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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 |