WebSVN – HelenOS – Blame – /trunk/kernel/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
1890	jermar	87	/**
		88	* Slab for as_t objects.
		89	*/
		90	static slab_cache_t *as_slab;
		91
1415	jermar	92	/** This lock protects inactive_as_with_asid_head list. It must be acquired before as_t mutex. */
		93	SPINLOCK_INITIALIZE(inactive_as_with_asid_lock);
823	jermar	94
		95	/**
		96	* This list contains address spaces that are not active on any
		97	* processor and that have valid ASID.
		98	*/
		99	LIST_INITIALIZE(inactive_as_with_asid_head);
		100
757	jermar	101	/** Kernel address space. */
		102	as_t *AS_KERNEL = NULL;
		103
1235	jermar	104	static int area_flags_to_page_flags(int aflags);
1780	jermar	105	static as_area_t find_area_and_lock(as_t as, uintptr_t va);
		106	static bool check_area_conflicts(as_t as, uintptr_t va, size_t size, as_area_t avoid_area);
1409	jermar	107	static void sh_info_remove_reference(share_info_t *sh_info);
703	jermar	108
756	jermar	109	/** Initialize address space subsystem. */
		110	void as_init(void)
		111	{
		112	as_arch_init();
1890	jermar	113
		114	as_slab = slab_cache_create("as_slab", sizeof(as_t), 0, NULL, NULL, SLAB_CACHE_MAGDEFERRED);
		115
789	palkovsky	116	AS_KERNEL = as_create(FLAG_AS_KERNEL);
1383	decky	117	if (!AS_KERNEL)
		118	panic("can't create kernel address space\n");
		119
756	jermar	120	}
		121
757	jermar	122	/** Create address space.
		123	*
		124	* @param flags Flags that influence way in wich the address space is created.
		125	*/
756	jermar	126	as_t *as_create(int flags)
703	jermar	127	{
		128	as_t *as;
		129
1890	jermar	130	as = (as_t *) slab_alloc(as_slab, 0);
823	jermar	131	link_initialize(&as->inactive_as_with_asid_link);
1380	jermar	132	mutex_initialize(&as->lock);
1147	jermar	133	btree_create(&as->as_area_btree);
822	palkovsky	134
		135	if (flags & FLAG_AS_KERNEL)
		136	as->asid = ASID_KERNEL;
		137	else
		138	as->asid = ASID_INVALID;
		139
1468	jermar	140	as->refcount = 0;
1415	jermar	141	as->cpu_refcount = 0;
822	palkovsky	142	as->page_table = page_table_create(flags);
703	jermar	143
		144	return as;
		145	}
		146
1468	jermar	147	/** Destroy adress space.
		148	*
		149	* When there are no tasks referencing this address space (i.e. its refcount is zero),
		150	* the address space can be destroyed.
		151	*/
		152	void as_destroy(as_t *as)
973	palkovsky	153	{
1468	jermar	154	ipl_t ipl;
1594	jermar	155	bool cond;
973	palkovsky	156
1468	jermar	157	ASSERT(as->refcount == 0);
		158
		159	/*
		160	* Since there is no reference to this area,
		161	* it is safe not to lock its mutex.
		162	*/
		163	ipl = interrupts_disable();
		164	spinlock_lock(&inactive_as_with_asid_lock);
1587	jermar	165	if (as->asid != ASID_INVALID && as != AS_KERNEL) {
1594	jermar	166	if (as != AS && as->cpu_refcount == 0)
1587	jermar	167	list_remove(&as->inactive_as_with_asid_link);
1468	jermar	168	asid_put(as->asid);
		169	}
		170	spinlock_unlock(&inactive_as_with_asid_lock);
		171
		172	/*
		173	* Destroy address space areas of the address space.
1594	jermar	174	* The B+tee must be walked carefully because it is
		175	* also being destroyed.
1468	jermar	176	*/
1594	jermar	177	for (cond = true; cond; ) {
1468	jermar	178	btree_node_t *node;
1594	jermar	179
		180	ASSERT(!list_empty(&as->as_area_btree.leaf_head));
		181	node = list_get_instance(as->as_area_btree.leaf_head.next, btree_node_t, leaf_link);
		182
		183	if ((cond = node->keys)) {
		184	as_area_destroy(as, node->key[0]);
		185	}
1468	jermar	186	}
1495	jermar	187
1483	jermar	188	btree_destroy(&as->as_area_btree);
1468	jermar	189	page_table_destroy(as->page_table);
		190
		191	interrupts_restore(ipl);
		192
1890	jermar	193	slab_free(as_slab, as);
973	palkovsky	194	}
		195
703	jermar	196	/** Create address space area of common attributes.
		197	*
		198	* The created address space area is added to the target address space.
		199	*
		200	* @param as Target address space.
1239	jermar	201	* @param flags Flags of the area memory.
1048	jermar	202	* @param size Size of area.
703	jermar	203	* @param base Base address of area.
1239	jermar	204	* @param attrs Attributes of the area.
1409	jermar	205	* @param backend Address space area backend. NULL if no backend is used.
		206	* @param backend_data NULL or a pointer to an array holding two void *.
703	jermar	207	*
		208	* @return Address space area on success or NULL on failure.
		209	*/
1780	jermar	210	as_area_t as_area_create(as_t as, int flags, size_t size, uintptr_t base, int attrs,
1424	jermar	211	mem_backend_t backend, mem_backend_data_t backend_data)
703	jermar	212	{
		213	ipl_t ipl;
		214	as_area_t *a;
		215
		216	if (base % PAGE_SIZE)
1048	jermar	217	return NULL;
		218
1233	jermar	219	if (!size)
		220	return NULL;
		221
1048	jermar	222	/* Writeable executable areas are not supported. */
		223	if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
		224	return NULL;
703	jermar	225
		226	ipl = interrupts_disable();
1380	jermar	227	mutex_lock(&as->lock);
703	jermar	228
1048	jermar	229	if (!check_area_conflicts(as, base, size, NULL)) {
1380	jermar	230	mutex_unlock(&as->lock);
1048	jermar	231	interrupts_restore(ipl);
		232	return NULL;
		233	}
703	jermar	234
822	palkovsky	235	a = (as_area_t *) malloc(sizeof(as_area_t), 0);
703	jermar	236
1380	jermar	237	mutex_initialize(&a->lock);
822	palkovsky	238
1424	jermar	239	a->as = as;
1026	jermar	240	a->flags = flags;
1239	jermar	241	a->attributes = attrs;
1048	jermar	242	a->pages = SIZE2FRAMES(size);
822	palkovsky	243	a->base = base;
1409	jermar	244	a->sh_info = NULL;
		245	a->backend = backend;
1424	jermar	246	if (backend_data)
		247	a->backend_data = *backend_data;
		248	else
1780	jermar	249	memsetb((uintptr_t) &a->backend_data, sizeof(a->backend_data), 0);
1424	jermar	250
1387	jermar	251	btree_create(&a->used_space);
822	palkovsky	252
1147	jermar	253	btree_insert(&as->as_area_btree, base, (void *) a, NULL);
822	palkovsky	254
1380	jermar	255	mutex_unlock(&as->lock);
703	jermar	256	interrupts_restore(ipl);
704	jermar	257
703	jermar	258	return a;
		259	}
		260
1235	jermar	261	/** Find address space area and change it.
		262	*
		263	* @param as Address space.
		264	* @param address Virtual address belonging to the area to be changed. Must be page-aligned.
		265	* @param size New size of the virtual memory block starting at address.
		266	* @param flags Flags influencing the remap operation. Currently unused.
		267	*
1306	jermar	268	* @return Zero on success or a value from @ref errno.h otherwise.
1235	jermar	269	*/
1780	jermar	270	int as_area_resize(as_t *as, uintptr_t address, size_t size, int flags)
1235	jermar	271	{
1306	jermar	272	as_area_t *area;
1235	jermar	273	ipl_t ipl;
		274	size_t pages;
		275
		276	ipl = interrupts_disable();
1380	jermar	277	mutex_lock(&as->lock);
1235	jermar	278
		279	/*
		280	* Locate the area.
		281	*/
		282	area = find_area_and_lock(as, address);
		283	if (!area) {
1380	jermar	284	mutex_unlock(&as->lock);
1235	jermar	285	interrupts_restore(ipl);
1306	jermar	286	return ENOENT;
1235	jermar	287	}
		288
1424	jermar	289	if (area->backend == &phys_backend) {
1235	jermar	290	/*
		291	* Remapping of address space areas associated
		292	* with memory mapped devices is not supported.
		293	*/
1380	jermar	294	mutex_unlock(&area->lock);
		295	mutex_unlock(&as->lock);
1235	jermar	296	interrupts_restore(ipl);
1306	jermar	297	return ENOTSUP;
1235	jermar	298	}
1409	jermar	299	if (area->sh_info) {
		300	/*
		301	* Remapping of shared address space areas
		302	* is not supported.
		303	*/
		304	mutex_unlock(&area->lock);
		305	mutex_unlock(&as->lock);
		306	interrupts_restore(ipl);
		307	return ENOTSUP;
		308	}
1235	jermar	309
		310	pages = SIZE2FRAMES((address - area->base) + size);
		311	if (!pages) {
		312	/*
		313	* Zero size address space areas are not allowed.
		314	*/
1380	jermar	315	mutex_unlock(&area->lock);
		316	mutex_unlock(&as->lock);
1235	jermar	317	interrupts_restore(ipl);
1306	jermar	318	return EPERM;
1235	jermar	319	}
		320
		321	if (pages < area->pages) {
1403	jermar	322	bool cond;
1780	jermar	323	uintptr_t start_free = area->base + pages*PAGE_SIZE;
1235	jermar	324
		325	/*
		326	* Shrinking the area.
		327	* No need to check for overlaps.
		328	*/
1403	jermar	329
		330	/*
1436	jermar	331	* Start TLB shootdown sequence.
		332	*/
		333	tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
		334
		335	/*
1403	jermar	336	* Remove frames belonging to used space starting from
		337	* the highest addresses downwards until an overlap with
		338	* the resized address space area is found. Note that this
		339	* is also the right way to remove part of the used_space
		340	* B+tree leaf list.
		341	*/
		342	for (cond = true; cond;) {
		343	btree_node_t *node;
		344
		345	ASSERT(!list_empty(&area->used_space.leaf_head));
		346	node = list_get_instance(area->used_space.leaf_head.prev, btree_node_t, leaf_link);
		347	if ((cond = (bool) node->keys)) {
1780	jermar	348	uintptr_t b = node->key[node->keys - 1];
1403	jermar	349	count_t c = (count_t) node->value[node->keys - 1];
		350	int i = 0;
1235	jermar	351
1403	jermar	352	if (overlaps(b, cPAGE_SIZE, area->base, pagesPAGE_SIZE)) {
		353
		354	if (b + c*PAGE_SIZE <= start_free) {
		355	/*
		356	* The whole interval fits completely
		357	* in the resized address space area.
		358	*/
		359	break;
		360	}
		361
		362	/*
		363	* Part of the interval corresponding to b and c
		364	* overlaps with the resized address space area.
		365	*/
		366
		367	cond = false; /* we are almost done */
		368	i = (start_free - b) >> PAGE_WIDTH;
		369	if (!used_space_remove(area, start_free, c - i))
1889	jermar	370	panic("Could not remove used space.\n");
1403	jermar	371	} else {
		372	/*
		373	* The interval of used space can be completely removed.
		374	*/
		375	if (!used_space_remove(area, b, c))
		376	panic("Could not remove used space.\n");
		377	}
		378
		379	for (; i < c; i++) {
		380	pte_t *pte;
		381
		382	page_table_lock(as, false);
		383	pte = page_mapping_find(as, b + i*PAGE_SIZE);
		384	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424	jermar	385	if (area->backend && area->backend->frame_free) {
		386	area->backend->frame_free(area,
1409	jermar	387	b + i*PAGE_SIZE, PTE_GET_FRAME(pte));
		388	}
1403	jermar	389	page_mapping_remove(as, b + i*PAGE_SIZE);
		390	page_table_unlock(as, false);
		391	}
1235	jermar	392	}
		393	}
1436	jermar	394
1235	jermar	395	/*
1436	jermar	396	* Finish TLB shootdown sequence.
1235	jermar	397	*/
		398	tlb_invalidate_pages(AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
		399	tlb_shootdown_finalize();
1889	jermar	400
		401	/*
		402	* Invalidate software translation caches (e.g. TSB on sparc64).
		403	*/
		404	as_invalidate_translation_cache(as, area->base + pages*PAGE_SIZE, area->pages - pages);
1235	jermar	405	} else {
		406	/*
		407	* Growing the area.
		408	* Check for overlaps with other address space areas.
		409	*/
		410	if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {
1380	jermar	411	mutex_unlock(&area->lock);
		412	mutex_unlock(&as->lock);
1235	jermar	413	interrupts_restore(ipl);
1306	jermar	414	return EADDRNOTAVAIL;
1235	jermar	415	}
		416	}
		417
		418	area->pages = pages;
		419
1380	jermar	420	mutex_unlock(&area->lock);
		421	mutex_unlock(&as->lock);
1235	jermar	422	interrupts_restore(ipl);
		423
1306	jermar	424	return 0;
1235	jermar	425	}
		426
1306	jermar	427	/** Destroy address space area.
		428	*
		429	* @param as Address space.
		430	* @param address Address withing the area to be deleted.
		431	*
		432	* @return Zero on success or a value from @ref errno.h on failure.
		433	*/
1780	jermar	434	int as_area_destroy(as_t *as, uintptr_t address)
1306	jermar	435	{
		436	as_area_t *area;
1780	jermar	437	uintptr_t base;
1495	jermar	438	link_t *cur;
1306	jermar	439	ipl_t ipl;
		440
		441	ipl = interrupts_disable();
1380	jermar	442	mutex_lock(&as->lock);
1306	jermar	443
		444	area = find_area_and_lock(as, address);
		445	if (!area) {
1380	jermar	446	mutex_unlock(&as->lock);
1306	jermar	447	interrupts_restore(ipl);
		448	return ENOENT;
		449	}
		450
1403	jermar	451	base = area->base;
		452
1411	jermar	453	/*
1436	jermar	454	* Start TLB shootdown sequence.
		455	*/
1889	jermar	456	tlb_shootdown_start(TLB_INVL_PAGES, as->asid, area->base, area->pages);
1436	jermar	457
		458	/*
1411	jermar	459	* Visit only the pages mapped by used_space B+tree.
		460	*/
1495	jermar	461	for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {
1411	jermar	462	btree_node_t *node;
1495	jermar	463	int i;
1403	jermar	464
1495	jermar	465	node = list_get_instance(cur, btree_node_t, leaf_link);
		466	for (i = 0; i < node->keys; i++) {
1780	jermar	467	uintptr_t b = node->key[i];
1495	jermar	468	count_t j;
1411	jermar	469	pte_t *pte;
1403	jermar	470
1495	jermar	471	for (j = 0; j < (count_t) node->value[i]; j++) {
1411	jermar	472	page_table_lock(as, false);
1495	jermar	473	pte = page_mapping_find(as, b + j*PAGE_SIZE);
1411	jermar	474	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424	jermar	475	if (area->backend && area->backend->frame_free) {
		476	area->backend->frame_free(area,
1495	jermar	477	b + j*PAGE_SIZE, PTE_GET_FRAME(pte));
1403	jermar	478	}
1889	jermar	479	page_mapping_remove(as, b + j*PAGE_SIZE);
1411	jermar	480	page_table_unlock(as, false);
1306	jermar	481	}
		482	}
		483	}
1403	jermar	484
1306	jermar	485	/*
1436	jermar	486	* Finish TLB shootdown sequence.
1306	jermar	487	*/
1889	jermar	488	tlb_invalidate_pages(as->asid, area->base, area->pages);
1306	jermar	489	tlb_shootdown_finalize();
1436	jermar	490
1889	jermar	491	/*
		492	* Invalidate potential software translation caches (e.g. TSB on sparc64).
		493	*/
		494	as_invalidate_translation_cache(as, area->base, area->pages);
		495
1436	jermar	496	btree_destroy(&area->used_space);
1306	jermar	497
1309	jermar	498	area->attributes \|= AS_AREA_ATTR_PARTIAL;
1409	jermar	499
		500	if (area->sh_info)
		501	sh_info_remove_reference(area->sh_info);
		502
1380	jermar	503	mutex_unlock(&area->lock);
1306	jermar	504
		505	/*
		506	* Remove the empty area from address space.
		507	*/
1889	jermar	508	btree_remove(&as->as_area_btree, base, NULL);
1306	jermar	509
1309	jermar	510	free(area);
		511
1889	jermar	512	mutex_unlock(&as->lock);
1306	jermar	513	interrupts_restore(ipl);
		514	return 0;
		515	}
		516
1413	jermar	517	/** Share address space area with another or the same address space.
1235	jermar	518	*
1424	jermar	519	* Address space area mapping is shared with a new address space area.
		520	* If the source address space area has not been shared so far,
		521	* a new sh_info is created. The new address space area simply gets the
		522	* sh_info of the source area. The process of duplicating the
		523	* mapping is done through the backend share function.
1413	jermar	524	*
1417	jermar	525	* @param src_as Pointer to source address space.
1239	jermar	526	* @param src_base Base address of the source address space area.
1417	jermar	527	* @param acc_size Expected size of the source area.
1428	palkovsky	528	* @param dst_as Pointer to destination address space.
1417	jermar	529	* @param dst_base Target base address.
		530	* @param dst_flags_mask Destination address space area flags mask.
1235	jermar	531	*
1306	jermar	532	* @return Zero on success or ENOENT if there is no such task or
1235	jermar	533	* if there is no such address space area,
		534	* EPERM if there was a problem in accepting the area or
		535	* ENOMEM if there was a problem in allocating destination
1413	jermar	536	* address space area. ENOTSUP is returned if an attempt
		537	* to share non-anonymous address space area is detected.
1235	jermar	538	*/
1780	jermar	539	int as_area_share(as_t *src_as, uintptr_t src_base, size_t acc_size,
		540	as_t *dst_as, uintptr_t dst_base, int dst_flags_mask)
1235	jermar	541	{
		542	ipl_t ipl;
1239	jermar	543	int src_flags;
		544	size_t src_size;
		545	as_area_t src_area, dst_area;
1413	jermar	546	share_info_t *sh_info;
1424	jermar	547	mem_backend_t *src_backend;
		548	mem_backend_data_t src_backend_data;
1434	palkovsky	549
1235	jermar	550	ipl = interrupts_disable();
1380	jermar	551	mutex_lock(&src_as->lock);
1329	palkovsky	552	src_area = find_area_and_lock(src_as, src_base);
1239	jermar	553	if (!src_area) {
1238	jermar	554	/*
		555	* Could not find the source address space area.
		556	*/
1380	jermar	557	mutex_unlock(&src_as->lock);
1238	jermar	558	interrupts_restore(ipl);
		559	return ENOENT;
		560	}
1413	jermar	561
1424	jermar	562	if (!src_area->backend \|\| !src_area->backend->share) {
1413	jermar	563	/*
1851	jermar	564	* There is no backend or the backend does not
1424	jermar	565	* know how to share the area.
1413	jermar	566	*/
		567	mutex_unlock(&src_area->lock);
		568	mutex_unlock(&src_as->lock);
		569	interrupts_restore(ipl);
		570	return ENOTSUP;
		571	}
		572
1239	jermar	573	src_size = src_area->pages * PAGE_SIZE;
		574	src_flags = src_area->flags;
1424	jermar	575	src_backend = src_area->backend;
		576	src_backend_data = src_area->backend_data;
1544	palkovsky	577
		578	/* Share the cacheable flag from the original mapping */
		579	if (src_flags & AS_AREA_CACHEABLE)
		580	dst_flags_mask \|= AS_AREA_CACHEABLE;
		581
1461	palkovsky	582	if (src_size != acc_size \|\| (src_flags & dst_flags_mask) != dst_flags_mask) {
1413	jermar	583	mutex_unlock(&src_area->lock);
		584	mutex_unlock(&src_as->lock);
1235	jermar	585	interrupts_restore(ipl);
		586	return EPERM;
		587	}
1413	jermar	588
1235	jermar	589	/*
1413	jermar	590	* Now we are committed to sharing the area.
		591	* First prepare the area for sharing.
		592	* Then it will be safe to unlock it.
		593	*/
		594	sh_info = src_area->sh_info;
		595	if (!sh_info) {
		596	sh_info = (share_info_t *) malloc(sizeof(share_info_t), 0);
		597	mutex_initialize(&sh_info->lock);
		598	sh_info->refcount = 2;
		599	btree_create(&sh_info->pagemap);
		600	src_area->sh_info = sh_info;
		601	} else {
		602	mutex_lock(&sh_info->lock);
		603	sh_info->refcount++;
		604	mutex_unlock(&sh_info->lock);
		605	}
		606
1424	jermar	607	src_area->backend->share(src_area);
1413	jermar	608
		609	mutex_unlock(&src_area->lock);
		610	mutex_unlock(&src_as->lock);
		611
		612	/*
1239	jermar	613	* Create copy of the source address space area.
		614	* The destination area is created with AS_AREA_ATTR_PARTIAL
		615	* attribute set which prevents race condition with
		616	* preliminary as_page_fault() calls.
1417	jermar	617	* The flags of the source area are masked against dst_flags_mask
		618	* to support sharing in less privileged mode.
1235	jermar	619	*/
1461	palkovsky	620	dst_area = as_area_create(dst_as, dst_flags_mask, src_size, dst_base,
1424	jermar	621	AS_AREA_ATTR_PARTIAL, src_backend, &src_backend_data);
1239	jermar	622	if (!dst_area) {
1235	jermar	623	/*
		624	* Destination address space area could not be created.
		625	*/
1413	jermar	626	sh_info_remove_reference(sh_info);
		627
1235	jermar	628	interrupts_restore(ipl);
		629	return ENOMEM;
		630	}
		631
		632	/*
1239	jermar	633	* Now the destination address space area has been
		634	* fully initialized. Clear the AS_AREA_ATTR_PARTIAL
1413	jermar	635	* attribute and set the sh_info.
1239	jermar	636	*/
1380	jermar	637	mutex_lock(&dst_area->lock);
1239	jermar	638	dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
1413	jermar	639	dst_area->sh_info = sh_info;
1380	jermar	640	mutex_unlock(&dst_area->lock);
1235	jermar	641
		642	interrupts_restore(ipl);
		643
		644	return 0;
		645	}
		646
1423	jermar	647	/** Check access mode for address space area.
		648	*
		649	* The address space area must be locked prior to this call.
		650	*
		651	* @param area Address space area.
		652	* @param access Access mode.
		653	*
		654	* @return False if access violates area's permissions, true otherwise.
		655	*/
		656	bool as_area_check_access(as_area_t *area, pf_access_t access)
		657	{
		658	int flagmap[] = {
		659	[PF_ACCESS_READ] = AS_AREA_READ,
		660	[PF_ACCESS_WRITE] = AS_AREA_WRITE,
		661	[PF_ACCESS_EXEC] = AS_AREA_EXEC
		662	};
		663
		664	if (!(area->flags & flagmap[access]))
		665	return false;
		666
		667	return true;
		668	}
		669
703	jermar	670	/** Handle page fault within the current address space.
		671	*
1409	jermar	672	* This is the high-level page fault handler. It decides
		673	* whether the page fault can be resolved by any backend
		674	* and if so, it invokes the backend to resolve the page
		675	* fault.
		676	*
703	jermar	677	* Interrupts are assumed disabled.
		678	*
		679	* @param page Faulting page.
1411	jermar	680	* @param access Access mode that caused the fault (i.e. read/write/exec).
1288	jermar	681	* @param istate Pointer to interrupted state.
703	jermar	682	*
1409	jermar	683	* @return AS_PF_FAULT on page fault, AS_PF_OK on success or AS_PF_DEFER if the
		684	* fault was caused by copy_to_uspace() or copy_from_uspace().
703	jermar	685	*/
1780	jermar	686	int as_page_fault(uintptr_t page, pf_access_t access, istate_t *istate)
703	jermar	687	{
1044	jermar	688	pte_t *pte;
977	jermar	689	as_area_t *area;
703	jermar	690
1380	jermar	691	if (!THREAD)
1409	jermar	692	return AS_PF_FAULT;
1380	jermar	693
703	jermar	694	ASSERT(AS);
1044	jermar	695
1380	jermar	696	mutex_lock(&AS->lock);
977	jermar	697	area = find_area_and_lock(AS, page);
703	jermar	698	if (!area) {
		699	/*
		700	* No area contained mapping for 'page'.
		701	* Signal page fault to low-level handler.
		702	*/
1380	jermar	703	mutex_unlock(&AS->lock);
1288	jermar	704	goto page_fault;
703	jermar	705	}
		706
1239	jermar	707	if (area->attributes & AS_AREA_ATTR_PARTIAL) {
		708	/*
		709	* The address space area is not fully initialized.
		710	* Avoid possible race by returning error.
		711	*/
1380	jermar	712	mutex_unlock(&area->lock);
		713	mutex_unlock(&AS->lock);
1288	jermar	714	goto page_fault;
1239	jermar	715	}
		716
1424	jermar	717	if (!area->backend \|\| !area->backend->page_fault) {
1409	jermar	718	/*
		719	* The address space area is not backed by any backend
		720	* or the backend cannot handle page faults.
		721	*/
		722	mutex_unlock(&area->lock);
		723	mutex_unlock(&AS->lock);
		724	goto page_fault;
		725	}
1179	jermar	726
1044	jermar	727	page_table_lock(AS, false);
		728
703	jermar	729	/*
1044	jermar	730	* To avoid race condition between two page faults
		731	* on the same address, we need to make sure
		732	* the mapping has not been already inserted.
		733	*/
		734	if ((pte = page_mapping_find(AS, page))) {
		735	if (PTE_PRESENT(pte)) {
1423	jermar	736	if (((access == PF_ACCESS_READ) && PTE_READABLE(pte)) \|\|
		737	(access == PF_ACCESS_WRITE && PTE_WRITABLE(pte)) \|\|
		738	(access == PF_ACCESS_EXEC && PTE_EXECUTABLE(pte))) {
		739	page_table_unlock(AS, false);
		740	mutex_unlock(&area->lock);
		741	mutex_unlock(&AS->lock);
		742	return AS_PF_OK;
		743	}
1044	jermar	744	}
		745	}
1409	jermar	746
1044	jermar	747	/*
1409	jermar	748	* Resort to the backend page fault handler.
703	jermar	749	*/
1424	jermar	750	if (area->backend->page_fault(area, page, access) != AS_PF_OK) {
1409	jermar	751	page_table_unlock(AS, false);
		752	mutex_unlock(&area->lock);
		753	mutex_unlock(&AS->lock);
		754	goto page_fault;
		755	}
703	jermar	756
1044	jermar	757	page_table_unlock(AS, false);
1380	jermar	758	mutex_unlock(&area->lock);
		759	mutex_unlock(&AS->lock);
1288	jermar	760	return AS_PF_OK;
		761
		762	page_fault:
		763	if (THREAD->in_copy_from_uspace) {
		764	THREAD->in_copy_from_uspace = false;
1780	jermar	765	istate_set_retaddr(istate, (uintptr_t) &memcpy_from_uspace_failover_address);
1288	jermar	766	} else if (THREAD->in_copy_to_uspace) {
		767	THREAD->in_copy_to_uspace = false;
1780	jermar	768	istate_set_retaddr(istate, (uintptr_t) &memcpy_to_uspace_failover_address);
1288	jermar	769	} else {
		770	return AS_PF_FAULT;
		771	}
		772
		773	return AS_PF_DEFER;
703	jermar	774	}
		775
823	jermar	776	/** Switch address spaces.
703	jermar	777	*
1380	jermar	778	* Note that this function cannot sleep as it is essentially a part of
1415	jermar	779	* scheduling. Sleeping here would lead to deadlock on wakeup.
1380	jermar	780	*
823	jermar	781	* @param old Old address space or NULL.
		782	* @param new New address space.
703	jermar	783	*/
823	jermar	784	void as_switch(as_t old, as_t new)
703	jermar	785	{
		786	ipl_t ipl;
823	jermar	787	bool needs_asid = false;
703	jermar	788
		789	ipl = interrupts_disable();
1415	jermar	790	spinlock_lock(&inactive_as_with_asid_lock);
703	jermar	791
		792	/*
823	jermar	793	* First, take care of the old address space.
		794	*/
		795	if (old) {
1380	jermar	796	mutex_lock_active(&old->lock);
1415	jermar	797	ASSERT(old->cpu_refcount);
		798	if((--old->cpu_refcount == 0) && (old != AS_KERNEL)) {
823	jermar	799	/*
		800	* The old address space is no longer active on
		801	* any processor. It can be appended to the
		802	* list of inactive address spaces with assigned
		803	* ASID.
		804	*/
		805	ASSERT(old->asid != ASID_INVALID);
		806	list_append(&old->inactive_as_with_asid_link, &inactive_as_with_asid_head);
		807	}
1380	jermar	808	mutex_unlock(&old->lock);
1890	jermar	809
		810	/*
		811	* Perform architecture-specific tasks when the address space
		812	* is being removed from the CPU.
		813	*/
		814	as_deinstall_arch(old);
823	jermar	815	}
		816
		817	/*
		818	* Second, prepare the new address space.
		819	*/
1380	jermar	820	mutex_lock_active(&new->lock);
1415	jermar	821	if ((new->cpu_refcount++ == 0) && (new != AS_KERNEL)) {
823	jermar	822	if (new->asid != ASID_INVALID)
		823	list_remove(&new->inactive_as_with_asid_link);
		824	else
		825	needs_asid = true; /* defer call to asid_get() until new->lock is released */
		826	}
		827	SET_PTL0_ADDRESS(new->page_table);
1380	jermar	828	mutex_unlock(&new->lock);
823	jermar	829
		830	if (needs_asid) {
		831	/*
		832	* Allocation of new ASID was deferred
		833	* until now in order to avoid deadlock.
		834	*/
		835	asid_t asid;
		836
		837	asid = asid_get();
1380	jermar	838	mutex_lock_active(&new->lock);
823	jermar	839	new->asid = asid;
1380	jermar	840	mutex_unlock(&new->lock);
823	jermar	841	}
1415	jermar	842	spinlock_unlock(&inactive_as_with_asid_lock);
823	jermar	843	interrupts_restore(ipl);
		844
		845	/*
703	jermar	846	* Perform architecture-specific steps.
727	jermar	847	* (e.g. write ASID to hardware register etc.)
703	jermar	848	*/
823	jermar	849	as_install_arch(new);
703	jermar	850
823	jermar	851	AS = new;
703	jermar	852	}
754	jermar	853
1235	jermar	854	/** Convert address space area flags to page flags.
754	jermar	855	*
1235	jermar	856	* @param aflags Flags of some address space area.
754	jermar	857	*
1235	jermar	858	* @return Flags to be passed to page_mapping_insert().
754	jermar	859	*/
1235	jermar	860	int area_flags_to_page_flags(int aflags)
754	jermar	861	{
		862	int flags;
		863
1178	jermar	864	flags = PAGE_USER \| PAGE_PRESENT;
754	jermar	865
1235	jermar	866	if (aflags & AS_AREA_READ)
1026	jermar	867	flags \|= PAGE_READ;
		868
1235	jermar	869	if (aflags & AS_AREA_WRITE)
1026	jermar	870	flags \|= PAGE_WRITE;
		871
1235	jermar	872	if (aflags & AS_AREA_EXEC)
1026	jermar	873	flags \|= PAGE_EXEC;
		874
1424	jermar	875	if (aflags & AS_AREA_CACHEABLE)
1178	jermar	876	flags \|= PAGE_CACHEABLE;
		877
754	jermar	878	return flags;
		879	}
756	jermar	880
1235	jermar	881	/** Compute flags for virtual address translation subsytem.
		882	*
		883	* The address space area must be locked.
		884	* Interrupts must be disabled.
		885	*
		886	* @param a Address space area.
		887	*
		888	* @return Flags to be used in page_mapping_insert().
		889	*/
1409	jermar	890	int as_area_get_flags(as_area_t *a)
1235	jermar	891	{
		892	return area_flags_to_page_flags(a->flags);
		893	}
		894
756	jermar	895	/** Create page table.
		896	*
		897	* Depending on architecture, create either address space
		898	* private or global page table.
		899	*
		900	* @param flags Flags saying whether the page table is for kernel address space.
		901	*
		902	* @return First entry of the page table.
		903	*/
		904	pte_t *page_table_create(int flags)
		905	{
		906	ASSERT(as_operations);
		907	ASSERT(as_operations->page_table_create);
		908
		909	return as_operations->page_table_create(flags);
		910	}
977	jermar	911
1468	jermar	912	/** Destroy page table.
		913	*
		914	* Destroy page table in architecture specific way.
		915	*
		916	* @param page_table Physical address of PTL0.
		917	*/
		918	void page_table_destroy(pte_t *page_table)
		919	{
		920	ASSERT(as_operations);
		921	ASSERT(as_operations->page_table_destroy);
		922
		923	as_operations->page_table_destroy(page_table);
		924	}
		925
1044	jermar	926	/** Lock page table.
		927	*
		928	* This function should be called before any page_mapping_insert(),
		929	* page_mapping_remove() and page_mapping_find().
		930	*
		931	* Locking order is such that address space areas must be locked
		932	* prior to this call. Address space can be locked prior to this
		933	* call in which case the lock argument is false.
		934	*
		935	* @param as Address space.
1248	jermar	936	* @param lock If false, do not attempt to lock as->lock.
1044	jermar	937	*/
		938	void page_table_lock(as_t *as, bool lock)
		939	{
		940	ASSERT(as_operations);
		941	ASSERT(as_operations->page_table_lock);
		942
		943	as_operations->page_table_lock(as, lock);
		944	}
		945
		946	/** Unlock page table.
		947	*
		948	* @param as Address space.
1248	jermar	949	* @param unlock If false, do not attempt to unlock as->lock.
1044	jermar	950	*/
		951	void page_table_unlock(as_t *as, bool unlock)
		952	{
		953	ASSERT(as_operations);
		954	ASSERT(as_operations->page_table_unlock);
		955
		956	as_operations->page_table_unlock(as, unlock);
		957	}
		958
977	jermar	959
		960	/** Find address space area and lock it.
		961	*
		962	* The address space must be locked and interrupts must be disabled.
		963	*
		964	* @param as Address space.
		965	* @param va Virtual address.
		966	*
		967	* @return Locked address space area containing va on success or NULL on failure.
		968	*/
1780	jermar	969	as_area_t find_area_and_lock(as_t as, uintptr_t va)
977	jermar	970	{
		971	as_area_t *a;
1147	jermar	972	btree_node_t leaf, lnode;
		973	int i;
977	jermar	974
1147	jermar	975	a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
		976	if (a) {
		977	/* va is the base address of an address space area */
1380	jermar	978	mutex_lock(&a->lock);
1147	jermar	979	return a;
		980	}
		981
		982	/*
1150	jermar	983	* Search the leaf node and the righmost record of its left neighbour
1147	jermar	984	* to find out whether this is a miss or va belongs to an address
		985	* space area found there.
		986	*/
		987
		988	/* First, search the leaf node itself. */
		989	for (i = 0; i < leaf->keys; i++) {
		990	a = (as_area_t *) leaf->value[i];
1380	jermar	991	mutex_lock(&a->lock);
1147	jermar	992	if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
		993	return a;
		994	}
1380	jermar	995	mutex_unlock(&a->lock);
1147	jermar	996	}
977	jermar	997
1147	jermar	998	/*
1150	jermar	999	* Second, locate the left neighbour and test its last record.
1148	jermar	1000	* Because of its position in the B+tree, it must have base < va.
1147	jermar	1001	*/
1150	jermar	1002	if ((lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	1003	a = (as_area_t *) lnode->value[lnode->keys - 1];
1380	jermar	1004	mutex_lock(&a->lock);
1147	jermar	1005	if (va < a->base + a->pages * PAGE_SIZE) {
1048	jermar	1006	return a;
1147	jermar	1007	}
1380	jermar	1008	mutex_unlock(&a->lock);
977	jermar	1009	}
		1010
		1011	return NULL;
		1012	}
1048	jermar	1013
		1014	/** Check area conflicts with other areas.
		1015	*
		1016	* The address space must be locked and interrupts must be disabled.
		1017	*
		1018	* @param as Address space.
		1019	* @param va Starting virtual address of the area being tested.
		1020	* @param size Size of the area being tested.
		1021	* @param avoid_area Do not touch this area.
		1022	*
		1023	* @return True if there is no conflict, false otherwise.
		1024	*/
1780	jermar	1025	bool check_area_conflicts(as_t as, uintptr_t va, size_t size, as_area_t avoid_area)
1048	jermar	1026	{
		1027	as_area_t *a;
1147	jermar	1028	btree_node_t leaf, node;
		1029	int i;
1048	jermar	1030
1070	jermar	1031	/*
		1032	* We don't want any area to have conflicts with NULL page.
		1033	*/
		1034	if (overlaps(va, size, NULL, PAGE_SIZE))
		1035	return false;
		1036
1147	jermar	1037	/*
		1038	* The leaf node is found in O(log n), where n is proportional to
		1039	* the number of address space areas belonging to as.
		1040	* The check for conflicts is then attempted on the rightmost
1150	jermar	1041	* record in the left neighbour, the leftmost record in the right
		1042	* neighbour and all records in the leaf node itself.
1147	jermar	1043	*/
1048	jermar	1044
1147	jermar	1045	if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
		1046	if (a != avoid_area)
		1047	return false;
		1048	}
		1049
		1050	/* First, check the two border cases. */
1150	jermar	1051	if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	1052	a = (as_area_t *) node->value[node->keys - 1];
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);
1147	jermar	1059	}
1150	jermar	1060	if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	1061	a = (as_area_t *) node->value[0];
1380	jermar	1062	mutex_lock(&a->lock);
1147	jermar	1063	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1064	mutex_unlock(&a->lock);
1147	jermar	1065	return false;
		1066	}
1380	jermar	1067	mutex_unlock(&a->lock);
1147	jermar	1068	}
		1069
		1070	/* Second, check the leaf node. */
		1071	for (i = 0; i < leaf->keys; i++) {
		1072	a = (as_area_t *) leaf->value[i];
		1073
1048	jermar	1074	if (a == avoid_area)
		1075	continue;
1147	jermar	1076
1380	jermar	1077	mutex_lock(&a->lock);
1147	jermar	1078	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1079	mutex_unlock(&a->lock);
1147	jermar	1080	return false;
		1081	}
1380	jermar	1082	mutex_unlock(&a->lock);
1048	jermar	1083	}
		1084
1070	jermar	1085	/*
		1086	* So far, the area does not conflict with other areas.
		1087	* Check if it doesn't conflict with kernel address space.
		1088	*/
		1089	if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
		1090	return !overlaps(va, size,
		1091	KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START);
		1092	}
		1093
1048	jermar	1094	return true;
		1095	}
1235	jermar	1096
1380	jermar	1097	/** Return size of the address space area with given base. */
1780	jermar	1098	size_t as_get_size(uintptr_t base)
1329	palkovsky	1099	{
		1100	ipl_t ipl;
		1101	as_area_t *src_area;
		1102	size_t size;
		1103
		1104	ipl = interrupts_disable();
		1105	src_area = find_area_and_lock(AS, base);
		1106	if (src_area){
		1107	size = src_area->pages * PAGE_SIZE;
1380	jermar	1108	mutex_unlock(&src_area->lock);
1329	palkovsky	1109	} else {
		1110	size = 0;
		1111	}
		1112	interrupts_restore(ipl);
		1113	return size;
		1114	}
		1115
1387	jermar	1116	/** Mark portion of address space area as used.
		1117	*
		1118	* The address space area must be already locked.
		1119	*
		1120	* @param a Address space area.
		1121	* @param page First page to be marked.
		1122	* @param count Number of page to be marked.
		1123	*
		1124	* @return 0 on failure and 1 on success.
		1125	*/
1780	jermar	1126	int used_space_insert(as_area_t *a, uintptr_t page, count_t count)
1387	jermar	1127	{
		1128	btree_node_t leaf, node;
		1129	count_t pages;
		1130	int i;
		1131
		1132	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1133	ASSERT(count);
		1134
		1135	pages = (count_t) btree_search(&a->used_space, page, &leaf);
		1136	if (pages) {
		1137	/*
		1138	* We hit the beginning of some used space.
		1139	*/
		1140	return 0;
		1141	}
		1142
1437	jermar	1143	if (!leaf->keys) {
		1144	btree_insert(&a->used_space, page, (void *) count, leaf);
		1145	return 1;
		1146	}
		1147
1387	jermar	1148	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1149	if (node) {
1780	jermar	1150	uintptr_t left_pg = node->key[node->keys - 1], right_pg = leaf->key[0];
1387	jermar	1151	count_t left_cnt = (count_t) node->value[node->keys - 1], right_cnt = (count_t) leaf->value[0];
		1152
		1153	/*
		1154	* Examine the possibility that the interval fits
		1155	* somewhere between the rightmost interval of
		1156	* the left neigbour and the first interval of the leaf.
		1157	*/
		1158
		1159	if (page >= right_pg) {
		1160	/* Do nothing. */
		1161	} else if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1162	/* The interval intersects with the left interval. */
		1163	return 0;
		1164	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1165	/* The interval intersects with the right interval. */
		1166	return 0;
		1167	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1168	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1169	node->value[node->keys - 1] += count + right_cnt;
1387	jermar	1170	btree_remove(&a->used_space, right_pg, leaf);
		1171	return 1;
		1172	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1173	/* The interval can be added by simply growing the left interval. */
1403	jermar	1174	node->value[node->keys - 1] += count;
1387	jermar	1175	return 1;
		1176	} else if (page + count*PAGE_SIZE == right_pg) {
		1177	/*
		1178	* The interval can be addded by simply moving base of the right
		1179	* interval down and increasing its size accordingly.
		1180	*/
1403	jermar	1181	leaf->value[0] += count;
1387	jermar	1182	leaf->key[0] = page;
		1183	return 1;
		1184	} else {
		1185	/*
		1186	* The interval is between both neigbouring intervals,
		1187	* but cannot be merged with any of them.
		1188	*/
		1189	btree_insert(&a->used_space, page, (void *) count, leaf);
		1190	return 1;
		1191	}
		1192	} else if (page < leaf->key[0]) {
1780	jermar	1193	uintptr_t right_pg = leaf->key[0];
1387	jermar	1194	count_t right_cnt = (count_t) leaf->value[0];
		1195
		1196	/*
		1197	* Investigate the border case in which the left neighbour does not
		1198	* exist but the interval fits from the left.
		1199	*/
		1200
		1201	if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1202	/* The interval intersects with the right interval. */
		1203	return 0;
		1204	} else if (page + count*PAGE_SIZE == right_pg) {
		1205	/*
		1206	* The interval can be added by moving the base of the right interval down
		1207	* and increasing its size accordingly.
		1208	*/
		1209	leaf->key[0] = page;
1403	jermar	1210	leaf->value[0] += count;
1387	jermar	1211	return 1;
		1212	} else {
		1213	/*
		1214	* The interval doesn't adjoin with the right interval.
		1215	* It must be added individually.
		1216	*/
		1217	btree_insert(&a->used_space, page, (void *) count, leaf);
		1218	return 1;
		1219	}
		1220	}
		1221
		1222	node = btree_leaf_node_right_neighbour(&a->used_space, leaf);
		1223	if (node) {
1780	jermar	1224	uintptr_t left_pg = leaf->key[leaf->keys - 1], right_pg = node->key[0];
1387	jermar	1225	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1], right_cnt = (count_t) node->value[0];
		1226
		1227	/*
		1228	* Examine the possibility that the interval fits
		1229	* somewhere between the leftmost interval of
		1230	* the right neigbour and the last interval of the leaf.
		1231	*/
		1232
		1233	if (page < left_pg) {
		1234	/* Do nothing. */
		1235	} else if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1236	/* The interval intersects with the left interval. */
		1237	return 0;
		1238	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1239	/* The interval intersects with the right interval. */
		1240	return 0;
		1241	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1242	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1243	leaf->value[leaf->keys - 1] += count + right_cnt;
1387	jermar	1244	btree_remove(&a->used_space, right_pg, node);
		1245	return 1;
		1246	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1247	/* The interval can be added by simply growing the left interval. */
1403	jermar	1248	leaf->value[leaf->keys - 1] += count;
1387	jermar	1249	return 1;
		1250	} else if (page + count*PAGE_SIZE == right_pg) {
		1251	/*
		1252	* The interval can be addded by simply moving base of the right
		1253	* interval down and increasing its size accordingly.
		1254	*/
1403	jermar	1255	node->value[0] += count;
1387	jermar	1256	node->key[0] = page;
		1257	return 1;
		1258	} else {
		1259	/*
		1260	* The interval is between both neigbouring intervals,
		1261	* but cannot be merged with any of them.
		1262	*/
		1263	btree_insert(&a->used_space, page, (void *) count, leaf);
		1264	return 1;
		1265	}
		1266	} else if (page >= leaf->key[leaf->keys - 1]) {
1780	jermar	1267	uintptr_t left_pg = leaf->key[leaf->keys - 1];
1387	jermar	1268	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1269
		1270	/*
		1271	* Investigate the border case in which the right neighbour does not
		1272	* exist but the interval fits from the right.
		1273	*/
		1274
		1275	if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
1403	jermar	1276	/* The interval intersects with the left interval. */
1387	jermar	1277	return 0;
		1278	} else if (left_pg + left_cnt*PAGE_SIZE == page) {
		1279	/* The interval can be added by growing the left interval. */
1403	jermar	1280	leaf->value[leaf->keys - 1] += count;
1387	jermar	1281	return 1;
		1282	} else {
		1283	/*
		1284	* The interval doesn't adjoin with the left interval.
		1285	* It must be added individually.
		1286	*/
		1287	btree_insert(&a->used_space, page, (void *) count, leaf);
		1288	return 1;
		1289	}
		1290	}
		1291
		1292	/*
		1293	* Note that if the algorithm made it thus far, the interval can fit only
		1294	* between two other intervals of the leaf. The two border cases were already
		1295	* resolved.
		1296	*/
		1297	for (i = 1; i < leaf->keys; i++) {
		1298	if (page < leaf->key[i]) {
1780	jermar	1299	uintptr_t left_pg = leaf->key[i - 1], right_pg = leaf->key[i];
1387	jermar	1300	count_t left_cnt = (count_t) leaf->value[i - 1], right_cnt = (count_t) leaf->value[i];
		1301
		1302	/*
		1303	* The interval fits between left_pg and right_pg.
		1304	*/
		1305
		1306	if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1307	/* The interval intersects with the left interval. */
		1308	return 0;
		1309	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1310	/* The interval intersects with the right interval. */
		1311	return 0;
		1312	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1313	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1314	leaf->value[i - 1] += count + right_cnt;
1387	jermar	1315	btree_remove(&a->used_space, right_pg, leaf);
		1316	return 1;
		1317	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1318	/* The interval can be added by simply growing the left interval. */
1403	jermar	1319	leaf->value[i - 1] += count;
1387	jermar	1320	return 1;
		1321	} else if (page + count*PAGE_SIZE == right_pg) {
		1322	/*
		1323	* The interval can be addded by simply moving base of the right
		1324	* interval down and increasing its size accordingly.
		1325	*/
1403	jermar	1326	leaf->value[i] += count;
1387	jermar	1327	leaf->key[i] = page;
		1328	return 1;
		1329	} else {
		1330	/*
		1331	* The interval is between both neigbouring intervals,
		1332	* but cannot be merged with any of them.
		1333	*/
		1334	btree_insert(&a->used_space, page, (void *) count, leaf);
		1335	return 1;
		1336	}
		1337	}
		1338	}
		1339
1735	decky	1340	panic("Inconsistency detected while adding %d pages of used space at %p.\n", count, page);
1387	jermar	1341	}
		1342
		1343	/** Mark portion of address space area as unused.
		1344	*
		1345	* The address space area must be already locked.
		1346	*
		1347	* @param a Address space area.
		1348	* @param page First page to be marked.
		1349	* @param count Number of page to be marked.
		1350	*
		1351	* @return 0 on failure and 1 on success.
		1352	*/
1780	jermar	1353	int used_space_remove(as_area_t *a, uintptr_t page, count_t count)
1387	jermar	1354	{
		1355	btree_node_t leaf, node;
		1356	count_t pages;
		1357	int i;
		1358
		1359	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1360	ASSERT(count);
		1361
		1362	pages = (count_t) btree_search(&a->used_space, page, &leaf);
		1363	if (pages) {
		1364	/*
		1365	* We are lucky, page is the beginning of some interval.
		1366	*/
		1367	if (count > pages) {
		1368	return 0;
		1369	} else if (count == pages) {
		1370	btree_remove(&a->used_space, page, leaf);
1403	jermar	1371	return 1;
1387	jermar	1372	} else {
		1373	/*
		1374	* Find the respective interval.
		1375	* Decrease its size and relocate its start address.
		1376	*/
		1377	for (i = 0; i < leaf->keys; i++) {
		1378	if (leaf->key[i] == page) {
		1379	leaf->key[i] += count*PAGE_SIZE;
1403	jermar	1380	leaf->value[i] -= count;
1387	jermar	1381	return 1;
		1382	}
		1383	}
		1384	goto error;
		1385	}
		1386	}
		1387
		1388	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1389	if (node && page < leaf->key[0]) {
1780	jermar	1390	uintptr_t left_pg = node->key[node->keys - 1];
1387	jermar	1391	count_t left_cnt = (count_t) node->value[node->keys - 1];
		1392
		1393	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1394	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1395	/*
		1396	* The interval is contained in the rightmost interval
		1397	* of the left neighbour and can be removed by
		1398	* updating the size of the bigger interval.
		1399	*/
1403	jermar	1400	node->value[node->keys - 1] -= count;
1387	jermar	1401	return 1;
		1402	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1403	count_t new_cnt;
1387	jermar	1404
		1405	/*
		1406	* The interval is contained in the rightmost interval
		1407	* of the left neighbour but its removal requires
		1408	* both updating the size of the original interval and
		1409	* also inserting a new interval.
		1410	*/
1403	jermar	1411	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1412	node->value[node->keys - 1] -= count + new_cnt;
1387	jermar	1413	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1414	return 1;
		1415	}
		1416	}
		1417	return 0;
		1418	} else if (page < leaf->key[0]) {
		1419	return 0;
		1420	}
		1421
		1422	if (page > leaf->key[leaf->keys - 1]) {
1780	jermar	1423	uintptr_t left_pg = leaf->key[leaf->keys - 1];
1387	jermar	1424	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1425
		1426	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1427	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1428	/*
		1429	* The interval is contained in the rightmost interval
		1430	* of the leaf and can be removed by updating the size
		1431	* of the bigger interval.
		1432	*/
1403	jermar	1433	leaf->value[leaf->keys - 1] -= count;
1387	jermar	1434	return 1;
		1435	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1436	count_t new_cnt;
1387	jermar	1437
		1438	/*
		1439	* The interval is contained in the rightmost interval
		1440	* of the leaf but its removal requires both updating
		1441	* the size of the original interval and
		1442	* also inserting a new interval.
		1443	*/
1403	jermar	1444	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1445	leaf->value[leaf->keys - 1] -= count + new_cnt;
1387	jermar	1446	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1447	return 1;
		1448	}
		1449	}
		1450	return 0;
		1451	}
		1452
		1453	/*
		1454	* The border cases have been already resolved.
		1455	* Now the interval can be only between intervals of the leaf.
		1456	*/
		1457	for (i = 1; i < leaf->keys - 1; i++) {
		1458	if (page < leaf->key[i]) {
1780	jermar	1459	uintptr_t left_pg = leaf->key[i - 1];
1387	jermar	1460	count_t left_cnt = (count_t) leaf->value[i - 1];
		1461
		1462	/*
		1463	* Now the interval is between intervals corresponding to (i - 1) and i.
		1464	*/
		1465	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1466	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1467	/*
		1468	* The interval is contained in the interval (i - 1)
		1469	* of the leaf and can be removed by updating the size
		1470	* of the bigger interval.
		1471	*/
1403	jermar	1472	leaf->value[i - 1] -= count;
1387	jermar	1473	return 1;
		1474	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1475	count_t new_cnt;
1387	jermar	1476
		1477	/*
		1478	* The interval is contained in the interval (i - 1)
		1479	* of the leaf but its removal requires both updating
		1480	* the size of the original interval and
		1481	* also inserting a new interval.
		1482	*/
1403	jermar	1483	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1484	leaf->value[i - 1] -= count + new_cnt;
1387	jermar	1485	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1486	return 1;
		1487	}
		1488	}
		1489	return 0;
		1490	}
		1491	}
		1492
		1493	error:
1735	decky	1494	panic("Inconsistency detected while removing %d pages of used space from %p.\n", count, page);
1387	jermar	1495	}
		1496
1409	jermar	1497	/** Remove reference to address space area share info.
		1498	*
		1499	* If the reference count drops to 0, the sh_info is deallocated.
		1500	*
		1501	* @param sh_info Pointer to address space area share info.
		1502	*/
		1503	void sh_info_remove_reference(share_info_t *sh_info)
		1504	{
		1505	bool dealloc = false;
		1506
		1507	mutex_lock(&sh_info->lock);
		1508	ASSERT(sh_info->refcount);
		1509	if (--sh_info->refcount == 0) {
		1510	dealloc = true;
1495	jermar	1511	link_t *cur;
1409	jermar	1512
		1513	/*
		1514	* Now walk carefully the pagemap B+tree and free/remove
		1515	* reference from all frames found there.
		1516	*/
1495	jermar	1517	for (cur = sh_info->pagemap.leaf_head.next; cur != &sh_info->pagemap.leaf_head; cur = cur->next) {
1409	jermar	1518	btree_node_t *node;
1495	jermar	1519	int i;
1409	jermar	1520
1495	jermar	1521	node = list_get_instance(cur, btree_node_t, leaf_link);
		1522	for (i = 0; i < node->keys; i++)
1780	jermar	1523	frame_free((uintptr_t) node->value[i]);
1409	jermar	1524	}
		1525
		1526	}
		1527	mutex_unlock(&sh_info->lock);
		1528
		1529	if (dealloc) {
		1530	btree_destroy(&sh_info->pagemap);
		1531	free(sh_info);
		1532	}
		1533	}
		1534
1235	jermar	1535	/*
		1536	* Address space related syscalls.
		1537	*/
		1538
		1539	/** Wrapper for as_area_create(). */
1780	jermar	1540	unative_t sys_as_area_create(uintptr_t address, size_t size, int flags)
1235	jermar	1541	{
1424	jermar	1542	if (as_area_create(AS, flags \| AS_AREA_CACHEABLE, size, address, AS_AREA_ATTR_NONE, &anon_backend, NULL))
1780	jermar	1543	return (unative_t) address;
1235	jermar	1544	else
1780	jermar	1545	return (unative_t) -1;
1235	jermar	1546	}
		1547
1793	jermar	1548	/** Wrapper for as_area_resize(). */
1780	jermar	1549	unative_t sys_as_area_resize(uintptr_t address, size_t size, int flags)
1235	jermar	1550	{
1780	jermar	1551	return (unative_t) as_area_resize(AS, address, size, 0);
1235	jermar	1552	}
		1553
1793	jermar	1554	/** Wrapper for as_area_destroy(). */
1780	jermar	1555	unative_t sys_as_area_destroy(uintptr_t address)
1306	jermar	1556	{
1780	jermar	1557	return (unative_t) as_area_destroy(AS, address);
1306	jermar	1558	}
1702	cejka	1559
1757	jermar	1560	/** @}
1702	cejka	1561	*/

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(root)/trunk/kernel/generic/src/mm/as.c @ 3790 – Rev 1890