WebSVN – HelenOS – Diff – /trunk/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 <arch/types.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>
 
/** Physical memory area of the real time clock. */
static parea_t clock_parea;
 
/* Pointers to public variables with time */
struct ptime {
    unative_t seconds1;
    unative_t useconds;
    unative_t seconds2;
};
struct ptime *public_time;
/* 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");
   
    public_time = (struct ptime *) PA2KA(faddr);
 
        /* TODO: We would need some arch dependent settings here */
    public_time->seconds1 = 0;
    public_time->seconds2 = 0;
    public_time->useconds = 0;
 
    clock_parea.pbase = (uintptr_t) faddr;
    clock_parea.vbase = (uintptr_t) public_time;
    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.fcolor", NULL, (unative_t)
        PAGE_COLOR(clock_parea.vbase));
    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;
            public_time->seconds1++;
            write_barrier();
            public_time->useconds = secfrag;
            write_barrier();
            public_time->seconds2 = public_time->seconds1;
        } else
            public_time->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;
    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();
        }
    }
 
}
 
/** @}
 */
 

Rev 2015	Rev 2071
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 <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	#include <mm/frame.h>	57	#include <mm/frame.h>
58	#include <ddi/ddi.h>	58	#include <ddi/ddi.h>
59		59
60	/** Physical memory area of the real time clock. */	60	/** Physical memory area of the real time clock. */
61	static parea_t clock_parea;	61	static parea_t clock_parea;
62		62
63	/* Pointers to public variables with time */	63	/* Pointers to public variables with time */
64	struct ptime {	64	struct ptime {
65	unative_t seconds1;	65	unative_t seconds1;
66	unative_t useconds;	66	unative_t useconds;
67	unative_t seconds2;	67	unative_t seconds2;
68	};	68	};
69	struct ptime *public_time;	69	struct ptime *public_time;
70	/* Variable holding fragment of second, so that we would update	70	/* Variable holding fragment of second, so that we would update
71	* seconds correctly	71	* seconds correctly
72	*/	72	*/
73	static unative_t secfrag = 0;	73	static unative_t secfrag = 0;
74		74
75	/** Initialize realtime clock counter	75	/** Initialize realtime clock counter
76	*	76	*
77	* The applications (and sometimes kernel) need to access accurate	77	* The applications (and sometimes kernel) need to access accurate
78	* information about realtime data. We allocate 1 page with these	78	* information about realtime data. We allocate 1 page with these
79	* data and update it periodically.	79	* data and update it periodically.
80	*/	80	*/
81	void clock_counter_init(void)	81	void clock_counter_init(void)
82	{	82	{
83	void *faddr;	83	void *faddr;
84		84
85	faddr = frame_alloc(ONE_FRAME, FRAME_ATOMIC);	85	faddr = frame_alloc(ONE_FRAME, FRAME_ATOMIC);
86	if (!faddr)	86	if (!faddr)
87	panic("Cannot allocate page for clock");	87	panic("Cannot allocate page for clock");
88		88
89	public_time = (struct ptime *) PA2KA(faddr);	89	public_time = (struct ptime *) PA2KA(faddr);
90		90
91	/* TODO: We would need some arch dependent settings here */	91	/* TODO: We would need some arch dependent settings here */
92	public_time->seconds1 = 0;	92	public_time->seconds1 = 0;
93	public_time->seconds2 = 0;	93	public_time->seconds2 = 0;
94	public_time->useconds = 0;	94	public_time->useconds = 0;
95		95
96	clock_parea.pbase = (uintptr_t) faddr;	96	clock_parea.pbase = (uintptr_t) faddr;
97	clock_parea.vbase = (uintptr_t) public_time;	97	clock_parea.vbase = (uintptr_t) public_time;
98	clock_parea.frames = 1;	98	clock_parea.frames = 1;
99	clock_parea.cacheable = true;	99	clock_parea.cacheable = true;
100	ddi_parea_register(&clock_parea);	100	ddi_parea_register(&clock_parea);
101		101
102	/*	102	/*
103	* Prepare information for the userspace so that it can successfully	103	* Prepare information for the userspace so that it can successfully
104	* physmem_map() the clock_parea.	104	* physmem_map() the clock_parea.
105	*/	105	*/
106	sysinfo_set_item_val("clock.cacheable", NULL, (unative_t) true);	106	sysinfo_set_item_val("clock.cacheable", NULL, (unative_t) true);
107	sysinfo_set_item_val("clock.fcolor", NULL, (unative_t)	107	sysinfo_set_item_val("clock.fcolor", NULL, (unative_t)
108	PAGE_COLOR(clock_parea.vbase));	108	PAGE_COLOR(clock_parea.vbase));
109	sysinfo_set_item_val("clock.faddr", NULL, (unative_t) faddr);	109	sysinfo_set_item_val("clock.faddr", NULL, (unative_t) faddr);
110	}	110	}
111		111
112		112
113	/** Update public counters	113	/** Update public counters
114	*	114	*
115	* Update it only on first processor	115	* Update it only on first processor
116	* TODO: Do we really need so many write barriers?	116	* TODO: Do we really need so many write barriers?
117	*/	117	*/
118	static void clock_update_counters(void)	118	static void clock_update_counters(void)
119	{	119	{
120	if (CPU->id == 0) {	120	if (CPU->id == 0) {
121	secfrag += 1000000/HZ;	121	secfrag += 1000000/HZ;
122	if (secfrag >= 1000000) {	122	if (secfrag >= 1000000) {
123	secfrag -= 1000000;	123	secfrag -= 1000000;
124	public_time->seconds1++;	124	public_time->seconds1++;
125	write_barrier();	125	write_barrier();
126	public_time->useconds = secfrag;	126	public_time->useconds = secfrag;
127	write_barrier();	127	write_barrier();
128	public_time->seconds2 = public_time->seconds1;	128	public_time->seconds2 = public_time->seconds1;
129	} else	129	} else
130	public_time->useconds += 1000000/HZ;	130	public_time->useconds += 1000000/HZ;
131	}	131	}
132	}	132	}
133		133
134	/** Clock routine	134	/** Clock routine
135	*	135	*
136	* Clock routine executed from clock interrupt handler	136	* Clock routine executed from clock interrupt handler
137	* (assuming interrupts_disable()'d). Runs expired timeouts	137	* (assuming interrupts_disable()'d). Runs expired timeouts
138	* and preemptive scheduling.	138	* and preemptive scheduling.
139	*	139	*
140	*/	140	*/
141	void clock(void)	141	void clock(void)
142	{	142	{
143	link_t *l;	143	link_t *l;
144	timeout_t *h;	144	timeout_t *h;
145	timeout_handler_t f;	145	timeout_handler_t f;
146	void *arg;	146	void *arg;
147	count_t missed_clock_ticks = CPU->missed_clock_ticks;	147	count_t missed_clock_ticks = CPU->missed_clock_ticks;
148	int i;	148	int i;
149		149
150	/*	150	/*
151	* To avoid lock ordering problems,	151	* To avoid lock ordering problems,
152	* run all expired timeouts as you visit them.	152	* run all expired timeouts as you visit them.
153	*/	153	*/
154	for (i = 0; i <= missed_clock_ticks; i++) {	154	for (i = 0; i <= missed_clock_ticks; i++) {
155	clock_update_counters();	155	clock_update_counters();
156	spinlock_lock(&CPU->timeoutlock);	156	spinlock_lock(&CPU->timeoutlock);
157	while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {	157	while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {
158	h = list_get_instance(l, timeout_t, link);	158	h = list_get_instance(l, timeout_t, link);
159	spinlock_lock(&h->lock);	159	spinlock_lock(&h->lock);
160	if (h->ticks-- != 0) {	160	if (h->ticks-- != 0) {
161	spinlock_unlock(&h->lock);	161	spinlock_unlock(&h->lock);
162	break;	162	break;
163	}	163	}
164	list_remove(l);	164	list_remove(l);
165	f = h->handler;	165	f = h->handler;
166	arg = h->arg;	166	arg = h->arg;
167	timeout_reinitialize(h);	167	timeout_reinitialize(h);
168	spinlock_unlock(&h->lock);	168	spinlock_unlock(&h->lock);
169	spinlock_unlock(&CPU->timeoutlock);	169	spinlock_unlock(&CPU->timeoutlock);
170		170
171	f(arg);	171	f(arg);
172		172
173	spinlock_lock(&CPU->timeoutlock);	173	spinlock_lock(&CPU->timeoutlock);
174	}	174	}
175	spinlock_unlock(&CPU->timeoutlock);	175	spinlock_unlock(&CPU->timeoutlock);
176	}	176	}
177	CPU->missed_clock_ticks = 0;	177	CPU->missed_clock_ticks = 0;
178		178
179	/*	179	/*
180	* Do CPU usage accounting and find out whether to preempt THREAD.	180	* Do CPU usage accounting and find out whether to preempt THREAD.
181	*/	181	*/
182		182
183	if (THREAD) {	183	if (THREAD) {
184	uint64_t ticks;	184	uint64_t ticks;
185		185
186	spinlock_lock(&CPU->lock);	186	spinlock_lock(&CPU->lock);
187	CPU->needs_relink += 1 + missed_clock_ticks;	187	CPU->needs_relink += 1 + missed_clock_ticks;
188	spinlock_unlock(&CPU->lock);	188	spinlock_unlock(&CPU->lock);
189		189
190	spinlock_lock(&THREAD->lock);	190	spinlock_lock(&THREAD->lock);
191	if ((ticks = THREAD->ticks)) {	191	if ((ticks = THREAD->ticks)) {
192	if (ticks >= 1 + missed_clock_ticks)	192	if (ticks >= 1 + missed_clock_ticks)
193	THREAD->ticks -= 1 + missed_clock_ticks;	193	THREAD->ticks -= 1 + missed_clock_ticks;
194	else	194	else
195	THREAD->ticks = 0;	195	THREAD->ticks = 0;
196	}	196	}
197	spinlock_unlock(&THREAD->lock);	197	spinlock_unlock(&THREAD->lock);
198		198
199	if (!ticks && !PREEMPTION_DISABLED) {	199	if (!ticks && !PREEMPTION_DISABLED) {
200	scheduler();	200	scheduler();
201	}	201	}
202	}	202	}
203		203
204	}	204	}
205		205
206	/** @}	206	/** @}
207	*/	207	*/
208		208

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/time/clock.c – Rev 2015 → 2071