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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 | 38 | ||
39 | /* |
39 | /* |
40 | * Note. |
40 | * Note. |
41 | * This is the preliminary code for controlling paging mechanism on ia32. It is |
41 | * This is the preliminary code for controlling paging mechanism on ia32. It is |
42 | * needed by other parts of the kernel for its ability to map virtual addresses |
42 | * needed by other parts of the kernel for its ability to map virtual addresses |
43 | * to physical. SMP code relies on this feature. Other than that, this code is |
43 | * to physical. SMP code relies on this feature. Other than that, this code is |
44 | * by no means meant to implement virtual memory in terms of swapping pages in |
44 | * by no means meant to implement virtual memory in terms of swapping pages in |
45 | * and out. |
45 | * and out. |
46 | */ |
46 | */ |
47 | 47 | ||
48 | __address bootstrap_dba; |
48 | __address bootstrap_dba; |
49 | 49 | ||
50 | void page_arch_init(void) |
50 | void page_arch_init(void) |
51 | { |
51 | { |
52 | __address dba; |
52 | __address dba; |
53 | __u32 i; |
53 | __u32 i; |
54 | 54 | ||
55 | if (config.cpu_active == 1) { |
55 | if (config.cpu_active == 1) { |
56 | dba = frame_alloc(FRAME_KA | FRAME_PANIC); |
56 | dba = frame_alloc(FRAME_KA | FRAME_PANIC); |
57 | memsetb(dba, PAGE_SIZE, 0); |
57 | memsetb(dba, PAGE_SIZE, 0); |
58 | cpu_write_dba(dba); |
58 | cpu_write_dba(dba); |
59 | 59 | ||
60 | bootstrap_dba = dba; |
60 | bootstrap_dba = dba; |
61 | 61 | ||
62 | /* |
62 | /* |
63 | * Identity mapping for all but 0th page. |
63 | * Identity mapping for all but 0th page. |
64 | */ |
64 | */ |
65 | for (i = 1; i < frames; i++) |
65 | for (i = 1; i < frames; i++) |
66 | map_page_to_frame(i * PAGE_SIZE, i * PAGE_SIZE, PAGE_CACHEABLE, 0); |
66 | map_page_to_frame(i * PAGE_SIZE, i * PAGE_SIZE, PAGE_CACHEABLE, 0); |
67 | 67 | ||
68 | trap_register(14, page_fault); |
68 | trap_register(14, page_fault); |
69 | } |
69 | } |
70 | else { |
70 | else { |
71 | 71 | ||
72 | /* |
72 | /* |
73 | * Application processors need to create their own view of the |
73 | * Application processors need to create their own view of the |
74 | * virtual address space. Because of that, each AP copies |
74 | * virtual address space. Because of that, each AP copies |
75 | * already-initialized paging information from the bootstrap |
75 | * already-initialized paging information from the bootstrap |
76 | * processor and adjusts it to fulfill its needs. |
76 | * processor and adjusts it to fulfill its needs. |
77 | */ |
77 | */ |
78 | 78 | ||
79 | dba = frame_alloc(FRAME_KA | FRAME_PANIC); |
79 | dba = frame_alloc(FRAME_KA | FRAME_PANIC); |
80 | memcopy(bootstrap_dba, dba, PAGE_SIZE); |
80 | memcopy(bootstrap_dba, dba, PAGE_SIZE); |
81 | cpu_write_dba(dba); |
81 | cpu_write_dba(dba); |
82 | } |
82 | } |
83 | 83 | ||
84 | paging_on(); |
84 | paging_on(); |
85 | } |
85 | } |
86 | 86 | ||
87 | /* |
87 | /* |
88 | * Besides mapping pages to frames, this function also sets the present bit of |
88 | * Besides mapping pages to frames, this function also sets the present bit of |
89 | * the page's specifier in both page directory and respective page table. If |
89 | * the page's specifier in both page directory and respective page table. If |
90 | * the page table for this page has not been allocated so far, it will take |
90 | * the page table for this page has not been allocated so far, it will take |
91 | * care of it and allocate the necessary frame. |
91 | * care of it and allocate the necessary frame. |
92 | * |
92 | * |
93 | * When the copy parameter is positive, map_page_to_frame will not overwrite |
93 | * When the copy parameter is positive, map_page_to_frame will not overwrite |
94 | * the current mapping. It will allocate a new frame and do the mapping on it |
94 | * the current mapping. It will allocate a new frame and do the mapping on it |
95 | * instead. |
95 | * instead. |
96 | * |
96 | * |
97 | * PAGE_CACHEABLE flag: when set, it turns caches for that page on |
97 | * PAGE_CACHEABLE flag: when set, it turns caches for that page on |
98 | * PAGE_NOT_PRESENT flag: when set, it marks the page not present |
98 | * PAGE_NOT_PRESENT flag: when set, it marks the page not present |
99 | * PAGE_USER flag: when set, the page is accessible from userspace |
99 | * PAGE_USER flag: when set, the page is accessible from userspace |
100 | */ |
100 | */ |
101 | void map_page_to_frame(__address page, __address frame, int flags, int copy) |
101 | void map_page_to_frame(__address page, __address frame, int flags, int copy) |
102 | { |
102 | { |
103 | struct page_specifier *pd, *pt; |
103 | struct page_specifier *pd, *pt; |
104 | __address dba, newpt; |
104 | __address dba, newpt; |
105 | int pde, pte; |
105 | int pde, pte; |
106 | 106 | ||
107 | dba = cpu_read_dba(); |
107 | dba = cpu_read_dba(); |
108 | 108 | ||
109 | pde = page >> 22; /* page directory entry */ |
109 | pde = page >> 22; /* page directory entry */ |
110 | pte = (page >> 12) & 0x3ff; /* page table entry */ |
110 | pte = (page >> 12) & 0x3ff; /* page table entry */ |
111 | 111 | ||
112 | pd = (struct page_specifier *) dba; |
112 | pd = (struct page_specifier *) dba; |
113 | 113 | ||
114 | if (!pd[pde].present) { |
114 | if (!pd[pde].present) { |
115 | /* |
115 | /* |
116 | * There is currently no page table for this address. Allocate |
116 | * There is currently no page table for this address. Allocate |
117 | * frame for the page table and clean it. |
117 | * frame for the page table and clean it. |
118 | */ |
118 | */ |
119 | newpt = frame_alloc(FRAME_KA); |
119 | newpt = frame_alloc(FRAME_KA); |
120 | pd[pde].frame_address = newpt >> 12; |
120 | pd[pde].frame_address = newpt >> 12; |
121 | memsetb(newpt, PAGE_SIZE, 0); |
121 | memsetb(newpt, PAGE_SIZE, 0); |
122 | pd[pde].present = 1; |
122 | pd[pde].present = 1; |
123 | pd[pde].uaccessible = 1; |
123 | pd[pde].uaccessible = 1; |
124 | } |
124 | } |
125 | if (copy) { |
125 | if (copy) { |
126 | newpt = frame_alloc(FRAME_KA); |
126 | newpt = frame_alloc(FRAME_KA); |
127 | memcopy(pd[pde].frame_address << 12, newpt, PAGE_SIZE); |
127 | memcopy(pd[pde].frame_address << 12, newpt, PAGE_SIZE); |
128 | pd[pde].frame_address = newpt >> 12; |
128 | pd[pde].frame_address = newpt >> 12; |
129 | } |
129 | } |
- | 130 | ||
130 | pt = (struct page_specifier *) (pd[pde].frame_address << 12); |
131 | pt = (struct page_specifier *) (pd[pde].frame_address << 12); |
131 | 132 | ||
132 | pt[pte].frame_address = frame >> 12; |
133 | pt[pte].frame_address = frame >> 12; |
133 | pt[pte].present = !(flags & PAGE_NOT_PRESENT); |
134 | pt[pte].present = !(flags & PAGE_NOT_PRESENT); |
134 | pt[pte].page_cache_disable = !(flags & PAGE_CACHEABLE); |
135 | pt[pte].page_cache_disable = !(flags & PAGE_CACHEABLE); |
135 | pt[pte].uaccessible = (flags & PAGE_USER) != 0; |
136 | pt[pte].uaccessible = (flags & PAGE_USER) != 0; |
136 | pt[pte].writeable = (flags & PAGE_WRITE) != 0; |
137 | pt[pte].writeable = (flags & PAGE_WRITE) != 0; |
137 | } |
138 | } |
138 | 139 |