WebSVN – HelenOS – Blame – //branches/dd/kernel/generic/src/mm/as.c

Rev	Author	Line No.	Line
703	jermar	1	/*
2071	jermar	2	* Copyright (c) 2001-2006 Jakub Jermar
703	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>
2183	jermar	60	#include <preemption.h>
703	jermar	61	#include <synch/spinlock.h>
1380	jermar	62	#include <synch/mutex.h>
788	jermar	63	#include <adt/list.h>
1147	jermar	64	#include <adt/btree.h>
1235	jermar	65	#include <proc/task.h>
1288	jermar	66	#include <proc/thread.h>
1235	jermar	67	#include <arch/asm.h>
703	jermar	68	#include <panic.h>
		69	#include <debug.h>
1235	jermar	70	#include <print.h>
703	jermar	71	#include <memstr.h>
1070	jermar	72	#include <macros.h>
703	jermar	73	#include <arch.h>
1235	jermar	74	#include <errno.h>
		75	#include <config.h>
1387	jermar	76	#include <align.h>
1235	jermar	77	#include <arch/types.h>
1288	jermar	78	#include <syscall/copy.h>
		79	#include <arch/interrupt.h>
703	jermar	80
2009	jermar	81	#ifdef CONFIG_VIRT_IDX_DCACHE
		82	#include <arch/mm/cache.h>
		83	#endif /* CONFIG_VIRT_IDX_DCACHE */
		84
1757	jermar	85	/**
		86	* Each architecture decides what functions will be used to carry out
		87	* address space operations such as creating or locking page tables.
		88	*/
756	jermar	89	as_operations_t *as_operations = NULL;
703	jermar	90
1890	jermar	91	/**
		92	* Slab for as_t objects.
		93	*/
		94	static slab_cache_t *as_slab;
		95
2087	jermar	96	/**
2170	jermar	97	* This lock serializes access to the ASID subsystem.
		98	* It protects:
		99	* - inactive_as_with_asid_head list
		100	* - as->asid for each as of the as_t type
		101	* - asids_allocated counter
2087	jermar	102	*/
2170	jermar	103	SPINLOCK_INITIALIZE(asidlock);
823	jermar	104
		105	/**
		106	* This list contains address spaces that are not active on any
		107	* processor and that have valid ASID.
		108	*/
		109	LIST_INITIALIZE(inactive_as_with_asid_head);
		110
757	jermar	111	/** Kernel address space. */
		112	as_t *AS_KERNEL = NULL;
		113
4055	trochtova	114	static int area_flags_to_page_flags(int);
		115	static as_area_t find_area_and_lock(as_t , uintptr_t);
		116	static bool check_area_conflicts(as_t , uintptr_t, size_t, as_area_t );
		117	static void sh_info_remove_reference(share_info_t *);
703	jermar	118
1891	jermar	119	static int as_constructor(void *obj, int flags)
		120	{
		121	as_t as = (as_t ) obj;
		122	int rc;
		123
		124	link_initialize(&as->inactive_as_with_asid_link);
4055	trochtova	125	mutex_initialize(&as->lock, MUTEX_PASSIVE);
1891	jermar	126
		127	rc = as_constructor_arch(as, flags);
		128
		129	return rc;
		130	}
		131
		132	static int as_destructor(void *obj)
		133	{
		134	as_t as = (as_t ) obj;
		135
		136	return as_destructor_arch(as);
		137	}
		138
756	jermar	139	/** Initialize address space subsystem. */
		140	void as_init(void)
		141	{
		142	as_arch_init();
2126	decky	143
1891	jermar	144	as_slab = slab_cache_create("as_slab", sizeof(as_t), 0,
2087	jermar	145	as_constructor, as_destructor, SLAB_CACHE_MAGDEFERRED);
1890	jermar	146
789	palkovsky	147	AS_KERNEL = as_create(FLAG_AS_KERNEL);
1383	decky	148	if (!AS_KERNEL)
4055	trochtova	149	panic("Cannot create kernel address space.");
1383	decky	150
4055	trochtova	151	/* Make sure the kernel address space
		152	* reference count never drops to zero.
		153	*/
		154	atomic_set(&AS_KERNEL->refcount, 1);
756	jermar	155	}
		156
757	jermar	157	/** Create address space.
		158	*
4055	trochtova	159	* @param flags Flags that influence the way in wich the address space
		160	* is created.
757	jermar	161	*/
756	jermar	162	as_t *as_create(int flags)
703	jermar	163	{
		164	as_t *as;
		165
1890	jermar	166	as = (as_t *) slab_alloc(as_slab, 0);
1891	jermar	167	(void) as_create_arch(as, 0);
		168
1147	jermar	169	btree_create(&as->as_area_btree);
822	palkovsky	170
		171	if (flags & FLAG_AS_KERNEL)
		172	as->asid = ASID_KERNEL;
		173	else
		174	as->asid = ASID_INVALID;
		175
2183	jermar	176	atomic_set(&as->refcount, 0);
1415	jermar	177	as->cpu_refcount = 0;
2089	decky	178	#ifdef AS_PAGE_TABLE
2106	jermar	179	as->genarch.page_table = page_table_create(flags);
2089	decky	180	#else
		181	page_table_create(flags);
		182	#endif
4055	trochtova	183
703	jermar	184	return as;
		185	}
		186
1468	jermar	187	/** Destroy adress space.
		188	*
2087	jermar	189	* When there are no tasks referencing this address space (i.e. its refcount is
		190	* zero), the address space can be destroyed.
2183	jermar	191	*
		192	* We know that we don't hold any spinlock.
4055	trochtova	193	*
		194	* @param as Address space to be destroyed.
1468	jermar	195	*/
		196	void as_destroy(as_t *as)
973	palkovsky	197	{
1468	jermar	198	ipl_t ipl;
1594	jermar	199	bool cond;
2183	jermar	200	DEADLOCK_PROBE_INIT(p_asidlock);
973	palkovsky	201
2183	jermar	202	ASSERT(atomic_get(&as->refcount) == 0);
1468	jermar	203
		204	/*
		205	* Since there is no reference to this area,
		206	* it is safe not to lock its mutex.
		207	*/
2170	jermar	208
2183	jermar	209	/*
		210	* We need to avoid deadlock between TLB shootdown and asidlock.
		211	* We therefore try to take asid conditionally and if we don't succeed,
		212	* we enable interrupts and try again. This is done while preemption is
		213	* disabled to prevent nested context switches. We also depend on the
		214	* fact that so far no spinlocks are held.
		215	*/
		216	preemption_disable();
		217	ipl = interrupts_read();
		218	retry:
		219	interrupts_disable();
		220	if (!spinlock_trylock(&asidlock)) {
		221	interrupts_enable();
		222	DEADLOCK_PROBE(p_asidlock, DEADLOCK_THRESHOLD);
		223	goto retry;
		224	}
		225	preemption_enable(); /* Interrupts disabled, enable preemption */
1587	jermar	226	if (as->asid != ASID_INVALID && as != AS_KERNEL) {
1594	jermar	227	if (as != AS && as->cpu_refcount == 0)
1587	jermar	228	list_remove(&as->inactive_as_with_asid_link);
1468	jermar	229	asid_put(as->asid);
		230	}
2170	jermar	231	spinlock_unlock(&asidlock);
1468	jermar	232
		233	/*
		234	* Destroy address space areas of the address space.
1954	jermar	235	* The B+tree must be walked carefully because it is
1594	jermar	236	* also being destroyed.
1468	jermar	237	*/
1594	jermar	238	for (cond = true; cond; ) {
1468	jermar	239	btree_node_t *node;
1594	jermar	240
		241	ASSERT(!list_empty(&as->as_area_btree.leaf_head));
2087	jermar	242	node = list_get_instance(as->as_area_btree.leaf_head.next,
		243	btree_node_t, leaf_link);
1594	jermar	244
		245	if ((cond = node->keys)) {
		246	as_area_destroy(as, node->key[0]);
		247	}
1468	jermar	248	}
1495	jermar	249
1483	jermar	250	btree_destroy(&as->as_area_btree);
2089	decky	251	#ifdef AS_PAGE_TABLE
2106	jermar	252	page_table_destroy(as->genarch.page_table);
2089	decky	253	#else
		254	page_table_destroy(NULL);
		255	#endif
1468	jermar	256
		257	interrupts_restore(ipl);
2126	decky	258
1890	jermar	259	slab_free(as_slab, as);
973	palkovsky	260	}
		261
703	jermar	262	/** Create address space area of common attributes.
		263	*
		264	* The created address space area is added to the target address space.
		265	*
4055	trochtova	266	* @param as Target address space.
		267	* @param flags Flags of the area memory.
		268	* @param size Size of area.
		269	* @param base Base address of area.
		270	* @param attrs Attributes of the area.
		271	* @param backend Address space area backend. NULL if no backend is used.
		272	* @param backend_data NULL or a pointer to an array holding two void *.
703	jermar	273	*
4055	trochtova	274	* @return Address space area on success or NULL on failure.
703	jermar	275	*/
2069	jermar	276	as_area_t *
		277	as_area_create(as_t *as, int flags, size_t size, uintptr_t base, int attrs,
4055	trochtova	278	mem_backend_t backend, mem_backend_data_t backend_data)
703	jermar	279	{
		280	ipl_t ipl;
		281	as_area_t *a;
		282
		283	if (base % PAGE_SIZE)
1048	jermar	284	return NULL;
		285
1233	jermar	286	if (!size)
		287	return NULL;
		288
1048	jermar	289	/* Writeable executable areas are not supported. */
		290	if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
		291	return NULL;
703	jermar	292
		293	ipl = interrupts_disable();
1380	jermar	294	mutex_lock(&as->lock);
703	jermar	295
1048	jermar	296	if (!check_area_conflicts(as, base, size, NULL)) {
1380	jermar	297	mutex_unlock(&as->lock);
1048	jermar	298	interrupts_restore(ipl);
		299	return NULL;
		300	}
703	jermar	301
822	palkovsky	302	a = (as_area_t *) malloc(sizeof(as_area_t), 0);
703	jermar	303
4055	trochtova	304	mutex_initialize(&a->lock, MUTEX_PASSIVE);
822	palkovsky	305
1424	jermar	306	a->as = as;
1026	jermar	307	a->flags = flags;
1239	jermar	308	a->attributes = attrs;
1048	jermar	309	a->pages = SIZE2FRAMES(size);
822	palkovsky	310	a->base = base;
1409	jermar	311	a->sh_info = NULL;
		312	a->backend = backend;
1424	jermar	313	if (backend_data)
		314	a->backend_data = *backend_data;
		315	else
4055	trochtova	316	memsetb(&a->backend_data, sizeof(a->backend_data), 0);
1424	jermar	317
1387	jermar	318	btree_create(&a->used_space);
822	palkovsky	319
1147	jermar	320	btree_insert(&as->as_area_btree, base, (void *) a, NULL);
822	palkovsky	321
1380	jermar	322	mutex_unlock(&as->lock);
703	jermar	323	interrupts_restore(ipl);
704	jermar	324
703	jermar	325	return a;
		326	}
		327
1235	jermar	328	/** Find address space area and change it.
		329	*
4055	trochtova	330	* @param as Address space.
		331	* @param address Virtual address belonging to the area to be changed.
		332	* Must be page-aligned.
		333	* @param size New size of the virtual memory block starting at
		334	* address.
		335	* @param flags Flags influencing the remap operation. Currently unused.
1235	jermar	336	*
4055	trochtova	337	* @return Zero on success or a value from @ref errno.h otherwise.
1235	jermar	338	*/
1780	jermar	339	int as_area_resize(as_t *as, uintptr_t address, size_t size, int flags)
1235	jermar	340	{
1306	jermar	341	as_area_t *area;
1235	jermar	342	ipl_t ipl;
		343	size_t pages;
		344
		345	ipl = interrupts_disable();
1380	jermar	346	mutex_lock(&as->lock);
1235	jermar	347
		348	/*
		349	* Locate the area.
		350	*/
		351	area = find_area_and_lock(as, address);
		352	if (!area) {
1380	jermar	353	mutex_unlock(&as->lock);
1235	jermar	354	interrupts_restore(ipl);
1306	jermar	355	return ENOENT;
1235	jermar	356	}
		357
1424	jermar	358	if (area->backend == &phys_backend) {
1235	jermar	359	/*
		360	* Remapping of address space areas associated
		361	* with memory mapped devices is not supported.
		362	*/
1380	jermar	363	mutex_unlock(&area->lock);
		364	mutex_unlock(&as->lock);
1235	jermar	365	interrupts_restore(ipl);
1306	jermar	366	return ENOTSUP;
1235	jermar	367	}
1409	jermar	368	if (area->sh_info) {
		369	/*
		370	* Remapping of shared address space areas
		371	* is not supported.
		372	*/
		373	mutex_unlock(&area->lock);
		374	mutex_unlock(&as->lock);
		375	interrupts_restore(ipl);
		376	return ENOTSUP;
		377	}
1235	jermar	378
		379	pages = SIZE2FRAMES((address - area->base) + size);
		380	if (!pages) {
		381	/*
		382	* Zero size address space areas are not allowed.
		383	*/
1380	jermar	384	mutex_unlock(&area->lock);
		385	mutex_unlock(&as->lock);
1235	jermar	386	interrupts_restore(ipl);
1306	jermar	387	return EPERM;
1235	jermar	388	}
		389
		390	if (pages < area->pages) {
1403	jermar	391	bool cond;
4055	trochtova	392	uintptr_t start_free = area->base + pages * PAGE_SIZE;
1235	jermar	393
		394	/*
		395	* Shrinking the area.
		396	* No need to check for overlaps.
		397	*/
1403	jermar	398
		399	/*
1436	jermar	400	* Start TLB shootdown sequence.
		401	*/
4055	trochtova	402	tlb_shootdown_start(TLB_INVL_PAGES, as->asid, area->base +
2087	jermar	403	pages * PAGE_SIZE, area->pages - pages);
1436	jermar	404
		405	/*
1403	jermar	406	* Remove frames belonging to used space starting from
		407	* the highest addresses downwards until an overlap with
		408	* the resized address space area is found. Note that this
		409	* is also the right way to remove part of the used_space
		410	* B+tree leaf list.
		411	*/
		412	for (cond = true; cond;) {
		413	btree_node_t *node;
		414
		415	ASSERT(!list_empty(&area->used_space.leaf_head));
2087	jermar	416	node =
		417	list_get_instance(area->used_space.leaf_head.prev,
		418	btree_node_t, leaf_link);
1403	jermar	419	if ((cond = (bool) node->keys)) {
1780	jermar	420	uintptr_t b = node->key[node->keys - 1];
4537	trochtova	421	size_t c =
		422	(size_t) node->value[node->keys - 1];
2745	decky	423	unsigned int i = 0;
1235	jermar	424
2087	jermar	425	if (overlaps(b, c * PAGE_SIZE, area->base,
2133	jermar	426	pages * PAGE_SIZE)) {
1403	jermar	427
2087	jermar	428	if (b + c * PAGE_SIZE <= start_free) {
1403	jermar	429	/*
2087	jermar	430	* The whole interval fits
		431	* completely in the resized
		432	* address space area.
1403	jermar	433	*/
		434	break;
		435	}
		436
		437	/*
2087	jermar	438	* Part of the interval corresponding
		439	* to b and c overlaps with the resized
		440	* address space area.
1403	jermar	441	*/
		442
		443	cond = false; /* we are almost done */
		444	i = (start_free - b) >> PAGE_WIDTH;
2087	jermar	445	if (!used_space_remove(area, start_free,
		446	c - i))
4055	trochtova	447	panic("Cannot remove used "
		448	"space.");
1403	jermar	449	} else {
		450	/*
2087	jermar	451	* The interval of used space can be
		452	* completely removed.
1403	jermar	453	*/
		454	if (!used_space_remove(area, b, c))
4055	trochtova	455	panic("Cannot remove used "
		456	"space.");
1403	jermar	457	}
		458
		459	for (; i < c; i++) {
		460	pte_t *pte;
		461
		462	page_table_lock(as, false);
2087	jermar	463	pte = page_mapping_find(as, b +
		464	i * PAGE_SIZE);
		465	ASSERT(pte && PTE_VALID(pte) &&
		466	PTE_PRESENT(pte));
		467	if (area->backend &&
		468	area->backend->frame_free) {
1424	jermar	469	area->backend->frame_free(area,
2087	jermar	470	b + i * PAGE_SIZE,
		471	PTE_GET_FRAME(pte));
1409	jermar	472	}
2087	jermar	473	page_mapping_remove(as, b +
		474	i * PAGE_SIZE);
1403	jermar	475	page_table_unlock(as, false);
		476	}
1235	jermar	477	}
		478	}
1436	jermar	479
1235	jermar	480	/*
1436	jermar	481	* Finish TLB shootdown sequence.
1235	jermar	482	*/
2183	jermar	483
2087	jermar	484	tlb_invalidate_pages(as->asid, area->base + pages * PAGE_SIZE,
		485	area->pages - pages);
1889	jermar	486	/*
		487	* Invalidate software translation caches (e.g. TSB on sparc64).
		488	*/
2087	jermar	489	as_invalidate_translation_cache(as, area->base +
		490	pages * PAGE_SIZE, area->pages - pages);
2183	jermar	491	tlb_shootdown_finalize();
		492
1235	jermar	493	} else {
		494	/*
		495	* Growing the area.
		496	* Check for overlaps with other address space areas.
		497	*/
2087	jermar	498	if (!check_area_conflicts(as, address, pages * PAGE_SIZE,
		499	area)) {
1380	jermar	500	mutex_unlock(&area->lock);
		501	mutex_unlock(&as->lock);
1235	jermar	502	interrupts_restore(ipl);
1306	jermar	503	return EADDRNOTAVAIL;
1235	jermar	504	}
		505	}
		506
		507	area->pages = pages;
		508
1380	jermar	509	mutex_unlock(&area->lock);
		510	mutex_unlock(&as->lock);
1235	jermar	511	interrupts_restore(ipl);
		512
1306	jermar	513	return 0;
1235	jermar	514	}
		515
1306	jermar	516	/** Destroy address space area.
		517	*
4055	trochtova	518	* @param as Address space.
		519	* @param address Address within the area to be deleted.
1306	jermar	520	*
4055	trochtova	521	* @return Zero on success or a value from @ref errno.h on failure.
1306	jermar	522	*/
1780	jermar	523	int as_area_destroy(as_t *as, uintptr_t address)
1306	jermar	524	{
		525	as_area_t *area;
1780	jermar	526	uintptr_t base;
1495	jermar	527	link_t *cur;
1306	jermar	528	ipl_t ipl;
		529
		530	ipl = interrupts_disable();
1380	jermar	531	mutex_lock(&as->lock);
1306	jermar	532
		533	area = find_area_and_lock(as, address);
		534	if (!area) {
1380	jermar	535	mutex_unlock(&as->lock);
1306	jermar	536	interrupts_restore(ipl);
		537	return ENOENT;
		538	}
		539
1403	jermar	540	base = area->base;
		541
1411	jermar	542	/*
1436	jermar	543	* Start TLB shootdown sequence.
		544	*/
1889	jermar	545	tlb_shootdown_start(TLB_INVL_PAGES, as->asid, area->base, area->pages);
1436	jermar	546
		547	/*
1411	jermar	548	* Visit only the pages mapped by used_space B+tree.
		549	*/
2087	jermar	550	for (cur = area->used_space.leaf_head.next;
		551	cur != &area->used_space.leaf_head; cur = cur->next) {
1411	jermar	552	btree_node_t *node;
2745	decky	553	unsigned int i;
1403	jermar	554
1495	jermar	555	node = list_get_instance(cur, btree_node_t, leaf_link);
		556	for (i = 0; i < node->keys; i++) {
1780	jermar	557	uintptr_t b = node->key[i];
4537	trochtova	558	size_t j;
1411	jermar	559	pte_t *pte;
1403	jermar	560
4537	trochtova	561	for (j = 0; j < (size_t) node->value[i]; j++) {
1411	jermar	562	page_table_lock(as, false);
2087	jermar	563	pte = page_mapping_find(as, b + j * PAGE_SIZE);
		564	ASSERT(pte && PTE_VALID(pte) &&
		565	PTE_PRESENT(pte));
		566	if (area->backend &&
		567	area->backend->frame_free) {
		568	area->backend->frame_free(area, b +
2133	jermar	569	j * PAGE_SIZE, PTE_GET_FRAME(pte));
1403	jermar	570	}
2087	jermar	571	page_mapping_remove(as, b + j * PAGE_SIZE);
1411	jermar	572	page_table_unlock(as, false);
1306	jermar	573	}
		574	}
		575	}
1403	jermar	576
1306	jermar	577	/*
1436	jermar	578	* Finish TLB shootdown sequence.
1306	jermar	579	*/
2183	jermar	580
1889	jermar	581	tlb_invalidate_pages(as->asid, area->base, area->pages);
		582	/*
2087	jermar	583	* Invalidate potential software translation caches (e.g. TSB on
		584	* sparc64).
1889	jermar	585	*/
		586	as_invalidate_translation_cache(as, area->base, area->pages);
2183	jermar	587	tlb_shootdown_finalize();
1889	jermar	588
1436	jermar	589	btree_destroy(&area->used_space);
1306	jermar	590
1309	jermar	591	area->attributes \|= AS_AREA_ATTR_PARTIAL;
1409	jermar	592
		593	if (area->sh_info)
		594	sh_info_remove_reference(area->sh_info);
		595
1380	jermar	596	mutex_unlock(&area->lock);
1306	jermar	597
		598	/*
		599	* Remove the empty area from address space.
		600	*/
1889	jermar	601	btree_remove(&as->as_area_btree, base, NULL);
1306	jermar	602
1309	jermar	603	free(area);
		604
1889	jermar	605	mutex_unlock(&as->lock);
1306	jermar	606	interrupts_restore(ipl);
		607	return 0;
		608	}
		609
1413	jermar	610	/** Share address space area with another or the same address space.
1235	jermar	611	*
1424	jermar	612	* Address space area mapping is shared with a new address space area.
		613	* If the source address space area has not been shared so far,
		614	* a new sh_info is created. The new address space area simply gets the
		615	* sh_info of the source area. The process of duplicating the
		616	* mapping is done through the backend share function.
1413	jermar	617	*
4055	trochtova	618	* @param src_as Pointer to source address space.
		619	* @param src_base Base address of the source address space area.
		620	* @param acc_size Expected size of the source area.
		621	* @param dst_as Pointer to destination address space.
		622	* @param dst_base Target base address.
1417	jermar	623	* @param dst_flags_mask Destination address space area flags mask.
1235	jermar	624	*
4055	trochtova	625	* @return Zero on success or ENOENT if there is no such task or if
		626	* there is no such address space area, EPERM if there was
		627	* a problem in accepting the area or ENOMEM if there was a
		628	* problem in allocating destination address space area.
		629	* ENOTSUP is returned if the address space area backend
		630	* does not support sharing.
1235	jermar	631	*/
1780	jermar	632	int as_area_share(as_t *src_as, uintptr_t src_base, size_t acc_size,
2647	jermar	633	as_t *dst_as, uintptr_t dst_base, int dst_flags_mask)
1235	jermar	634	{
		635	ipl_t ipl;
1239	jermar	636	int src_flags;
		637	size_t src_size;
		638	as_area_t src_area, dst_area;
1413	jermar	639	share_info_t *sh_info;
1424	jermar	640	mem_backend_t *src_backend;
		641	mem_backend_data_t src_backend_data;
1434	palkovsky	642
1235	jermar	643	ipl = interrupts_disable();
1380	jermar	644	mutex_lock(&src_as->lock);
1329	palkovsky	645	src_area = find_area_and_lock(src_as, src_base);
1239	jermar	646	if (!src_area) {
1238	jermar	647	/*
		648	* Could not find the source address space area.
		649	*/
1380	jermar	650	mutex_unlock(&src_as->lock);
1238	jermar	651	interrupts_restore(ipl);
		652	return ENOENT;
		653	}
2007	jermar	654
1424	jermar	655	if (!src_area->backend \|\| !src_area->backend->share) {
1413	jermar	656	/*
1851	jermar	657	* There is no backend or the backend does not
1424	jermar	658	* know how to share the area.
1413	jermar	659	*/
		660	mutex_unlock(&src_area->lock);
		661	mutex_unlock(&src_as->lock);
		662	interrupts_restore(ipl);
		663	return ENOTSUP;
		664	}
		665
1239	jermar	666	src_size = src_area->pages * PAGE_SIZE;
		667	src_flags = src_area->flags;
1424	jermar	668	src_backend = src_area->backend;
		669	src_backend_data = src_area->backend_data;
1544	palkovsky	670
		671	/* Share the cacheable flag from the original mapping */
		672	if (src_flags & AS_AREA_CACHEABLE)
		673	dst_flags_mask \|= AS_AREA_CACHEABLE;
		674
2087	jermar	675	if (src_size != acc_size \|\|
		676	(src_flags & dst_flags_mask) != dst_flags_mask) {
1413	jermar	677	mutex_unlock(&src_area->lock);
		678	mutex_unlock(&src_as->lock);
1235	jermar	679	interrupts_restore(ipl);
		680	return EPERM;
		681	}
1413	jermar	682
1235	jermar	683	/*
1413	jermar	684	* Now we are committed to sharing the area.
1954	jermar	685	* First, prepare the area for sharing.
1413	jermar	686	* Then it will be safe to unlock it.
		687	*/
		688	sh_info = src_area->sh_info;
		689	if (!sh_info) {
		690	sh_info = (share_info_t *) malloc(sizeof(share_info_t), 0);
4055	trochtova	691	mutex_initialize(&sh_info->lock, MUTEX_PASSIVE);
1413	jermar	692	sh_info->refcount = 2;
		693	btree_create(&sh_info->pagemap);
		694	src_area->sh_info = sh_info;
2647	jermar	695	/*
		696	* Call the backend to setup sharing.
		697	*/
		698	src_area->backend->share(src_area);
1413	jermar	699	} else {
		700	mutex_lock(&sh_info->lock);
		701	sh_info->refcount++;
		702	mutex_unlock(&sh_info->lock);
		703	}
		704
		705	mutex_unlock(&src_area->lock);
		706	mutex_unlock(&src_as->lock);
		707
		708	/*
1239	jermar	709	* Create copy of the source address space area.
		710	* The destination area is created with AS_AREA_ATTR_PARTIAL
		711	* attribute set which prevents race condition with
		712	* preliminary as_page_fault() calls.
1417	jermar	713	* The flags of the source area are masked against dst_flags_mask
		714	* to support sharing in less privileged mode.
1235	jermar	715	*/
1461	palkovsky	716	dst_area = as_area_create(dst_as, dst_flags_mask, src_size, dst_base,
2087	jermar	717	AS_AREA_ATTR_PARTIAL, src_backend, &src_backend_data);
1239	jermar	718	if (!dst_area) {
1235	jermar	719	/*
		720	* Destination address space area could not be created.
		721	*/
1413	jermar	722	sh_info_remove_reference(sh_info);
		723
1235	jermar	724	interrupts_restore(ipl);
		725	return ENOMEM;
		726	}
2009	jermar	727
1235	jermar	728	/*
1239	jermar	729	* Now the destination address space area has been
		730	* fully initialized. Clear the AS_AREA_ATTR_PARTIAL
1413	jermar	731	* attribute and set the sh_info.
1239	jermar	732	*/
2009	jermar	733	mutex_lock(&dst_as->lock);
1380	jermar	734	mutex_lock(&dst_area->lock);
1239	jermar	735	dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
1413	jermar	736	dst_area->sh_info = sh_info;
1380	jermar	737	mutex_unlock(&dst_area->lock);
2009	jermar	738	mutex_unlock(&dst_as->lock);
		739
1235	jermar	740	interrupts_restore(ipl);
		741
		742	return 0;
		743	}
		744
1423	jermar	745	/** Check access mode for address space area.
		746	*
		747	* The address space area must be locked prior to this call.
		748	*
4055	trochtova	749	* @param area Address space area.
		750	* @param access Access mode.
1423	jermar	751	*
4055	trochtova	752	* @return False if access violates area's permissions, true
		753	* otherwise.
1423	jermar	754	*/
		755	bool as_area_check_access(as_area_t *area, pf_access_t access)
		756	{
		757	int flagmap[] = {
		758	[PF_ACCESS_READ] = AS_AREA_READ,
		759	[PF_ACCESS_WRITE] = AS_AREA_WRITE,
		760	[PF_ACCESS_EXEC] = AS_AREA_EXEC
		761	};
		762
		763	if (!(area->flags & flagmap[access]))
		764	return false;
		765
		766	return true;
		767	}
		768
4055	trochtova	769	/** Change adress space area flags.
		770	*
		771	* The idea is to have the same data, but with a different access mode.
		772	* This is needed e.g. for writing code into memory and then executing it.
		773	* In order for this to work properly, this may copy the data
		774	* into private anonymous memory (unless it's already there).
		775	*
		776	* @param as Address space.
		777	* @param flags Flags of the area memory.
		778	* @param address Address within the area to be changed.
		779	*
		780	* @return Zero on success or a value from @ref errno.h on failure.
		781	*
		782	*/
		783	int as_area_change_flags(as_t *as, int flags, uintptr_t address)
		784	{
		785	as_area_t *area;
		786	uintptr_t base;
		787	link_t *cur;
		788	ipl_t ipl;
		789	int page_flags;
		790	uintptr_t *old_frame;
4537	trochtova	791	size_t frame_idx;
		792	size_t used_pages;
4055	trochtova	793
		794	/* Flags for the new memory mapping */
		795	page_flags = area_flags_to_page_flags(flags);
		796
		797	ipl = interrupts_disable();
		798	mutex_lock(&as->lock);
		799
		800	area = find_area_and_lock(as, address);
		801	if (!area) {
		802	mutex_unlock(&as->lock);
		803	interrupts_restore(ipl);
		804	return ENOENT;
		805	}
		806
		807	if ((area->sh_info) \|\| (area->backend != &anon_backend)) {
		808	/* Copying shared areas not supported yet */
		809	/* Copying non-anonymous memory not supported yet */
		810	mutex_unlock(&area->lock);
		811	mutex_unlock(&as->lock);
		812	interrupts_restore(ipl);
		813	return ENOTSUP;
		814	}
		815
		816	base = area->base;
		817
		818	/*
		819	* Compute total number of used pages in the used_space B+tree
		820	*/
		821	used_pages = 0;
		822
		823	for (cur = area->used_space.leaf_head.next;
		824	cur != &area->used_space.leaf_head; cur = cur->next) {
		825	btree_node_t *node;
		826	unsigned int i;
		827
		828	node = list_get_instance(cur, btree_node_t, leaf_link);
		829	for (i = 0; i < node->keys; i++) {
4537	trochtova	830	used_pages += (size_t) node->value[i];
4055	trochtova	831	}
		832	}
		833
		834	/* An array for storing frame numbers */
		835	old_frame = malloc(used_pages * sizeof(uintptr_t), 0);
		836
		837	/*
		838	* Start TLB shootdown sequence.
		839	*/
		840	tlb_shootdown_start(TLB_INVL_PAGES, as->asid, area->base, area->pages);
		841
		842	/*
		843	* Remove used pages from page tables and remember their frame
		844	* numbers.
		845	*/
		846	frame_idx = 0;
		847
		848	for (cur = area->used_space.leaf_head.next;
		849	cur != &area->used_space.leaf_head; cur = cur->next) {
		850	btree_node_t *node;
		851	unsigned int i;
		852
		853	node = list_get_instance(cur, btree_node_t, leaf_link);
		854	for (i = 0; i < node->keys; i++) {
		855	uintptr_t b = node->key[i];
4537	trochtova	856	size_t j;
4055	trochtova	857	pte_t *pte;
		858
4537	trochtova	859	for (j = 0; j < (size_t) node->value[i]; j++) {
4055	trochtova	860	page_table_lock(as, false);
		861	pte = page_mapping_find(as, b + j * PAGE_SIZE);
		862	ASSERT(pte && PTE_VALID(pte) &&
		863	PTE_PRESENT(pte));
		864	old_frame[frame_idx++] = PTE_GET_FRAME(pte);
		865
		866	/* Remove old mapping */
		867	page_mapping_remove(as, b + j * PAGE_SIZE);
		868	page_table_unlock(as, false);
		869	}
		870	}
		871	}
		872
		873	/*
		874	* Finish TLB shootdown sequence.
		875	*/
		876
		877	tlb_invalidate_pages(as->asid, area->base, area->pages);
		878
		879	/*
		880	* Invalidate potential software translation caches (e.g. TSB on
		881	* sparc64).
		882	*/
		883	as_invalidate_translation_cache(as, area->base, area->pages);
		884	tlb_shootdown_finalize();
		885
		886	/*
		887	* Set the new flags.
		888	*/
		889	area->flags = flags;
		890
		891	/*
		892	* Map pages back in with new flags. This step is kept separate
		893	* so that the memory area could not be accesed with both the old and
		894	* the new flags at once.
		895	*/
		896	frame_idx = 0;
		897
		898	for (cur = area->used_space.leaf_head.next;
		899	cur != &area->used_space.leaf_head; cur = cur->next) {
		900	btree_node_t *node;
		901	unsigned int i;
		902
		903	node = list_get_instance(cur, btree_node_t, leaf_link);
		904	for (i = 0; i < node->keys; i++) {
		905	uintptr_t b = node->key[i];
4537	trochtova	906	size_t j;
4055	trochtova	907
4537	trochtova	908	for (j = 0; j < (size_t) node->value[i]; j++) {
4055	trochtova	909	page_table_lock(as, false);
		910
		911	/* Insert the new mapping */
		912	page_mapping_insert(as, b + j * PAGE_SIZE,
		913	old_frame[frame_idx++], page_flags);
		914
		915	page_table_unlock(as, false);
		916	}
		917	}
		918	}
		919
		920	free(old_frame);
		921
		922	mutex_unlock(&area->lock);
		923	mutex_unlock(&as->lock);
		924	interrupts_restore(ipl);
		925
		926	return 0;
		927	}
		928
		929
703	jermar	930	/** Handle page fault within the current address space.
		931	*
4055	trochtova	932	* This is the high-level page fault handler. It decides whether the page fault
		933	* can be resolved by any backend and if so, it invokes the backend to resolve
		934	* the page fault.
1409	jermar	935	*
703	jermar	936	* Interrupts are assumed disabled.
		937	*
4055	trochtova	938	* @param page Faulting page.
		939	* @param access Access mode that caused the page fault (i.e.
		940	* read/write/exec).
		941	* @param istate Pointer to the interrupted state.
703	jermar	942	*
4055	trochtova	943	* @return AS_PF_FAULT on page fault, AS_PF_OK on success or
		944	* AS_PF_DEFER if the fault was caused by copy_to_uspace()
		945	* or copy_from_uspace().
703	jermar	946	*/
1780	jermar	947	int as_page_fault(uintptr_t page, pf_access_t access, istate_t *istate)
703	jermar	948	{
1044	jermar	949	pte_t *pte;
977	jermar	950	as_area_t *area;
703	jermar	951
1380	jermar	952	if (!THREAD)
1409	jermar	953	return AS_PF_FAULT;
1380	jermar	954
703	jermar	955	ASSERT(AS);
1044	jermar	956
1380	jermar	957	mutex_lock(&AS->lock);
977	jermar	958	area = find_area_and_lock(AS, page);
703	jermar	959	if (!area) {
		960	/*
		961	* No area contained mapping for 'page'.
		962	* Signal page fault to low-level handler.
		963	*/
1380	jermar	964	mutex_unlock(&AS->lock);
1288	jermar	965	goto page_fault;
703	jermar	966	}
		967
1239	jermar	968	if (area->attributes & AS_AREA_ATTR_PARTIAL) {
		969	/*
		970	* The address space area is not fully initialized.
		971	* Avoid possible race by returning error.
		972	*/
1380	jermar	973	mutex_unlock(&area->lock);
		974	mutex_unlock(&AS->lock);
1288	jermar	975	goto page_fault;
1239	jermar	976	}
		977
1424	jermar	978	if (!area->backend \|\| !area->backend->page_fault) {
1409	jermar	979	/*
		980	* The address space area is not backed by any backend
		981	* or the backend cannot handle page faults.
		982	*/
		983	mutex_unlock(&area->lock);
		984	mutex_unlock(&AS->lock);
		985	goto page_fault;
		986	}
1179	jermar	987
1044	jermar	988	page_table_lock(AS, false);
		989
703	jermar	990	/*
4055	trochtova	991	* To avoid race condition between two page faults on the same address,
		992	* we need to make sure the mapping has not been already inserted.
1044	jermar	993	*/
		994	if ((pte = page_mapping_find(AS, page))) {
		995	if (PTE_PRESENT(pte)) {
1423	jermar	996	if (((access == PF_ACCESS_READ) && PTE_READABLE(pte)) \|\|
2087	jermar	997	(access == PF_ACCESS_WRITE && PTE_WRITABLE(pte)) \|\|
		998	(access == PF_ACCESS_EXEC && PTE_EXECUTABLE(pte))) {
1423	jermar	999	page_table_unlock(AS, false);
		1000	mutex_unlock(&area->lock);
		1001	mutex_unlock(&AS->lock);
		1002	return AS_PF_OK;
		1003	}
1044	jermar	1004	}
		1005	}
1409	jermar	1006
1044	jermar	1007	/*
1409	jermar	1008	* Resort to the backend page fault handler.
703	jermar	1009	*/
1424	jermar	1010	if (area->backend->page_fault(area, page, access) != AS_PF_OK) {
1409	jermar	1011	page_table_unlock(AS, false);
		1012	mutex_unlock(&area->lock);
		1013	mutex_unlock(&AS->lock);
		1014	goto page_fault;
		1015	}
703	jermar	1016
1044	jermar	1017	page_table_unlock(AS, false);
1380	jermar	1018	mutex_unlock(&area->lock);
		1019	mutex_unlock(&AS->lock);
1288	jermar	1020	return AS_PF_OK;
		1021
		1022	page_fault:
		1023	if (THREAD->in_copy_from_uspace) {
		1024	THREAD->in_copy_from_uspace = false;
2087	jermar	1025	istate_set_retaddr(istate,
		1026	(uintptr_t) &memcpy_from_uspace_failover_address);
1288	jermar	1027	} else if (THREAD->in_copy_to_uspace) {
		1028	THREAD->in_copy_to_uspace = false;
2087	jermar	1029	istate_set_retaddr(istate,
		1030	(uintptr_t) &memcpy_to_uspace_failover_address);
1288	jermar	1031	} else {
		1032	return AS_PF_FAULT;
		1033	}
		1034
		1035	return AS_PF_DEFER;
703	jermar	1036	}
		1037
823	jermar	1038	/** Switch address spaces.
703	jermar	1039	*
1380	jermar	1040	* Note that this function cannot sleep as it is essentially a part of
2170	jermar	1041	* scheduling. Sleeping here would lead to deadlock on wakeup. Another
		1042	* thing which is forbidden in this context is locking the address space.
1380	jermar	1043	*
2183	jermar	1044	* When this function is enetered, no spinlocks may be held.
		1045	*
4055	trochtova	1046	* @param old Old address space or NULL.
		1047	* @param new New address space.
703	jermar	1048	*/
2106	jermar	1049	void as_switch(as_t old_as, as_t new_as)
703	jermar	1050	{
2183	jermar	1051	DEADLOCK_PROBE_INIT(p_asidlock);
		1052	preemption_disable();
		1053	retry:
		1054	(void) interrupts_disable();
		1055	if (!spinlock_trylock(&asidlock)) {
		1056	/*
		1057	* Avoid deadlock with TLB shootdown.
		1058	* We can enable interrupts here because
		1059	* preemption is disabled. We should not be
		1060	* holding any other lock.
		1061	*/
		1062	(void) interrupts_enable();
		1063	DEADLOCK_PROBE(p_asidlock, DEADLOCK_THRESHOLD);
		1064	goto retry;
		1065	}
		1066	preemption_enable();
703	jermar	1067
		1068	/*
823	jermar	1069	* First, take care of the old address space.
		1070	*/
2106	jermar	1071	if (old_as) {
		1072	ASSERT(old_as->cpu_refcount);
		1073	if((--old_as->cpu_refcount == 0) && (old_as != AS_KERNEL)) {
823	jermar	1074	/*
		1075	* The old address space is no longer active on
		1076	* any processor. It can be appended to the
		1077	* list of inactive address spaces with assigned
		1078	* ASID.
		1079	*/
2141	jermar	1080	ASSERT(old_as->asid != ASID_INVALID);
		1081	list_append(&old_as->inactive_as_with_asid_link,
		1082	&inactive_as_with_asid_head);
823	jermar	1083	}
1890	jermar	1084
		1085	/*
		1086	* Perform architecture-specific tasks when the address space
		1087	* is being removed from the CPU.
		1088	*/
2106	jermar	1089	as_deinstall_arch(old_as);
823	jermar	1090	}
		1091
		1092	/*
		1093	* Second, prepare the new address space.
		1094	*/
2106	jermar	1095	if ((new_as->cpu_refcount++ == 0) && (new_as != AS_KERNEL)) {
2170	jermar	1096	if (new_as->asid != ASID_INVALID)
2106	jermar	1097	list_remove(&new_as->inactive_as_with_asid_link);
2170	jermar	1098	else
		1099	new_as->asid = asid_get();
823	jermar	1100	}
2106	jermar	1101	#ifdef AS_PAGE_TABLE
		1102	SET_PTL0_ADDRESS(new_as->genarch.page_table);
		1103	#endif
823	jermar	1104
		1105	/*
703	jermar	1106	* Perform architecture-specific steps.
727	jermar	1107	* (e.g. write ASID to hardware register etc.)
703	jermar	1108	*/
2106	jermar	1109	as_install_arch(new_as);
2170	jermar	1110
		1111	spinlock_unlock(&asidlock);
703	jermar	1112
2106	jermar	1113	AS = new_as;
703	jermar	1114	}
754	jermar	1115
1235	jermar	1116	/** Convert address space area flags to page flags.
754	jermar	1117	*
4055	trochtova	1118	* @param aflags Flags of some address space area.
754	jermar	1119	*
4055	trochtova	1120	* @return Flags to be passed to page_mapping_insert().
754	jermar	1121	*/
1235	jermar	1122	int area_flags_to_page_flags(int aflags)
754	jermar	1123	{
		1124	int flags;
		1125
1178	jermar	1126	flags = PAGE_USER \| PAGE_PRESENT;
754	jermar	1127
1235	jermar	1128	if (aflags & AS_AREA_READ)
1026	jermar	1129	flags \|= PAGE_READ;
		1130
1235	jermar	1131	if (aflags & AS_AREA_WRITE)
1026	jermar	1132	flags \|= PAGE_WRITE;
		1133
1235	jermar	1134	if (aflags & AS_AREA_EXEC)
1026	jermar	1135	flags \|= PAGE_EXEC;
		1136
1424	jermar	1137	if (aflags & AS_AREA_CACHEABLE)
1178	jermar	1138	flags \|= PAGE_CACHEABLE;
		1139
754	jermar	1140	return flags;
		1141	}
756	jermar	1142
1235	jermar	1143	/** Compute flags for virtual address translation subsytem.
		1144	*
		1145	* The address space area must be locked.
		1146	* Interrupts must be disabled.
		1147	*
4055	trochtova	1148	* @param a Address space area.
1235	jermar	1149	*
4055	trochtova	1150	* @return Flags to be used in page_mapping_insert().
1235	jermar	1151	*/
1409	jermar	1152	int as_area_get_flags(as_area_t *a)
1235	jermar	1153	{
		1154	return area_flags_to_page_flags(a->flags);
		1155	}
		1156
756	jermar	1157	/** Create page table.
		1158	*
4055	trochtova	1159	* Depending on architecture, create either address space private or global page
		1160	* table.
756	jermar	1161	*
4055	trochtova	1162	* @param flags Flags saying whether the page table is for the kernel
		1163	* address space.
756	jermar	1164	*
4055	trochtova	1165	* @return First entry of the page table.
756	jermar	1166	*/
		1167	pte_t *page_table_create(int flags)
		1168	{
2125	decky	1169	ASSERT(as_operations);
		1170	ASSERT(as_operations->page_table_create);
		1171
		1172	return as_operations->page_table_create(flags);
756	jermar	1173	}
977	jermar	1174
1468	jermar	1175	/** Destroy page table.
		1176	*
		1177	* Destroy page table in architecture specific way.
		1178	*
4055	trochtova	1179	* @param page_table Physical address of PTL0.
1468	jermar	1180	*/
		1181	void page_table_destroy(pte_t *page_table)
		1182	{
2125	decky	1183	ASSERT(as_operations);
		1184	ASSERT(as_operations->page_table_destroy);
		1185
		1186	as_operations->page_table_destroy(page_table);
1468	jermar	1187	}
		1188
1044	jermar	1189	/** Lock page table.
		1190	*
		1191	* This function should be called before any page_mapping_insert(),
		1192	* page_mapping_remove() and page_mapping_find().
		1193	*
		1194	* Locking order is such that address space areas must be locked
		1195	* prior to this call. Address space can be locked prior to this
		1196	* call in which case the lock argument is false.
		1197	*
4055	trochtova	1198	* @param as Address space.
		1199	* @param lock If false, do not attempt to lock as->lock.
1044	jermar	1200	*/
		1201	void page_table_lock(as_t *as, bool lock)
		1202	{
		1203	ASSERT(as_operations);
		1204	ASSERT(as_operations->page_table_lock);
2125	decky	1205
1044	jermar	1206	as_operations->page_table_lock(as, lock);
		1207	}
		1208
		1209	/** Unlock page table.
		1210	*
4055	trochtova	1211	* @param as Address space.
		1212	* @param unlock If false, do not attempt to unlock as->lock.
1044	jermar	1213	*/
		1214	void page_table_unlock(as_t *as, bool unlock)
		1215	{
		1216	ASSERT(as_operations);
		1217	ASSERT(as_operations->page_table_unlock);
2125	decky	1218
1044	jermar	1219	as_operations->page_table_unlock(as, unlock);
		1220	}
		1221
977	jermar	1222
		1223	/** Find address space area and lock it.
		1224	*
		1225	* The address space must be locked and interrupts must be disabled.
		1226	*
4055	trochtova	1227	* @param as Address space.
		1228	* @param va Virtual address.
977	jermar	1229	*
4055	trochtova	1230	* @return Locked address space area containing va on success or
		1231	* NULL on failure.
977	jermar	1232	*/
1780	jermar	1233	as_area_t find_area_and_lock(as_t as, uintptr_t va)
977	jermar	1234	{
		1235	as_area_t *a;
1147	jermar	1236	btree_node_t leaf, lnode;
2745	decky	1237	unsigned int i;
977	jermar	1238
1147	jermar	1239	a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
		1240	if (a) {
		1241	/* va is the base address of an address space area */
1380	jermar	1242	mutex_lock(&a->lock);
1147	jermar	1243	return a;
		1244	}
		1245
		1246	/*
1150	jermar	1247	* Search the leaf node and the righmost record of its left neighbour
1147	jermar	1248	* to find out whether this is a miss or va belongs to an address
		1249	* space area found there.
		1250	*/
		1251
		1252	/* First, search the leaf node itself. */
		1253	for (i = 0; i < leaf->keys; i++) {
		1254	a = (as_area_t *) leaf->value[i];
1380	jermar	1255	mutex_lock(&a->lock);
1147	jermar	1256	if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
		1257	return a;
		1258	}
1380	jermar	1259	mutex_unlock(&a->lock);
1147	jermar	1260	}
977	jermar	1261
1147	jermar	1262	/*
1150	jermar	1263	* Second, locate the left neighbour and test its last record.
1148	jermar	1264	* Because of its position in the B+tree, it must have base < va.
1147	jermar	1265	*/
2087	jermar	1266	lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf);
		1267	if (lnode) {
1147	jermar	1268	a = (as_area_t *) lnode->value[lnode->keys - 1];
1380	jermar	1269	mutex_lock(&a->lock);
1147	jermar	1270	if (va < a->base + a->pages * PAGE_SIZE) {
1048	jermar	1271	return a;
1147	jermar	1272	}
1380	jermar	1273	mutex_unlock(&a->lock);
977	jermar	1274	}
		1275
		1276	return NULL;
		1277	}
1048	jermar	1278
		1279	/** Check area conflicts with other areas.
		1280	*
		1281	* The address space must be locked and interrupts must be disabled.
		1282	*
4055	trochtova	1283	* @param as Address space.
		1284	* @param va Starting virtual address of the area being tested.
		1285	* @param size Size of the area being tested.
		1286	* @param avoid_area Do not touch this area.
1048	jermar	1287	*
4055	trochtova	1288	* @return True if there is no conflict, false otherwise.
1048	jermar	1289	*/
4055	trochtova	1290	bool
		1291	check_area_conflicts(as_t as, uintptr_t va, size_t size, as_area_t avoid_area)
1048	jermar	1292	{
		1293	as_area_t *a;
1147	jermar	1294	btree_node_t leaf, node;
2745	decky	1295	unsigned int i;
1048	jermar	1296
1070	jermar	1297	/*
		1298	* We don't want any area to have conflicts with NULL page.
		1299	*/
		1300	if (overlaps(va, size, NULL, PAGE_SIZE))
		1301	return false;
		1302
1147	jermar	1303	/*
		1304	* The leaf node is found in O(log n), where n is proportional to
		1305	* the number of address space areas belonging to as.
		1306	* The check for conflicts is then attempted on the rightmost
1150	jermar	1307	* record in the left neighbour, the leftmost record in the right
		1308	* neighbour and all records in the leaf node itself.
1147	jermar	1309	*/
1048	jermar	1310
1147	jermar	1311	if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
		1312	if (a != avoid_area)
		1313	return false;
		1314	}
		1315
		1316	/* First, check the two border cases. */
1150	jermar	1317	if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	1318	a = (as_area_t *) node->value[node->keys - 1];
1380	jermar	1319	mutex_lock(&a->lock);
1147	jermar	1320	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1321	mutex_unlock(&a->lock);
1147	jermar	1322	return false;
		1323	}
1380	jermar	1324	mutex_unlock(&a->lock);
1147	jermar	1325	}
2087	jermar	1326	node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf);
		1327	if (node) {
1147	jermar	1328	a = (as_area_t *) node->value[0];
1380	jermar	1329	mutex_lock(&a->lock);
1147	jermar	1330	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1331	mutex_unlock(&a->lock);
1147	jermar	1332	return false;
		1333	}
1380	jermar	1334	mutex_unlock(&a->lock);
1147	jermar	1335	}
		1336
		1337	/* Second, check the leaf node. */
		1338	for (i = 0; i < leaf->keys; i++) {
		1339	a = (as_area_t *) leaf->value[i];
		1340
1048	jermar	1341	if (a == avoid_area)
		1342	continue;
1147	jermar	1343
1380	jermar	1344	mutex_lock(&a->lock);
1147	jermar	1345	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1346	mutex_unlock(&a->lock);
1147	jermar	1347	return false;
		1348	}
1380	jermar	1349	mutex_unlock(&a->lock);
1048	jermar	1350	}
		1351
1070	jermar	1352	/*
		1353	* So far, the area does not conflict with other areas.
		1354	* Check if it doesn't conflict with kernel address space.
		1355	*/
		1356	if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
		1357	return !overlaps(va, size,
2087	jermar	1358	KERNEL_ADDRESS_SPACE_START,
		1359	KERNEL_ADDRESS_SPACE_END - KERNEL_ADDRESS_SPACE_START);
1070	jermar	1360	}
		1361
1048	jermar	1362	return true;
		1363	}
1235	jermar	1364
2556	jermar	1365	/** Return size of the address space area with given base.
		1366	*
		1367	* @param base Arbitrary address insede the address space area.
		1368	*
		1369	* @return Size of the address space area in bytes or zero if it
		1370	* does not exist.
		1371	*/
		1372	size_t as_area_get_size(uintptr_t base)
1329	palkovsky	1373	{
		1374	ipl_t ipl;
		1375	as_area_t *src_area;
		1376	size_t size;
		1377
		1378	ipl = interrupts_disable();
		1379	src_area = find_area_and_lock(AS, base);
4055	trochtova	1380	if (src_area) {
1329	palkovsky	1381	size = src_area->pages * PAGE_SIZE;
1380	jermar	1382	mutex_unlock(&src_area->lock);
1329	palkovsky	1383	} else {
		1384	size = 0;
		1385	}
		1386	interrupts_restore(ipl);
		1387	return size;
		1388	}
		1389
1387	jermar	1390	/** Mark portion of address space area as used.
		1391	*
		1392	* The address space area must be already locked.
		1393	*
4055	trochtova	1394	* @param a Address space area.
		1395	* @param page First page to be marked.
		1396	* @param count Number of page to be marked.
1387	jermar	1397	*
4055	trochtova	1398	* @return Zero on failure and non-zero on success.
1387	jermar	1399	*/
4537	trochtova	1400	int used_space_insert(as_area_t *a, uintptr_t page, size_t count)
1387	jermar	1401	{
		1402	btree_node_t leaf, node;
4537	trochtova	1403	size_t pages;
2745	decky	1404	unsigned int i;
1387	jermar	1405
		1406	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1407	ASSERT(count);
		1408
4537	trochtova	1409	pages = (size_t) btree_search(&a->used_space, page, &leaf);
1387	jermar	1410	if (pages) {
		1411	/*
		1412	* We hit the beginning of some used space.
		1413	*/
		1414	return 0;
		1415	}
		1416
1437	jermar	1417	if (!leaf->keys) {
		1418	btree_insert(&a->used_space, page, (void *) count, leaf);
		1419	return 1;
		1420	}
		1421
1387	jermar	1422	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1423	if (node) {
2087	jermar	1424	uintptr_t left_pg = node->key[node->keys - 1];
		1425	uintptr_t right_pg = leaf->key[0];
4537	trochtova	1426	size_t left_cnt = (size_t) node->value[node->keys - 1];
		1427	size_t right_cnt = (size_t) leaf->value[0];
1387	jermar	1428
		1429	/*
		1430	* Examine the possibility that the interval fits
		1431	* somewhere between the rightmost interval of
		1432	* the left neigbour and the first interval of the leaf.
		1433	*/
		1434
		1435	if (page >= right_pg) {
		1436	/* Do nothing. */
2087	jermar	1437	} else if (overlaps(page, count * PAGE_SIZE, left_pg,
		1438	left_cnt * PAGE_SIZE)) {
1387	jermar	1439	/* The interval intersects with the left interval. */
		1440	return 0;
2087	jermar	1441	} else if (overlaps(page, count * PAGE_SIZE, right_pg,
		1442	right_cnt * PAGE_SIZE)) {
1387	jermar	1443	/* The interval intersects with the right interval. */
		1444	return 0;
2087	jermar	1445	} else if ((page == left_pg + left_cnt * PAGE_SIZE) &&
		1446	(page + count * PAGE_SIZE == right_pg)) {
		1447	/*
		1448	* The interval can be added by merging the two already
		1449	* present intervals.
		1450	*/
1403	jermar	1451	node->value[node->keys - 1] += count + right_cnt;
1387	jermar	1452	btree_remove(&a->used_space, right_pg, leaf);
		1453	return 1;
2087	jermar	1454	} else if (page == left_pg + left_cnt * PAGE_SIZE) {
		1455	/*
		1456	* The interval can be added by simply growing the left
		1457	* interval.
		1458	*/
1403	jermar	1459	node->value[node->keys - 1] += count;
1387	jermar	1460	return 1;
2087	jermar	1461	} else if (page + count * PAGE_SIZE == right_pg) {
1387	jermar	1462	/*
2087	jermar	1463	* The interval can be addded by simply moving base of
		1464	* the right interval down and increasing its size
		1465	* accordingly.
1387	jermar	1466	*/
1403	jermar	1467	leaf->value[0] += count;
1387	jermar	1468	leaf->key[0] = page;
		1469	return 1;
		1470	} else {
		1471	/*
		1472	* The interval is between both neigbouring intervals,
		1473	* but cannot be merged with any of them.
		1474	*/
2087	jermar	1475	btree_insert(&a->used_space, page, (void *) count,
		1476	leaf);
1387	jermar	1477	return 1;
		1478	}
		1479	} else if (page < leaf->key[0]) {
1780	jermar	1480	uintptr_t right_pg = leaf->key[0];
4537	trochtova	1481	size_t right_cnt = (size_t) leaf->value[0];
1387	jermar	1482
		1483	/*
2087	jermar	1484	* Investigate the border case in which the left neighbour does
		1485	* not exist but the interval fits from the left.
1387	jermar	1486	*/
		1487
2087	jermar	1488	if (overlaps(page, count * PAGE_SIZE, right_pg,
		1489	right_cnt * PAGE_SIZE)) {
1387	jermar	1490	/* The interval intersects with the right interval. */
		1491	return 0;
2087	jermar	1492	} else if (page + count * PAGE_SIZE == right_pg) {
1387	jermar	1493	/*
2087	jermar	1494	* The interval can be added by moving the base of the
		1495	* right interval down and increasing its size
		1496	* accordingly.
1387	jermar	1497	*/
		1498	leaf->key[0] = page;
1403	jermar	1499	leaf->value[0] += count;
1387	jermar	1500	return 1;
		1501	} else {
		1502	/*
		1503	* The interval doesn't adjoin with the right interval.
		1504	* It must be added individually.
		1505	*/
2087	jermar	1506	btree_insert(&a->used_space, page, (void *) count,
		1507	leaf);
1387	jermar	1508	return 1;
		1509	}
		1510	}
		1511
		1512	node = btree_leaf_node_right_neighbour(&a->used_space, leaf);
		1513	if (node) {
2087	jermar	1514	uintptr_t left_pg = leaf->key[leaf->keys - 1];
		1515	uintptr_t right_pg = node->key[0];
4537	trochtova	1516	size_t left_cnt = (size_t) leaf->value[leaf->keys - 1];
		1517	size_t right_cnt = (size_t) node->value[0];
1387	jermar	1518
		1519	/*
		1520	* Examine the possibility that the interval fits
		1521	* somewhere between the leftmost interval of
		1522	* the right neigbour and the last interval of the leaf.
		1523	*/
		1524
		1525	if (page < left_pg) {
		1526	/* Do nothing. */
2087	jermar	1527	} else if (overlaps(page, count * PAGE_SIZE, left_pg,
		1528	left_cnt * PAGE_SIZE)) {
1387	jermar	1529	/* The interval intersects with the left interval. */
		1530	return 0;
2087	jermar	1531	} else if (overlaps(page, count * PAGE_SIZE, right_pg,
		1532	right_cnt * PAGE_SIZE)) {
1387	jermar	1533	/* The interval intersects with the right interval. */
		1534	return 0;
2087	jermar	1535	} else if ((page == left_pg + left_cnt * PAGE_SIZE) &&
		1536	(page + count * PAGE_SIZE == right_pg)) {
		1537	/*
		1538	* The interval can be added by merging the two already
		1539	* present intervals.
		1540	* */
1403	jermar	1541	leaf->value[leaf->keys - 1] += count + right_cnt;
1387	jermar	1542	btree_remove(&a->used_space, right_pg, node);
		1543	return 1;
2087	jermar	1544	} else if (page == left_pg + left_cnt * PAGE_SIZE) {
		1545	/*
		1546	* The interval can be added by simply growing the left
		1547	* interval.
		1548	* */
1403	jermar	1549	leaf->value[leaf->keys - 1] += count;
1387	jermar	1550	return 1;
2087	jermar	1551	} else if (page + count * PAGE_SIZE == right_pg) {
1387	jermar	1552	/*
2087	jermar	1553	* The interval can be addded by simply moving base of
		1554	* the right interval down and increasing its size
		1555	* accordingly.
1387	jermar	1556	*/
1403	jermar	1557	node->value[0] += count;
1387	jermar	1558	node->key[0] = page;
		1559	return 1;
		1560	} else {
		1561	/*
		1562	* The interval is between both neigbouring intervals,
		1563	* but cannot be merged with any of them.
		1564	*/
2087	jermar	1565	btree_insert(&a->used_space, page, (void *) count,
		1566	leaf);
1387	jermar	1567	return 1;
		1568	}
		1569	} else if (page >= leaf->key[leaf->keys - 1]) {
1780	jermar	1570	uintptr_t left_pg = leaf->key[leaf->keys - 1];
4537	trochtova	1571	size_t left_cnt = (size_t) leaf->value[leaf->keys - 1];
1387	jermar	1572
		1573	/*
2087	jermar	1574	* Investigate the border case in which the right neighbour
		1575	* does not exist but the interval fits from the right.
1387	jermar	1576	*/
		1577
2087	jermar	1578	if (overlaps(page, count * PAGE_SIZE, left_pg,
		1579	left_cnt * PAGE_SIZE)) {
1403	jermar	1580	/* The interval intersects with the left interval. */
1387	jermar	1581	return 0;
2087	jermar	1582	} else if (left_pg + left_cnt * PAGE_SIZE == page) {
		1583	/*
		1584	* The interval can be added by growing the left
		1585	* interval.
		1586	*/
1403	jermar	1587	leaf->value[leaf->keys - 1] += count;
1387	jermar	1588	return 1;
		1589	} else {
		1590	/*
		1591	* The interval doesn't adjoin with the left interval.
		1592	* It must be added individually.
		1593	*/
2087	jermar	1594	btree_insert(&a->used_space, page, (void *) count,
		1595	leaf);
1387	jermar	1596	return 1;
		1597	}
		1598	}
		1599
		1600	/*
2087	jermar	1601	* Note that if the algorithm made it thus far, the interval can fit
		1602	* only between two other intervals of the leaf. The two border cases
		1603	* were already resolved.
1387	jermar	1604	*/
		1605	for (i = 1; i < leaf->keys; i++) {
		1606	if (page < leaf->key[i]) {
2087	jermar	1607	uintptr_t left_pg = leaf->key[i - 1];
		1608	uintptr_t right_pg = leaf->key[i];
4537	trochtova	1609	size_t left_cnt = (size_t) leaf->value[i - 1];
		1610	size_t right_cnt = (size_t) leaf->value[i];
1387	jermar	1611
		1612	/*
		1613	* The interval fits between left_pg and right_pg.
		1614	*/
		1615
2087	jermar	1616	if (overlaps(page, count * PAGE_SIZE, left_pg,
		1617	left_cnt * PAGE_SIZE)) {
		1618	/*
		1619	* The interval intersects with the left
		1620	* interval.
		1621	*/
1387	jermar	1622	return 0;
2087	jermar	1623	} else if (overlaps(page, count * PAGE_SIZE, right_pg,
		1624	right_cnt * PAGE_SIZE)) {
		1625	/*
		1626	* The interval intersects with the right
		1627	* interval.
		1628	*/
1387	jermar	1629	return 0;
2087	jermar	1630	} else if ((page == left_pg + left_cnt * PAGE_SIZE) &&
		1631	(page + count * PAGE_SIZE == right_pg)) {
		1632	/*
		1633	* The interval can be added by merging the two
		1634	* already present intervals.
		1635	*/
1403	jermar	1636	leaf->value[i - 1] += count + right_cnt;
1387	jermar	1637	btree_remove(&a->used_space, right_pg, leaf);
		1638	return 1;
2087	jermar	1639	} else if (page == left_pg + left_cnt * PAGE_SIZE) {
		1640	/*
		1641	* The interval can be added by simply growing
		1642	* the left interval.
		1643	*/
1403	jermar	1644	leaf->value[i - 1] += count;
1387	jermar	1645	return 1;
2087	jermar	1646	} else if (page + count * PAGE_SIZE == right_pg) {
1387	jermar	1647	/*
2087	jermar	1648	* The interval can be addded by simply moving
		1649	* base of the right interval down and
		1650	* increasing its size accordingly.
1387	jermar	1651	*/
1403	jermar	1652	leaf->value[i] += count;
1387	jermar	1653	leaf->key[i] = page;
		1654	return 1;
		1655	} else {
		1656	/*
2087	jermar	1657	* The interval is between both neigbouring
		1658	* intervals, but cannot be merged with any of
		1659	* them.
1387	jermar	1660	*/
2087	jermar	1661	btree_insert(&a->used_space, page,
		1662	(void *) count, leaf);
1387	jermar	1663	return 1;
		1664	}
		1665	}
		1666	}
		1667
4537	trochtova	1668	panic("Inconsistency detected while adding %" PRIs " pages of used "
4055	trochtova	1669	"space at %p.", count, page);
1387	jermar	1670	}
		1671
		1672	/** Mark portion of address space area as unused.
		1673	*
		1674	* The address space area must be already locked.
		1675	*
4055	trochtova	1676	* @param a Address space area.
		1677	* @param page First page to be marked.
		1678	* @param count Number of page to be marked.
1387	jermar	1679	*
4055	trochtova	1680	* @return Zero on failure and non-zero on success.
1387	jermar	1681	*/
4537	trochtova	1682	int used_space_remove(as_area_t *a, uintptr_t page, size_t count)
1387	jermar	1683	{
		1684	btree_node_t leaf, node;
4537	trochtova	1685	size_t pages;
2745	decky	1686	unsigned int i;
1387	jermar	1687
		1688	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1689	ASSERT(count);
		1690
4537	trochtova	1691	pages = (size_t) btree_search(&a->used_space, page, &leaf);
1387	jermar	1692	if (pages) {
		1693	/*
		1694	* We are lucky, page is the beginning of some interval.
		1695	*/
		1696	if (count > pages) {
		1697	return 0;
		1698	} else if (count == pages) {
		1699	btree_remove(&a->used_space, page, leaf);
1403	jermar	1700	return 1;
1387	jermar	1701	} else {
		1702	/*
		1703	* Find the respective interval.
		1704	* Decrease its size and relocate its start address.
		1705	*/
		1706	for (i = 0; i < leaf->keys; i++) {
		1707	if (leaf->key[i] == page) {
2087	jermar	1708	leaf->key[i] += count * PAGE_SIZE;
1403	jermar	1709	leaf->value[i] -= count;
1387	jermar	1710	return 1;
		1711	}
		1712	}
		1713	goto error;
		1714	}
		1715	}
		1716
		1717	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1718	if (node && page < leaf->key[0]) {
1780	jermar	1719	uintptr_t left_pg = node->key[node->keys - 1];
4537	trochtova	1720	size_t left_cnt = (size_t) node->value[node->keys - 1];
1387	jermar	1721
2087	jermar	1722	if (overlaps(left_pg, left_cnt * PAGE_SIZE, page,
		1723	count * PAGE_SIZE)) {
		1724	if (page + count * PAGE_SIZE ==
		1725	left_pg + left_cnt * PAGE_SIZE) {
1387	jermar	1726	/*
2087	jermar	1727	* The interval is contained in the rightmost
		1728	* interval of the left neighbour and can be
		1729	* removed by updating the size of the bigger
		1730	* interval.
1387	jermar	1731	*/
1403	jermar	1732	node->value[node->keys - 1] -= count;
1387	jermar	1733	return 1;
2087	jermar	1734	} else if (page + count * PAGE_SIZE <
		1735	left_pg + left_cnt*PAGE_SIZE) {
4537	trochtova	1736	size_t new_cnt;
1387	jermar	1737
		1738	/*
2087	jermar	1739	* The interval is contained in the rightmost
		1740	* interval of the left neighbour but its
		1741	* removal requires both updating the size of
		1742	* the original interval and also inserting a
		1743	* new interval.
1387	jermar	1744	*/
2087	jermar	1745	new_cnt = ((left_pg + left_cnt * PAGE_SIZE) -
		1746	(page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1403	jermar	1747	node->value[node->keys - 1] -= count + new_cnt;
2087	jermar	1748	btree_insert(&a->used_space, page +
		1749	count * PAGE_SIZE, (void *) new_cnt, leaf);
1387	jermar	1750	return 1;
		1751	}
		1752	}
		1753	return 0;
		1754	} else if (page < leaf->key[0]) {
		1755	return 0;
		1756	}
		1757
		1758	if (page > leaf->key[leaf->keys - 1]) {
1780	jermar	1759	uintptr_t left_pg = leaf->key[leaf->keys - 1];
4537	trochtova	1760	size_t left_cnt = (size_t) leaf->value[leaf->keys - 1];
1387	jermar	1761
2087	jermar	1762	if (overlaps(left_pg, left_cnt * PAGE_SIZE, page,
		1763	count * PAGE_SIZE)) {
		1764	if (page + count * PAGE_SIZE ==
		1765	left_pg + left_cnt * PAGE_SIZE) {
1387	jermar	1766	/*
2087	jermar	1767	* The interval is contained in the rightmost
		1768	* interval of the leaf and can be removed by
		1769	* updating the size of the bigger interval.
1387	jermar	1770	*/
1403	jermar	1771	leaf->value[leaf->keys - 1] -= count;
1387	jermar	1772	return 1;
2087	jermar	1773	} else if (page + count * PAGE_SIZE < left_pg +
		1774	left_cnt * PAGE_SIZE) {
4537	trochtova	1775	size_t new_cnt;
1387	jermar	1776
		1777	/*
2087	jermar	1778	* The interval is contained in the rightmost
		1779	* interval of the leaf but its removal
		1780	* requires both updating the size of the
		1781	* original interval and also inserting a new
		1782	* interval.
1387	jermar	1783	*/
2087	jermar	1784	new_cnt = ((left_pg + left_cnt * PAGE_SIZE) -
		1785	(page + count * PAGE_SIZE)) >> PAGE_WIDTH;
1403	jermar	1786	leaf->value[leaf->keys - 1] -= count + new_cnt;
2087	jermar	1787	btree_insert(&a->used_space, page +
		1788	count * PAGE_SIZE, (void *) new_cnt, leaf);
1387	jermar	1789	return 1;
		1790	}
		1791	}
		1792	return 0;
		1793	}
		1794
		1795	/*
		1796	* The border cases have been already resolved.
		1797	* Now the interval can be only between intervals of the leaf.
		1798	*/
		1799	for (i = 1; i < leaf->keys - 1; i++) {
		1800	if (page < leaf->key[i]) {
1780	jermar	1801	uintptr_t left_pg = leaf->key[i - 1];
4537	trochtova	1802	size_t left_cnt = (size_t) leaf->value[i - 1];
1387	jermar	1803
		1804	/*
2087	jermar	1805	* Now the interval is between intervals corresponding
		1806	* to (i - 1) and i.
1387	jermar	1807	*/
2087	jermar	1808	if (overlaps(left_pg, left_cnt * PAGE_SIZE, page,
		1809	count * PAGE_SIZE)) {
		1810	if (page + count * PAGE_SIZE ==
		1811	left_pg + left_cnt*PAGE_SIZE) {
1387	jermar	1812	/*
2087	jermar	1813	* The interval is contained in the
		1814	* interval (i - 1) of the leaf and can
		1815	* be removed by updating the size of
		1816	* the bigger interval.
1387	jermar	1817	*/
1403	jermar	1818	leaf->value[i - 1] -= count;
1387	jermar	1819	return 1;
2087	jermar	1820	} else if (page + count * PAGE_SIZE <
		1821	left_pg + left_cnt * PAGE_SIZE) {
4537	trochtova	1822	size_t new_cnt;
1387	jermar	1823
		1824	/*
2087	jermar	1825	* The interval is contained in the
		1826	* interval (i - 1) of the leaf but its
		1827	* removal requires both updating the
		1828	* size of the original interval and
1387	jermar	1829	* also inserting a new interval.
		1830	*/
2087	jermar	1831	new_cnt = ((left_pg +
		1832	left_cnt * PAGE_SIZE) -
		1833	(page + count * PAGE_SIZE)) >>
		1834	PAGE_WIDTH;
1403	jermar	1835	leaf->value[i - 1] -= count + new_cnt;
2087	jermar	1836	btree_insert(&a->used_space, page +
		1837	count * PAGE_SIZE, (void *) new_cnt,
		1838	leaf);
1387	jermar	1839	return 1;
		1840	}
		1841	}
		1842	return 0;
		1843	}
		1844	}
		1845
		1846	error:
4537	trochtova	1847	panic("Inconsistency detected while removing %" PRIs " pages of used "
4055	trochtova	1848	"space from %p.", count, page);
1387	jermar	1849	}
		1850
1409	jermar	1851	/** Remove reference to address space area share info.
		1852	*
		1853	* If the reference count drops to 0, the sh_info is deallocated.
		1854	*
4055	trochtova	1855	* @param sh_info Pointer to address space area share info.
1409	jermar	1856	*/
		1857	void sh_info_remove_reference(share_info_t *sh_info)
		1858	{
		1859	bool dealloc = false;
		1860
		1861	mutex_lock(&sh_info->lock);
		1862	ASSERT(sh_info->refcount);
		1863	if (--sh_info->refcount == 0) {
		1864	dealloc = true;
1495	jermar	1865	link_t *cur;
1409	jermar	1866
		1867	/*
		1868	* Now walk carefully the pagemap B+tree and free/remove
		1869	* reference from all frames found there.
		1870	*/
2087	jermar	1871	for (cur = sh_info->pagemap.leaf_head.next;
		1872	cur != &sh_info->pagemap.leaf_head; cur = cur->next) {
1409	jermar	1873	btree_node_t *node;
2745	decky	1874	unsigned int i;
1409	jermar	1875
1495	jermar	1876	node = list_get_instance(cur, btree_node_t, leaf_link);
		1877	for (i = 0; i < node->keys; i++)
1780	jermar	1878	frame_free((uintptr_t) node->value[i]);
1409	jermar	1879	}
		1880
		1881	}
		1882	mutex_unlock(&sh_info->lock);
		1883
		1884	if (dealloc) {
		1885	btree_destroy(&sh_info->pagemap);
		1886	free(sh_info);
		1887	}
		1888	}
		1889
1235	jermar	1890	/*
		1891	* Address space related syscalls.
		1892	*/
		1893
		1894	/** Wrapper for as_area_create(). */
1780	jermar	1895	unative_t sys_as_area_create(uintptr_t address, size_t size, int flags)
1235	jermar	1896	{
2087	jermar	1897	if (as_area_create(AS, flags \| AS_AREA_CACHEABLE, size, address,
		1898	AS_AREA_ATTR_NONE, &anon_backend, NULL))
1780	jermar	1899	return (unative_t) address;
1235	jermar	1900	else
1780	jermar	1901	return (unative_t) -1;
1235	jermar	1902	}
		1903
1793	jermar	1904	/** Wrapper for as_area_resize(). */
1780	jermar	1905	unative_t sys_as_area_resize(uintptr_t address, size_t size, int flags)
1235	jermar	1906	{
1780	jermar	1907	return (unative_t) as_area_resize(AS, address, size, 0);
1235	jermar	1908	}
		1909
4055	trochtova	1910	/** Wrapper for as_area_change_flags(). */
		1911	unative_t sys_as_area_change_flags(uintptr_t address, int flags)
		1912	{
		1913	return (unative_t) as_area_change_flags(AS, flags, address);
		1914	}
		1915
1793	jermar	1916	/** Wrapper for as_area_destroy(). */
1780	jermar	1917	unative_t sys_as_area_destroy(uintptr_t address)
1306	jermar	1918	{
1780	jermar	1919	return (unative_t) as_area_destroy(AS, address);
1306	jermar	1920	}
1702	cejka	1921
1914	jermar	1922	/** Print out information about address space.
		1923	*
4055	trochtova	1924	* @param as Address space.
1914	jermar	1925	*/
		1926	void as_print(as_t *as)
		1927	{
		1928	ipl_t ipl;
		1929
		1930	ipl = interrupts_disable();
		1931	mutex_lock(&as->lock);
		1932
		1933	/* print out info about address space areas */
		1934	link_t *cur;
2087	jermar	1935	for (cur = as->as_area_btree.leaf_head.next;
		1936	cur != &as->as_area_btree.leaf_head; cur = cur->next) {
		1937	btree_node_t *node;
1914	jermar	1938
2087	jermar	1939	node = list_get_instance(cur, btree_node_t, leaf_link);
		1940
2745	decky	1941	unsigned int i;
1914	jermar	1942	for (i = 0; i < node->keys; i++) {
1915	jermar	1943	as_area_t *area = node->value[i];
1914	jermar	1944
		1945	mutex_lock(&area->lock);
4537	trochtova	1946	printf("as_area: %p, base=%p, pages=%" PRIs
4055	trochtova	1947	" (%p - %p)\n", area, area->base, area->pages,
		1948	area->base, area->base + FRAMES2SIZE(area->pages));
1914	jermar	1949	mutex_unlock(&area->lock);
		1950	}
		1951	}
		1952
		1953	mutex_unlock(&as->lock);
		1954	interrupts_restore(ipl);
		1955	}
		1956
1757	jermar	1957	/** @}
1702	cejka	1958	*/

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(root)//branches/dd/kernel/generic/src/mm/as.c – Rev 4537