WebSVN – HelenOS – Diff – /branches/tracing/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 <arch/interrupt.h>
#include <mm/frame.h>
#include <ddi/ddi.h>
#include <udebug/udebug.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.vbase = (uintptr_t) uptime;
    clock_parea.frames = 1;
    clock_parea.cacheable = true;
    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;
    count_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) {
 
            scheduler();
 
#ifdef CONFIG_UDEBUG
            /*
             * Give udebug chance to stop the thread
             * before it begins executing.
             */
            if (istate_from_uspace(THREAD->udebug.uspace_state))
                udebug_before_thread_runs();
#endif
        }
    }
 
}
 
/** @}
 */
 

Rev 3431	Rev 3610
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 <arch/interrupt.h>
56	#include <mm/frame.h>	57	#include <mm/frame.h>
57	#include <ddi/ddi.h>	58	#include <ddi/ddi.h>
58	#include <udebug/udebug.h>	59	#include <udebug/udebug.h>
59		60
60	/* Pointer to variable with uptime */	61	/* Pointer to variable with uptime */
61	uptime_t *uptime;	62	uptime_t *uptime;
62		63
63	/** Physical memory area of the real time clock */	64	/** Physical memory area of the real time clock */
64	static parea_t clock_parea;	65	static parea_t clock_parea;
65		66
66	/* Variable holding fragment of second, so that we would update	67	/* Variable holding fragment of second, so that we would update
67	* seconds correctly	68	* seconds correctly
68	*/	69	*/
69	static unative_t secfrag = 0;	70	static unative_t secfrag = 0;
70		71
71	/** Initialize realtime clock counter	72	/** Initialize realtime clock counter
72	*	73	*
73	* The applications (and sometimes kernel) need to access accurate	74	* The applications (and sometimes kernel) need to access accurate
74	* information about realtime data. We allocate 1 page with these	75	* information about realtime data. We allocate 1 page with these
75	* data and update it periodically.	76	* data and update it periodically.
76	*/	77	*/
77	void clock_counter_init(void)	78	void clock_counter_init(void)
78	{	79	{
79	void *faddr;	80	void *faddr;
80		81
81	faddr = frame_alloc(ONE_FRAME, FRAME_ATOMIC);	82	faddr = frame_alloc(ONE_FRAME, FRAME_ATOMIC);
82	if (!faddr)	83	if (!faddr)
83	panic("Cannot allocate page for clock");	84	panic("Cannot allocate page for clock");
84		85
85	uptime = (uptime_t *) PA2KA(faddr);	86	uptime = (uptime_t *) PA2KA(faddr);
86		87
87	uptime->seconds1 = 0;	88	uptime->seconds1 = 0;
88	uptime->seconds2 = 0;	89	uptime->seconds2 = 0;
89	uptime->useconds = 0;	90	uptime->useconds = 0;
90		91
91	clock_parea.pbase = (uintptr_t) faddr;	92	clock_parea.pbase = (uintptr_t) faddr;
92	clock_parea.vbase = (uintptr_t) uptime;	93	clock_parea.vbase = (uintptr_t) uptime;
93	clock_parea.frames = 1;	94	clock_parea.frames = 1;
94	clock_parea.cacheable = true;	95	clock_parea.cacheable = true;
95	ddi_parea_register(&clock_parea);	96	ddi_parea_register(&clock_parea);
96		97
97	/*	98	/*
98	* Prepare information for the userspace so that it can successfully	99	* Prepare information for the userspace so that it can successfully
99	* physmem_map() the clock_parea.	100	* physmem_map() the clock_parea.
100	*/	101	*/
101	sysinfo_set_item_val("clock.cacheable", NULL, (unative_t) true);	102	sysinfo_set_item_val("clock.cacheable", NULL, (unative_t) true);
102	sysinfo_set_item_val("clock.faddr", NULL, (unative_t) faddr);	103	sysinfo_set_item_val("clock.faddr", NULL, (unative_t) faddr);
103	}	104	}
104		105
105		106
106	/** Update public counters	107	/** Update public counters
107	*	108	*
108	* Update it only on first processor	109	* Update it only on first processor
109	* TODO: Do we really need so many write barriers?	110	* TODO: Do we really need so many write barriers?
110	*/	111	*/
111	static void clock_update_counters(void)	112	static void clock_update_counters(void)
112	{	113	{
113	if (CPU->id == 0) {	114	if (CPU->id == 0) {
114	secfrag += 1000000 / HZ;	115	secfrag += 1000000 / HZ;
115	if (secfrag >= 1000000) {	116	if (secfrag >= 1000000) {
116	secfrag -= 1000000;	117	secfrag -= 1000000;
117	uptime->seconds1++;	118	uptime->seconds1++;
118	write_barrier();	119	write_barrier();
119	uptime->useconds = secfrag;	120	uptime->useconds = secfrag;
120	write_barrier();	121	write_barrier();
121	uptime->seconds2 = uptime->seconds1;	122	uptime->seconds2 = uptime->seconds1;
122	} else	123	} else
123	uptime->useconds += 1000000 / HZ;	124	uptime->useconds += 1000000 / HZ;
124	}	125	}
125	}	126	}
126		127
127	/** Clock routine	128	/** Clock routine
128	*	129	*
129	* Clock routine executed from clock interrupt handler	130	* Clock routine executed from clock interrupt handler
130	* (assuming interrupts_disable()'d). Runs expired timeouts	131	* (assuming interrupts_disable()'d). Runs expired timeouts
131	* and preemptive scheduling.	132	* and preemptive scheduling.
132	*	133	*
133	*/	134	*/
134	void clock(void)	135	void clock(void)
135	{	136	{
136	link_t *l;	137	link_t *l;
137	timeout_t *h;	138	timeout_t *h;
138	timeout_handler_t f;	139	timeout_handler_t f;
139	void *arg;	140	void *arg;
140	count_t missed_clock_ticks = CPU->missed_clock_ticks;	141	count_t missed_clock_ticks = CPU->missed_clock_ticks;
141	unsigned int i;	142	unsigned int i;
142		143
143	/*	144	/*
144	* To avoid lock ordering problems,	145	* To avoid lock ordering problems,
145	* run all expired timeouts as you visit them.	146	* run all expired timeouts as you visit them.
146	*/	147	*/
147	for (i = 0; i <= missed_clock_ticks; i++) {	148	for (i = 0; i <= missed_clock_ticks; i++) {
148	clock_update_counters();	149	clock_update_counters();
149	spinlock_lock(&CPU->timeoutlock);	150	spinlock_lock(&CPU->timeoutlock);
150	while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {	151	while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {
151	h = list_get_instance(l, timeout_t, link);	152	h = list_get_instance(l, timeout_t, link);
152	spinlock_lock(&h->lock);	153	spinlock_lock(&h->lock);
153	if (h->ticks-- != 0) {	154	if (h->ticks-- != 0) {
154	spinlock_unlock(&h->lock);	155	spinlock_unlock(&h->lock);
155	break;	156	break;
156	}	157	}
157	list_remove(l);	158	list_remove(l);
158	f = h->handler;	159	f = h->handler;
159	arg = h->arg;	160	arg = h->arg;
160	timeout_reinitialize(h);	161	timeout_reinitialize(h);
161	spinlock_unlock(&h->lock);	162	spinlock_unlock(&h->lock);
162	spinlock_unlock(&CPU->timeoutlock);	163	spinlock_unlock(&CPU->timeoutlock);
163		164
164	f(arg);	165	f(arg);
165		166
166	spinlock_lock(&CPU->timeoutlock);	167	spinlock_lock(&CPU->timeoutlock);
167	}	168	}
168	spinlock_unlock(&CPU->timeoutlock);	169	spinlock_unlock(&CPU->timeoutlock);
169	}	170	}
170	CPU->missed_clock_ticks = 0;	171	CPU->missed_clock_ticks = 0;
171		172
172	/*	173	/*
173	* Do CPU usage accounting and find out whether to preempt THREAD.	174	* Do CPU usage accounting and find out whether to preempt THREAD.
174	*/	175	*/
175		176
176	if (THREAD) {	177	if (THREAD) {
177	uint64_t ticks;	178	uint64_t ticks;
178		179
179	spinlock_lock(&CPU->lock);	180	spinlock_lock(&CPU->lock);
180	CPU->needs_relink += 1 + missed_clock_ticks;	181	CPU->needs_relink += 1 + missed_clock_ticks;
181	spinlock_unlock(&CPU->lock);	182	spinlock_unlock(&CPU->lock);
182		183
183	spinlock_lock(&THREAD->lock);	184	spinlock_lock(&THREAD->lock);
184	if ((ticks = THREAD->ticks)) {	185	if ((ticks = THREAD->ticks)) {
185	if (ticks >= 1 + missed_clock_ticks)	186	if (ticks >= 1 + missed_clock_ticks)
186	THREAD->ticks -= 1 + missed_clock_ticks;	187	THREAD->ticks -= 1 + missed_clock_ticks;
187	else	188	else
188	THREAD->ticks = 0;	189	THREAD->ticks = 0;
189	}	190	}
190	spinlock_unlock(&THREAD->lock);	191	spinlock_unlock(&THREAD->lock);
191		192
192	if (!ticks && !PREEMPTION_DISABLED) {	193	if (!ticks && !PREEMPTION_DISABLED) {
193		194
194	scheduler();	195	scheduler();
195		196
196	#ifdef CONFIG_UDEBUG	197	#ifdef CONFIG_UDEBUG
197	/*	198	/*
198	* Give udebug chance to stop the thread	199	* Give udebug chance to stop the thread
199	* before it begins executing.	200	* before it begins executing.
200	*/	201	*/
-		202	if (istate_from_uspace(THREAD->udebug.uspace_state))
201	udebug_before_thread_runs();	203	udebug_before_thread_runs();
202	#endif	204	#endif
203	}	205	}
204	}	206	}
205		207
206	}	208	}
207		209
208	/** @}	210	/** @}
209	*/	211	*/
210		212

Subversion Repositories HelenOS

(root)/branches/tracing/kernel/generic/src/time/clock.c – Rev 3431 → 3610