WebSVN – HelenOS – Diff – /trunk/kernel/generic/src/mm/backend_anon.c


/*
 * Copyright (c) 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.
 */
 
/** @addtogroup genericmm
 * @{
 */
 
/**
 * @file
 * @brief   Backend for anonymous memory address space areas.
 *
 */
 
#include <mm/as.h>
#include <mm/page.h>
#include <genarch/mm/page_pt.h>
#include <genarch/mm/page_ht.h>
#include <mm/frame.h>
#include <mm/slab.h>
#include <synch/mutex.h>
#include <adt/list.h>
#include <adt/btree.h>
#include <errno.h>
#include <arch/types.h>
 
#include <align.h>
#include <arch.h>
 
#ifdef CONFIG_VIRT_IDX_DCACHE
#include <arch/mm/cache.h>
#endif
 
static int anon_page_fault(as_area_t *area, uintptr_t addr, pf_access_t access);
static void anon_frame_free(as_area_t *area, uintptr_t page, uintptr_t frame);
static void anon_share(as_area_t *area);
 
mem_backend_t anon_backend = {
    .page_fault = anon_page_fault,
    .frame_free = anon_frame_free,
    .share = anon_share
};
 
/** Service a page fault in the anonymous memory address space area.
 *
 * The address space area and page tables must be already locked.
 *
 * @param area Pointer to the address space area.
 * @param addr Faulting virtual address.
 * @param access Access mode that caused the fault (i.e. read/write/exec).
 *
 * @return AS_PF_FAULT on failure (i.e. page fault) or AS_PF_OK on success (i.e. serviced).
 */
int anon_page_fault(as_area_t *area, uintptr_t addr, pf_access_t access)
{
    uintptr_t frame;
 
    if (!as_area_check_access(area, access))
        return AS_PF_FAULT;
 
    if (area->sh_info) {
        btree_node_t *leaf;
       
        /*
         * The area is shared, chances are that the mapping can be found
         * in the pagemap of the address space area share info structure.
         * In the case that the pagemap does not contain the respective
         * mapping, a new frame is allocated and the mapping is created.
         */
        mutex_lock(&area->sh_info->lock);
        frame = (uintptr_t) btree_search(&area->sh_info->pagemap,
            ALIGN_DOWN(addr, PAGE_SIZE) - area->base, &leaf);
        if (!frame) {
            bool allocate = true;
            int i;
           
            /*
             * Zero can be returned as a valid frame address.
             * Just a small workaround.
             */
            for (i = 0; i < leaf->keys; i++) {
                if (leaf->key[i] == ALIGN_DOWN(addr, PAGE_SIZE)) {
                    allocate = false;
                    break;
                }
            }
            if (allocate) {
                frame = (uintptr_t) frame_alloc(ONE_FRAME, 0);
                memsetb(PA2KA(frame), FRAME_SIZE, 0);
               
                /*
                 * Insert the address of the newly allocated frame to the pagemap.
                 */
                btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base, (void *) frame, leaf);
            }
        }
        frame_reference_add(ADDR2PFN(frame));
        mutex_unlock(&area->sh_info->lock);
    } else {
 
        /*
         * In general, there can be several reasons that
         * can have caused this fault.
         *
         * - non-existent mapping: the area is an anonymous
         *   area (e.g. heap or 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 = (uintptr_t) frame_alloc(ONE_FRAME, 0);
        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, addr, frame, as_area_get_flags(area));
    if (!used_space_insert(area, ALIGN_DOWN(addr, PAGE_SIZE), 1))
        panic("Could not insert used space.\n");
       
    return AS_PF_OK;
}
 
/** Free a frame that is backed by the anonymous memory backend.
 *
 * The address space area and page tables must be already locked.
 *
 * @param area Ignored.
 * @param page Virtual address of the page corresponding to the frame.
 * @param frame Frame to be released.
 */
void anon_frame_free(as_area_t *area, uintptr_t page, uintptr_t frame)
{
    frame_free(frame);
#ifdef CONFIG_VIRT_IDX_DCACHE
    dcache_flush_frame(page, frame);
#endif
}
 
/** Share the anonymous address space area.
 *
 * Sharing of anonymous area is done by duplicating its entire mapping
 * to the pagemap. Page faults will primarily search for frames there.
 *
 * The address space and address space area must be already locked.
 *
 * @param area Address space area to be shared.
 */
void anon_share(as_area_t *area)
{
    link_t *cur;
 
    /*
     * Copy used portions of the area to sh_info's page map.
     */
    mutex_lock(&area->sh_info->lock);
    for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {
        btree_node_t *node;
        int i;
       
        node = list_get_instance(cur, btree_node_t, leaf_link);
        for (i = 0; i < node->keys; i++) {
            uintptr_t base = node->key[i];
            count_t count = (count_t) node->value[i];
            int j;
           
            for (j = 0; j < count; j++) {
                pte_t *pte;
           
                page_table_lock(area->as, false);
                pte = page_mapping_find(area->as, base + j*PAGE_SIZE);
                ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
                btree_insert(&area->sh_info->pagemap, (base + j*PAGE_SIZE) - area->base,
                    (void *) PTE_GET_FRAME(pte), NULL);
                page_table_unlock(area->as, false);
                frame_reference_add(ADDR2PFN(PTE_GET_FRAME(pte)));
            }
               
        }
    }
    mutex_unlock(&area->sh_info->lock);
}
 
/** @}
 */
 

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/mm/backend_anon.c – Rev 2076 → 2089

Rev 2076		Rev 2089
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 genericmm	29	/** @addtogroup genericmm
30	* @{	30	* @{
31	*/	31	*/
32		32
33	/**	33	/**
34	* @file	34	* @file
35	* @brief Backend for anonymous memory address space areas.	35	* @brief Backend for anonymous memory address space areas.
36	*	36	*
37	*/	37	*/
38		38
39	#include <mm/as.h>	39	#include <mm/as.h>
40	#include <mm/page.h>	40	#include <mm/page.h>
41	#include <genarch/mm/page_pt.h>	41	#include <genarch/mm/page_pt.h>
42	#include <genarch/mm/page_ht.h>	42	#include <genarch/mm/page_ht.h>
43	#include <mm/frame.h>	43	#include <mm/frame.h>
44	#include <mm/slab.h>	44	#include <mm/slab.h>
45	#include <synch/mutex.h>	45	#include <synch/mutex.h>
46	#include <adt/list.h>	46	#include <adt/list.h>
47	#include <adt/btree.h>	47	#include <adt/btree.h>
48	#include <errno.h>	48	#include <errno.h>
49	#include <arch/types.h>	49	#include <arch/types.h>
50	#include <typedefs.h>	-
51	#include <align.h>	50	#include <align.h>
52	#include <arch.h>	51	#include <arch.h>
53		52
54	#ifdef CONFIG_VIRT_IDX_DCACHE	53	#ifdef CONFIG_VIRT_IDX_DCACHE
55	#include <arch/mm/cache.h>	54	#include <arch/mm/cache.h>
56	#endif	55	#endif
57		56
58	static int anon_page_fault(as_area_t *area, uintptr_t addr, pf_access_t access);	57	static int anon_page_fault(as_area_t *area, uintptr_t addr, pf_access_t access);
59	static void anon_frame_free(as_area_t *area, uintptr_t page, uintptr_t frame);	58	static void anon_frame_free(as_area_t *area, uintptr_t page, uintptr_t frame);
60	static void anon_share(as_area_t *area);	59	static void anon_share(as_area_t *area);
61		60
62	mem_backend_t anon_backend = {	61	mem_backend_t anon_backend = {
63	.page_fault = anon_page_fault,	62	.page_fault = anon_page_fault,
64	.frame_free = anon_frame_free,	63	.frame_free = anon_frame_free,
65	.share = anon_share	64	.share = anon_share
66	};	65	};
67		66
68	/** Service a page fault in the anonymous memory address space area.	67	/** Service a page fault in the anonymous memory address space area.
69	*	68	*
70	* The address space area and page tables must be already locked.	69	* The address space area and page tables must be already locked.
71	*	70	*
72	* @param area Pointer to the address space area.	71	* @param area Pointer to the address space area.
73	* @param addr Faulting virtual address.	72	* @param addr Faulting virtual address.
74	* @param access Access mode that caused the fault (i.e. read/write/exec).	73	* @param access Access mode that caused the fault (i.e. read/write/exec).
75	*	74	*
76	* @return AS_PF_FAULT on failure (i.e. page fault) or AS_PF_OK on success (i.e. serviced).	75	* @return AS_PF_FAULT on failure (i.e. page fault) or AS_PF_OK on success (i.e. serviced).
77	*/	76	*/
78	int anon_page_fault(as_area_t *area, uintptr_t addr, pf_access_t access)	77	int anon_page_fault(as_area_t *area, uintptr_t addr, pf_access_t access)
79	{	78	{
80	uintptr_t frame;	79	uintptr_t frame;
81		80
82	if (!as_area_check_access(area, access))	81	if (!as_area_check_access(area, access))
83	return AS_PF_FAULT;	82	return AS_PF_FAULT;
84		83
85	if (area->sh_info) {	84	if (area->sh_info) {
86	btree_node_t *leaf;	85	btree_node_t *leaf;
87		86
88	/*	87	/*
89	* The area is shared, chances are that the mapping can be found	88	* The area is shared, chances are that the mapping can be found
90	* in the pagemap of the address space area share info structure.	89	* in the pagemap of the address space area share info structure.
91	* In the case that the pagemap does not contain the respective	90	* In the case that the pagemap does not contain the respective
92	* mapping, a new frame is allocated and the mapping is created.	91	* mapping, a new frame is allocated and the mapping is created.
93	*/	92	*/
94	mutex_lock(&area->sh_info->lock);	93	mutex_lock(&area->sh_info->lock);
95	frame = (uintptr_t) btree_search(&area->sh_info->pagemap,	94	frame = (uintptr_t) btree_search(&area->sh_info->pagemap,
96	ALIGN_DOWN(addr, PAGE_SIZE) - area->base, &leaf);	95	ALIGN_DOWN(addr, PAGE_SIZE) - area->base, &leaf);
97	if (!frame) {	96	if (!frame) {
98	bool allocate = true;	97	bool allocate = true;
99	int i;	98	int i;
100		99
101	/*	100	/*
102	* Zero can be returned as a valid frame address.	101	* Zero can be returned as a valid frame address.
103	* Just a small workaround.	102	* Just a small workaround.
104	*/	103	*/
105	for (i = 0; i < leaf->keys; i++) {	104	for (i = 0; i < leaf->keys; i++) {
106	if (leaf->key[i] == ALIGN_DOWN(addr, PAGE_SIZE)) {	105	if (leaf->key[i] == ALIGN_DOWN(addr, PAGE_SIZE)) {
107	allocate = false;	106	allocate = false;
108	break;	107	break;
109	}	108	}
110	}	109	}
111	if (allocate) {	110	if (allocate) {
112	frame = (uintptr_t) frame_alloc(ONE_FRAME, 0);	111	frame = (uintptr_t) frame_alloc(ONE_FRAME, 0);
113	memsetb(PA2KA(frame), FRAME_SIZE, 0);	112	memsetb(PA2KA(frame), FRAME_SIZE, 0);
114		113
115	/*	114	/*
116	* Insert the address of the newly allocated frame to the pagemap.	115	* Insert the address of the newly allocated frame to the pagemap.
117	*/	116	*/
118	btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base, (void *) frame, leaf);	117	btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base, (void *) frame, leaf);
119	}	118	}
120	}	119	}
121	frame_reference_add(ADDR2PFN(frame));	120	frame_reference_add(ADDR2PFN(frame));
122	mutex_unlock(&area->sh_info->lock);	121	mutex_unlock(&area->sh_info->lock);
123	} else {	122	} else {
124		123
125	/*	124	/*
126	* In general, there can be several reasons that	125	* In general, there can be several reasons that
127	* can have caused this fault.	126	* can have caused this fault.
128	*	127	*
129	* - non-existent mapping: the area is an anonymous	128	* - non-existent mapping: the area is an anonymous
130	* area (e.g. heap or stack) and so far has not been	129	* area (e.g. heap or stack) and so far has not been
131	* allocated a frame for the faulting page	130	* allocated a frame for the faulting page
132	*	131	*
133	* - non-present mapping: another possibility,	132	* - non-present mapping: another possibility,
134	* currently not implemented, would be frame	133	* currently not implemented, would be frame
135	* reuse; when this becomes a possibility,	134	* reuse; when this becomes a possibility,
136	* do not forget to distinguish between	135	* do not forget to distinguish between
137	* the different causes	136	* the different causes
138	*/	137	*/
139	frame = (uintptr_t) frame_alloc(ONE_FRAME, 0);	138	frame = (uintptr_t) frame_alloc(ONE_FRAME, 0);
140	memsetb(PA2KA(frame), FRAME_SIZE, 0);	139	memsetb(PA2KA(frame), FRAME_SIZE, 0);
141	}	140	}
142		141
143	/*	142	/*
144	* Map 'page' to 'frame'.	143	* Map 'page' to 'frame'.
145	* Note that TLB shootdown is not attempted as only new information is being	144	* Note that TLB shootdown is not attempted as only new information is being
146	* inserted into page tables.	145	* inserted into page tables.
147	*/	146	*/
148	page_mapping_insert(AS, addr, frame, as_area_get_flags(area));	147	page_mapping_insert(AS, addr, frame, as_area_get_flags(area));
149	if (!used_space_insert(area, ALIGN_DOWN(addr, PAGE_SIZE), 1))	148	if (!used_space_insert(area, ALIGN_DOWN(addr, PAGE_SIZE), 1))
150	panic("Could not insert used space.\n");	149	panic("Could not insert used space.\n");
151		150
152	return AS_PF_OK;	151	return AS_PF_OK;
153	}	152	}
154		153
155	/** Free a frame that is backed by the anonymous memory backend.	154	/** Free a frame that is backed by the anonymous memory backend.
156	*	155	*
157	* The address space area and page tables must be already locked.	156	* The address space area and page tables must be already locked.
158	*	157	*
159	* @param area Ignored.	158	* @param area Ignored.
160	* @param page Virtual address of the page corresponding to the frame.	159	* @param page Virtual address of the page corresponding to the frame.
161	* @param frame Frame to be released.	160	* @param frame Frame to be released.
162	*/	161	*/
163	void anon_frame_free(as_area_t *area, uintptr_t page, uintptr_t frame)	162	void anon_frame_free(as_area_t *area, uintptr_t page, uintptr_t frame)
164	{	163	{
165	frame_free(frame);	164	frame_free(frame);
166	#ifdef CONFIG_VIRT_IDX_DCACHE	165	#ifdef CONFIG_VIRT_IDX_DCACHE
167	dcache_flush_frame(page, frame);	166	dcache_flush_frame(page, frame);
168	#endif	167	#endif
169	}	168	}
170		169
171	/** Share the anonymous address space area.	170	/** Share the anonymous address space area.
172	*	171	*
173	* Sharing of anonymous area is done by duplicating its entire mapping	172	* Sharing of anonymous area is done by duplicating its entire mapping
174	* to the pagemap. Page faults will primarily search for frames there.	173	* to the pagemap. Page faults will primarily search for frames there.
175	*	174	*
176	* The address space and address space area must be already locked.	175	* The address space and address space area must be already locked.
177	*	176	*
178	* @param area Address space area to be shared.	177	* @param area Address space area to be shared.
179	*/	178	*/
180	void anon_share(as_area_t *area)	179	void anon_share(as_area_t *area)
181	{	180	{
182	link_t *cur;	181	link_t *cur;
183		182
184	/*	183	/*
185	* Copy used portions of the area to sh_info's page map.	184	* Copy used portions of the area to sh_info's page map.
186	*/	185	*/
187	mutex_lock(&area->sh_info->lock);	186	mutex_lock(&area->sh_info->lock);
188	for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {	187	for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {
189	btree_node_t *node;	188	btree_node_t *node;
190	int i;	189	int i;
191		190
192	node = list_get_instance(cur, btree_node_t, leaf_link);	191	node = list_get_instance(cur, btree_node_t, leaf_link);
193	for (i = 0; i < node->keys; i++) {	192	for (i = 0; i < node->keys; i++) {
194	uintptr_t base = node->key[i];	193	uintptr_t base = node->key[i];
195	count_t count = (count_t) node->value[i];	194	count_t count = (count_t) node->value[i];
196	int j;	195	int j;
197		196
198	for (j = 0; j < count; j++) {	197	for (j = 0; j < count; j++) {
199	pte_t *pte;	198	pte_t *pte;
200		199
201	page_table_lock(area->as, false);	200	page_table_lock(area->as, false);
202	pte = page_mapping_find(area->as, base + j*PAGE_SIZE);	201	pte = page_mapping_find(area->as, base + j*PAGE_SIZE);
203	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));	202	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
204	btree_insert(&area->sh_info->pagemap, (base + j*PAGE_SIZE) - area->base,	203	btree_insert(&area->sh_info->pagemap, (base + j*PAGE_SIZE) - area->base,
205	(void *) PTE_GET_FRAME(pte), NULL);	204	(void *) PTE_GET_FRAME(pte), NULL);
206	page_table_unlock(area->as, false);	205	page_table_unlock(area->as, false);
207	frame_reference_add(ADDR2PFN(PTE_GET_FRAME(pte)));	206	frame_reference_add(ADDR2PFN(PTE_GET_FRAME(pte)));
208	}	207	}
209		208
210	}	209	}
211	}	210	}
212	mutex_unlock(&area->sh_info->lock);	211	mutex_unlock(&area->sh_info->lock);
213	}	212	}
214		213
215	/** @}	214	/** @}
216	*/	215	*/
217		216