WebSVN – HelenOS – Diff – /SPARTAN/trunk/arch/ia32/src/mm/page.c


/*
 * Copyright (C) 2001-2004 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/types.h>
#include <config.h>
#include <func.h>
#include <mm/frame.h>
#include <mm/page.h>
#include <arch/mm/page.h>
#include <arch/interrupt.h>
#include <arch/asm.h>
#include <synch/spinlock.h>
#include <debug.h>
 
/*
 * Note.
 * This is the preliminary code for controlling paging mechanism on ia32. It is
 * needed by other parts of the kernel for its ability to map virtual addresses
 * to physical. SMP code relies on this feature. Other than that, this code is
 * by no means meant to implement virtual memory in terms of swapping pages in
 * and out.
 */
 
__address bootstrap_dba;
 
void page_arch_init(void)
{
    __address dba;
    __u32 i;
 
    if (config.cpu_active == 1) {
        dba = frame_alloc(FRAME_KA | FRAME_PANIC);
        memsetb(dba, PAGE_SIZE, 0);
       
        bootstrap_dba = dba;
 
        /*
         * Identity mapping for all but 0th page.
         * PA2KA(identity) mapping for all but 0th page.
         */
        for (i = 1; i < frames; i++) {
            map_page_to_frame(i * PAGE_SIZE, i * PAGE_SIZE, PAGE_CACHEABLE, KA2PA(dba));
            map_page_to_frame(PA2KA(i * PAGE_SIZE), i * PAGE_SIZE, PAGE_CACHEABLE, KA2PA(dba));
        }
 
        trap_register(14, page_fault);
        write_cr3(KA2PA(dba));
    }
    else {
        /*
         * Application processors need to create their own view of the
         * virtual address space. Because of that, each AP copies
         * already-initialized paging information from the bootstrap
         * processor and adjusts it to fulfill its needs.
         */
 
        dba = frame_alloc(FRAME_KA | FRAME_PANIC);
        memcopy(bootstrap_dba, dba, PAGE_SIZE);
        write_cr3(KA2PA(dba));
    }
 
    paging_on();
}
 
/*
 * Besides mapping pages to frames, this function also sets the present bit of
 * the page's specifier in both page directory and respective page table. If
 * the page table for this page has not been allocated so far, it will take
 * care of it and allocate the necessary frame.
 *
 * PAGE_CACHEABLE flag: when set, it turns caches for that page on
 * PAGE_NOT_PRESENT flag: when set, it marks the page not present
 * PAGE_USER flag: when set, the page is accessible from userspace
 *
 * When the root parameter is non-zero, it is used as the page directory address.
 * Otherwise, the page directory address is read from CPU.
 */
void map_page_to_frame(__address page, __address frame, int flags, __address root)
{
    struct page_specifier *pd, *pt;
    __address dba, newpt;
    int pde, pte;
 
    if (root) dba = root;
    else dba = read_cr3();
 
    pde = page >> 22;       /* page directory entry */
    pte = (page >> 12) & 0x3ff; /* page table entry */
   
    pd = (struct page_specifier *) PA2KA(dba);
   
    if (!pd[pde].present) {
        /*
         * There is currently no page table for this address. Allocate
         * frame for the page table and clean it.
         */
        newpt = frame_alloc(FRAME_KA);
        pd[pde].frame_address = KA2PA(newpt) >> 12;
        memsetb(newpt, PAGE_SIZE, 0);
        pd[pde].present = 1;
        pd[pde].uaccessible = 1;
    }
   
    pt = (struct page_specifier *) PA2KA((pd[pde].frame_address << 12));
 
    pt[pte].frame_address = frame >> 12;
    pt[pte].present = !(flags & PAGE_NOT_PRESENT);
    pt[pte].page_cache_disable = !(flags & PAGE_CACHEABLE);
    pt[pte].uaccessible = (flags & PAGE_USER) != 0;
    pt[pte].writeable = (flags & PAGE_WRITE) != 0; 
}
 

Subversion Repositories HelenOS

(root)/SPARTAN/trunk/arch/ia32/src/mm/page.c – Rev 113 → 115

Rev 113		Rev 115
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 but 0th page.	63	* Identity mapping for all but 0th page.
64	* PA2KA(identity) mapping for all but 0th page.	64	* PA2KA(identity) mapping for all but 0th page.
65	*/	65	*/
66	for (i = 1; i < frames; i++) {	66	for (i = 1; 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	cpu_write_dba(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	cpu_write_dba(KA2PA(dba));	84	write_cr3(KA2PA(dba));
85	}	85	}
86		86
87	paging_on();	87	paging_on();
88	}	88	}
89		89
90	/*	90	/*
91	* Besides mapping pages to frames, this function also sets the present bit of	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	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	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.	94	* care of it and allocate the necessary frame.
95	*	95	*
96	* PAGE_CACHEABLE flag: when set, it turns caches for that page on	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	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	98	* PAGE_USER flag: when set, the page is accessible from userspace
99	*	99	*
100	* When the root parameter is non-zero, it is used as the page directory address.	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.	101	* Otherwise, the page directory address is read from CPU.
102	*/	102	*/
103	void map_page_to_frame(__address page, __address frame, int flags, __address root)	103	void map_page_to_frame(__address page, __address frame, int flags, __address root)
104	{	104	{
105	struct page_specifier pd, pt;	105	struct page_specifier pd, pt;
106	__address dba, newpt;	106	__address dba, newpt;
107	int pde, pte;	107	int pde, pte;
108		108
109	if (root) dba = root;	109	if (root) dba = root;
110	else dba = cpu_read_dba();	110	else dba = read_cr3();
111		111
112	pde = page >> 22; /* page directory entry */	112	pde = page >> 22; /* page directory entry */
113	pte = (page >> 12) & 0x3ff; /* page table entry */	113	pte = (page >> 12) & 0x3ff; /* page table entry */
114		114
115	pd = (struct page_specifier *) PA2KA(dba);	115	pd = (struct page_specifier *) PA2KA(dba);
116		116
117	if (!pd[pde].present) {	117	if (!pd[pde].present) {
118	/*	118	/*
119	* There is currently no page table for this address. Allocate	119	* There is currently no page table for this address. Allocate
120	* frame for the page table and clean it.	120	* frame for the page table and clean it.
121	*/	121	*/
122	newpt = frame_alloc(FRAME_KA);	122	newpt = frame_alloc(FRAME_KA);
123	pd[pde].frame_address = KA2PA(newpt) >> 12;	123	pd[pde].frame_address = KA2PA(newpt) >> 12;
124	memsetb(newpt, PAGE_SIZE, 0);	124	memsetb(newpt, PAGE_SIZE, 0);
125	pd[pde].present = 1;	125	pd[pde].present = 1;
126	pd[pde].uaccessible = 1;	126	pd[pde].uaccessible = 1;
127	}	127	}
128		128
129	pt = (struct page_specifier *) PA2KA((pd[pde].frame_address << 12));	129	pt = (struct page_specifier *) PA2KA((pd[pde].frame_address << 12));
130		130
131	pt[pte].frame_address = frame >> 12;	131	pt[pte].frame_address = frame >> 12;
132	pt[pte].present = !(flags & PAGE_NOT_PRESENT);	132	pt[pte].present = !(flags & PAGE_NOT_PRESENT);
133	pt[pte].page_cache_disable = !(flags & PAGE_CACHEABLE);	133	pt[pte].page_cache_disable = !(flags & PAGE_CACHEABLE);
134	pt[pte].uaccessible = (flags & PAGE_USER) != 0;	134	pt[pte].uaccessible = (flags & PAGE_USER) != 0;
135	pt[pte].writeable = (flags & PAGE_WRITE) != 0;	135	pt[pte].writeable = (flags & PAGE_WRITE) != 0;
136	}	136	}
137		137