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

Rev	Author	Line No.	Line
703	jermar	1	/*
		2	* Copyright (C) 2001-2006 Jakub Jermar
		3	* All rights reserved.
		4	*
		5	* Redistribution and use in source and binary forms, with or without
		6	* modification, are permitted provided that the following conditions
		7	* are met:
		8	*
		9	* - Redistributions of source code must retain the above copyright
		10	* notice, this list of conditions and the following disclaimer.
		11	* - Redistributions in binary form must reproduce the above copyright
		12	* notice, this list of conditions and the following disclaimer in the
		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
		15	* derived from this software without specific prior written permission.
		16	*
		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
		19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
		20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
		21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
		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
		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
		26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
		27	*/
		28
1757	jermar	29	/** @addtogroup genericmm
1702	cejka	30	* @{
		31	*/
		32
1248	jermar	33	/**
1702	cejka	34	* @file
1248	jermar	35	* @brief Address space related functions.
		36	*
703	jermar	37	* This file contains address space manipulation functions.
		38	* Roughly speaking, this is a higher-level client of
		39	* Virtual Address Translation (VAT) subsystem.
1248	jermar	40	*
		41	* Functionality provided by this file allows one to
1757	jermar	42	* create address spaces and create, resize and share
1248	jermar	43	* address space areas.
		44	*
		45	* @see page.c
		46	*
703	jermar	47	*/
		48
		49	#include <mm/as.h>
756	jermar	50	#include <arch/mm/as.h>
703	jermar	51	#include <mm/page.h>
		52	#include <mm/frame.h>
814	palkovsky	53	#include <mm/slab.h>
703	jermar	54	#include <mm/tlb.h>
		55	#include <arch/mm/page.h>
		56	#include <genarch/mm/page_pt.h>
1108	jermar	57	#include <genarch/mm/page_ht.h>
727	jermar	58	#include <mm/asid.h>
703	jermar	59	#include <arch/mm/asid.h>
		60	#include <synch/spinlock.h>
1380	jermar	61	#include <synch/mutex.h>
788	jermar	62	#include <adt/list.h>
1147	jermar	63	#include <adt/btree.h>
1235	jermar	64	#include <proc/task.h>
1288	jermar	65	#include <proc/thread.h>
1235	jermar	66	#include <arch/asm.h>
703	jermar	67	#include <panic.h>
		68	#include <debug.h>
1235	jermar	69	#include <print.h>
703	jermar	70	#include <memstr.h>
1070	jermar	71	#include <macros.h>
703	jermar	72	#include <arch.h>
1235	jermar	73	#include <errno.h>
		74	#include <config.h>
1387	jermar	75	#include <align.h>
1235	jermar	76	#include <arch/types.h>
		77	#include <typedefs.h>
1288	jermar	78	#include <syscall/copy.h>
		79	#include <arch/interrupt.h>
703	jermar	80
1757	jermar	81	/**
		82	* Each architecture decides what functions will be used to carry out
		83	* address space operations such as creating or locking page tables.
		84	*/
756	jermar	85	as_operations_t *as_operations = NULL;
703	jermar	86
1415	jermar	87	/** This lock protects inactive_as_with_asid_head list. It must be acquired before as_t mutex. */
		88	SPINLOCK_INITIALIZE(inactive_as_with_asid_lock);
823	jermar	89
		90	/**
		91	* This list contains address spaces that are not active on any
		92	* processor and that have valid ASID.
		93	*/
		94	LIST_INITIALIZE(inactive_as_with_asid_head);
		95
757	jermar	96	/** Kernel address space. */
		97	as_t *AS_KERNEL = NULL;
		98
1235	jermar	99	static int area_flags_to_page_flags(int aflags);
977	jermar	100	static as_area_t find_area_and_lock(as_t as, __address va);
1048	jermar	101	static bool check_area_conflicts(as_t as, __address va, size_t size, as_area_t avoid_area);
1409	jermar	102	static void sh_info_remove_reference(share_info_t *sh_info);
703	jermar	103
756	jermar	104	/** Initialize address space subsystem. */
		105	void as_init(void)
		106	{
		107	as_arch_init();
789	palkovsky	108	AS_KERNEL = as_create(FLAG_AS_KERNEL);
1383	decky	109	if (!AS_KERNEL)
		110	panic("can't create kernel address space\n");
		111
756	jermar	112	}
		113
757	jermar	114	/** Create address space.
		115	*
		116	* @param flags Flags that influence way in wich the address space is created.
		117	*/
756	jermar	118	as_t *as_create(int flags)
703	jermar	119	{
		120	as_t *as;
		121
822	palkovsky	122	as = (as_t *) malloc(sizeof(as_t), 0);
823	jermar	123	link_initialize(&as->inactive_as_with_asid_link);
1380	jermar	124	mutex_initialize(&as->lock);
1147	jermar	125	btree_create(&as->as_area_btree);
822	palkovsky	126
		127	if (flags & FLAG_AS_KERNEL)
		128	as->asid = ASID_KERNEL;
		129	else
		130	as->asid = ASID_INVALID;
		131
1468	jermar	132	as->refcount = 0;
1415	jermar	133	as->cpu_refcount = 0;
822	palkovsky	134	as->page_table = page_table_create(flags);
703	jermar	135
		136	return as;
		137	}
		138
1468	jermar	139	/** Destroy adress space.
		140	*
		141	* When there are no tasks referencing this address space (i.e. its refcount is zero),
		142	* the address space can be destroyed.
		143	*/
		144	void as_destroy(as_t *as)
973	palkovsky	145	{
1468	jermar	146	ipl_t ipl;
1594	jermar	147	bool cond;
973	palkovsky	148
1468	jermar	149	ASSERT(as->refcount == 0);
		150
		151	/*
		152	* Since there is no reference to this area,
		153	* it is safe not to lock its mutex.
		154	*/
		155	ipl = interrupts_disable();
		156	spinlock_lock(&inactive_as_with_asid_lock);
1587	jermar	157	if (as->asid != ASID_INVALID && as != AS_KERNEL) {
1594	jermar	158	if (as != AS && as->cpu_refcount == 0)
1587	jermar	159	list_remove(&as->inactive_as_with_asid_link);
1468	jermar	160	asid_put(as->asid);
		161	}
		162	spinlock_unlock(&inactive_as_with_asid_lock);
		163
		164	/*
		165	* Destroy address space areas of the address space.
1594	jermar	166	* The B+tee must be walked carefully because it is
		167	* also being destroyed.
1468	jermar	168	*/
1594	jermar	169	for (cond = true; cond; ) {
1468	jermar	170	btree_node_t *node;
1594	jermar	171
		172	ASSERT(!list_empty(&as->as_area_btree.leaf_head));
		173	node = list_get_instance(as->as_area_btree.leaf_head.next, btree_node_t, leaf_link);
		174
		175	if ((cond = node->keys)) {
		176	as_area_destroy(as, node->key[0]);
		177	}
1468	jermar	178	}
1495	jermar	179
1483	jermar	180	btree_destroy(&as->as_area_btree);
1468	jermar	181	page_table_destroy(as->page_table);
		182
		183	interrupts_restore(ipl);
		184
973	palkovsky	185	free(as);
		186	}
		187
703	jermar	188	/** Create address space area of common attributes.
		189	*
		190	* The created address space area is added to the target address space.
		191	*
		192	* @param as Target address space.
1239	jermar	193	* @param flags Flags of the area memory.
1048	jermar	194	* @param size Size of area.
703	jermar	195	* @param base Base address of area.
1239	jermar	196	* @param attrs Attributes of the area.
1409	jermar	197	* @param backend Address space area backend. NULL if no backend is used.
		198	* @param backend_data NULL or a pointer to an array holding two void *.
703	jermar	199	*
		200	* @return Address space area on success or NULL on failure.
		201	*/
1409	jermar	202	as_area_t as_area_create(as_t as, int flags, size_t size, __address base, int attrs,
1424	jermar	203	mem_backend_t backend, mem_backend_data_t backend_data)
703	jermar	204	{
		205	ipl_t ipl;
		206	as_area_t *a;
		207
		208	if (base % PAGE_SIZE)
1048	jermar	209	return NULL;
		210
1233	jermar	211	if (!size)
		212	return NULL;
		213
1048	jermar	214	/* Writeable executable areas are not supported. */
		215	if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
		216	return NULL;
703	jermar	217
		218	ipl = interrupts_disable();
1380	jermar	219	mutex_lock(&as->lock);
703	jermar	220
1048	jermar	221	if (!check_area_conflicts(as, base, size, NULL)) {
1380	jermar	222	mutex_unlock(&as->lock);
1048	jermar	223	interrupts_restore(ipl);
		224	return NULL;
		225	}
703	jermar	226
822	palkovsky	227	a = (as_area_t *) malloc(sizeof(as_area_t), 0);
703	jermar	228
1380	jermar	229	mutex_initialize(&a->lock);
822	palkovsky	230
1424	jermar	231	a->as = as;
1026	jermar	232	a->flags = flags;
1239	jermar	233	a->attributes = attrs;
1048	jermar	234	a->pages = SIZE2FRAMES(size);
822	palkovsky	235	a->base = base;
1409	jermar	236	a->sh_info = NULL;
		237	a->backend = backend;
1424	jermar	238	if (backend_data)
		239	a->backend_data = *backend_data;
		240	else
		241	memsetb((__address) &a->backend_data, sizeof(a->backend_data), 0);
		242
1387	jermar	243	btree_create(&a->used_space);
822	palkovsky	244
1147	jermar	245	btree_insert(&as->as_area_btree, base, (void *) a, NULL);
822	palkovsky	246
1380	jermar	247	mutex_unlock(&as->lock);
703	jermar	248	interrupts_restore(ipl);
704	jermar	249
703	jermar	250	return a;
		251	}
		252
1235	jermar	253	/** Find address space area and change it.
		254	*
		255	* @param as Address space.
		256	* @param address Virtual address belonging to the area to be changed. Must be page-aligned.
		257	* @param size New size of the virtual memory block starting at address.
		258	* @param flags Flags influencing the remap operation. Currently unused.
		259	*
1306	jermar	260	* @return Zero on success or a value from @ref errno.h otherwise.
1235	jermar	261	*/
1306	jermar	262	int as_area_resize(as_t *as, __address address, size_t size, int flags)
1235	jermar	263	{
1306	jermar	264	as_area_t *area;
1235	jermar	265	ipl_t ipl;
		266	size_t pages;
		267
		268	ipl = interrupts_disable();
1380	jermar	269	mutex_lock(&as->lock);
1235	jermar	270
		271	/*
		272	* Locate the area.
		273	*/
		274	area = find_area_and_lock(as, address);
		275	if (!area) {
1380	jermar	276	mutex_unlock(&as->lock);
1235	jermar	277	interrupts_restore(ipl);
1306	jermar	278	return ENOENT;
1235	jermar	279	}
		280
1424	jermar	281	if (area->backend == &phys_backend) {
1235	jermar	282	/*
		283	* Remapping of address space areas associated
		284	* with memory mapped devices is not supported.
		285	*/
1380	jermar	286	mutex_unlock(&area->lock);
		287	mutex_unlock(&as->lock);
1235	jermar	288	interrupts_restore(ipl);
1306	jermar	289	return ENOTSUP;
1235	jermar	290	}
1409	jermar	291	if (area->sh_info) {
		292	/*
		293	* Remapping of shared address space areas
		294	* is not supported.
		295	*/
		296	mutex_unlock(&area->lock);
		297	mutex_unlock(&as->lock);
		298	interrupts_restore(ipl);
		299	return ENOTSUP;
		300	}
1235	jermar	301
		302	pages = SIZE2FRAMES((address - area->base) + size);
		303	if (!pages) {
		304	/*
		305	* Zero size address space areas are not allowed.
		306	*/
1380	jermar	307	mutex_unlock(&area->lock);
		308	mutex_unlock(&as->lock);
1235	jermar	309	interrupts_restore(ipl);
1306	jermar	310	return EPERM;
1235	jermar	311	}
		312
		313	if (pages < area->pages) {
1403	jermar	314	bool cond;
		315	__address start_free = area->base + pages*PAGE_SIZE;
1235	jermar	316
		317	/*
		318	* Shrinking the area.
		319	* No need to check for overlaps.
		320	*/
1403	jermar	321
		322	/*
1436	jermar	323	* Start TLB shootdown sequence.
		324	*/
		325	tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
		326
		327	/*
1403	jermar	328	* Remove frames belonging to used space starting from
		329	* the highest addresses downwards until an overlap with
		330	* the resized address space area is found. Note that this
		331	* is also the right way to remove part of the used_space
		332	* B+tree leaf list.
		333	*/
		334	for (cond = true; cond;) {
		335	btree_node_t *node;
		336
		337	ASSERT(!list_empty(&area->used_space.leaf_head));
		338	node = list_get_instance(area->used_space.leaf_head.prev, btree_node_t, leaf_link);
		339	if ((cond = (bool) node->keys)) {
		340	__address b = node->key[node->keys - 1];
		341	count_t c = (count_t) node->value[node->keys - 1];
		342	int i = 0;
1235	jermar	343
1403	jermar	344	if (overlaps(b, cPAGE_SIZE, area->base, pagesPAGE_SIZE)) {
		345
		346	if (b + c*PAGE_SIZE <= start_free) {
		347	/*
		348	* The whole interval fits completely
		349	* in the resized address space area.
		350	*/
		351	break;
		352	}
		353
		354	/*
		355	* Part of the interval corresponding to b and c
		356	* overlaps with the resized address space area.
		357	*/
		358
		359	cond = false; /* we are almost done */
		360	i = (start_free - b) >> PAGE_WIDTH;
		361	if (!used_space_remove(area, start_free, c - i))
		362	panic("Could not remove used space.");
		363	} else {
		364	/*
		365	* The interval of used space can be completely removed.
		366	*/
		367	if (!used_space_remove(area, b, c))
		368	panic("Could not remove used space.\n");
		369	}
		370
		371	for (; i < c; i++) {
		372	pte_t *pte;
		373
		374	page_table_lock(as, false);
		375	pte = page_mapping_find(as, b + i*PAGE_SIZE);
		376	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424	jermar	377	if (area->backend && area->backend->frame_free) {
		378	area->backend->frame_free(area,
1409	jermar	379	b + i*PAGE_SIZE, PTE_GET_FRAME(pte));
		380	}
1403	jermar	381	page_mapping_remove(as, b + i*PAGE_SIZE);
		382	page_table_unlock(as, false);
		383	}
1235	jermar	384	}
		385	}
1436	jermar	386
1235	jermar	387	/*
1436	jermar	388	* Finish TLB shootdown sequence.
1235	jermar	389	*/
		390	tlb_invalidate_pages(AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
		391	tlb_shootdown_finalize();
		392	} else {
		393	/*
		394	* Growing the area.
		395	* Check for overlaps with other address space areas.
		396	*/
		397	if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {
1380	jermar	398	mutex_unlock(&area->lock);
		399	mutex_unlock(&as->lock);
1235	jermar	400	interrupts_restore(ipl);
1306	jermar	401	return EADDRNOTAVAIL;
1235	jermar	402	}
		403	}
		404
		405	area->pages = pages;
		406
1380	jermar	407	mutex_unlock(&area->lock);
		408	mutex_unlock(&as->lock);
1235	jermar	409	interrupts_restore(ipl);
		410
1306	jermar	411	return 0;
1235	jermar	412	}
		413
1306	jermar	414	/** Destroy address space area.
		415	*
		416	* @param as Address space.
		417	* @param address Address withing the area to be deleted.
		418	*
		419	* @return Zero on success or a value from @ref errno.h on failure.
		420	*/
		421	int as_area_destroy(as_t *as, __address address)
		422	{
		423	as_area_t *area;
		424	__address base;
1495	jermar	425	link_t *cur;
1306	jermar	426	ipl_t ipl;
		427
		428	ipl = interrupts_disable();
1380	jermar	429	mutex_lock(&as->lock);
1306	jermar	430
		431	area = find_area_and_lock(as, address);
		432	if (!area) {
1380	jermar	433	mutex_unlock(&as->lock);
1306	jermar	434	interrupts_restore(ipl);
		435	return ENOENT;
		436	}
		437
1403	jermar	438	base = area->base;
		439
1411	jermar	440	/*
1436	jermar	441	* Start TLB shootdown sequence.
		442	*/
		443	tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages);
		444
		445	/*
1411	jermar	446	* Visit only the pages mapped by used_space B+tree.
		447	*/
1495	jermar	448	for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {
1411	jermar	449	btree_node_t *node;
1495	jermar	450	int i;
1403	jermar	451
1495	jermar	452	node = list_get_instance(cur, btree_node_t, leaf_link);
		453	for (i = 0; i < node->keys; i++) {
		454	__address b = node->key[i];
		455	count_t j;
1411	jermar	456	pte_t *pte;
1403	jermar	457
1495	jermar	458	for (j = 0; j < (count_t) node->value[i]; j++) {
1411	jermar	459	page_table_lock(as, false);
1495	jermar	460	pte = page_mapping_find(as, b + j*PAGE_SIZE);
1411	jermar	461	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424	jermar	462	if (area->backend && area->backend->frame_free) {
		463	area->backend->frame_free(area,
1495	jermar	464	b + j*PAGE_SIZE, PTE_GET_FRAME(pte));
1403	jermar	465	}
1495	jermar	466	page_mapping_remove(as, b + j*PAGE_SIZE);
1411	jermar	467	page_table_unlock(as, false);
1306	jermar	468	}
		469	}
		470	}
1403	jermar	471
1306	jermar	472	/*
1436	jermar	473	* Finish TLB shootdown sequence.
1306	jermar	474	*/
		475	tlb_invalidate_pages(AS->asid, area->base, area->pages);
		476	tlb_shootdown_finalize();
1436	jermar	477
		478	btree_destroy(&area->used_space);
1306	jermar	479
1309	jermar	480	area->attributes \|= AS_AREA_ATTR_PARTIAL;
1409	jermar	481
		482	if (area->sh_info)
		483	sh_info_remove_reference(area->sh_info);
		484
1380	jermar	485	mutex_unlock(&area->lock);
1306	jermar	486
		487	/*
		488	* Remove the empty area from address space.
		489	*/
		490	btree_remove(&AS->as_area_btree, base, NULL);
		491
1309	jermar	492	free(area);
		493
1380	jermar	494	mutex_unlock(&AS->lock);
1306	jermar	495	interrupts_restore(ipl);
		496	return 0;
		497	}
		498
1413	jermar	499	/** Share address space area with another or the same address space.
1235	jermar	500	*
1424	jermar	501	* Address space area mapping is shared with a new address space area.
		502	* If the source address space area has not been shared so far,
		503	* a new sh_info is created. The new address space area simply gets the
		504	* sh_info of the source area. The process of duplicating the
		505	* mapping is done through the backend share function.
1413	jermar	506	*
1417	jermar	507	* @param src_as Pointer to source address space.
1239	jermar	508	* @param src_base Base address of the source address space area.
1417	jermar	509	* @param acc_size Expected size of the source area.
1428	palkovsky	510	* @param dst_as Pointer to destination address space.
1417	jermar	511	* @param dst_base Target base address.
		512	* @param dst_flags_mask Destination address space area flags mask.
1235	jermar	513	*
1306	jermar	514	* @return Zero on success or ENOENT if there is no such task or
1235	jermar	515	* if there is no such address space area,
		516	* EPERM if there was a problem in accepting the area or
		517	* ENOMEM if there was a problem in allocating destination
1413	jermar	518	* address space area. ENOTSUP is returned if an attempt
		519	* to share non-anonymous address space area is detected.
1235	jermar	520	*/
1413	jermar	521	int as_area_share(as_t *src_as, __address src_base, size_t acc_size,
1428	palkovsky	522	as_t *dst_as, __address dst_base, int dst_flags_mask)
1235	jermar	523	{
		524	ipl_t ipl;
1239	jermar	525	int src_flags;
		526	size_t src_size;
		527	as_area_t src_area, dst_area;
1413	jermar	528	share_info_t *sh_info;
1424	jermar	529	mem_backend_t *src_backend;
		530	mem_backend_data_t src_backend_data;
1434	palkovsky	531
1235	jermar	532	ipl = interrupts_disable();
1380	jermar	533	mutex_lock(&src_as->lock);
1329	palkovsky	534	src_area = find_area_and_lock(src_as, src_base);
1239	jermar	535	if (!src_area) {
1238	jermar	536	/*
		537	* Could not find the source address space area.
		538	*/
1380	jermar	539	mutex_unlock(&src_as->lock);
1238	jermar	540	interrupts_restore(ipl);
		541	return ENOENT;
		542	}
1413	jermar	543
1424	jermar	544	if (!src_area->backend \|\| !src_area->backend->share) {
1413	jermar	545	/*
1424	jermar	546	* There is now backend or the backend does not
		547	* know how to share the area.
1413	jermar	548	*/
		549	mutex_unlock(&src_area->lock);
		550	mutex_unlock(&src_as->lock);
		551	interrupts_restore(ipl);
		552	return ENOTSUP;
		553	}
		554
1239	jermar	555	src_size = src_area->pages * PAGE_SIZE;
		556	src_flags = src_area->flags;
1424	jermar	557	src_backend = src_area->backend;
		558	src_backend_data = src_area->backend_data;
1544	palkovsky	559
		560	/* Share the cacheable flag from the original mapping */
		561	if (src_flags & AS_AREA_CACHEABLE)
		562	dst_flags_mask \|= AS_AREA_CACHEABLE;
		563
1461	palkovsky	564	if (src_size != acc_size \|\| (src_flags & dst_flags_mask) != dst_flags_mask) {
1413	jermar	565	mutex_unlock(&src_area->lock);
		566	mutex_unlock(&src_as->lock);
1235	jermar	567	interrupts_restore(ipl);
		568	return EPERM;
		569	}
1413	jermar	570
1235	jermar	571	/*
1413	jermar	572	* Now we are committed to sharing the area.
		573	* First prepare the area for sharing.
		574	* Then it will be safe to unlock it.
		575	*/
		576	sh_info = src_area->sh_info;
		577	if (!sh_info) {
		578	sh_info = (share_info_t *) malloc(sizeof(share_info_t), 0);
		579	mutex_initialize(&sh_info->lock);
		580	sh_info->refcount = 2;
		581	btree_create(&sh_info->pagemap);
		582	src_area->sh_info = sh_info;
		583	} else {
		584	mutex_lock(&sh_info->lock);
		585	sh_info->refcount++;
		586	mutex_unlock(&sh_info->lock);
		587	}
		588
1424	jermar	589	src_area->backend->share(src_area);
1413	jermar	590
		591	mutex_unlock(&src_area->lock);
		592	mutex_unlock(&src_as->lock);
		593
		594	/*
1239	jermar	595	* Create copy of the source address space area.
		596	* The destination area is created with AS_AREA_ATTR_PARTIAL
		597	* attribute set which prevents race condition with
		598	* preliminary as_page_fault() calls.
1417	jermar	599	* The flags of the source area are masked against dst_flags_mask
		600	* to support sharing in less privileged mode.
1235	jermar	601	*/
1461	palkovsky	602	dst_area = as_area_create(dst_as, dst_flags_mask, src_size, dst_base,
1424	jermar	603	AS_AREA_ATTR_PARTIAL, src_backend, &src_backend_data);
1239	jermar	604	if (!dst_area) {
1235	jermar	605	/*
		606	* Destination address space area could not be created.
		607	*/
1413	jermar	608	sh_info_remove_reference(sh_info);
		609
1235	jermar	610	interrupts_restore(ipl);
		611	return ENOMEM;
		612	}
		613
		614	/*
1239	jermar	615	* Now the destination address space area has been
		616	* fully initialized. Clear the AS_AREA_ATTR_PARTIAL
1413	jermar	617	* attribute and set the sh_info.
1239	jermar	618	*/
1380	jermar	619	mutex_lock(&dst_area->lock);
1239	jermar	620	dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
1413	jermar	621	dst_area->sh_info = sh_info;
1380	jermar	622	mutex_unlock(&dst_area->lock);
1235	jermar	623
		624	interrupts_restore(ipl);
		625
		626	return 0;
		627	}
		628
1423	jermar	629	/** Check access mode for address space area.
		630	*
		631	* The address space area must be locked prior to this call.
		632	*
		633	* @param area Address space area.
		634	* @param access Access mode.
		635	*
		636	* @return False if access violates area's permissions, true otherwise.
		637	*/
		638	bool as_area_check_access(as_area_t *area, pf_access_t access)
		639	{
		640	int flagmap[] = {
		641	[PF_ACCESS_READ] = AS_AREA_READ,
		642	[PF_ACCESS_WRITE] = AS_AREA_WRITE,
		643	[PF_ACCESS_EXEC] = AS_AREA_EXEC
		644	};
		645
		646	if (!(area->flags & flagmap[access]))
		647	return false;
		648
		649	return true;
		650	}
		651
703	jermar	652	/** Handle page fault within the current address space.
		653	*
1409	jermar	654	* This is the high-level page fault handler. It decides
		655	* whether the page fault can be resolved by any backend
		656	* and if so, it invokes the backend to resolve the page
		657	* fault.
		658	*
703	jermar	659	* Interrupts are assumed disabled.
		660	*
		661	* @param page Faulting page.
1411	jermar	662	* @param access Access mode that caused the fault (i.e. read/write/exec).
1288	jermar	663	* @param istate Pointer to interrupted state.
703	jermar	664	*
1409	jermar	665	* @return AS_PF_FAULT on page fault, AS_PF_OK on success or AS_PF_DEFER if the
		666	* fault was caused by copy_to_uspace() or copy_from_uspace().
703	jermar	667	*/
1411	jermar	668	int as_page_fault(__address page, pf_access_t access, istate_t *istate)
703	jermar	669	{
1044	jermar	670	pte_t *pte;
977	jermar	671	as_area_t *area;
703	jermar	672
1380	jermar	673	if (!THREAD)
1409	jermar	674	return AS_PF_FAULT;
1380	jermar	675
703	jermar	676	ASSERT(AS);
1044	jermar	677
1380	jermar	678	mutex_lock(&AS->lock);
977	jermar	679	area = find_area_and_lock(AS, page);
703	jermar	680	if (!area) {
		681	/*
		682	* No area contained mapping for 'page'.
		683	* Signal page fault to low-level handler.
		684	*/
1380	jermar	685	mutex_unlock(&AS->lock);
1288	jermar	686	goto page_fault;
703	jermar	687	}
		688
1239	jermar	689	if (area->attributes & AS_AREA_ATTR_PARTIAL) {
		690	/*
		691	* The address space area is not fully initialized.
		692	* Avoid possible race by returning error.
		693	*/
1380	jermar	694	mutex_unlock(&area->lock);
		695	mutex_unlock(&AS->lock);
1288	jermar	696	goto page_fault;
1239	jermar	697	}
		698
1424	jermar	699	if (!area->backend \|\| !area->backend->page_fault) {
1409	jermar	700	/*
		701	* The address space area is not backed by any backend
		702	* or the backend cannot handle page faults.
		703	*/
		704	mutex_unlock(&area->lock);
		705	mutex_unlock(&AS->lock);
		706	goto page_fault;
		707	}
1179	jermar	708
1044	jermar	709	page_table_lock(AS, false);
		710
703	jermar	711	/*
1044	jermar	712	* To avoid race condition between two page faults
		713	* on the same address, we need to make sure
		714	* the mapping has not been already inserted.
		715	*/
		716	if ((pte = page_mapping_find(AS, page))) {
		717	if (PTE_PRESENT(pte)) {
1423	jermar	718	if (((access == PF_ACCESS_READ) && PTE_READABLE(pte)) \|\|
		719	(access == PF_ACCESS_WRITE && PTE_WRITABLE(pte)) \|\|
		720	(access == PF_ACCESS_EXEC && PTE_EXECUTABLE(pte))) {
		721	page_table_unlock(AS, false);
		722	mutex_unlock(&area->lock);
		723	mutex_unlock(&AS->lock);
		724	return AS_PF_OK;
		725	}
1044	jermar	726	}
		727	}
1409	jermar	728
1044	jermar	729	/*
1409	jermar	730	* Resort to the backend page fault handler.
703	jermar	731	*/
1424	jermar	732	if (area->backend->page_fault(area, page, access) != AS_PF_OK) {
1409	jermar	733	page_table_unlock(AS, false);
		734	mutex_unlock(&area->lock);
		735	mutex_unlock(&AS->lock);
		736	goto page_fault;
		737	}
703	jermar	738
1044	jermar	739	page_table_unlock(AS, false);
1380	jermar	740	mutex_unlock(&area->lock);
		741	mutex_unlock(&AS->lock);
1288	jermar	742	return AS_PF_OK;
		743
		744	page_fault:
		745	if (THREAD->in_copy_from_uspace) {
		746	THREAD->in_copy_from_uspace = false;
		747	istate_set_retaddr(istate, (__address) &memcpy_from_uspace_failover_address);
		748	} else if (THREAD->in_copy_to_uspace) {
		749	THREAD->in_copy_to_uspace = false;
		750	istate_set_retaddr(istate, (__address) &memcpy_to_uspace_failover_address);
		751	} else {
		752	return AS_PF_FAULT;
		753	}
		754
		755	return AS_PF_DEFER;
703	jermar	756	}
		757
823	jermar	758	/** Switch address spaces.
703	jermar	759	*
1380	jermar	760	* Note that this function cannot sleep as it is essentially a part of
1415	jermar	761	* scheduling. Sleeping here would lead to deadlock on wakeup.
1380	jermar	762	*
823	jermar	763	* @param old Old address space or NULL.
		764	* @param new New address space.
703	jermar	765	*/
823	jermar	766	void as_switch(as_t old, as_t new)
703	jermar	767	{
		768	ipl_t ipl;
823	jermar	769	bool needs_asid = false;
703	jermar	770
		771	ipl = interrupts_disable();
1415	jermar	772	spinlock_lock(&inactive_as_with_asid_lock);
703	jermar	773
		774	/*
823	jermar	775	* First, take care of the old address space.
		776	*/
		777	if (old) {
1380	jermar	778	mutex_lock_active(&old->lock);
1415	jermar	779	ASSERT(old->cpu_refcount);
		780	if((--old->cpu_refcount == 0) && (old != AS_KERNEL)) {
823	jermar	781	/*
		782	* The old address space is no longer active on
		783	* any processor. It can be appended to the
		784	* list of inactive address spaces with assigned
		785	* ASID.
		786	*/
		787	ASSERT(old->asid != ASID_INVALID);
		788	list_append(&old->inactive_as_with_asid_link, &inactive_as_with_asid_head);
		789	}
1380	jermar	790	mutex_unlock(&old->lock);
823	jermar	791	}
		792
		793	/*
		794	* Second, prepare the new address space.
		795	*/
1380	jermar	796	mutex_lock_active(&new->lock);
1415	jermar	797	if ((new->cpu_refcount++ == 0) && (new != AS_KERNEL)) {
823	jermar	798	if (new->asid != ASID_INVALID)
		799	list_remove(&new->inactive_as_with_asid_link);
		800	else
		801	needs_asid = true; /* defer call to asid_get() until new->lock is released */
		802	}
		803	SET_PTL0_ADDRESS(new->page_table);
1380	jermar	804	mutex_unlock(&new->lock);
823	jermar	805
		806	if (needs_asid) {
		807	/*
		808	* Allocation of new ASID was deferred
		809	* until now in order to avoid deadlock.
		810	*/
		811	asid_t asid;
		812
		813	asid = asid_get();
1380	jermar	814	mutex_lock_active(&new->lock);
823	jermar	815	new->asid = asid;
1380	jermar	816	mutex_unlock(&new->lock);
823	jermar	817	}
1415	jermar	818	spinlock_unlock(&inactive_as_with_asid_lock);
823	jermar	819	interrupts_restore(ipl);
		820
		821	/*
703	jermar	822	* Perform architecture-specific steps.
727	jermar	823	* (e.g. write ASID to hardware register etc.)
703	jermar	824	*/
823	jermar	825	as_install_arch(new);
703	jermar	826
823	jermar	827	AS = new;
703	jermar	828	}
754	jermar	829
1235	jermar	830	/** Convert address space area flags to page flags.
754	jermar	831	*
1235	jermar	832	* @param aflags Flags of some address space area.
754	jermar	833	*
1235	jermar	834	* @return Flags to be passed to page_mapping_insert().
754	jermar	835	*/
1235	jermar	836	int area_flags_to_page_flags(int aflags)
754	jermar	837	{
		838	int flags;
		839
1178	jermar	840	flags = PAGE_USER \| PAGE_PRESENT;
754	jermar	841
1235	jermar	842	if (aflags & AS_AREA_READ)
1026	jermar	843	flags \|= PAGE_READ;
		844
1235	jermar	845	if (aflags & AS_AREA_WRITE)
1026	jermar	846	flags \|= PAGE_WRITE;
		847
1235	jermar	848	if (aflags & AS_AREA_EXEC)
1026	jermar	849	flags \|= PAGE_EXEC;
		850
1424	jermar	851	if (aflags & AS_AREA_CACHEABLE)
1178	jermar	852	flags \|= PAGE_CACHEABLE;
		853
754	jermar	854	return flags;
		855	}
756	jermar	856
1235	jermar	857	/** Compute flags for virtual address translation subsytem.
		858	*
		859	* The address space area must be locked.
		860	* Interrupts must be disabled.
		861	*
		862	* @param a Address space area.
		863	*
		864	* @return Flags to be used in page_mapping_insert().
		865	*/
1409	jermar	866	int as_area_get_flags(as_area_t *a)
1235	jermar	867	{
		868	return area_flags_to_page_flags(a->flags);
		869	}
		870
756	jermar	871	/** Create page table.
		872	*
		873	* Depending on architecture, create either address space
		874	* private or global page table.
		875	*
		876	* @param flags Flags saying whether the page table is for kernel address space.
		877	*
		878	* @return First entry of the page table.
		879	*/
		880	pte_t *page_table_create(int flags)
		881	{
		882	ASSERT(as_operations);
		883	ASSERT(as_operations->page_table_create);
		884
		885	return as_operations->page_table_create(flags);
		886	}
977	jermar	887
1468	jermar	888	/** Destroy page table.
		889	*
		890	* Destroy page table in architecture specific way.
		891	*
		892	* @param page_table Physical address of PTL0.
		893	*/
		894	void page_table_destroy(pte_t *page_table)
		895	{
		896	ASSERT(as_operations);
		897	ASSERT(as_operations->page_table_destroy);
		898
		899	as_operations->page_table_destroy(page_table);
		900	}
		901
1044	jermar	902	/** Lock page table.
		903	*
		904	* This function should be called before any page_mapping_insert(),
		905	* page_mapping_remove() and page_mapping_find().
		906	*
		907	* Locking order is such that address space areas must be locked
		908	* prior to this call. Address space can be locked prior to this
		909	* call in which case the lock argument is false.
		910	*
		911	* @param as Address space.
1248	jermar	912	* @param lock If false, do not attempt to lock as->lock.
1044	jermar	913	*/
		914	void page_table_lock(as_t *as, bool lock)
		915	{
		916	ASSERT(as_operations);
		917	ASSERT(as_operations->page_table_lock);
		918
		919	as_operations->page_table_lock(as, lock);
		920	}
		921
		922	/** Unlock page table.
		923	*
		924	* @param as Address space.
1248	jermar	925	* @param unlock If false, do not attempt to unlock as->lock.
1044	jermar	926	*/
		927	void page_table_unlock(as_t *as, bool unlock)
		928	{
		929	ASSERT(as_operations);
		930	ASSERT(as_operations->page_table_unlock);
		931
		932	as_operations->page_table_unlock(as, unlock);
		933	}
		934
977	jermar	935
		936	/** Find address space area and lock it.
		937	*
		938	* The address space must be locked and interrupts must be disabled.
		939	*
		940	* @param as Address space.
		941	* @param va Virtual address.
		942	*
		943	* @return Locked address space area containing va on success or NULL on failure.
		944	*/
		945	as_area_t find_area_and_lock(as_t as, __address va)
		946	{
		947	as_area_t *a;
1147	jermar	948	btree_node_t leaf, lnode;
		949	int i;
977	jermar	950
1147	jermar	951	a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
		952	if (a) {
		953	/* va is the base address of an address space area */
1380	jermar	954	mutex_lock(&a->lock);
1147	jermar	955	return a;
		956	}
		957
		958	/*
1150	jermar	959	* Search the leaf node and the righmost record of its left neighbour
1147	jermar	960	* to find out whether this is a miss or va belongs to an address
		961	* space area found there.
		962	*/
		963
		964	/* First, search the leaf node itself. */
		965	for (i = 0; i < leaf->keys; i++) {
		966	a = (as_area_t *) leaf->value[i];
1380	jermar	967	mutex_lock(&a->lock);
1147	jermar	968	if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
		969	return a;
		970	}
1380	jermar	971	mutex_unlock(&a->lock);
1147	jermar	972	}
977	jermar	973
1147	jermar	974	/*
1150	jermar	975	* Second, locate the left neighbour and test its last record.
1148	jermar	976	* Because of its position in the B+tree, it must have base < va.
1147	jermar	977	*/
1150	jermar	978	if ((lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	979	a = (as_area_t *) lnode->value[lnode->keys - 1];
1380	jermar	980	mutex_lock(&a->lock);
1147	jermar	981	if (va < a->base + a->pages * PAGE_SIZE) {
1048	jermar	982	return a;
1147	jermar	983	}
1380	jermar	984	mutex_unlock(&a->lock);
977	jermar	985	}
		986
		987	return NULL;
		988	}
1048	jermar	989
		990	/** Check area conflicts with other areas.
		991	*
		992	* The address space must be locked and interrupts must be disabled.
		993	*
		994	* @param as Address space.
		995	* @param va Starting virtual address of the area being tested.
		996	* @param size Size of the area being tested.
		997	* @param avoid_area Do not touch this area.
		998	*
		999	* @return True if there is no conflict, false otherwise.
		1000	*/
		1001	bool check_area_conflicts(as_t as, __address va, size_t size, as_area_t avoid_area)
		1002	{
		1003	as_area_t *a;
1147	jermar	1004	btree_node_t leaf, node;
		1005	int i;
1048	jermar	1006
1070	jermar	1007	/*
		1008	* We don't want any area to have conflicts with NULL page.
		1009	*/
		1010	if (overlaps(va, size, NULL, PAGE_SIZE))
		1011	return false;
		1012
1147	jermar	1013	/*
		1014	* The leaf node is found in O(log n), where n is proportional to
		1015	* the number of address space areas belonging to as.
		1016	* The check for conflicts is then attempted on the rightmost
1150	jermar	1017	* record in the left neighbour, the leftmost record in the right
		1018	* neighbour and all records in the leaf node itself.
1147	jermar	1019	*/
1048	jermar	1020
1147	jermar	1021	if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
		1022	if (a != avoid_area)
		1023	return false;
		1024	}
		1025
		1026	/* First, check the two border cases. */
1150	jermar	1027	if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	1028	a = (as_area_t *) node->value[node->keys - 1];
1380	jermar	1029	mutex_lock(&a->lock);
1147	jermar	1030	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1031	mutex_unlock(&a->lock);
1147	jermar	1032	return false;
		1033	}
1380	jermar	1034	mutex_unlock(&a->lock);
1147	jermar	1035	}
1150	jermar	1036	if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	1037	a = (as_area_t *) node->value[0];
1380	jermar	1038	mutex_lock(&a->lock);
1147	jermar	1039	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1040	mutex_unlock(&a->lock);
1147	jermar	1041	return false;
		1042	}
1380	jermar	1043	mutex_unlock(&a->lock);
1147	jermar	1044	}
		1045
		1046	/* Second, check the leaf node. */
		1047	for (i = 0; i < leaf->keys; i++) {
		1048	a = (as_area_t *) leaf->value[i];
		1049
1048	jermar	1050	if (a == avoid_area)
		1051	continue;
1147	jermar	1052
1380	jermar	1053	mutex_lock(&a->lock);
1147	jermar	1054	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1055	mutex_unlock(&a->lock);
1147	jermar	1056	return false;
		1057	}
1380	jermar	1058	mutex_unlock(&a->lock);
1048	jermar	1059	}
		1060
1070	jermar	1061	/*
		1062	* So far, the area does not conflict with other areas.
		1063	* Check if it doesn't conflict with kernel address space.
		1064	*/
		1065	if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
		1066	return !overlaps(va, size,
		1067	KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START);
		1068	}
		1069
1048	jermar	1070	return true;
		1071	}
1235	jermar	1072
1380	jermar	1073	/** Return size of the address space area with given base. */
1329	palkovsky	1074	size_t as_get_size(__address base)
		1075	{
		1076	ipl_t ipl;
		1077	as_area_t *src_area;
		1078	size_t size;
		1079
		1080	ipl = interrupts_disable();
		1081	src_area = find_area_and_lock(AS, base);
		1082	if (src_area){
		1083	size = src_area->pages * PAGE_SIZE;
1380	jermar	1084	mutex_unlock(&src_area->lock);
1329	palkovsky	1085	} else {
		1086	size = 0;
		1087	}
		1088	interrupts_restore(ipl);
		1089	return size;
		1090	}
		1091
1387	jermar	1092	/** Mark portion of address space area as used.
		1093	*
		1094	* The address space area must be already locked.
		1095	*
		1096	* @param a Address space area.
		1097	* @param page First page to be marked.
		1098	* @param count Number of page to be marked.
		1099	*
		1100	* @return 0 on failure and 1 on success.
		1101	*/
		1102	int used_space_insert(as_area_t *a, __address page, count_t count)
		1103	{
		1104	btree_node_t leaf, node;
		1105	count_t pages;
		1106	int i;
		1107
		1108	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1109	ASSERT(count);
		1110
		1111	pages = (count_t) btree_search(&a->used_space, page, &leaf);
		1112	if (pages) {
		1113	/*
		1114	* We hit the beginning of some used space.
		1115	*/
		1116	return 0;
		1117	}
		1118
1437	jermar	1119	if (!leaf->keys) {
		1120	btree_insert(&a->used_space, page, (void *) count, leaf);
		1121	return 1;
		1122	}
		1123
1387	jermar	1124	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1125	if (node) {
		1126	__address left_pg = node->key[node->keys - 1], right_pg = leaf->key[0];
		1127	count_t left_cnt = (count_t) node->value[node->keys - 1], right_cnt = (count_t) leaf->value[0];
		1128
		1129	/*
		1130	* Examine the possibility that the interval fits
		1131	* somewhere between the rightmost interval of
		1132	* the left neigbour and the first interval of the leaf.
		1133	*/
		1134
		1135	if (page >= right_pg) {
		1136	/* Do nothing. */
		1137	} else if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1138	/* The interval intersects with the left interval. */
		1139	return 0;
		1140	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1141	/* The interval intersects with the right interval. */
		1142	return 0;
		1143	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1144	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1145	node->value[node->keys - 1] += count + right_cnt;
1387	jermar	1146	btree_remove(&a->used_space, right_pg, leaf);
		1147	return 1;
		1148	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1149	/* The interval can be added by simply growing the left interval. */
1403	jermar	1150	node->value[node->keys - 1] += count;
1387	jermar	1151	return 1;
		1152	} else if (page + count*PAGE_SIZE == right_pg) {
		1153	/*
		1154	* The interval can be addded by simply moving base of the right
		1155	* interval down and increasing its size accordingly.
		1156	*/
1403	jermar	1157	leaf->value[0] += count;
1387	jermar	1158	leaf->key[0] = page;
		1159	return 1;
		1160	} else {
		1161	/*
		1162	* The interval is between both neigbouring intervals,
		1163	* but cannot be merged with any of them.
		1164	*/
		1165	btree_insert(&a->used_space, page, (void *) count, leaf);
		1166	return 1;
		1167	}
		1168	} else if (page < leaf->key[0]) {
		1169	__address right_pg = leaf->key[0];
		1170	count_t right_cnt = (count_t) leaf->value[0];
		1171
		1172	/*
		1173	* Investigate the border case in which the left neighbour does not
		1174	* exist but the interval fits from the left.
		1175	*/
		1176
		1177	if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1178	/* The interval intersects with the right interval. */
		1179	return 0;
		1180	} else if (page + count*PAGE_SIZE == right_pg) {
		1181	/*
		1182	* The interval can be added by moving the base of the right interval down
		1183	* and increasing its size accordingly.
		1184	*/
		1185	leaf->key[0] = page;
1403	jermar	1186	leaf->value[0] += count;
1387	jermar	1187	return 1;
		1188	} else {
		1189	/*
		1190	* The interval doesn't adjoin with the right interval.
		1191	* It must be added individually.
		1192	*/
		1193	btree_insert(&a->used_space, page, (void *) count, leaf);
		1194	return 1;
		1195	}
		1196	}
		1197
		1198	node = btree_leaf_node_right_neighbour(&a->used_space, leaf);
		1199	if (node) {
		1200	__address left_pg = leaf->key[leaf->keys - 1], right_pg = node->key[0];
		1201	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1], right_cnt = (count_t) node->value[0];
		1202
		1203	/*
		1204	* Examine the possibility that the interval fits
		1205	* somewhere between the leftmost interval of
		1206	* the right neigbour and the last interval of the leaf.
		1207	*/
		1208
		1209	if (page < left_pg) {
		1210	/* Do nothing. */
		1211	} else if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1212	/* The interval intersects with the left interval. */
		1213	return 0;
		1214	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1215	/* The interval intersects with the right interval. */
		1216	return 0;
		1217	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1218	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1219	leaf->value[leaf->keys - 1] += count + right_cnt;
1387	jermar	1220	btree_remove(&a->used_space, right_pg, node);
		1221	return 1;
		1222	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1223	/* The interval can be added by simply growing the left interval. */
1403	jermar	1224	leaf->value[leaf->keys - 1] += count;
1387	jermar	1225	return 1;
		1226	} else if (page + count*PAGE_SIZE == right_pg) {
		1227	/*
		1228	* The interval can be addded by simply moving base of the right
		1229	* interval down and increasing its size accordingly.
		1230	*/
1403	jermar	1231	node->value[0] += count;
1387	jermar	1232	node->key[0] = page;
		1233	return 1;
		1234	} else {
		1235	/*
		1236	* The interval is between both neigbouring intervals,
		1237	* but cannot be merged with any of them.
		1238	*/
		1239	btree_insert(&a->used_space, page, (void *) count, leaf);
		1240	return 1;
		1241	}
		1242	} else if (page >= leaf->key[leaf->keys - 1]) {
		1243	__address left_pg = leaf->key[leaf->keys - 1];
		1244	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1245
		1246	/*
		1247	* Investigate the border case in which the right neighbour does not
		1248	* exist but the interval fits from the right.
		1249	*/
		1250
		1251	if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
1403	jermar	1252	/* The interval intersects with the left interval. */
1387	jermar	1253	return 0;
		1254	} else if (left_pg + left_cnt*PAGE_SIZE == page) {
		1255	/* The interval can be added by growing the left interval. */
1403	jermar	1256	leaf->value[leaf->keys - 1] += count;
1387	jermar	1257	return 1;
		1258	} else {
		1259	/*
		1260	* The interval doesn't adjoin with the left interval.
		1261	* It must be added individually.
		1262	*/
		1263	btree_insert(&a->used_space, page, (void *) count, leaf);
		1264	return 1;
		1265	}
		1266	}
		1267
		1268	/*
		1269	* Note that if the algorithm made it thus far, the interval can fit only
		1270	* between two other intervals of the leaf. The two border cases were already
		1271	* resolved.
		1272	*/
		1273	for (i = 1; i < leaf->keys; i++) {
		1274	if (page < leaf->key[i]) {
		1275	__address left_pg = leaf->key[i - 1], right_pg = leaf->key[i];
		1276	count_t left_cnt = (count_t) leaf->value[i - 1], right_cnt = (count_t) leaf->value[i];
		1277
		1278	/*
		1279	* The interval fits between left_pg and right_pg.
		1280	*/
		1281
		1282	if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1283	/* The interval intersects with the left interval. */
		1284	return 0;
		1285	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1286	/* The interval intersects with the right interval. */
		1287	return 0;
		1288	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1289	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1290	leaf->value[i - 1] += count + right_cnt;
1387	jermar	1291	btree_remove(&a->used_space, right_pg, leaf);
		1292	return 1;
		1293	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1294	/* The interval can be added by simply growing the left interval. */
1403	jermar	1295	leaf->value[i - 1] += count;
1387	jermar	1296	return 1;
		1297	} else if (page + count*PAGE_SIZE == right_pg) {
		1298	/*
		1299	* The interval can be addded by simply moving base of the right
		1300	* interval down and increasing its size accordingly.
		1301	*/
1403	jermar	1302	leaf->value[i] += count;
1387	jermar	1303	leaf->key[i] = page;
		1304	return 1;
		1305	} else {
		1306	/*
		1307	* The interval is between both neigbouring intervals,
		1308	* but cannot be merged with any of them.
		1309	*/
		1310	btree_insert(&a->used_space, page, (void *) count, leaf);
		1311	return 1;
		1312	}
		1313	}
		1314	}
		1315
1735	decky	1316	panic("Inconsistency detected while adding %d pages of used space at %p.\n", count, page);
1387	jermar	1317	}
		1318
		1319	/** Mark portion of address space area as unused.
		1320	*
		1321	* The address space area must be already locked.
		1322	*
		1323	* @param a Address space area.
		1324	* @param page First page to be marked.
		1325	* @param count Number of page to be marked.
		1326	*
		1327	* @return 0 on failure and 1 on success.
		1328	*/
		1329	int used_space_remove(as_area_t *a, __address page, count_t count)
		1330	{
		1331	btree_node_t leaf, node;
		1332	count_t pages;
		1333	int i;
		1334
		1335	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1336	ASSERT(count);
		1337
		1338	pages = (count_t) btree_search(&a->used_space, page, &leaf);
		1339	if (pages) {
		1340	/*
		1341	* We are lucky, page is the beginning of some interval.
		1342	*/
		1343	if (count > pages) {
		1344	return 0;
		1345	} else if (count == pages) {
		1346	btree_remove(&a->used_space, page, leaf);
1403	jermar	1347	return 1;
1387	jermar	1348	} else {
		1349	/*
		1350	* Find the respective interval.
		1351	* Decrease its size and relocate its start address.
		1352	*/
		1353	for (i = 0; i < leaf->keys; i++) {
		1354	if (leaf->key[i] == page) {
		1355	leaf->key[i] += count*PAGE_SIZE;
1403	jermar	1356	leaf->value[i] -= count;
1387	jermar	1357	return 1;
		1358	}
		1359	}
		1360	goto error;
		1361	}
		1362	}
		1363
		1364	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1365	if (node && page < leaf->key[0]) {
		1366	__address left_pg = node->key[node->keys - 1];
		1367	count_t left_cnt = (count_t) node->value[node->keys - 1];
		1368
		1369	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1370	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1371	/*
		1372	* The interval is contained in the rightmost interval
		1373	* of the left neighbour and can be removed by
		1374	* updating the size of the bigger interval.
		1375	*/
1403	jermar	1376	node->value[node->keys - 1] -= count;
1387	jermar	1377	return 1;
		1378	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1379	count_t new_cnt;
1387	jermar	1380
		1381	/*
		1382	* The interval is contained in the rightmost interval
		1383	* of the left neighbour but its removal requires
		1384	* both updating the size of the original interval and
		1385	* also inserting a new interval.
		1386	*/
1403	jermar	1387	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1388	node->value[node->keys - 1] -= count + new_cnt;
1387	jermar	1389	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1390	return 1;
		1391	}
		1392	}
		1393	return 0;
		1394	} else if (page < leaf->key[0]) {
		1395	return 0;
		1396	}
		1397
		1398	if (page > leaf->key[leaf->keys - 1]) {
		1399	__address left_pg = leaf->key[leaf->keys - 1];
		1400	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1401
		1402	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1403	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1404	/*
		1405	* The interval is contained in the rightmost interval
		1406	* of the leaf and can be removed by updating the size
		1407	* of the bigger interval.
		1408	*/
1403	jermar	1409	leaf->value[leaf->keys - 1] -= count;
1387	jermar	1410	return 1;
		1411	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1412	count_t new_cnt;
1387	jermar	1413
		1414	/*
		1415	* The interval is contained in the rightmost interval
		1416	* of the leaf but its removal requires both updating
		1417	* the size of the original interval and
		1418	* also inserting a new interval.
		1419	*/
1403	jermar	1420	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1421	leaf->value[leaf->keys - 1] -= count + new_cnt;
1387	jermar	1422	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1423	return 1;
		1424	}
		1425	}
		1426	return 0;
		1427	}
		1428
		1429	/*
		1430	* The border cases have been already resolved.
		1431	* Now the interval can be only between intervals of the leaf.
		1432	*/
		1433	for (i = 1; i < leaf->keys - 1; i++) {
		1434	if (page < leaf->key[i]) {
		1435	__address left_pg = leaf->key[i - 1];
		1436	count_t left_cnt = (count_t) leaf->value[i - 1];
		1437
		1438	/*
		1439	* Now the interval is between intervals corresponding to (i - 1) and i.
		1440	*/
		1441	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1442	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1443	/*
		1444	* The interval is contained in the interval (i - 1)
		1445	* of the leaf and can be removed by updating the size
		1446	* of the bigger interval.
		1447	*/
1403	jermar	1448	leaf->value[i - 1] -= count;
1387	jermar	1449	return 1;
		1450	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1451	count_t new_cnt;
1387	jermar	1452
		1453	/*
		1454	* The interval is contained in the interval (i - 1)
		1455	* of the leaf but its removal requires both updating
		1456	* the size of the original interval and
		1457	* also inserting a new interval.
		1458	*/
1403	jermar	1459	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1460	leaf->value[i - 1] -= count + new_cnt;
1387	jermar	1461	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1462	return 1;
		1463	}
		1464	}
		1465	return 0;
		1466	}
		1467	}
		1468
		1469	error:
1735	decky	1470	panic("Inconsistency detected while removing %d pages of used space from %p.\n", count, page);
1387	jermar	1471	}
		1472
1409	jermar	1473	/** Remove reference to address space area share info.
		1474	*
		1475	* If the reference count drops to 0, the sh_info is deallocated.
		1476	*
		1477	* @param sh_info Pointer to address space area share info.
		1478	*/
		1479	void sh_info_remove_reference(share_info_t *sh_info)
		1480	{
		1481	bool dealloc = false;
		1482
		1483	mutex_lock(&sh_info->lock);
		1484	ASSERT(sh_info->refcount);
		1485	if (--sh_info->refcount == 0) {
		1486	dealloc = true;
1495	jermar	1487	link_t *cur;
1409	jermar	1488
		1489	/*
		1490	* Now walk carefully the pagemap B+tree and free/remove
		1491	* reference from all frames found there.
		1492	*/
1495	jermar	1493	for (cur = sh_info->pagemap.leaf_head.next; cur != &sh_info->pagemap.leaf_head; cur = cur->next) {
1409	jermar	1494	btree_node_t *node;
1495	jermar	1495	int i;
1409	jermar	1496
1495	jermar	1497	node = list_get_instance(cur, btree_node_t, leaf_link);
		1498	for (i = 0; i < node->keys; i++)
1760	palkovsky	1499	frame_free((__address) node->value[i]);
1409	jermar	1500	}
		1501
		1502	}
		1503	mutex_unlock(&sh_info->lock);
		1504
		1505	if (dealloc) {
		1506	btree_destroy(&sh_info->pagemap);
		1507	free(sh_info);
		1508	}
		1509	}
		1510
1235	jermar	1511	/*
		1512	* Address space related syscalls.
		1513	*/
		1514
		1515	/** Wrapper for as_area_create(). */
		1516	__native sys_as_area_create(__address address, size_t size, int flags)
		1517	{
1424	jermar	1518	if (as_area_create(AS, flags \| AS_AREA_CACHEABLE, size, address, AS_AREA_ATTR_NONE, &anon_backend, NULL))
1235	jermar	1519	return (__native) address;
		1520	else
		1521	return (__native) -1;
		1522	}
		1523
		1524	/** Wrapper for as_area_resize. */
		1525	__native sys_as_area_resize(__address address, size_t size, int flags)
		1526	{
1306	jermar	1527	return (__native) as_area_resize(AS, address, size, 0);
1235	jermar	1528	}
		1529
1306	jermar	1530	/** Wrapper for as_area_destroy. */
		1531	__native sys_as_area_destroy(__address address)
		1532	{
		1533	return (__native) as_area_destroy(AS, address);
		1534	}
1702	cejka	1535
1757	jermar	1536	/** @}
1702	cejka	1537	*/

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(root)//kernel/trunk/generic/src/mm/as.c – Rev 1760