WebSVN – HelenOS-historic – Diff – /kernel/trunk/arch/mips32/src/mm/asid.c


/*
 * Copyright (C) 2005 Martin Decky
 * Copyright (C) 2005 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.
 */
 
#include <arch/mm/asid.h>
#include <synch/spinlock.h>
#include <arch.h>
#include <debug.h>
#include <typedefs.h>
 
SPINLOCK_INITIALIZE(asid_usage_lock);
static count_t asid_usage[ASIDS];   /**< Usage tracking array for ASIDs */
 
/** Get ASID
 *
 * Get the least used ASID.
 *
 * @return ASID
 */
asid_t asid_get(void)
{
    ipl_t ipl;
    int i, j;
    count_t min;
   
    min = (unsigned) -1;
   
    ipl = interrupts_disable();
    spinlock_lock(&asid_usage_lock);
   
    for (i = ASID_START, j = ASID_START; i < ASIDS; i++) {
        if (asid_usage[i] < min) {
            j = i;
            min = asid_usage[i];
            if (!min)
                break;
        }
    }
 
    asid_usage[j]++;
 
    spinlock_unlock(&asid_usage_lock);
    interrupts_restore(ipl);
 
    return i;
}
 
/** Release ASID
 *
 * Release ASID by decrementing its usage count.
 *
 * @param asid ASID.
 */
void asid_put(asid_t asid)
{
    ipl_t ipl;
 
    ipl = interrupts_disable();
    spinlock_lock(&asid_usage_lock);
 
    ASSERT(asid != ASID_INVALID);
   
    ASSERT(asid_usage[asid] > 0);
    asid_usage[asid]--;
 
    spinlock_unlock(&asid_usage_lock);
    interrupts_restore(ipl);
}
 
/** Find out whether ASID is used by more address spaces
 *
 * Find out whether ASID is used by more address spaces.
 *
 * @param asid ASID in question.
 *
 * @return True if 'asid' is used by more address spaces, false otherwise.
 */
bool asid_has_conflicts(asid_t asid)
{
    bool has_conflicts = false;
    ipl_t ipl;
 
    ASSERT(asid != ASID_INVALID);
 
    ipl = interrupts_disable();
    spinlock_lock(&asid_usage_lock);
 
    if (asid_usage[asid] > 1)
        has_conflicts = true;
 
    spinlock_unlock(&asid_usage_lock);
    interrupts_restore(ipl);
 
    return has_conflicts;
}
 

Rev 534	Rev 623
1	/*	1	/*
2	* Copyright (C) 2005 Martin Decky	2	* Copyright (C) 2005 Martin Decky
3	* Copyright (C) 2005 Jakub Jermar	3	* Copyright (C) 2005 Jakub Jermar
4	* All rights reserved.	4	* All rights reserved.
5	*	5	*
6	* Redistribution and use in source and binary forms, with or without	6	* Redistribution and use in source and binary forms, with or without
7	* modification, are permitted provided that the following conditions	7	* modification, are permitted provided that the following conditions
8	* are met:	8	* are met:
9	*	9	*
10	* - Redistributions of source code must retain the above copyright	10	* - Redistributions of source code must retain the above copyright
11	* notice, this list of conditions and the following disclaimer.	11	* notice, this list of conditions and the following disclaimer.
12	* - Redistributions in binary form must reproduce the above copyright	12	* - Redistributions in binary form must reproduce the above copyright
13	* notice, this list of conditions and the following disclaimer in the	13	* notice, this list of conditions and the following disclaimer in the
14	* documentation and/or other materials provided with the distribution.	14	* documentation and/or other materials provided with the distribution.
15	* - The name of the author may not be used to endorse or promote products	15	* - The name of the author may not be used to endorse or promote products
16	* derived from this software without specific prior written permission.	16	* derived from this software without specific prior written permission.
17	*	17	*
18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28	*/	28	*/
29		29
30	#include <arch/mm/asid.h>	30	#include <arch/mm/asid.h>
31	#include <synch/spinlock.h>	31	#include <synch/spinlock.h>
32	#include <arch.h>	32	#include <arch.h>
33	#include <debug.h>	33	#include <debug.h>
34	#include <typedefs.h>	34	#include <typedefs.h>
35		35
36	static spinlock_t asid_usage_lock;	36	SPINLOCK_INITIALIZE(asid_usage_lock);
37	static count_t asid_usage[ASIDS]; /*< Usage tracking array for ASIDs /	37	static count_t asid_usage[ASIDS]; /*< Usage tracking array for ASIDs /
38		38
39	/** Get ASID	39	/** Get ASID
40	*	40	*
41	* Get the least used ASID.	41	* Get the least used ASID.
42	*	42	*
43	* @return ASID	43	* @return ASID
44	*/	44	*/
45	asid_t asid_get(void)	45	asid_t asid_get(void)
46	{	46	{
47	ipl_t ipl;	47	ipl_t ipl;
48	int i, j;	48	int i, j;
49	count_t min;	49	count_t min;
50		50
51	min = (unsigned) -1;	51	min = (unsigned) -1;
52		52
53	ipl = interrupts_disable();	53	ipl = interrupts_disable();
54	spinlock_lock(&asid_usage_lock);	54	spinlock_lock(&asid_usage_lock);
55		55
56	for (i = ASID_START, j = ASID_START; i < ASIDS; i++) {	56	for (i = ASID_START, j = ASID_START; i < ASIDS; i++) {
57	if (asid_usage[i] < min) {	57	if (asid_usage[i] < min) {
58	j = i;	58	j = i;
59	min = asid_usage[i];	59	min = asid_usage[i];
60	if (!min)	60	if (!min)
61	break;	61	break;
62	}	62	}
63	}	63	}
64		64
65	asid_usage[j]++;	65	asid_usage[j]++;
66		66
67	spinlock_unlock(&asid_usage_lock);	67	spinlock_unlock(&asid_usage_lock);
68	interrupts_restore(ipl);	68	interrupts_restore(ipl);
69		69
70	return i;	70	return i;
71	}	71	}
72		72
73	/** Release ASID	73	/** Release ASID
74	*	74	*
75	* Release ASID by decrementing its usage count.	75	* Release ASID by decrementing its usage count.
76	*	76	*
77	* @param asid ASID.	77	* @param asid ASID.
78	*/	78	*/
79	void asid_put(asid_t asid)	79	void asid_put(asid_t asid)
80	{	80	{
81	ipl_t ipl;	81	ipl_t ipl;
82		82
83	ipl = interrupts_disable();	83	ipl = interrupts_disable();
84	spinlock_lock(&asid_usage_lock);	84	spinlock_lock(&asid_usage_lock);
85		85
86	ASSERT(asid != ASID_INVALID);	86	ASSERT(asid != ASID_INVALID);
87		87
88	ASSERT(asid_usage[asid] > 0);	88	ASSERT(asid_usage[asid] > 0);
89	asid_usage[asid]--;	89	asid_usage[asid]--;
90		90
91	spinlock_unlock(&asid_usage_lock);	91	spinlock_unlock(&asid_usage_lock);
92	interrupts_restore(ipl);	92	interrupts_restore(ipl);
93	}	93	}
94		94
95	/** Find out whether ASID is used by more address spaces	95	/** Find out whether ASID is used by more address spaces
96	*	96	*
97	* Find out whether ASID is used by more address spaces.	97	* Find out whether ASID is used by more address spaces.
98	*	98	*
99	* @param asid ASID in question.	99	* @param asid ASID in question.
100	*	100	*
101	* @return True if 'asid' is used by more address spaces, false otherwise.	101	* @return True if 'asid' is used by more address spaces, false otherwise.
102	*/	102	*/
103	bool asid_has_conflicts(asid_t asid)	103	bool asid_has_conflicts(asid_t asid)
104	{	104	{
105	bool has_conflicts = false;	105	bool has_conflicts = false;
106	ipl_t ipl;	106	ipl_t ipl;
107		107
108	ASSERT(asid != ASID_INVALID);	108	ASSERT(asid != ASID_INVALID);
109		109
110	ipl = interrupts_disable();	110	ipl = interrupts_disable();
111	spinlock_lock(&asid_usage_lock);	111	spinlock_lock(&asid_usage_lock);
112		112
113	if (asid_usage[asid] > 1)	113	if (asid_usage[asid] > 1)
114	has_conflicts = true;	114	has_conflicts = true;
115		115
116	spinlock_unlock(&asid_usage_lock);	116	spinlock_unlock(&asid_usage_lock);
117	interrupts_restore(ipl);	117	interrupts_restore(ipl);
118		118
119	return has_conflicts;	119	return has_conflicts;
120	}	120	}
121		121

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(root)/kernel/trunk/arch/mips32/src/mm/asid.c – Rev 534 → 623