void clock_counter_init(void)
{
    void *faddr;
 
    faddr = frame_alloc(ONE_FRAME, FRAME_ATOMIC);
    if (!faddr)
        panic("Cannot allocate page for clock.");
   
    uptime = (uptime_t *) PA2KA(faddr);
   
    uptime->seconds1 = 0;
    uptime->seconds2 = 0;
    uptime->useconds = 0;
 
    clock_parea.pbase = (uintptr_t) faddr;
    clock_parea.frames = 1;
    ddi_parea_register(&clock_parea);
 
    /*
     * Prepare information for the userspace so that it can successfully
     * physmem_map() the clock_parea.
     */
    sysinfo_set_item_val("clock.cacheable", NULL, (unative_t) true);
    sysinfo_set_item_val("clock.faddr", NULL, (unative_t) faddr);
}
 
 
/** Update public counters
 *
 * Update it only on first processor
 * TODO: Do we really need so many write barriers?
 */
static void clock_update_counters(void)
{
    if (CPU->id == 0) {
        secfrag += 1000000 / HZ;
        if (secfrag >= 1000000) {
            secfrag -= 1000000;
            uptime->seconds1++;
            write_barrier();
            uptime->useconds = secfrag;
            write_barrier();
            uptime->seconds2 = uptime->seconds1;
        } else
            uptime->useconds += 1000000 / HZ;
    }
}
 
/** Clock routine
 *
 * Clock routine executed from clock interrupt handler
 * (assuming interrupts_disable()'d). Runs expired timeouts
 * and preemptive scheduling.
 *
 */
void clock(void)
{
    link_t *l;
    timeout_t *h;
    timeout_handler_t f;
    void *arg;
    size_t missed_clock_ticks = CPU->missed_clock_ticks;
    unsigned int i;
 
    /*
     * To avoid lock ordering problems,
     * run all expired timeouts as you visit them.
     */
    for (i = 0; i <= missed_clock_ticks; i++) {
        clock_update_counters();
        spinlock_lock(&CPU->timeoutlock);
        while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {
            h = list_get_instance(l, timeout_t, link);
            spinlock_lock(&h->lock);
            if (h->ticks-- != 0) {
                spinlock_unlock(&h->lock);
                break;
            }
            list_remove(l);
            f = h->handler;
            arg = h->arg;
            timeout_reinitialize(h);
            spinlock_unlock(&h->lock); 
            spinlock_unlock(&CPU->timeoutlock);
 
            f(arg);
 
            spinlock_lock(&CPU->timeoutlock);
        }
        spinlock_unlock(&CPU->timeoutlock);
    }
    CPU->missed_clock_ticks = 0;
 
    /*
     * Do CPU usage accounting and find out whether to preempt THREAD.
     */
 
    if (THREAD) {
        uint64_t ticks;
       
        spinlock_lock(&CPU->lock);
        CPU->needs_relink += 1 + missed_clock_ticks;
        spinlock_unlock(&CPU->lock);   
   
        spinlock_lock(&THREAD->lock);
        if ((ticks = THREAD->ticks)) {
            if (ticks >= 1 + missed_clock_ticks)
                THREAD->ticks -= 1 + missed_clock_ticks;
            else
                THREAD->ticks = 0;
        }
        spinlock_unlock(&THREAD->lock);
       
        if (!ticks && !PREEMPTION_DISABLED) {
#ifdef CONFIG_UDEBUG
            istate_t *istate;
#endif
            scheduler();
#ifdef CONFIG_UDEBUG
            /*
             * Give udebug chance to stop the thread
             * before it begins executing userspace code.
             */
            istate = THREAD->udebug.uspace_state;
            if (istate && istate_from_uspace(istate))
                udebug_before_thread_runs();
#endif
        }
    }
 
}
 
/** @}
 */
 

Rev 4153	Rev 4581
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

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(root)/branches/network/kernel/generic/src/time/clock.c – Rev 4153 → 4581