WebSVN – HelenOS – Diff – /branches/dynload/kernel/genarch/src/mm/asid.c


/*
 * Copyright (c) 2006 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 genarchmm
 * @{
 */
 
/**
 * @file
 * @brief ASID management.
 *
 * Modern processor architectures optimize TLB utilization
 * by using ASIDs (a.k.a. memory contexts on sparc64 and
 * region identifiers on ia64). These ASIDs help to associate
 * each TLB item with an address space, thus making
 * finer-grained TLB invalidation possible.
 *
 * Unfortunatelly, there are usually less ASIDs available than
 * there can be unique as_t structures (i.e. address spaces
 * recognized by the kernel).
 *
 * When system runs short of ASIDs, it will attempt to steal
 * ASID from an address space that has not been active for
 * a while.
 *
 * This code depends on the fact that ASIDS_ALLOCABLE
 * is greater than number of supported CPUs (i.e. the
 * amount of concurently active address spaces).
 *
 * Architectures that don't have hardware support for address
 * spaces do not compile with this file.
 */
 
#include <mm/asid.h>
#include <mm/as.h>
#include <mm/tlb.h>
#include <arch/mm/asid.h>
#include <synch/spinlock.h>
#include <synch/mutex.h>
#include <adt/list.h>
#include <debug.h>
 
static count_t asids_allocated = 0;
 
/** Allocate free address space identifier.
 *
 * Interrupts must be disabled and inactive_as_with_asid_lock must be held
 * prior to this call
 *
 * @return New ASID.
 */
asid_t asid_get(void)
{
    asid_t asid;
    link_t *tmp;
    as_t *as;
 
    /*
     * Check if there is an unallocated ASID.
     */
   
    if (asids_allocated == ASIDS_ALLOCABLE) {
 
        /*
         * All ASIDs are already allocated.
         * Resort to stealing.
         */
       
        /*
         * Remove the first item on the list.
         * It is guaranteed to belong to an
         * inactive address space.
         */
        ASSERT(!list_empty(&inactive_as_with_asid_head));
        tmp = inactive_as_with_asid_head.next;
        list_remove(tmp);
       
        as = list_get_instance(tmp, as_t, inactive_as_with_asid_link);
 
        /*
         * Steal the ASID.
         * Note that the stolen ASID is not active.
         */
        asid = as->asid;
        ASSERT(asid != ASID_INVALID);
 
        /*
         * Notify the address space from wich the ASID
         * was stolen by invalidating its asid member.
         */
        as->asid = ASID_INVALID;
       
        /*
         * If the architecture uses some software cache
         * of TLB entries (e.g. TSB on sparc64), the
         * cache must be invalidated as well.
         */
        as_invalidate_translation_cache(as, 0, (count_t) -1);
       
        /*
         * Get the system rid of the stolen ASID.
         */
        tlb_shootdown_start(TLB_INVL_ASID, asid, 0, 0);
        tlb_invalidate_asid(asid);
        tlb_shootdown_finalize();
    } else {
 
        /*
         * There is at least one unallocated ASID.
         * Find it and assign it.
         */
 
        asid = asid_find_free();
        asids_allocated++;
 
        /*
         * Purge the allocated ASID from TLBs.
         */
        tlb_shootdown_start(TLB_INVL_ASID, asid, 0, 0);
        tlb_invalidate_asid(asid);
        tlb_shootdown_finalize();
    }
   
    return asid;
}
 
/** Release address space identifier.
 *
 * This code relies on architecture
 * dependent functionality.
 *
 * @param asid ASID to be released.
 */
void asid_put(asid_t asid)
{
    asids_allocated--;
    asid_put_arch(asid);
}
 
/** @}
 */
 

Rev 2927	Rev 4337
1	/*	1	/*
2	* Copyright (c) 2006 Jakub Jermar	2	* Copyright (c) 2006 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 genarchmm	29	/** @addtogroup genarchmm
30	* @{	30	* @{
31	*/	31	*/
32		32
33	/**	33	/**
34	* @file	34	* @file
35	* @brief ASID management.	35	* @brief ASID management.
36	*	36	*
37	* Modern processor architectures optimize TLB utilization	37	* Modern processor architectures optimize TLB utilization
38	* by using ASIDs (a.k.a. memory contexts on sparc64 and	38	* by using ASIDs (a.k.a. memory contexts on sparc64 and
39	* region identifiers on ia64). These ASIDs help to associate	39	* region identifiers on ia64). These ASIDs help to associate
40	* each TLB item with an address space, thus making	40	* each TLB item with an address space, thus making
41	* finer-grained TLB invalidation possible.	41	* finer-grained TLB invalidation possible.
42	*	42	*
43	* Unfortunatelly, there are usually less ASIDs available than	43	* Unfortunatelly, there are usually less ASIDs available than
44	* there can be unique as_t structures (i.e. address spaces	44	* there can be unique as_t structures (i.e. address spaces
45	* recognized by the kernel).	45	* recognized by the kernel).
46	*	46	*
47	* When system runs short of ASIDs, it will attempt to steal	47	* When system runs short of ASIDs, it will attempt to steal
48	* ASID from an address space that has not been active for	48	* ASID from an address space that has not been active for
49	* a while.	49	* a while.
50	*	50	*
51	* This code depends on the fact that ASIDS_ALLOCABLE	51	* This code depends on the fact that ASIDS_ALLOCABLE
52	* is greater than number of supported CPUs (i.e. the	52	* is greater than number of supported CPUs (i.e. the
53	* amount of concurently active address spaces).	53	* amount of concurently active address spaces).
54	*	54	*
55	* Architectures that don't have hardware support for address	55	* Architectures that don't have hardware support for address
56	* spaces do not compile with this file.	56	* spaces do not compile with this file.
57	*/	57	*/
58		58
59	#include <mm/asid.h>	59	#include <mm/asid.h>
60	#include <mm/as.h>	60	#include <mm/as.h>
61	#include <mm/tlb.h>	61	#include <mm/tlb.h>
62	#include <arch/mm/asid.h>	62	#include <arch/mm/asid.h>
63	#include <synch/spinlock.h>	63	#include <synch/spinlock.h>
64	#include <synch/mutex.h>	64	#include <synch/mutex.h>
65	#include <adt/list.h>	65	#include <adt/list.h>
66	#include <debug.h>	66	#include <debug.h>
67		67
68	static count_t asids_allocated = 0;	68	static count_t asids_allocated = 0;
69		69
70	/** Allocate free address space identifier.	70	/** Allocate free address space identifier.
71	*	71	*
72	* Interrupts must be disabled and inactive_as_with_asid_lock must be held	72	* Interrupts must be disabled and inactive_as_with_asid_lock must be held
73	* prior to this call	73	* prior to this call
74	*	74	*
75	* @return New ASID.	75	* @return New ASID.
76	*/	76	*/
77	asid_t asid_get(void)	77	asid_t asid_get(void)
78	{	78	{
79	asid_t asid;	79	asid_t asid;
80	link_t *tmp;	80	link_t *tmp;
81	as_t *as;	81	as_t *as;
82		82
83	/*	83	/*
84	* Check if there is an unallocated ASID.	84	* Check if there is an unallocated ASID.
85	*/	85	*/
86		86
87	if (asids_allocated == ASIDS_ALLOCABLE) {	87	if (asids_allocated == ASIDS_ALLOCABLE) {
88		88
89	/*	89	/*
90	* All ASIDs are already allocated.	90	* All ASIDs are already allocated.
91	* Resort to stealing.	91	* Resort to stealing.
92	*/	92	*/
93		93
94	/*	94	/*
95	* Remove the first item on the list.	95	* Remove the first item on the list.
96	* It is guaranteed to belong to an	96	* It is guaranteed to belong to an
97	* inactive address space.	97	* inactive address space.
98	*/	98	*/
99	ASSERT(!list_empty(&inactive_as_with_asid_head));	99	ASSERT(!list_empty(&inactive_as_with_asid_head));
100	tmp = inactive_as_with_asid_head.next;	100	tmp = inactive_as_with_asid_head.next;
101	list_remove(tmp);	101	list_remove(tmp);
102		102
103	as = list_get_instance(tmp, as_t, inactive_as_with_asid_link);	103	as = list_get_instance(tmp, as_t, inactive_as_with_asid_link);
104		104
105	/*	105	/*
106	* Steal the ASID.	106	* Steal the ASID.
107	* Note that the stolen ASID is not active.	107	* Note that the stolen ASID is not active.
108	*/	108	*/
109	asid = as->asid;	109	asid = as->asid;
110	ASSERT(asid != ASID_INVALID);	110	ASSERT(asid != ASID_INVALID);
111		111
112	/*	112	/*
113	* Notify the address space from wich the ASID	113	* Notify the address space from wich the ASID
114	* was stolen by invalidating its asid member.	114	* was stolen by invalidating its asid member.
115	*/	115	*/
116	as->asid = ASID_INVALID;	116	as->asid = ASID_INVALID;
117		117
118	/*	118	/*
119	* If the architecture uses some software cache	119	* If the architecture uses some software cache
120	* of TLB entries (e.g. TSB on sparc64), the	120	* of TLB entries (e.g. TSB on sparc64), the
121	* cache must be invalidated as well.	121	* cache must be invalidated as well.
122	*/	122	*/
123	as_invalidate_translation_cache(as, 0, (count_t) -1);	123	as_invalidate_translation_cache(as, 0, (count_t) -1);
124		124
125	/*	125	/*
126	* Get the system rid of the stolen ASID.	126	* Get the system rid of the stolen ASID.
127	*/	127	*/
128	tlb_shootdown_start(TLB_INVL_ASID, asid, 0, 0);	128	tlb_shootdown_start(TLB_INVL_ASID, asid, 0, 0);
129	tlb_invalidate_asid(asid);	129	tlb_invalidate_asid(asid);
130	tlb_shootdown_finalize();	130	tlb_shootdown_finalize();
131	} else {	131	} else {
132		132
133	/*	133	/*
134	* There is at least one unallocated ASID.	134	* There is at least one unallocated ASID.
135	* Find it and assign it.	135	* Find it and assign it.
136	*/	136	*/
137		137
138	asid = asid_find_free();	138	asid = asid_find_free();
139	asids_allocated++;	139	asids_allocated++;
140		140
141	/*	141	/*
142	* Purge the allocated ASID from TLBs.	142	* Purge the allocated ASID from TLBs.
143	*/	143	*/
144	tlb_shootdown_start(TLB_INVL_ASID, asid, 0, 0);	144	tlb_shootdown_start(TLB_INVL_ASID, asid, 0, 0);
145	tlb_invalidate_asid(asid);	145	tlb_invalidate_asid(asid);
146	tlb_shootdown_finalize();	146	tlb_shootdown_finalize();
147	}	147	}
148		148
149	return asid;	149	return asid;
150	}	150	}
151		151
152	/** Release address space identifier.	152	/** Release address space identifier.
153	*	153	*
154	* This code relies on architecture	154	* This code relies on architecture
155	* dependent functionality.	155	* dependent functionality.
156	*	156	*
157	* @param asid ASID to be released.	157	* @param asid ASID to be released.
158	*/	158	*/
159	void asid_put(asid_t asid)	159	void asid_put(asid_t asid)
160	{	160	{
161	asids_allocated--;	161	asids_allocated--;
162	asid_put_arch(asid);	162	asid_put_arch(asid);
163	}	163	}
164		164
165	/** @}	165	/** @}
166	*/	166	*/
167		167

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