WebSVN – HelenOS-historic – Diff – /kernel/trunk/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 <typedefs.h>
#include <align.h>
#include <arch.h>
 
static int anon_page_fault(as_area_t *area, __address addr, pf_access_t access);
static void anon_frame_free(as_area_t *area, __address page, __address 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, __address addr, pf_access_t access)
{
    __address 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 = (__address) 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 = PFN2ADDR(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 = PFN2ADDR(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 Ignored.
 * @param frame Frame to be released.
 */
void anon_frame_free(as_area_t *area, __address page, __address frame)
{
    frame_free(ADDR2PFN(frame));
}
 
/** 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++) {
            __address 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-historic

(root)/kernel/trunk/generic/src/mm/backend_anon.c – Rev 1545 → 1702

Rev 1545		Rev 1702
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
-		30	* @{
-		31	*/
-		32
29	/**	33	/**
30	* @file backend_anon.c	34	* @file
31	* @brief Backend for anonymous memory address space areas.	35	* @brief Backend for anonymous memory address space areas.
32	*	36	*
33	*/	37	*/
34		38
35	#include <mm/as.h>	39	#include <mm/as.h>
36	#include <mm/page.h>	40	#include <mm/page.h>
37	#include <genarch/mm/page_pt.h>	41	#include <genarch/mm/page_pt.h>
38	#include <genarch/mm/page_ht.h>	42	#include <genarch/mm/page_ht.h>
39	#include <mm/frame.h>	43	#include <mm/frame.h>
40	#include <mm/slab.h>	44	#include <mm/slab.h>
41	#include <synch/mutex.h>	45	#include <synch/mutex.h>
42	#include <adt/list.h>	46	#include <adt/list.h>
43	#include <adt/btree.h>	47	#include <adt/btree.h>
44	#include <errno.h>	48	#include <errno.h>
45	#include <arch/types.h>	49	#include <arch/types.h>
46	#include <typedefs.h>	50	#include <typedefs.h>
47	#include <align.h>	51	#include <align.h>
48	#include <arch.h>	52	#include <arch.h>
49		53
50	static int anon_page_fault(as_area_t *area, __address addr, pf_access_t access);	54	static int anon_page_fault(as_area_t *area, __address addr, pf_access_t access);
51	static void anon_frame_free(as_area_t *area, __address page, __address frame);	55	static void anon_frame_free(as_area_t *area, __address page, __address frame);
52	static void anon_share(as_area_t *area);	56	static void anon_share(as_area_t *area);
53		57
54	mem_backend_t anon_backend = {	58	mem_backend_t anon_backend = {
55	.page_fault = anon_page_fault,	59	.page_fault = anon_page_fault,
56	.frame_free = anon_frame_free,	60	.frame_free = anon_frame_free,
57	.share = anon_share	61	.share = anon_share
58	};	62	};
59		63
60	/** Service a page fault in the anonymous memory address space area.	64	/** Service a page fault in the anonymous memory address space area.
61	*	65	*
62	* The address space area and page tables must be already locked.	66	* The address space area and page tables must be already locked.
63	*	67	*
64	* @param area Pointer to the address space area.	68	* @param area Pointer to the address space area.
65	* @param addr Faulting virtual address.	69	* @param addr Faulting virtual address.
66	* @param access Access mode that caused the fault (i.e. read/write/exec).	70	* @param access Access mode that caused the fault (i.e. read/write/exec).
67	*	71	*
68	* @return AS_PF_FAULT on failure (i.e. page fault) or AS_PF_OK on success (i.e. serviced).	72	* @return AS_PF_FAULT on failure (i.e. page fault) or AS_PF_OK on success (i.e. serviced).
69	*/	73	*/
70	int anon_page_fault(as_area_t *area, __address addr, pf_access_t access)	74	int anon_page_fault(as_area_t *area, __address addr, pf_access_t access)
71	{	75	{
72	__address frame;	76	__address frame;
73		77
74	if (!as_area_check_access(area, access))	78	if (!as_area_check_access(area, access))
75	return AS_PF_FAULT;	79	return AS_PF_FAULT;
76		80
77	if (area->sh_info) {	81	if (area->sh_info) {
78	btree_node_t *leaf;	82	btree_node_t *leaf;
79		83
80	/*	84	/*
81	* The area is shared, chances are that the mapping can be found	85	* The area is shared, chances are that the mapping can be found
82	* in the pagemap of the address space area share info structure.	86	* in the pagemap of the address space area share info structure.
83	* In the case that the pagemap does not contain the respective	87	* In the case that the pagemap does not contain the respective
84	* mapping, a new frame is allocated and the mapping is created.	88	* mapping, a new frame is allocated and the mapping is created.
85	*/	89	*/
86	mutex_lock(&area->sh_info->lock);	90	mutex_lock(&area->sh_info->lock);
87	frame = (__address) btree_search(&area->sh_info->pagemap,	91	frame = (__address) btree_search(&area->sh_info->pagemap,
88	ALIGN_DOWN(addr, PAGE_SIZE) - area->base, &leaf);	92	ALIGN_DOWN(addr, PAGE_SIZE) - area->base, &leaf);
89	if (!frame) {	93	if (!frame) {
90	bool allocate = true;	94	bool allocate = true;
91	int i;	95	int i;
92		96
93	/*	97	/*
94	* Zero can be returned as a valid frame address.	98	* Zero can be returned as a valid frame address.
95	* Just a small workaround.	99	* Just a small workaround.
96	*/	100	*/
97	for (i = 0; i < leaf->keys; i++) {	101	for (i = 0; i < leaf->keys; i++) {
98	if (leaf->key[i] == ALIGN_DOWN(addr, PAGE_SIZE)) {	102	if (leaf->key[i] == ALIGN_DOWN(addr, PAGE_SIZE)) {
99	allocate = false;	103	allocate = false;
100	break;	104	break;
101	}	105	}
102	}	106	}
103	if (allocate) {	107	if (allocate) {
104	frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));	108	frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
105	memsetb(PA2KA(frame), FRAME_SIZE, 0);	109	memsetb(PA2KA(frame), FRAME_SIZE, 0);
106		110
107	/*	111	/*
108	* Insert the address of the newly allocated frame to the pagemap.	112	* Insert the address of the newly allocated frame to the pagemap.
109	*/	113	*/
110	btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base, (void *) frame, leaf);	114	btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base, (void *) frame, leaf);
111	}	115	}
112	}	116	}
113	frame_reference_add(ADDR2PFN(frame));	117	frame_reference_add(ADDR2PFN(frame));
114	mutex_unlock(&area->sh_info->lock);	118	mutex_unlock(&area->sh_info->lock);
115	} else {	119	} else {
116		120
117	/*	121	/*
118	* In general, there can be several reasons that	122	* In general, there can be several reasons that
119	* can have caused this fault.	123	* can have caused this fault.
120	*	124	*
121	* - non-existent mapping: the area is an anonymous	125	* - non-existent mapping: the area is an anonymous
122	* area (e.g. heap or stack) and so far has not been	126	* area (e.g. heap or stack) and so far has not been
123	* allocated a frame for the faulting page	127	* allocated a frame for the faulting page
124	*	128	*
125	* - non-present mapping: another possibility,	129	* - non-present mapping: another possibility,
126	* currently not implemented, would be frame	130	* currently not implemented, would be frame
127	* reuse; when this becomes a possibility,	131	* reuse; when this becomes a possibility,
128	* do not forget to distinguish between	132	* do not forget to distinguish between
129	* the different causes	133	* the different causes
130	*/	134	*/
131	frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));	135	frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
132	memsetb(PA2KA(frame), FRAME_SIZE, 0);	136	memsetb(PA2KA(frame), FRAME_SIZE, 0);
133	}	137	}
134		138
135	/*	139	/*
136	* Map 'page' to 'frame'.	140	* Map 'page' to 'frame'.
137	* Note that TLB shootdown is not attempted as only new information is being	141	* Note that TLB shootdown is not attempted as only new information is being
138	* inserted into page tables.	142	* inserted into page tables.
139	*/	143	*/
140	page_mapping_insert(AS, addr, frame, as_area_get_flags(area));	144	page_mapping_insert(AS, addr, frame, as_area_get_flags(area));
141	if (!used_space_insert(area, ALIGN_DOWN(addr, PAGE_SIZE), 1))	145	if (!used_space_insert(area, ALIGN_DOWN(addr, PAGE_SIZE), 1))
142	panic("Could not insert used space.\n");	146	panic("Could not insert used space.\n");
143		147
144	return AS_PF_OK;	148	return AS_PF_OK;
145	}	149	}
146		150
147	/** Free a frame that is backed by the anonymous memory backend.	151	/** Free a frame that is backed by the anonymous memory backend.
148	*	152	*
149	* The address space area and page tables must be already locked.	153	* The address space area and page tables must be already locked.
150	*	154	*
151	* @param area Ignored.	155	* @param area Ignored.
152	* @param page Ignored.	156	* @param page Ignored.
153	* @param frame Frame to be released.	157	* @param frame Frame to be released.
154	*/	158	*/
155	void anon_frame_free(as_area_t *area, __address page, __address frame)	159	void anon_frame_free(as_area_t *area, __address page, __address frame)
156	{	160	{
157	frame_free(ADDR2PFN(frame));	161	frame_free(ADDR2PFN(frame));
158	}	162	}
159		163
160	/** Share the anonymous address space area.	164	/** Share the anonymous address space area.
161	*	165	*
162	* Sharing of anonymous area is done by duplicating its entire mapping	166	* Sharing of anonymous area is done by duplicating its entire mapping
163	* to the pagemap. Page faults will primarily search for frames there.	167	* to the pagemap. Page faults will primarily search for frames there.
164	*	168	*
165	* The address space and address space area must be already locked.	169	* The address space and address space area must be already locked.
166	*	170	*
167	* @param area Address space area to be shared.	171	* @param area Address space area to be shared.
168	*/	172	*/
169	void anon_share(as_area_t *area)	173	void anon_share(as_area_t *area)
170	{	174	{
171	link_t *cur;	175	link_t *cur;
172		176
173	/*	177	/*
174	* Copy used portions of the area to sh_info's page map.	178	* Copy used portions of the area to sh_info's page map.
175	*/	179	*/
176	mutex_lock(&area->sh_info->lock);	180	mutex_lock(&area->sh_info->lock);
177	for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {	181	for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {
178	btree_node_t *node;	182	btree_node_t *node;
179	int i;	183	int i;
180		184
181	node = list_get_instance(cur, btree_node_t, leaf_link);	185	node = list_get_instance(cur, btree_node_t, leaf_link);
182	for (i = 0; i < node->keys; i++) {	186	for (i = 0; i < node->keys; i++) {
183	__address base = node->key[i];	187	__address base = node->key[i];
184	count_t count = (count_t) node->value[i];	188	count_t count = (count_t) node->value[i];
185	int j;	189	int j;
186		190
187	for (j = 0; j < count; j++) {	191	for (j = 0; j < count; j++) {
188	pte_t *pte;	192	pte_t *pte;
189		193
190	page_table_lock(area->as, false);	194	page_table_lock(area->as, false);
191	pte = page_mapping_find(area->as, base + j*PAGE_SIZE);	195	pte = page_mapping_find(area->as, base + j*PAGE_SIZE);
192	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));	196	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
193	btree_insert(&area->sh_info->pagemap, (base + j*PAGE_SIZE) - area->base,	197	btree_insert(&area->sh_info->pagemap, (base + j*PAGE_SIZE) - area->base,
194	(void *) PTE_GET_FRAME(pte), NULL);	198	(void *) PTE_GET_FRAME(pte), NULL);
195	page_table_unlock(area->as, false);	199	page_table_unlock(area->as, false);
196	frame_reference_add(ADDR2PFN(PTE_GET_FRAME(pte)));	200	frame_reference_add(ADDR2PFN(PTE_GET_FRAME(pte)));
197	}	201	}
198		202
199	}	203	}
200	}	204	}
201	mutex_unlock(&area->sh_info->lock);	205	mutex_unlock(&area->sh_info->lock);
202	}	206	}
-		207
-		208	/** @}
-		209	*/
-		210
203		211