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
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);
1780	jermar	100	static as_area_t find_area_and_lock(as_t as, uintptr_t va);
		101	static bool check_area_conflicts(as_t as, uintptr_t 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	*/
1780	jermar	202	as_area_t as_area_create(as_t as, int flags, size_t size, uintptr_t 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
1780	jermar	241	memsetb((uintptr_t) &a->backend_data, sizeof(a->backend_data), 0);
1424	jermar	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	*/
1780	jermar	262	int as_area_resize(as_t *as, uintptr_t 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;
1780	jermar	315	uintptr_t 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)) {
1780	jermar	340	uintptr_t b = node->key[node->keys - 1];
1403	jermar	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))
1889	jermar	362	panic("Could not remove used space.\n");
1403	jermar	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();
1889	jermar	392
		393	/*
		394	* Invalidate software translation caches (e.g. TSB on sparc64).
		395	*/
		396	as_invalidate_translation_cache(as, area->base + pages*PAGE_SIZE, area->pages - pages);
1235	jermar	397	} else {
		398	/*
		399	* Growing the area.
		400	* Check for overlaps with other address space areas.
		401	*/
		402	if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {
1380	jermar	403	mutex_unlock(&area->lock);
		404	mutex_unlock(&as->lock);
1235	jermar	405	interrupts_restore(ipl);
1306	jermar	406	return EADDRNOTAVAIL;
1235	jermar	407	}
		408	}
		409
		410	area->pages = pages;
		411
1380	jermar	412	mutex_unlock(&area->lock);
		413	mutex_unlock(&as->lock);
1235	jermar	414	interrupts_restore(ipl);
		415
1306	jermar	416	return 0;
1235	jermar	417	}
		418
1306	jermar	419	/** Destroy address space area.
		420	*
		421	* @param as Address space.
		422	* @param address Address withing the area to be deleted.
		423	*
		424	* @return Zero on success or a value from @ref errno.h on failure.
		425	*/
1780	jermar	426	int as_area_destroy(as_t *as, uintptr_t address)
1306	jermar	427	{
		428	as_area_t *area;
1780	jermar	429	uintptr_t base;
1495	jermar	430	link_t *cur;
1306	jermar	431	ipl_t ipl;
		432
		433	ipl = interrupts_disable();
1380	jermar	434	mutex_lock(&as->lock);
1306	jermar	435
		436	area = find_area_and_lock(as, address);
		437	if (!area) {
1380	jermar	438	mutex_unlock(&as->lock);
1306	jermar	439	interrupts_restore(ipl);
		440	return ENOENT;
		441	}
		442
1403	jermar	443	base = area->base;
		444
1411	jermar	445	/*
1436	jermar	446	* Start TLB shootdown sequence.
		447	*/
1889	jermar	448	tlb_shootdown_start(TLB_INVL_PAGES, as->asid, area->base, area->pages);
1436	jermar	449
		450	/*
1411	jermar	451	* Visit only the pages mapped by used_space B+tree.
		452	*/
1495	jermar	453	for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {
1411	jermar	454	btree_node_t *node;
1495	jermar	455	int i;
1403	jermar	456
1495	jermar	457	node = list_get_instance(cur, btree_node_t, leaf_link);
		458	for (i = 0; i < node->keys; i++) {
1780	jermar	459	uintptr_t b = node->key[i];
1495	jermar	460	count_t j;
1411	jermar	461	pte_t *pte;
1403	jermar	462
1495	jermar	463	for (j = 0; j < (count_t) node->value[i]; j++) {
1411	jermar	464	page_table_lock(as, false);
1495	jermar	465	pte = page_mapping_find(as, b + j*PAGE_SIZE);
1411	jermar	466	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424	jermar	467	if (area->backend && area->backend->frame_free) {
		468	area->backend->frame_free(area,
1495	jermar	469	b + j*PAGE_SIZE, PTE_GET_FRAME(pte));
1403	jermar	470	}
1889	jermar	471	page_mapping_remove(as, b + j*PAGE_SIZE);
1411	jermar	472	page_table_unlock(as, false);
1306	jermar	473	}
		474	}
		475	}
1403	jermar	476
1306	jermar	477	/*
1436	jermar	478	* Finish TLB shootdown sequence.
1306	jermar	479	*/
1889	jermar	480	tlb_invalidate_pages(as->asid, area->base, area->pages);
1306	jermar	481	tlb_shootdown_finalize();
1436	jermar	482
1889	jermar	483	/*
		484	* Invalidate potential software translation caches (e.g. TSB on sparc64).
		485	*/
		486	as_invalidate_translation_cache(as, area->base, area->pages);
		487
1436	jermar	488	btree_destroy(&area->used_space);
1306	jermar	489
1309	jermar	490	area->attributes \|= AS_AREA_ATTR_PARTIAL;
1409	jermar	491
		492	if (area->sh_info)
		493	sh_info_remove_reference(area->sh_info);
		494
1380	jermar	495	mutex_unlock(&area->lock);
1306	jermar	496
		497	/*
		498	* Remove the empty area from address space.
		499	*/
1889	jermar	500	btree_remove(&as->as_area_btree, base, NULL);
1306	jermar	501
1309	jermar	502	free(area);
		503
1889	jermar	504	mutex_unlock(&as->lock);
1306	jermar	505	interrupts_restore(ipl);
		506	return 0;
		507	}
		508
1413	jermar	509	/** Share address space area with another or the same address space.
1235	jermar	510	*
1424	jermar	511	* Address space area mapping is shared with a new address space area.
		512	* If the source address space area has not been shared so far,
		513	* a new sh_info is created. The new address space area simply gets the
		514	* sh_info of the source area. The process of duplicating the
		515	* mapping is done through the backend share function.
1413	jermar	516	*
1417	jermar	517	* @param src_as Pointer to source address space.
1239	jermar	518	* @param src_base Base address of the source address space area.
1417	jermar	519	* @param acc_size Expected size of the source area.
1428	palkovsky	520	* @param dst_as Pointer to destination address space.
1417	jermar	521	* @param dst_base Target base address.
		522	* @param dst_flags_mask Destination address space area flags mask.
1235	jermar	523	*
1306	jermar	524	* @return Zero on success or ENOENT if there is no such task or
1235	jermar	525	* if there is no such address space area,
		526	* EPERM if there was a problem in accepting the area or
		527	* ENOMEM if there was a problem in allocating destination
1413	jermar	528	* address space area. ENOTSUP is returned if an attempt
		529	* to share non-anonymous address space area is detected.
1235	jermar	530	*/
1780	jermar	531	int as_area_share(as_t *src_as, uintptr_t src_base, size_t acc_size,
		532	as_t *dst_as, uintptr_t dst_base, int dst_flags_mask)
1235	jermar	533	{
		534	ipl_t ipl;
1239	jermar	535	int src_flags;
		536	size_t src_size;
		537	as_area_t src_area, dst_area;
1413	jermar	538	share_info_t *sh_info;
1424	jermar	539	mem_backend_t *src_backend;
		540	mem_backend_data_t src_backend_data;
1434	palkovsky	541
1235	jermar	542	ipl = interrupts_disable();
1380	jermar	543	mutex_lock(&src_as->lock);
1329	palkovsky	544	src_area = find_area_and_lock(src_as, src_base);
1239	jermar	545	if (!src_area) {
1238	jermar	546	/*
		547	* Could not find the source address space area.
		548	*/
1380	jermar	549	mutex_unlock(&src_as->lock);
1238	jermar	550	interrupts_restore(ipl);
		551	return ENOENT;
		552	}
1413	jermar	553
1424	jermar	554	if (!src_area->backend \|\| !src_area->backend->share) {
1413	jermar	555	/*
1851	jermar	556	* There is no backend or the backend does not
1424	jermar	557	* know how to share the area.
1413	jermar	558	*/
		559	mutex_unlock(&src_area->lock);
		560	mutex_unlock(&src_as->lock);
		561	interrupts_restore(ipl);
		562	return ENOTSUP;
		563	}
		564
1239	jermar	565	src_size = src_area->pages * PAGE_SIZE;
		566	src_flags = src_area->flags;
1424	jermar	567	src_backend = src_area->backend;
		568	src_backend_data = src_area->backend_data;
1544	palkovsky	569
		570	/* Share the cacheable flag from the original mapping */
		571	if (src_flags & AS_AREA_CACHEABLE)
		572	dst_flags_mask \|= AS_AREA_CACHEABLE;
		573
1461	palkovsky	574	if (src_size != acc_size \|\| (src_flags & dst_flags_mask) != dst_flags_mask) {
1413	jermar	575	mutex_unlock(&src_area->lock);
		576	mutex_unlock(&src_as->lock);
1235	jermar	577	interrupts_restore(ipl);
		578	return EPERM;
		579	}
1413	jermar	580
1235	jermar	581	/*
1413	jermar	582	* Now we are committed to sharing the area.
		583	* First prepare the area for sharing.
		584	* Then it will be safe to unlock it.
		585	*/
		586	sh_info = src_area->sh_info;
		587	if (!sh_info) {
		588	sh_info = (share_info_t *) malloc(sizeof(share_info_t), 0);
		589	mutex_initialize(&sh_info->lock);
		590	sh_info->refcount = 2;
		591	btree_create(&sh_info->pagemap);
		592	src_area->sh_info = sh_info;
		593	} else {
		594	mutex_lock(&sh_info->lock);
		595	sh_info->refcount++;
		596	mutex_unlock(&sh_info->lock);
		597	}
		598
1424	jermar	599	src_area->backend->share(src_area);
1413	jermar	600
		601	mutex_unlock(&src_area->lock);
		602	mutex_unlock(&src_as->lock);
		603
		604	/*
1239	jermar	605	* Create copy of the source address space area.
		606	* The destination area is created with AS_AREA_ATTR_PARTIAL
		607	* attribute set which prevents race condition with
		608	* preliminary as_page_fault() calls.
1417	jermar	609	* The flags of the source area are masked against dst_flags_mask
		610	* to support sharing in less privileged mode.
1235	jermar	611	*/
1461	palkovsky	612	dst_area = as_area_create(dst_as, dst_flags_mask, src_size, dst_base,
1424	jermar	613	AS_AREA_ATTR_PARTIAL, src_backend, &src_backend_data);
1239	jermar	614	if (!dst_area) {
1235	jermar	615	/*
		616	* Destination address space area could not be created.
		617	*/
1413	jermar	618	sh_info_remove_reference(sh_info);
		619
1235	jermar	620	interrupts_restore(ipl);
		621	return ENOMEM;
		622	}
		623
		624	/*
1239	jermar	625	* Now the destination address space area has been
		626	* fully initialized. Clear the AS_AREA_ATTR_PARTIAL
1413	jermar	627	* attribute and set the sh_info.
1239	jermar	628	*/
1380	jermar	629	mutex_lock(&dst_area->lock);
1239	jermar	630	dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
1413	jermar	631	dst_area->sh_info = sh_info;
1380	jermar	632	mutex_unlock(&dst_area->lock);
1235	jermar	633
		634	interrupts_restore(ipl);
		635
		636	return 0;
		637	}
		638
1423	jermar	639	/** Check access mode for address space area.
		640	*
		641	* The address space area must be locked prior to this call.
		642	*
		643	* @param area Address space area.
		644	* @param access Access mode.
		645	*
		646	* @return False if access violates area's permissions, true otherwise.
		647	*/
		648	bool as_area_check_access(as_area_t *area, pf_access_t access)
		649	{
		650	int flagmap[] = {
		651	[PF_ACCESS_READ] = AS_AREA_READ,
		652	[PF_ACCESS_WRITE] = AS_AREA_WRITE,
		653	[PF_ACCESS_EXEC] = AS_AREA_EXEC
		654	};
		655
		656	if (!(area->flags & flagmap[access]))
		657	return false;
		658
		659	return true;
		660	}
		661
703	jermar	662	/** Handle page fault within the current address space.
		663	*
1409	jermar	664	* This is the high-level page fault handler. It decides
		665	* whether the page fault can be resolved by any backend
		666	* and if so, it invokes the backend to resolve the page
		667	* fault.
		668	*
703	jermar	669	* Interrupts are assumed disabled.
		670	*
		671	* @param page Faulting page.
1411	jermar	672	* @param access Access mode that caused the fault (i.e. read/write/exec).
1288	jermar	673	* @param istate Pointer to interrupted state.
703	jermar	674	*
1409	jermar	675	* @return AS_PF_FAULT on page fault, AS_PF_OK on success or AS_PF_DEFER if the
		676	* fault was caused by copy_to_uspace() or copy_from_uspace().
703	jermar	677	*/
1780	jermar	678	int as_page_fault(uintptr_t page, pf_access_t access, istate_t *istate)
703	jermar	679	{
1044	jermar	680	pte_t *pte;
977	jermar	681	as_area_t *area;
703	jermar	682
1380	jermar	683	if (!THREAD)
1409	jermar	684	return AS_PF_FAULT;
1380	jermar	685
703	jermar	686	ASSERT(AS);
1044	jermar	687
1380	jermar	688	mutex_lock(&AS->lock);
977	jermar	689	area = find_area_and_lock(AS, page);
703	jermar	690	if (!area) {
		691	/*
		692	* No area contained mapping for 'page'.
		693	* Signal page fault to low-level handler.
		694	*/
1380	jermar	695	mutex_unlock(&AS->lock);
1288	jermar	696	goto page_fault;
703	jermar	697	}
		698
1239	jermar	699	if (area->attributes & AS_AREA_ATTR_PARTIAL) {
		700	/*
		701	* The address space area is not fully initialized.
		702	* Avoid possible race by returning error.
		703	*/
1380	jermar	704	mutex_unlock(&area->lock);
		705	mutex_unlock(&AS->lock);
1288	jermar	706	goto page_fault;
1239	jermar	707	}
		708
1424	jermar	709	if (!area->backend \|\| !area->backend->page_fault) {
1409	jermar	710	/*
		711	* The address space area is not backed by any backend
		712	* or the backend cannot handle page faults.
		713	*/
		714	mutex_unlock(&area->lock);
		715	mutex_unlock(&AS->lock);
		716	goto page_fault;
		717	}
1179	jermar	718
1044	jermar	719	page_table_lock(AS, false);
		720
703	jermar	721	/*
1044	jermar	722	* To avoid race condition between two page faults
		723	* on the same address, we need to make sure
		724	* the mapping has not been already inserted.
		725	*/
		726	if ((pte = page_mapping_find(AS, page))) {
		727	if (PTE_PRESENT(pte)) {
1423	jermar	728	if (((access == PF_ACCESS_READ) && PTE_READABLE(pte)) \|\|
		729	(access == PF_ACCESS_WRITE && PTE_WRITABLE(pte)) \|\|
		730	(access == PF_ACCESS_EXEC && PTE_EXECUTABLE(pte))) {
		731	page_table_unlock(AS, false);
		732	mutex_unlock(&area->lock);
		733	mutex_unlock(&AS->lock);
		734	return AS_PF_OK;
		735	}
1044	jermar	736	}
		737	}
1409	jermar	738
1044	jermar	739	/*
1409	jermar	740	* Resort to the backend page fault handler.
703	jermar	741	*/
1424	jermar	742	if (area->backend->page_fault(area, page, access) != AS_PF_OK) {
1409	jermar	743	page_table_unlock(AS, false);
		744	mutex_unlock(&area->lock);
		745	mutex_unlock(&AS->lock);
		746	goto page_fault;
		747	}
703	jermar	748
1044	jermar	749	page_table_unlock(AS, false);
1380	jermar	750	mutex_unlock(&area->lock);
		751	mutex_unlock(&AS->lock);
1288	jermar	752	return AS_PF_OK;
		753
		754	page_fault:
		755	if (THREAD->in_copy_from_uspace) {
		756	THREAD->in_copy_from_uspace = false;
1780	jermar	757	istate_set_retaddr(istate, (uintptr_t) &memcpy_from_uspace_failover_address);
1288	jermar	758	} else if (THREAD->in_copy_to_uspace) {
		759	THREAD->in_copy_to_uspace = false;
1780	jermar	760	istate_set_retaddr(istate, (uintptr_t) &memcpy_to_uspace_failover_address);
1288	jermar	761	} else {
		762	return AS_PF_FAULT;
		763	}
		764
		765	return AS_PF_DEFER;
703	jermar	766	}
		767
823	jermar	768	/** Switch address spaces.
703	jermar	769	*
1380	jermar	770	* Note that this function cannot sleep as it is essentially a part of
1415	jermar	771	* scheduling. Sleeping here would lead to deadlock on wakeup.
1380	jermar	772	*
823	jermar	773	* @param old Old address space or NULL.
		774	* @param new New address space.
703	jermar	775	*/
823	jermar	776	void as_switch(as_t old, as_t new)
703	jermar	777	{
		778	ipl_t ipl;
823	jermar	779	bool needs_asid = false;
703	jermar	780
		781	ipl = interrupts_disable();
1415	jermar	782	spinlock_lock(&inactive_as_with_asid_lock);
703	jermar	783
		784	/*
823	jermar	785	* First, take care of the old address space.
		786	*/
		787	if (old) {
1380	jermar	788	mutex_lock_active(&old->lock);
1415	jermar	789	ASSERT(old->cpu_refcount);
		790	if((--old->cpu_refcount == 0) && (old != AS_KERNEL)) {
823	jermar	791	/*
		792	* The old address space is no longer active on
		793	* any processor. It can be appended to the
		794	* list of inactive address spaces with assigned
		795	* ASID.
		796	*/
		797	ASSERT(old->asid != ASID_INVALID);
		798	list_append(&old->inactive_as_with_asid_link, &inactive_as_with_asid_head);
		799	}
1380	jermar	800	mutex_unlock(&old->lock);
823	jermar	801	}
		802
		803	/*
		804	* Second, prepare the new address space.
		805	*/
1380	jermar	806	mutex_lock_active(&new->lock);
1415	jermar	807	if ((new->cpu_refcount++ == 0) && (new != AS_KERNEL)) {
823	jermar	808	if (new->asid != ASID_INVALID)
		809	list_remove(&new->inactive_as_with_asid_link);
		810	else
		811	needs_asid = true; /* defer call to asid_get() until new->lock is released */
		812	}
		813	SET_PTL0_ADDRESS(new->page_table);
1380	jermar	814	mutex_unlock(&new->lock);
823	jermar	815
		816	if (needs_asid) {
		817	/*
		818	* Allocation of new ASID was deferred
		819	* until now in order to avoid deadlock.
		820	*/
		821	asid_t asid;
		822
		823	asid = asid_get();
1380	jermar	824	mutex_lock_active(&new->lock);
823	jermar	825	new->asid = asid;
1380	jermar	826	mutex_unlock(&new->lock);
823	jermar	827	}
1415	jermar	828	spinlock_unlock(&inactive_as_with_asid_lock);
823	jermar	829	interrupts_restore(ipl);
		830
		831	/*
703	jermar	832	* Perform architecture-specific steps.
727	jermar	833	* (e.g. write ASID to hardware register etc.)
703	jermar	834	*/
823	jermar	835	as_install_arch(new);
703	jermar	836
823	jermar	837	AS = new;
703	jermar	838	}
754	jermar	839
1235	jermar	840	/** Convert address space area flags to page flags.
754	jermar	841	*
1235	jermar	842	* @param aflags Flags of some address space area.
754	jermar	843	*
1235	jermar	844	* @return Flags to be passed to page_mapping_insert().
754	jermar	845	*/
1235	jermar	846	int area_flags_to_page_flags(int aflags)
754	jermar	847	{
		848	int flags;
		849
1178	jermar	850	flags = PAGE_USER \| PAGE_PRESENT;
754	jermar	851
1235	jermar	852	if (aflags & AS_AREA_READ)
1026	jermar	853	flags \|= PAGE_READ;
		854
1235	jermar	855	if (aflags & AS_AREA_WRITE)
1026	jermar	856	flags \|= PAGE_WRITE;
		857
1235	jermar	858	if (aflags & AS_AREA_EXEC)
1026	jermar	859	flags \|= PAGE_EXEC;
		860
1424	jermar	861	if (aflags & AS_AREA_CACHEABLE)
1178	jermar	862	flags \|= PAGE_CACHEABLE;
		863
754	jermar	864	return flags;
		865	}
756	jermar	866
1235	jermar	867	/** Compute flags for virtual address translation subsytem.
		868	*
		869	* The address space area must be locked.
		870	* Interrupts must be disabled.
		871	*
		872	* @param a Address space area.
		873	*
		874	* @return Flags to be used in page_mapping_insert().
		875	*/
1409	jermar	876	int as_area_get_flags(as_area_t *a)
1235	jermar	877	{
		878	return area_flags_to_page_flags(a->flags);
		879	}
		880
756	jermar	881	/** Create page table.
		882	*
		883	* Depending on architecture, create either address space
		884	* private or global page table.
		885	*
		886	* @param flags Flags saying whether the page table is for kernel address space.
		887	*
		888	* @return First entry of the page table.
		889	*/
		890	pte_t *page_table_create(int flags)
		891	{
		892	ASSERT(as_operations);
		893	ASSERT(as_operations->page_table_create);
		894
		895	return as_operations->page_table_create(flags);
		896	}
977	jermar	897
1468	jermar	898	/** Destroy page table.
		899	*
		900	* Destroy page table in architecture specific way.
		901	*
		902	* @param page_table Physical address of PTL0.
		903	*/
		904	void page_table_destroy(pte_t *page_table)
		905	{
		906	ASSERT(as_operations);
		907	ASSERT(as_operations->page_table_destroy);
		908
		909	as_operations->page_table_destroy(page_table);
		910	}
		911
1044	jermar	912	/** Lock page table.
		913	*
		914	* This function should be called before any page_mapping_insert(),
		915	* page_mapping_remove() and page_mapping_find().
		916	*
		917	* Locking order is such that address space areas must be locked
		918	* prior to this call. Address space can be locked prior to this
		919	* call in which case the lock argument is false.
		920	*
		921	* @param as Address space.
1248	jermar	922	* @param lock If false, do not attempt to lock as->lock.
1044	jermar	923	*/
		924	void page_table_lock(as_t *as, bool lock)
		925	{
		926	ASSERT(as_operations);
		927	ASSERT(as_operations->page_table_lock);
		928
		929	as_operations->page_table_lock(as, lock);
		930	}
		931
		932	/** Unlock page table.
		933	*
		934	* @param as Address space.
1248	jermar	935	* @param unlock If false, do not attempt to unlock as->lock.
1044	jermar	936	*/
		937	void page_table_unlock(as_t *as, bool unlock)
		938	{
		939	ASSERT(as_operations);
		940	ASSERT(as_operations->page_table_unlock);
		941
		942	as_operations->page_table_unlock(as, unlock);
		943	}
		944
977	jermar	945
		946	/** Find address space area and lock it.
		947	*
		948	* The address space must be locked and interrupts must be disabled.
		949	*
		950	* @param as Address space.
		951	* @param va Virtual address.
		952	*
		953	* @return Locked address space area containing va on success or NULL on failure.
		954	*/
1780	jermar	955	as_area_t find_area_and_lock(as_t as, uintptr_t va)
977	jermar	956	{
		957	as_area_t *a;
1147	jermar	958	btree_node_t leaf, lnode;
		959	int i;
977	jermar	960
1147	jermar	961	a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
		962	if (a) {
		963	/* va is the base address of an address space area */
1380	jermar	964	mutex_lock(&a->lock);
1147	jermar	965	return a;
		966	}
		967
		968	/*
1150	jermar	969	* Search the leaf node and the righmost record of its left neighbour
1147	jermar	970	* to find out whether this is a miss or va belongs to an address
		971	* space area found there.
		972	*/
		973
		974	/* First, search the leaf node itself. */
		975	for (i = 0; i < leaf->keys; i++) {
		976	a = (as_area_t *) leaf->value[i];
1380	jermar	977	mutex_lock(&a->lock);
1147	jermar	978	if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
		979	return a;
		980	}
1380	jermar	981	mutex_unlock(&a->lock);
1147	jermar	982	}
977	jermar	983
1147	jermar	984	/*
1150	jermar	985	* Second, locate the left neighbour and test its last record.
1148	jermar	986	* Because of its position in the B+tree, it must have base < va.
1147	jermar	987	*/
1150	jermar	988	if ((lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	989	a = (as_area_t *) lnode->value[lnode->keys - 1];
1380	jermar	990	mutex_lock(&a->lock);
1147	jermar	991	if (va < a->base + a->pages * PAGE_SIZE) {
1048	jermar	992	return a;
1147	jermar	993	}
1380	jermar	994	mutex_unlock(&a->lock);
977	jermar	995	}
		996
		997	return NULL;
		998	}
1048	jermar	999
		1000	/** Check area conflicts with other areas.
		1001	*
		1002	* The address space must be locked and interrupts must be disabled.
		1003	*
		1004	* @param as Address space.
		1005	* @param va Starting virtual address of the area being tested.
		1006	* @param size Size of the area being tested.
		1007	* @param avoid_area Do not touch this area.
		1008	*
		1009	* @return True if there is no conflict, false otherwise.
		1010	*/
1780	jermar	1011	bool check_area_conflicts(as_t as, uintptr_t va, size_t size, as_area_t avoid_area)
1048	jermar	1012	{
		1013	as_area_t *a;
1147	jermar	1014	btree_node_t leaf, node;
		1015	int i;
1048	jermar	1016
1070	jermar	1017	/*
		1018	* We don't want any area to have conflicts with NULL page.
		1019	*/
		1020	if (overlaps(va, size, NULL, PAGE_SIZE))
		1021	return false;
		1022
1147	jermar	1023	/*
		1024	* The leaf node is found in O(log n), where n is proportional to
		1025	* the number of address space areas belonging to as.
		1026	* The check for conflicts is then attempted on the rightmost
1150	jermar	1027	* record in the left neighbour, the leftmost record in the right
		1028	* neighbour and all records in the leaf node itself.
1147	jermar	1029	*/
1048	jermar	1030
1147	jermar	1031	if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
		1032	if (a != avoid_area)
		1033	return false;
		1034	}
		1035
		1036	/* First, check the two border cases. */
1150	jermar	1037	if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	1038	a = (as_area_t *) node->value[node->keys - 1];
1380	jermar	1039	mutex_lock(&a->lock);
1147	jermar	1040	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1041	mutex_unlock(&a->lock);
1147	jermar	1042	return false;
		1043	}
1380	jermar	1044	mutex_unlock(&a->lock);
1147	jermar	1045	}
1150	jermar	1046	if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	1047	a = (as_area_t *) node->value[0];
1380	jermar	1048	mutex_lock(&a->lock);
1147	jermar	1049	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1050	mutex_unlock(&a->lock);
1147	jermar	1051	return false;
		1052	}
1380	jermar	1053	mutex_unlock(&a->lock);
1147	jermar	1054	}
		1055
		1056	/* Second, check the leaf node. */
		1057	for (i = 0; i < leaf->keys; i++) {
		1058	a = (as_area_t *) leaf->value[i];
		1059
1048	jermar	1060	if (a == avoid_area)
		1061	continue;
1147	jermar	1062
1380	jermar	1063	mutex_lock(&a->lock);
1147	jermar	1064	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1065	mutex_unlock(&a->lock);
1147	jermar	1066	return false;
		1067	}
1380	jermar	1068	mutex_unlock(&a->lock);
1048	jermar	1069	}
		1070
1070	jermar	1071	/*
		1072	* So far, the area does not conflict with other areas.
		1073	* Check if it doesn't conflict with kernel address space.
		1074	*/
		1075	if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
		1076	return !overlaps(va, size,
		1077	KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START);
		1078	}
		1079
1048	jermar	1080	return true;
		1081	}
1235	jermar	1082
1380	jermar	1083	/** Return size of the address space area with given base. */
1780	jermar	1084	size_t as_get_size(uintptr_t base)
1329	palkovsky	1085	{
		1086	ipl_t ipl;
		1087	as_area_t *src_area;
		1088	size_t size;
		1089
		1090	ipl = interrupts_disable();
		1091	src_area = find_area_and_lock(AS, base);
		1092	if (src_area){
		1093	size = src_area->pages * PAGE_SIZE;
1380	jermar	1094	mutex_unlock(&src_area->lock);
1329	palkovsky	1095	} else {
		1096	size = 0;
		1097	}
		1098	interrupts_restore(ipl);
		1099	return size;
		1100	}
		1101
1387	jermar	1102	/** Mark portion of address space area as used.
		1103	*
		1104	* The address space area must be already locked.
		1105	*
		1106	* @param a Address space area.
		1107	* @param page First page to be marked.
		1108	* @param count Number of page to be marked.
		1109	*
		1110	* @return 0 on failure and 1 on success.
		1111	*/
1780	jermar	1112	int used_space_insert(as_area_t *a, uintptr_t page, count_t count)
1387	jermar	1113	{
		1114	btree_node_t leaf, node;
		1115	count_t pages;
		1116	int i;
		1117
		1118	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1119	ASSERT(count);
		1120
		1121	pages = (count_t) btree_search(&a->used_space, page, &leaf);
		1122	if (pages) {
		1123	/*
		1124	* We hit the beginning of some used space.
		1125	*/
		1126	return 0;
		1127	}
		1128
1437	jermar	1129	if (!leaf->keys) {
		1130	btree_insert(&a->used_space, page, (void *) count, leaf);
		1131	return 1;
		1132	}
		1133
1387	jermar	1134	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1135	if (node) {
1780	jermar	1136	uintptr_t left_pg = node->key[node->keys - 1], right_pg = leaf->key[0];
1387	jermar	1137	count_t left_cnt = (count_t) node->value[node->keys - 1], right_cnt = (count_t) leaf->value[0];
		1138
		1139	/*
		1140	* Examine the possibility that the interval fits
		1141	* somewhere between the rightmost interval of
		1142	* the left neigbour and the first interval of the leaf.
		1143	*/
		1144
		1145	if (page >= right_pg) {
		1146	/* Do nothing. */
		1147	} else if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1148	/* The interval intersects with the left interval. */
		1149	return 0;
		1150	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1151	/* The interval intersects with the right interval. */
		1152	return 0;
		1153	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1154	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1155	node->value[node->keys - 1] += count + right_cnt;
1387	jermar	1156	btree_remove(&a->used_space, right_pg, leaf);
		1157	return 1;
		1158	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1159	/* The interval can be added by simply growing the left interval. */
1403	jermar	1160	node->value[node->keys - 1] += count;
1387	jermar	1161	return 1;
		1162	} else if (page + count*PAGE_SIZE == right_pg) {
		1163	/*
		1164	* The interval can be addded by simply moving base of the right
		1165	* interval down and increasing its size accordingly.
		1166	*/
1403	jermar	1167	leaf->value[0] += count;
1387	jermar	1168	leaf->key[0] = page;
		1169	return 1;
		1170	} else {
		1171	/*
		1172	* The interval is between both neigbouring intervals,
		1173	* but cannot be merged with any of them.
		1174	*/
		1175	btree_insert(&a->used_space, page, (void *) count, leaf);
		1176	return 1;
		1177	}
		1178	} else if (page < leaf->key[0]) {
1780	jermar	1179	uintptr_t right_pg = leaf->key[0];
1387	jermar	1180	count_t right_cnt = (count_t) leaf->value[0];
		1181
		1182	/*
		1183	* Investigate the border case in which the left neighbour does not
		1184	* exist but the interval fits from the left.
		1185	*/
		1186
		1187	if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1188	/* The interval intersects with the right interval. */
		1189	return 0;
		1190	} else if (page + count*PAGE_SIZE == right_pg) {
		1191	/*
		1192	* The interval can be added by moving the base of the right interval down
		1193	* and increasing its size accordingly.
		1194	*/
		1195	leaf->key[0] = page;
1403	jermar	1196	leaf->value[0] += count;
1387	jermar	1197	return 1;
		1198	} else {
		1199	/*
		1200	* The interval doesn't adjoin with the right interval.
		1201	* It must be added individually.
		1202	*/
		1203	btree_insert(&a->used_space, page, (void *) count, leaf);
		1204	return 1;
		1205	}
		1206	}
		1207
		1208	node = btree_leaf_node_right_neighbour(&a->used_space, leaf);
		1209	if (node) {
1780	jermar	1210	uintptr_t left_pg = leaf->key[leaf->keys - 1], right_pg = node->key[0];
1387	jermar	1211	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1], right_cnt = (count_t) node->value[0];
		1212
		1213	/*
		1214	* Examine the possibility that the interval fits
		1215	* somewhere between the leftmost interval of
		1216	* the right neigbour and the last interval of the leaf.
		1217	*/
		1218
		1219	if (page < left_pg) {
		1220	/* Do nothing. */
		1221	} else if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1222	/* The interval intersects with the left interval. */
		1223	return 0;
		1224	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1225	/* The interval intersects with the right interval. */
		1226	return 0;
		1227	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1228	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1229	leaf->value[leaf->keys - 1] += count + right_cnt;
1387	jermar	1230	btree_remove(&a->used_space, right_pg, node);
		1231	return 1;
		1232	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1233	/* The interval can be added by simply growing the left interval. */
1403	jermar	1234	leaf->value[leaf->keys - 1] += count;
1387	jermar	1235	return 1;
		1236	} else if (page + count*PAGE_SIZE == right_pg) {
		1237	/*
		1238	* The interval can be addded by simply moving base of the right
		1239	* interval down and increasing its size accordingly.
		1240	*/
1403	jermar	1241	node->value[0] += count;
1387	jermar	1242	node->key[0] = page;
		1243	return 1;
		1244	} else {
		1245	/*
		1246	* The interval is between both neigbouring intervals,
		1247	* but cannot be merged with any of them.
		1248	*/
		1249	btree_insert(&a->used_space, page, (void *) count, leaf);
		1250	return 1;
		1251	}
		1252	} else if (page >= leaf->key[leaf->keys - 1]) {
1780	jermar	1253	uintptr_t left_pg = leaf->key[leaf->keys - 1];
1387	jermar	1254	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1255
		1256	/*
		1257	* Investigate the border case in which the right neighbour does not
		1258	* exist but the interval fits from the right.
		1259	*/
		1260
		1261	if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
1403	jermar	1262	/* The interval intersects with the left interval. */
1387	jermar	1263	return 0;
		1264	} else if (left_pg + left_cnt*PAGE_SIZE == page) {
		1265	/* The interval can be added by growing the left interval. */
1403	jermar	1266	leaf->value[leaf->keys - 1] += count;
1387	jermar	1267	return 1;
		1268	} else {
		1269	/*
		1270	* The interval doesn't adjoin with the left interval.
		1271	* It must be added individually.
		1272	*/
		1273	btree_insert(&a->used_space, page, (void *) count, leaf);
		1274	return 1;
		1275	}
		1276	}
		1277
		1278	/*
		1279	* Note that if the algorithm made it thus far, the interval can fit only
		1280	* between two other intervals of the leaf. The two border cases were already
		1281	* resolved.
		1282	*/
		1283	for (i = 1; i < leaf->keys; i++) {
		1284	if (page < leaf->key[i]) {
1780	jermar	1285	uintptr_t left_pg = leaf->key[i - 1], right_pg = leaf->key[i];
1387	jermar	1286	count_t left_cnt = (count_t) leaf->value[i - 1], right_cnt = (count_t) leaf->value[i];
		1287
		1288	/*
		1289	* The interval fits between left_pg and right_pg.
		1290	*/
		1291
		1292	if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1293	/* The interval intersects with the left interval. */
		1294	return 0;
		1295	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1296	/* The interval intersects with the right interval. */
		1297	return 0;
		1298	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1299	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1300	leaf->value[i - 1] += count + right_cnt;
1387	jermar	1301	btree_remove(&a->used_space, right_pg, leaf);
		1302	return 1;
		1303	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1304	/* The interval can be added by simply growing the left interval. */
1403	jermar	1305	leaf->value[i - 1] += count;
1387	jermar	1306	return 1;
		1307	} else if (page + count*PAGE_SIZE == right_pg) {
		1308	/*
		1309	* The interval can be addded by simply moving base of the right
		1310	* interval down and increasing its size accordingly.
		1311	*/
1403	jermar	1312	leaf->value[i] += count;
1387	jermar	1313	leaf->key[i] = page;
		1314	return 1;
		1315	} else {
		1316	/*
		1317	* The interval is between both neigbouring intervals,
		1318	* but cannot be merged with any of them.
		1319	*/
		1320	btree_insert(&a->used_space, page, (void *) count, leaf);
		1321	return 1;
		1322	}
		1323	}
		1324	}
		1325
1735	decky	1326	panic("Inconsistency detected while adding %d pages of used space at %p.\n", count, page);
1387	jermar	1327	}
		1328
		1329	/** Mark portion of address space area as unused.
		1330	*
		1331	* The address space area must be already locked.
		1332	*
		1333	* @param a Address space area.
		1334	* @param page First page to be marked.
		1335	* @param count Number of page to be marked.
		1336	*
		1337	* @return 0 on failure and 1 on success.
		1338	*/
1780	jermar	1339	int used_space_remove(as_area_t *a, uintptr_t page, count_t count)
1387	jermar	1340	{
		1341	btree_node_t leaf, node;
		1342	count_t pages;
		1343	int i;
		1344
		1345	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1346	ASSERT(count);
		1347
		1348	pages = (count_t) btree_search(&a->used_space, page, &leaf);
		1349	if (pages) {
		1350	/*
		1351	* We are lucky, page is the beginning of some interval.
		1352	*/
		1353	if (count > pages) {
		1354	return 0;
		1355	} else if (count == pages) {
		1356	btree_remove(&a->used_space, page, leaf);
1403	jermar	1357	return 1;
1387	jermar	1358	} else {
		1359	/*
		1360	* Find the respective interval.
		1361	* Decrease its size and relocate its start address.
		1362	*/
		1363	for (i = 0; i < leaf->keys; i++) {
		1364	if (leaf->key[i] == page) {
		1365	leaf->key[i] += count*PAGE_SIZE;
1403	jermar	1366	leaf->value[i] -= count;
1387	jermar	1367	return 1;
		1368	}
		1369	}
		1370	goto error;
		1371	}
		1372	}
		1373
		1374	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1375	if (node && page < leaf->key[0]) {
1780	jermar	1376	uintptr_t left_pg = node->key[node->keys - 1];
1387	jermar	1377	count_t left_cnt = (count_t) node->value[node->keys - 1];
		1378
		1379	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1380	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1381	/*
		1382	* The interval is contained in the rightmost interval
		1383	* of the left neighbour and can be removed by
		1384	* updating the size of the bigger interval.
		1385	*/
1403	jermar	1386	node->value[node->keys - 1] -= count;
1387	jermar	1387	return 1;
		1388	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1389	count_t new_cnt;
1387	jermar	1390
		1391	/*
		1392	* The interval is contained in the rightmost interval
		1393	* of the left neighbour but its removal requires
		1394	* both updating the size of the original interval and
		1395	* also inserting a new interval.
		1396	*/
1403	jermar	1397	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1398	node->value[node->keys - 1] -= count + new_cnt;
1387	jermar	1399	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1400	return 1;
		1401	}
		1402	}
		1403	return 0;
		1404	} else if (page < leaf->key[0]) {
		1405	return 0;
		1406	}
		1407
		1408	if (page > leaf->key[leaf->keys - 1]) {
1780	jermar	1409	uintptr_t left_pg = leaf->key[leaf->keys - 1];
1387	jermar	1410	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1411
		1412	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1413	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1414	/*
		1415	* The interval is contained in the rightmost interval
		1416	* of the leaf and can be removed by updating the size
		1417	* of the bigger interval.
		1418	*/
1403	jermar	1419	leaf->value[leaf->keys - 1] -= count;
1387	jermar	1420	return 1;
		1421	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1422	count_t new_cnt;
1387	jermar	1423
		1424	/*
		1425	* The interval is contained in the rightmost interval
		1426	* of the leaf but its removal requires both updating
		1427	* the size of the original interval and
		1428	* also inserting a new interval.
		1429	*/
1403	jermar	1430	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1431	leaf->value[leaf->keys - 1] -= count + new_cnt;
1387	jermar	1432	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1433	return 1;
		1434	}
		1435	}
		1436	return 0;
		1437	}
		1438
		1439	/*
		1440	* The border cases have been already resolved.
		1441	* Now the interval can be only between intervals of the leaf.
		1442	*/
		1443	for (i = 1; i < leaf->keys - 1; i++) {
		1444	if (page < leaf->key[i]) {
1780	jermar	1445	uintptr_t left_pg = leaf->key[i - 1];
1387	jermar	1446	count_t left_cnt = (count_t) leaf->value[i - 1];
		1447
		1448	/*
		1449	* Now the interval is between intervals corresponding to (i - 1) and i.
		1450	*/
		1451	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1452	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1453	/*
		1454	* The interval is contained in the interval (i - 1)
		1455	* of the leaf and can be removed by updating the size
		1456	* of the bigger interval.
		1457	*/
1403	jermar	1458	leaf->value[i - 1] -= count;
1387	jermar	1459	return 1;
		1460	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1461	count_t new_cnt;
1387	jermar	1462
		1463	/*
		1464	* The interval is contained in the interval (i - 1)
		1465	* of the leaf but its removal requires both updating
		1466	* the size of the original interval and
		1467	* also inserting a new interval.
		1468	*/
1403	jermar	1469	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1470	leaf->value[i - 1] -= count + new_cnt;
1387	jermar	1471	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1472	return 1;
		1473	}
		1474	}
		1475	return 0;
		1476	}
		1477	}
		1478
		1479	error:
1735	decky	1480	panic("Inconsistency detected while removing %d pages of used space from %p.\n", count, page);
1387	jermar	1481	}
		1482
1409	jermar	1483	/** Remove reference to address space area share info.
		1484	*
		1485	* If the reference count drops to 0, the sh_info is deallocated.
		1486	*
		1487	* @param sh_info Pointer to address space area share info.
		1488	*/
		1489	void sh_info_remove_reference(share_info_t *sh_info)
		1490	{
		1491	bool dealloc = false;
		1492
		1493	mutex_lock(&sh_info->lock);
		1494	ASSERT(sh_info->refcount);
		1495	if (--sh_info->refcount == 0) {
		1496	dealloc = true;
1495	jermar	1497	link_t *cur;
1409	jermar	1498
		1499	/*
		1500	* Now walk carefully the pagemap B+tree and free/remove
		1501	* reference from all frames found there.
		1502	*/
1495	jermar	1503	for (cur = sh_info->pagemap.leaf_head.next; cur != &sh_info->pagemap.leaf_head; cur = cur->next) {
1409	jermar	1504	btree_node_t *node;
1495	jermar	1505	int i;
1409	jermar	1506
1495	jermar	1507	node = list_get_instance(cur, btree_node_t, leaf_link);
		1508	for (i = 0; i < node->keys; i++)
1780	jermar	1509	frame_free((uintptr_t) node->value[i]);
1409	jermar	1510	}
		1511
		1512	}
		1513	mutex_unlock(&sh_info->lock);
		1514
		1515	if (dealloc) {
		1516	btree_destroy(&sh_info->pagemap);
		1517	free(sh_info);
		1518	}
		1519	}
		1520
1235	jermar	1521	/*
		1522	* Address space related syscalls.
		1523	*/
		1524
		1525	/** Wrapper for as_area_create(). */
1780	jermar	1526	unative_t sys_as_area_create(uintptr_t address, size_t size, int flags)
1235	jermar	1527	{
1424	jermar	1528	if (as_area_create(AS, flags \| AS_AREA_CACHEABLE, size, address, AS_AREA_ATTR_NONE, &anon_backend, NULL))
1780	jermar	1529	return (unative_t) address;
1235	jermar	1530	else
1780	jermar	1531	return (unative_t) -1;
1235	jermar	1532	}
		1533
1793	jermar	1534	/** Wrapper for as_area_resize(). */
1780	jermar	1535	unative_t sys_as_area_resize(uintptr_t address, size_t size, int flags)
1235	jermar	1536	{
1780	jermar	1537	return (unative_t) as_area_resize(AS, address, size, 0);
1235	jermar	1538	}
		1539
1793	jermar	1540	/** Wrapper for as_area_destroy(). */
1780	jermar	1541	unative_t sys_as_area_destroy(uintptr_t address)
1306	jermar	1542	{
1780	jermar	1543	return (unative_t) as_area_destroy(AS, address);
1306	jermar	1544	}
1702	cejka	1545
1757	jermar	1546	/** @}
1702	cejka	1547	*/

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(root)//trunk/kernel/generic/src/mm/as.c – Rev 1889