WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/mm/as.c


/*
 * Copyright (C) 2001-2006 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.
 */
 
/*
 * This file contains address space manipulation functions.
 * Roughly speaking, this is a higher-level client of
 * Virtual Address Translation (VAT) subsystem.
 */
 
#include <mm/as.h>
#include <arch/mm/as.h>
#include <mm/page.h>
#include <mm/frame.h>
#include <mm/tlb.h>
#include <mm/heap.h>
#include <arch/mm/page.h>
#include <genarch/mm/page_pt.h>
#include <mm/asid.h>
#include <arch/mm/asid.h>
#include <arch/types.h>
#include <typedefs.h>
#include <synch/spinlock.h>
#include <config.h>
#include <list.h>
#include <panic.h>
#include <arch/asm.h>
#include <debug.h>
#include <memstr.h>
#include <arch.h>
#include <print.h>
 
as_operations_t *as_operations = NULL;
 
/** Kernel address space. */
as_t *AS_KERNEL = NULL;
 
static int get_area_flags(as_area_t *a);
 
/** Initialize address space subsystem. */
void as_init(void)
{
    as_arch_init();
    AS_KERNEL = as_create(FLAG_AS_KERNEL);
        if (!AS_KERNEL)
                panic("can't create kernel address space\n");
}
 
/** Create address space.
 *
 * @param flags Flags that influence way in wich the address space is created.
 */
as_t *as_create(int flags)
{
    as_t *as;
 
    as = (as_t *) malloc(sizeof(as_t));
    if (as) {
        list_initialize(&as->as_with_asid_link);
        spinlock_initialize(&as->lock, "as_lock");
        list_initialize(&as->as_area_head);
 
        if (flags & FLAG_AS_KERNEL)
            as->asid = ASID_KERNEL;
        else
            as->asid = ASID_INVALID;
 
        as->page_table = page_table_create(flags);
    }
 
    return as;
}
 
/** Create address space area of common attributes.
 *
 * The created address space area is added to the target address space.
 *
 * @param as Target address space.
 * @param type Type of area.
 * @param size Size of area in multiples of PAGE_SIZE.
 * @param base Base address of area.
 *
 * @return Address space area on success or NULL on failure.
 */
as_area_t *as_area_create(as_t *as, as_area_type_t type, size_t size, __address base)
{
    ipl_t ipl;
    as_area_t *a;
   
    if (base % PAGE_SIZE)
        panic("addr not aligned to a page boundary");
   
    ipl = interrupts_disable();
    spinlock_lock(&as->lock);
   
    /*
     * TODO: test as_area which is to be created doesn't overlap with an existing one.
     */
   
    a = (as_area_t *) malloc(sizeof(as_area_t));
    if (a) {   
        spinlock_initialize(&a->lock, "as_area_lock");
           
        link_initialize(&a->link);         
        a->type = type;
        a->size = size;
        a->base = base;
       
        list_append(&a->link, &as->as_area_head);
    }
 
    spinlock_unlock(&as->lock);
    interrupts_restore(ipl);
 
    return a;
}
 
/** Initialize mapping for one page of address space.
 *
 * This functions maps 'page' to 'frame' according
 * to attributes of the address space area to
 * wich 'page' belongs.
 *
 * @param a Target address space.
 * @param page Virtual page within the area.
 * @param frame Physical frame to which page will be mapped.
 */
void as_set_mapping(as_t *as, __address page, __address frame)
{
    as_area_t *a, *area = NULL;
    link_t *cur;
    ipl_t ipl;
   
    ipl = interrupts_disable();
    spinlock_lock(&as->lock);
   
    /*
     * First, try locate an area.
     */
    for (cur = as->as_area_head.next; cur != &as->as_area_head; cur = cur->next) {
        a = list_get_instance(cur, as_area_t, link);
        spinlock_lock(&a->lock);
 
        if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {
            area = a;
            break;
        }
       
        spinlock_unlock(&a->lock);
    }
   
    if (!area) {
        panic("page not part of any as_area\n");
    }
 
    /*
     * Note: area->lock is held.
     */
   
    page_mapping_insert(as, page, frame, get_area_flags(area));
   
    spinlock_unlock(&area->lock);
    spinlock_unlock(&as->lock);
    interrupts_restore(ipl);
}
 
/** Handle page fault within the current address space.
 *
 * This is the high-level page fault handler.
 * Interrupts are assumed disabled.
 *
 * @param page Faulting page.
 *
 * @return 0 on page fault, 1 on success.
 */
int as_page_fault(__address page)
{
    link_t *cur;
    as_area_t *a, *area = NULL;
    __address frame;
   
    ASSERT(AS);
    spinlock_lock(&AS->lock);
   
    /*
     * Search this areas of this address space for presence of 'page'.
     */
    for (cur = AS->as_area_head.next; cur != &AS->as_area_head; cur = cur->next) {
        a = list_get_instance(cur, as_area_t, link);
        spinlock_lock(&a->lock);
 
        if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {
 
            /*
             * We found the area containing 'page'.
             * TODO: access checking
             */
            area = a;
            break;
        }
       
        spinlock_unlock(&a->lock);
    }
   
    if (!area) {
        /*
         * No area contained mapping for 'page'.
         * Signal page fault to low-level handler.
         */
        spinlock_unlock(&AS->lock);
        return 0;
    }
 
    /*
     * Note: area->lock is held.
     */
   
    /*
     * In general, there can be several reasons that
     * can have caused this fault.
     *
     * - non-existent mapping: the area is a scratch
     *   area (e.g. stack) and so far has not been
     *   allocated a frame for the faulting page
     *
     * - non-present mapping: another possibility,
     *   currently not implemented, would be frame
     *   reuse; when this becomes a possibility,
     *   do not forget to distinguish between
     *   the different causes
     */
    frame = frame_alloc(0, ONE_FRAME, NULL);
    memsetb(PA2KA(frame), FRAME_SIZE, 0);
   
    /*
     * Map 'page' to 'frame'.
     * Note that TLB shootdown is not attempted as only new information is being
     * inserted into page tables.
     */
    page_mapping_insert(AS, page, frame, get_area_flags(area));
   
    spinlock_unlock(&area->lock);
    spinlock_unlock(&AS->lock);
 
    return 1;
}
 
/** Install address space on CPU.
 *
 * @param as Address space.
 */
void as_install(as_t *as)
{
    ipl_t ipl;
   
    asid_install(as);
   
    ipl = interrupts_disable();
    spinlock_lock(&as->lock);
    ASSERT(as->page_table);
    SET_PTL0_ADDRESS(as->page_table);
    spinlock_unlock(&as->lock);
    interrupts_restore(ipl);
 
    /*
     * Perform architecture-specific steps.
     * (e.g. write ASID to hardware register etc.)
     */
    as_install_arch(as);
   
    AS = as;
}
 
/** Compute flags for virtual address translation subsytem.
 *
 * The address space area must be locked.
 * Interrupts must be disabled.
 *
 * @param a Address space area.
 *
 * @return Flags to be used in page_mapping_insert().
 */
int get_area_flags(as_area_t *a)
{
    int flags;
 
    switch (a->type) {
        case AS_AREA_TEXT:
            flags = PAGE_EXEC | PAGE_READ | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE;
            break;
        case AS_AREA_DATA:
        case AS_AREA_STACK:
            flags = PAGE_READ | PAGE_WRITE | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE;
            break;
        default:
            panic("unexpected as_area_type_t %d", a->type);
    }
   
    return flags;
}
 
/** Create page table.
 *
 * Depending on architecture, create either address space
 * private or global page table.
 *
 * @param flags Flags saying whether the page table is for kernel address space.
 *
 * @return First entry of the page table.
 */
pte_t *page_table_create(int flags)
{
        ASSERT(as_operations);
        ASSERT(as_operations->page_table_create);
 
        return as_operations->page_table_create(flags);
}
 

Rev 756	Rev 757
1	/*	1	/*
2	* Copyright (C) 2001-2006 Jakub Jermar	2	* Copyright (C) 2001-2006 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	/*	29	/*
30	* This file contains address space manipulation functions.	30	* This file contains address space manipulation functions.
31	* Roughly speaking, this is a higher-level client of	31	* Roughly speaking, this is a higher-level client of
32	* Virtual Address Translation (VAT) subsystem.	32	* Virtual Address Translation (VAT) subsystem.
33	*/	33	*/
34		34
35	#include <mm/as.h>	35	#include <mm/as.h>
36	#include <arch/mm/as.h>	36	#include <arch/mm/as.h>
37	#include <mm/page.h>	37	#include <mm/page.h>
38	#include <mm/frame.h>	38	#include <mm/frame.h>
39	#include <mm/tlb.h>	39	#include <mm/tlb.h>
40	#include <mm/heap.h>	40	#include <mm/heap.h>
41	#include <arch/mm/page.h>	41	#include <arch/mm/page.h>
42	#include <genarch/mm/page_pt.h>	42	#include <genarch/mm/page_pt.h>
43	#include <mm/asid.h>	43	#include <mm/asid.h>
44	#include <arch/mm/asid.h>	44	#include <arch/mm/asid.h>
45	#include <arch/types.h>	45	#include <arch/types.h>
46	#include <typedefs.h>	46	#include <typedefs.h>
47	#include <synch/spinlock.h>	47	#include <synch/spinlock.h>
48	#include <config.h>	48	#include <config.h>
49	#include <list.h>	49	#include <list.h>
50	#include <panic.h>	50	#include <panic.h>
51	#include <arch/asm.h>	51	#include <arch/asm.h>
52	#include <debug.h>	52	#include <debug.h>
53	#include <memstr.h>	53	#include <memstr.h>
54	#include <arch.h>	54	#include <arch.h>
55	#include <print.h>	55	#include <print.h>
56		56
57	as_operations_t *as_operations = NULL;	57	as_operations_t *as_operations = NULL;
58		58
-		59	/** Kernel address space. */
-		60	as_t *AS_KERNEL = NULL;
-		61
59	static int get_area_flags(as_area_t *a);	62	static int get_area_flags(as_area_t *a);
60		63
61	/** Initialize address space subsystem. */	64	/** Initialize address space subsystem. */
62	void as_init(void)	65	void as_init(void)
63	{	66	{
64	as_arch_init();	67	as_arch_init();
65	AS_KERNEL = as_create(FLAG_AS_KERNEL);	68	AS_KERNEL = as_create(FLAG_AS_KERNEL);
66	if (!AS_KERNEL)	69	if (!AS_KERNEL)
67	panic("can't create kernel address space\n");	70	panic("can't create kernel address space\n");
68	}	71	}
69		72
70	/** Create address space. */	73	/** Create address space.
-		74	*
-		75	* @param flags Flags that influence way in wich the address space is created.
-		76	*/
71	as_t *as_create(int flags)	77	as_t *as_create(int flags)
72	{	78	{
73	as_t *as;	79	as_t *as;
74		80
75	as = (as_t *) malloc(sizeof(as_t));	81	as = (as_t *) malloc(sizeof(as_t));
76	if (as) {	82	if (as) {
77	list_initialize(&as->as_with_asid_link);	83	list_initialize(&as->as_with_asid_link);
78	spinlock_initialize(&as->lock, "as_lock");	84	spinlock_initialize(&as->lock, "as_lock");
79	list_initialize(&as->as_area_head);	85	list_initialize(&as->as_area_head);
80		86
81	if (flags & FLAG_AS_KERNEL)	87	if (flags & FLAG_AS_KERNEL)
82	as->asid = ASID_KERNEL;	88	as->asid = ASID_KERNEL;
83	else	89	else
84	as->asid = ASID_INVALID;	90	as->asid = ASID_INVALID;
85		91
86	as->page_table = page_table_create(flags);	92	as->page_table = page_table_create(flags);
87	}	93	}
88		94
89	return as;	95	return as;
90	}	96	}
91		97
92	/** Create address space area of common attributes.	98	/** Create address space area of common attributes.
93	*	99	*
94	* The created address space area is added to the target address space.	100	* The created address space area is added to the target address space.
95	*	101	*
96	* @param as Target address space.	102	* @param as Target address space.
97	* @param type Type of area.	103	* @param type Type of area.
98	* @param size Size of area in multiples of PAGE_SIZE.	104	* @param size Size of area in multiples of PAGE_SIZE.
99	* @param base Base address of area.	105	* @param base Base address of area.
100	*	106	*
101	* @return Address space area on success or NULL on failure.	107	* @return Address space area on success or NULL on failure.
102	*/	108	*/
103	as_area_t as_area_create(as_t as, as_area_type_t type, size_t size, __address base)	109	as_area_t as_area_create(as_t as, as_area_type_t type, size_t size, __address base)
104	{	110	{
105	ipl_t ipl;	111	ipl_t ipl;
106	as_area_t *a;	112	as_area_t *a;
107		113
108	if (base % PAGE_SIZE)	114	if (base % PAGE_SIZE)
109	panic("addr not aligned to a page boundary");	115	panic("addr not aligned to a page boundary");
110		116
111	ipl = interrupts_disable();	117	ipl = interrupts_disable();
112	spinlock_lock(&as->lock);	118	spinlock_lock(&as->lock);
113		119
114	/*	120	/*
115	* TODO: test as_area which is to be created doesn't overlap with an existing one.	121	* TODO: test as_area which is to be created doesn't overlap with an existing one.
116	*/	122	*/
117		123
118	a = (as_area_t *) malloc(sizeof(as_area_t));	124	a = (as_area_t *) malloc(sizeof(as_area_t));
119	if (a) {	125	if (a) {
120	spinlock_initialize(&a->lock, "as_area_lock");	126	spinlock_initialize(&a->lock, "as_area_lock");
121		127
122	link_initialize(&a->link);	128	link_initialize(&a->link);
123	a->type = type;	129	a->type = type;
124	a->size = size;	130	a->size = size;
125	a->base = base;	131	a->base = base;
126		132
127	list_append(&a->link, &as->as_area_head);	133	list_append(&a->link, &as->as_area_head);
128	}	134	}
129		135
130	spinlock_unlock(&as->lock);	136	spinlock_unlock(&as->lock);
131	interrupts_restore(ipl);	137	interrupts_restore(ipl);
132		138
133	return a;	139	return a;
134	}	140	}
135		141
136	/** Initialize mapping for one page of address space.	142	/** Initialize mapping for one page of address space.
137	*	143	*
138	* This functions maps 'page' to 'frame' according	144	* This functions maps 'page' to 'frame' according
139	* to attributes of the address space area to	145	* to attributes of the address space area to
140	* wich 'page' belongs.	146	* wich 'page' belongs.
141	*	147	*
142	* @param a Target address space.	148	* @param a Target address space.
143	* @param page Virtual page within the area.	149	* @param page Virtual page within the area.
144	* @param frame Physical frame to which page will be mapped.	150	* @param frame Physical frame to which page will be mapped.
145	*/	151	*/
146	void as_set_mapping(as_t *as, __address page, __address frame)	152	void as_set_mapping(as_t *as, __address page, __address frame)
147	{	153	{
148	as_area_t a, area = NULL;	154	as_area_t a, area = NULL;
149	link_t *cur;	155	link_t *cur;
150	ipl_t ipl;	156	ipl_t ipl;
151		157
152	ipl = interrupts_disable();	158	ipl = interrupts_disable();
153	spinlock_lock(&as->lock);	159	spinlock_lock(&as->lock);
154		160
155	/*	161	/*
156	* First, try locate an area.	162	* First, try locate an area.
157	*/	163	*/
158	for (cur = as->as_area_head.next; cur != &as->as_area_head; cur = cur->next) {	164	for (cur = as->as_area_head.next; cur != &as->as_area_head; cur = cur->next) {
159	a = list_get_instance(cur, as_area_t, link);	165	a = list_get_instance(cur, as_area_t, link);
160	spinlock_lock(&a->lock);	166	spinlock_lock(&a->lock);
161		167
162	if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {	168	if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {
163	area = a;	169	area = a;
164	break;	170	break;
165	}	171	}
166		172
167	spinlock_unlock(&a->lock);	173	spinlock_unlock(&a->lock);
168	}	174	}
169		175
170	if (!area) {	176	if (!area) {
171	panic("page not part of any as_area\n");	177	panic("page not part of any as_area\n");
172	}	178	}
173		179
174	/*	180	/*
175	* Note: area->lock is held.	181	* Note: area->lock is held.
176	*/	182	*/
177		183
178	page_mapping_insert(as, page, frame, get_area_flags(area));	184	page_mapping_insert(as, page, frame, get_area_flags(area));
179		185
180	spinlock_unlock(&area->lock);	186	spinlock_unlock(&area->lock);
181	spinlock_unlock(&as->lock);	187	spinlock_unlock(&as->lock);
182	interrupts_restore(ipl);	188	interrupts_restore(ipl);
183	}	189	}
184		190
185	/** Handle page fault within the current address space.	191	/** Handle page fault within the current address space.
186	*	192	*
187	* This is the high-level page fault handler.	193	* This is the high-level page fault handler.
188	* Interrupts are assumed disabled.	194	* Interrupts are assumed disabled.
189	*	195	*
190	* @param page Faulting page.	196	* @param page Faulting page.
191	*	197	*
192	* @return 0 on page fault, 1 on success.	198	* @return 0 on page fault, 1 on success.
193	*/	199	*/
194	int as_page_fault(__address page)	200	int as_page_fault(__address page)
195	{	201	{
196	link_t *cur;	202	link_t *cur;
197	as_area_t a, area = NULL;	203	as_area_t a, area = NULL;
198	__address frame;	204	__address frame;
199		205
200	ASSERT(AS);	206	ASSERT(AS);
201	spinlock_lock(&AS->lock);	207	spinlock_lock(&AS->lock);
202		208
203	/*	209	/*
204	* Search this areas of this address space for presence of 'page'.	210	* Search this areas of this address space for presence of 'page'.
205	*/	211	*/
206	for (cur = AS->as_area_head.next; cur != &AS->as_area_head; cur = cur->next) {	212	for (cur = AS->as_area_head.next; cur != &AS->as_area_head; cur = cur->next) {
207	a = list_get_instance(cur, as_area_t, link);	213	a = list_get_instance(cur, as_area_t, link);
208	spinlock_lock(&a->lock);	214	spinlock_lock(&a->lock);
209		215
210	if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {	216	if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {
211		217
212	/*	218	/*
213	* We found the area containing 'page'.	219	* We found the area containing 'page'.
214	* TODO: access checking	220	* TODO: access checking
215	*/	221	*/
216	area = a;	222	area = a;
217	break;	223	break;
218	}	224	}
219		225
220	spinlock_unlock(&a->lock);	226	spinlock_unlock(&a->lock);
221	}	227	}
222		228
223	if (!area) {	229	if (!area) {
224	/*	230	/*
225	* No area contained mapping for 'page'.	231	* No area contained mapping for 'page'.
226	* Signal page fault to low-level handler.	232	* Signal page fault to low-level handler.
227	*/	233	*/
228	spinlock_unlock(&AS->lock);	234	spinlock_unlock(&AS->lock);
229	return 0;	235	return 0;
230	}	236	}
231		237
232	/*	238	/*
233	* Note: area->lock is held.	239	* Note: area->lock is held.
234	*/	240	*/
235		241
236	/*	242	/*
237	* In general, there can be several reasons that	243	* In general, there can be several reasons that
238	* can have caused this fault.	244	* can have caused this fault.
239	*	245	*
240	* - non-existent mapping: the area is a scratch	246	* - non-existent mapping: the area is a scratch
241	* area (e.g. stack) and so far has not been	247	* area (e.g. stack) and so far has not been
242	* allocated a frame for the faulting page	248	* allocated a frame for the faulting page
243	*	249	*
244	* - non-present mapping: another possibility,	250	* - non-present mapping: another possibility,
245	* currently not implemented, would be frame	251	* currently not implemented, would be frame
246	* reuse; when this becomes a possibility,	252	* reuse; when this becomes a possibility,
247	* do not forget to distinguish between	253	* do not forget to distinguish between
248	* the different causes	254	* the different causes
249	*/	255	*/
250	frame = frame_alloc(0, ONE_FRAME, NULL);	256	frame = frame_alloc(0, ONE_FRAME, NULL);
251	memsetb(PA2KA(frame), FRAME_SIZE, 0);	257	memsetb(PA2KA(frame), FRAME_SIZE, 0);
252		258
253	/*	259	/*
254	* Map 'page' to 'frame'.	260	* Map 'page' to 'frame'.
255	* Note that TLB shootdown is not attempted as only new information is being	261	* Note that TLB shootdown is not attempted as only new information is being
256	* inserted into page tables.	262	* inserted into page tables.
257	*/	263	*/
258	page_mapping_insert(AS, page, frame, get_area_flags(area));	264	page_mapping_insert(AS, page, frame, get_area_flags(area));
259		265
260	spinlock_unlock(&area->lock);	266	spinlock_unlock(&area->lock);
261	spinlock_unlock(&AS->lock);	267	spinlock_unlock(&AS->lock);
262		268
263	return 1;	269	return 1;
264	}	270	}
265		271
266	/** Install address space on CPU.	272	/** Install address space on CPU.
267	*	273	*
268	* @param as Address space.	274	* @param as Address space.
269	*/	275	*/
270	void as_install(as_t *as)	276	void as_install(as_t *as)
271	{	277	{
272	ipl_t ipl;	278	ipl_t ipl;
273		279
274	asid_install(as);	280	asid_install(as);
275		281
276	ipl = interrupts_disable();	282	ipl = interrupts_disable();
277	spinlock_lock(&as->lock);	283	spinlock_lock(&as->lock);
278	ASSERT(as->page_table);	284	ASSERT(as->page_table);
279	SET_PTL0_ADDRESS(as->page_table);	285	SET_PTL0_ADDRESS(as->page_table);
280	spinlock_unlock(&as->lock);	286	spinlock_unlock(&as->lock);
281	interrupts_restore(ipl);	287	interrupts_restore(ipl);
282		288
283	/*	289	/*
284	* Perform architecture-specific steps.	290	* Perform architecture-specific steps.
285	* (e.g. write ASID to hardware register etc.)	291	* (e.g. write ASID to hardware register etc.)
286	*/	292	*/
287	as_install_arch(as);	293	as_install_arch(as);
288		294
289	AS = as;	295	AS = as;
290	}	296	}
291		297
292	/** Compute flags for virtual address translation subsytem.	298	/** Compute flags for virtual address translation subsytem.
293	*	299	*
294	* The address space area must be locked.	300	* The address space area must be locked.
295	* Interrupts must be disabled.	301	* Interrupts must be disabled.
296	*	302	*
297	* @param a Address space area.	303	* @param a Address space area.
298	*	304	*
299	* @return Flags to be used in page_mapping_insert().	305	* @return Flags to be used in page_mapping_insert().
300	*/	306	*/
301	int get_area_flags(as_area_t *a)	307	int get_area_flags(as_area_t *a)
302	{	308	{
303	int flags;	309	int flags;
304		310
305	switch (a->type) {	311	switch (a->type) {
306	case AS_AREA_TEXT:	312	case AS_AREA_TEXT:
307	flags = PAGE_EXEC \| PAGE_READ \| PAGE_USER \| PAGE_PRESENT \| PAGE_CACHEABLE;	313	flags = PAGE_EXEC \| PAGE_READ \| PAGE_USER \| PAGE_PRESENT \| PAGE_CACHEABLE;
308	break;	314	break;
309	case AS_AREA_DATA:	315	case AS_AREA_DATA:
310	case AS_AREA_STACK:	316	case AS_AREA_STACK:
311	flags = PAGE_READ \| PAGE_WRITE \| PAGE_USER \| PAGE_PRESENT \| PAGE_CACHEABLE;	317	flags = PAGE_READ \| PAGE_WRITE \| PAGE_USER \| PAGE_PRESENT \| PAGE_CACHEABLE;
312	break;	318	break;
313	default:	319	default:
314	panic("unexpected as_area_type_t %d", a->type);	320	panic("unexpected as_area_type_t %d", a->type);
315	}	321	}
316		322
317	return flags;	323	return flags;
318	}	324	}
319		325
320	/** Create page table.	326	/** Create page table.
321	*	327	*
322	* Depending on architecture, create either address space	328	* Depending on architecture, create either address space
323	* private or global page table.	329	* private or global page table.
324	*	330	*
325	* @param flags Flags saying whether the page table is for kernel address space.	331	* @param flags Flags saying whether the page table is for kernel address space.
326	*	332	*
327	* @return First entry of the page table.	333	* @return First entry of the page table.
328	*/	334	*/
329	pte_t *page_table_create(int flags)	335	pte_t *page_table_create(int flags)
330	{	336	{
331	ASSERT(as_operations);	337	ASSERT(as_operations);
332	ASSERT(as_operations->page_table_create);	338	ASSERT(as_operations->page_table_create);
333		339
334	return as_operations->page_table_create(flags);	340	return as_operations->page_table_create(flags);
335	}	341	}
336		342

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(root)/kernel/trunk/generic/src/mm/as.c @ 1780 – Rev 756 → 757