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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 | #include <arch/types.h> |
29 | #include <arch/types.h> |
30 | #include <config.h> |
30 | #include <config.h> |
31 | #include <func.h> |
31 | #include <func.h> |
32 | #include <mm/frame.h> |
32 | #include <mm/frame.h> |
33 | #include <mm/page.h> |
33 | #include <mm/page.h> |
34 | #include <arch/mm/page.h> |
34 | #include <arch/mm/page.h> |
35 | #include <arch/interrupt.h> |
35 | #include <arch/interrupt.h> |
36 | #include <arch/asm.h> |
36 | #include <arch/asm.h> |
37 | #include <synch/spinlock.h> |
37 | #include <synch/spinlock.h> |
38 | #include <debug.h> |
38 | #include <debug.h> |
39 | 39 | ||
40 | /* |
40 | /* |
41 | * Note. |
41 | * Note. |
42 | * This is the preliminary code for controlling paging mechanism on ia32. It is |
42 | * This is the preliminary code for controlling paging mechanism on ia32. It is |
43 | * needed by other parts of the kernel for its ability to map virtual addresses |
43 | * needed by other parts of the kernel for its ability to map virtual addresses |
44 | * to physical. SMP code relies on this feature. Other than that, this code is |
44 | * to physical. SMP code relies on this feature. Other than that, this code is |
45 | * by no means meant to implement virtual memory in terms of swapping pages in |
45 | * by no means meant to implement virtual memory in terms of swapping pages in |
46 | * and out. |
46 | * and out. |
47 | */ |
47 | */ |
48 | 48 | ||
49 | __address bootstrap_dba; |
49 | __address bootstrap_dba; |
50 | 50 | ||
51 | void page_arch_init(void) |
51 | void page_arch_init(void) |
52 | { |
52 | { |
53 | __address dba; |
53 | __address dba; |
54 | __u32 i; |
54 | __u32 i; |
55 | 55 | ||
56 | if (config.cpu_active == 1) { |
56 | if (config.cpu_active == 1) { |
57 | dba = frame_alloc(FRAME_KA | FRAME_PANIC); |
57 | dba = frame_alloc(FRAME_KA | FRAME_PANIC); |
58 | memsetb(dba, PAGE_SIZE, 0); |
58 | memsetb(dba, PAGE_SIZE, 0); |
59 | 59 | ||
60 | bootstrap_dba = dba; |
60 | bootstrap_dba = dba; |
61 | 61 | ||
62 | /* |
62 | /* |
63 | * Identity mapping for all frames. |
63 | * Identity mapping for all frames. |
64 | * PA2KA(identity) mapping for all frames. |
64 | * PA2KA(identity) mapping for all frames. |
65 | */ |
65 | */ |
66 | for (i = 0; i < frames; i++) { |
66 | for (i = 0; i < frames; i++) { |
67 | map_page_to_frame(i * PAGE_SIZE, i * PAGE_SIZE, PAGE_CACHEABLE, KA2PA(dba)); |
67 | map_page_to_frame(i * PAGE_SIZE, i * PAGE_SIZE, PAGE_CACHEABLE, KA2PA(dba)); |
68 | map_page_to_frame(PA2KA(i * PAGE_SIZE), i * PAGE_SIZE, PAGE_CACHEABLE, KA2PA(dba)); |
68 | map_page_to_frame(PA2KA(i * PAGE_SIZE), i * PAGE_SIZE, PAGE_CACHEABLE, KA2PA(dba)); |
69 | } |
69 | } |
70 | 70 | ||
71 | trap_register(14, page_fault); |
71 | trap_register(14, page_fault); |
72 | write_cr3(KA2PA(dba)); |
72 | write_cr3(KA2PA(dba)); |
73 | } |
73 | } |
74 | else { |
74 | else { |
75 | /* |
75 | /* |
76 | * Application processors need to create their own view of the |
76 | * Application processors need to create their own view of the |
77 | * virtual address space. Because of that, each AP copies |
77 | * virtual address space. Because of that, each AP copies |
78 | * already-initialized paging information from the bootstrap |
78 | * already-initialized paging information from the bootstrap |
79 | * processor and adjusts it to fulfill its needs. |
79 | * processor and adjusts it to fulfill its needs. |
80 | */ |
80 | */ |
81 | 81 | ||
82 | dba = frame_alloc(FRAME_KA | FRAME_PANIC); |
82 | dba = frame_alloc(FRAME_KA | FRAME_PANIC); |
83 | memcopy(bootstrap_dba, dba, PAGE_SIZE); |
83 | memcopy(bootstrap_dba, dba, PAGE_SIZE); |
84 | write_cr3(KA2PA(dba)); |
84 | write_cr3(KA2PA(dba)); |
85 | } |
85 | } |
86 | 86 | ||
87 | paging_on(); |
87 | paging_on(); |
88 | } |
88 | } |
89 | - | ||
90 | /* |
- | |
91 | * Besides mapping pages to frames, this function also sets the present bit of |
- | |
92 | * the page's specifier in both page directory and respective page table. If |
- | |
93 | * the page table for this page has not been allocated so far, it will take |
- | |
94 | * care of it and allocate the necessary frame. |
- | |
95 | * |
- | |
96 | * PAGE_CACHEABLE flag: when set, it turns caches for that page on |
- | |
97 | * PAGE_NOT_PRESENT flag: when set, it marks the page not present |
- | |
98 | * PAGE_USER flag: when set, the page is accessible from userspace |
- | |
99 | * |
- | |
100 | * When the root parameter is non-zero, it is used as the page directory address. |
- | |
101 | * Otherwise, the page directory address is read from CPU. |
- | |
102 | */ |
- | |
103 | void map_page_to_frame(__address page, __address frame, int flags, __address root) |
- | |
104 | { |
- | |
105 | struct page_specifier *pd, *pt; |
- | |
106 | __address dba, newpt; |
- | |
107 | int pde, pte; |
- | |
108 | - | ||
109 | if (root) dba = root; |
- | |
110 | else dba = read_cr3(); |
- | |
111 | - | ||
112 | pde = page >> 22; /* page directory entry */ |
- | |
113 | pte = (page >> 12) & 0x3ff; /* page table entry */ |
- | |
114 | - | ||
115 | pd = (struct page_specifier *) PA2KA(dba); |
- | |
116 | - | ||
117 | if (!pd[pde].present) { |
- | |
118 | /* |
- | |
119 | * There is currently no page table for this address. Allocate |
- | |
120 | * frame for the page table and clean it. |
- | |
121 | */ |
- | |
122 | newpt = frame_alloc(FRAME_KA); |
- | |
123 | pd[pde].frame_address = KA2PA(newpt) >> 12; |
- | |
124 | memsetb(newpt, PAGE_SIZE, 0); |
- | |
125 | pd[pde].present = 1; |
- | |
126 | pd[pde].uaccessible = 1; |
- | |
127 | } |
- | |
128 | - | ||
129 | pt = (struct page_specifier *) PA2KA((pd[pde].frame_address << 12)); |
- | |
130 | - | ||
131 | pt[pte].frame_address = frame >> 12; |
- | |
132 | pt[pte].present = !(flags & PAGE_NOT_PRESENT); |
- | |
133 | pt[pte].page_cache_disable = !(flags & PAGE_CACHEABLE); |
- | |
134 | pt[pte].uaccessible = (flags & PAGE_USER) != 0; |
- | |
135 | pt[pte].writeable = (flags & PAGE_WRITE) != 0; |
- | |
136 | } |
- | |
137 | 89 |