WebSVN – HelenOS – Blame – /trunk/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
2125	decky	85	#ifndef __OBJC__
1757	jermar	86	/**
		87	* Each architecture decides what functions will be used to carry out
		88	* address space operations such as creating or locking page tables.
		89	*/
756	jermar	90	as_operations_t *as_operations = NULL;
703	jermar	91
1890	jermar	92	/**
		93	* Slab for as_t objects.
		94	*/
		95	static slab_cache_t *as_slab;
2126	decky	96	#endif
1890	jermar	97
2087	jermar	98	/**
2170	jermar	99	* This lock serializes access to the ASID subsystem.
		100	* It protects:
		101	* - inactive_as_with_asid_head list
		102	* - as->asid for each as of the as_t type
		103	* - asids_allocated counter
2087	jermar	104	*/
2170	jermar	105	SPINLOCK_INITIALIZE(asidlock);
823	jermar	106
		107	/**
		108	* This list contains address spaces that are not active on any
		109	* processor and that have valid ASID.
		110	*/
		111	LIST_INITIALIZE(inactive_as_with_asid_head);
		112
757	jermar	113	/** Kernel address space. */
		114	as_t *AS_KERNEL = NULL;
		115
1235	jermar	116	static int area_flags_to_page_flags(int aflags);
1780	jermar	117	static as_area_t find_area_and_lock(as_t as, uintptr_t va);
2087	jermar	118	static bool check_area_conflicts(as_t *as, uintptr_t va, size_t size,
		119	as_area_t *avoid_area);
1409	jermar	120	static void sh_info_remove_reference(share_info_t *sh_info);
703	jermar	121
2126	decky	122	#ifndef __OBJC__
1891	jermar	123	static int as_constructor(void *obj, int flags)
		124	{
		125	as_t as = (as_t ) obj;
		126	int rc;
		127
		128	link_initialize(&as->inactive_as_with_asid_link);
3186	jermar	129	mutex_initialize(&as->lock, MUTEX_PASSIVE);
1891	jermar	130
		131	rc = as_constructor_arch(as, flags);
		132
		133	return rc;
		134	}
		135
		136	static int as_destructor(void *obj)
		137	{
		138	as_t as = (as_t ) obj;
		139
		140	return as_destructor_arch(as);
		141	}
2126	decky	142	#endif
1891	jermar	143
756	jermar	144	/** Initialize address space subsystem. */
		145	void as_init(void)
		146	{
		147	as_arch_init();
2126	decky	148
		149	#ifndef __OBJC__
1891	jermar	150	as_slab = slab_cache_create("as_slab", sizeof(as_t), 0,
2087	jermar	151	as_constructor, as_destructor, SLAB_CACHE_MAGDEFERRED);
2126	decky	152	#endif
1890	jermar	153
789	palkovsky	154	AS_KERNEL = as_create(FLAG_AS_KERNEL);
1383	decky	155	if (!AS_KERNEL)
		156	panic("can't create kernel address space\n");
		157
756	jermar	158	}
		159
757	jermar	160	/** Create address space.
		161	*
		162	* @param flags Flags that influence way in wich the address space is created.
		163	*/
756	jermar	164	as_t *as_create(int flags)
703	jermar	165	{
		166	as_t *as;
		167
2126	decky	168	#ifdef __OBJC__
		169	as = [as_t new];
		170	link_initialize(&as->inactive_as_with_asid_link);
3186	jermar	171	mutex_initialize(&as->lock, MUTEX_PASSIVE);
2126	decky	172	(void) as_constructor_arch(as, flags);
		173	#else
1890	jermar	174	as = (as_t *) slab_alloc(as_slab, 0);
2126	decky	175	#endif
1891	jermar	176	(void) as_create_arch(as, 0);
		177
1147	jermar	178	btree_create(&as->as_area_btree);
822	palkovsky	179
		180	if (flags & FLAG_AS_KERNEL)
		181	as->asid = ASID_KERNEL;
		182	else
		183	as->asid = ASID_INVALID;
		184
2183	jermar	185	atomic_set(&as->refcount, 0);
1415	jermar	186	as->cpu_refcount = 0;
2089	decky	187	#ifdef AS_PAGE_TABLE
2106	jermar	188	as->genarch.page_table = page_table_create(flags);
2089	decky	189	#else
		190	page_table_create(flags);
		191	#endif
703	jermar	192
		193	return as;
		194	}
		195
1468	jermar	196	/** Destroy adress space.
		197	*
2087	jermar	198	* When there are no tasks referencing this address space (i.e. its refcount is
		199	* zero), the address space can be destroyed.
2183	jermar	200	*
		201	* We know that we don't hold any spinlock.
1468	jermar	202	*/
		203	void as_destroy(as_t *as)
973	palkovsky	204	{
1468	jermar	205	ipl_t ipl;
1594	jermar	206	bool cond;
2183	jermar	207	DEADLOCK_PROBE_INIT(p_asidlock);
973	palkovsky	208
2183	jermar	209	ASSERT(atomic_get(&as->refcount) == 0);
1468	jermar	210
		211	/*
		212	* Since there is no reference to this area,
		213	* it is safe not to lock its mutex.
		214	*/
2170	jermar	215
2183	jermar	216	/*
		217	* We need to avoid deadlock between TLB shootdown and asidlock.
		218	* We therefore try to take asid conditionally and if we don't succeed,
		219	* we enable interrupts and try again. This is done while preemption is
		220	* disabled to prevent nested context switches. We also depend on the
		221	* fact that so far no spinlocks are held.
		222	*/
		223	preemption_disable();
		224	ipl = interrupts_read();
		225	retry:
		226	interrupts_disable();
		227	if (!spinlock_trylock(&asidlock)) {
		228	interrupts_enable();
		229	DEADLOCK_PROBE(p_asidlock, DEADLOCK_THRESHOLD);
		230	goto retry;
		231	}
		232	preemption_enable(); /* Interrupts disabled, enable preemption */
1587	jermar	233	if (as->asid != ASID_INVALID && as != AS_KERNEL) {
1594	jermar	234	if (as != AS && as->cpu_refcount == 0)
1587	jermar	235	list_remove(&as->inactive_as_with_asid_link);
1468	jermar	236	asid_put(as->asid);
		237	}
2170	jermar	238	spinlock_unlock(&asidlock);
1468	jermar	239
		240	/*
		241	* Destroy address space areas of the address space.
1954	jermar	242	* The B+tree must be walked carefully because it is
1594	jermar	243	* also being destroyed.
1468	jermar	244	*/
1594	jermar	245	for (cond = true; cond; ) {
1468	jermar	246	btree_node_t *node;
1594	jermar	247
		248	ASSERT(!list_empty(&as->as_area_btree.leaf_head));
2087	jermar	249	node = list_get_instance(as->as_area_btree.leaf_head.next,
		250	btree_node_t, leaf_link);
1594	jermar	251
		252	if ((cond = node->keys)) {
		253	as_area_destroy(as, node->key[0]);
		254	}
1468	jermar	255	}
1495	jermar	256
1483	jermar	257	btree_destroy(&as->as_area_btree);
2089	decky	258	#ifdef AS_PAGE_TABLE
2106	jermar	259	page_table_destroy(as->genarch.page_table);
2089	decky	260	#else
		261	page_table_destroy(NULL);
		262	#endif
1468	jermar	263
		264	interrupts_restore(ipl);
2126	decky	265
		266	#ifdef __OBJC__
		267	[as free];
		268	#else
1890	jermar	269	slab_free(as_slab, as);
2126	decky	270	#endif
973	palkovsky	271	}
		272
703	jermar	273	/** Create address space area of common attributes.
		274	*
		275	* The created address space area is added to the target address space.
		276	*
		277	* @param as Target address space.
1239	jermar	278	* @param flags Flags of the area memory.
1048	jermar	279	* @param size Size of area.
703	jermar	280	* @param base Base address of area.
1239	jermar	281	* @param attrs Attributes of the area.
1409	jermar	282	* @param backend Address space area backend. NULL if no backend is used.
		283	* @param backend_data NULL or a pointer to an array holding two void *.
703	jermar	284	*
		285	* @return Address space area on success or NULL on failure.
		286	*/
2069	jermar	287	as_area_t *
		288	as_area_create(as_t *as, int flags, size_t size, uintptr_t base, int attrs,
1424	jermar	289	mem_backend_t backend, mem_backend_data_t backend_data)
703	jermar	290	{
		291	ipl_t ipl;
		292	as_area_t *a;
		293
		294	if (base % PAGE_SIZE)
1048	jermar	295	return NULL;
		296
1233	jermar	297	if (!size)
		298	return NULL;
		299
1048	jermar	300	/* Writeable executable areas are not supported. */
		301	if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
		302	return NULL;
703	jermar	303
		304	ipl = interrupts_disable();
1380	jermar	305	mutex_lock(&as->lock);
703	jermar	306
1048	jermar	307	if (!check_area_conflicts(as, base, size, NULL)) {
1380	jermar	308	mutex_unlock(&as->lock);
1048	jermar	309	interrupts_restore(ipl);
		310	return NULL;
		311	}
703	jermar	312
822	palkovsky	313	a = (as_area_t *) malloc(sizeof(as_area_t), 0);
703	jermar	314
3186	jermar	315	mutex_initialize(&a->lock, MUTEX_PASSIVE);
822	palkovsky	316
1424	jermar	317	a->as = as;
1026	jermar	318	a->flags = flags;
1239	jermar	319	a->attributes = attrs;
1048	jermar	320	a->pages = SIZE2FRAMES(size);
822	palkovsky	321	a->base = base;
1409	jermar	322	a->sh_info = NULL;
		323	a->backend = backend;
1424	jermar	324	if (backend_data)
		325	a->backend_data = *backend_data;
		326	else
3104	svoboda	327	memsetb(&a->backend_data, sizeof(a->backend_data), 0);
1424	jermar	328
1387	jermar	329	btree_create(&a->used_space);
822	palkovsky	330
1147	jermar	331	btree_insert(&as->as_area_btree, base, (void *) a, NULL);
822	palkovsky	332
1380	jermar	333	mutex_unlock(&as->lock);
703	jermar	334	interrupts_restore(ipl);
704	jermar	335
703	jermar	336	return a;
		337	}
		338
1235	jermar	339	/** Find address space area and change it.
		340	*
		341	* @param as Address space.
2087	jermar	342	* @param address Virtual address belonging to the area to be changed. Must be
		343	* page-aligned.
1235	jermar	344	* @param size New size of the virtual memory block starting at address.
		345	* @param flags Flags influencing the remap operation. Currently unused.
		346	*
1306	jermar	347	* @return Zero on success or a value from @ref errno.h otherwise.
1235	jermar	348	*/
1780	jermar	349	int as_area_resize(as_t *as, uintptr_t address, size_t size, int flags)
1235	jermar	350	{
1306	jermar	351	as_area_t *area;
1235	jermar	352	ipl_t ipl;
		353	size_t pages;
		354
		355	ipl = interrupts_disable();
1380	jermar	356	mutex_lock(&as->lock);
1235	jermar	357
		358	/*
		359	* Locate the area.
		360	*/
		361	area = find_area_and_lock(as, address);
		362	if (!area) {
1380	jermar	363	mutex_unlock(&as->lock);
1235	jermar	364	interrupts_restore(ipl);
1306	jermar	365	return ENOENT;
1235	jermar	366	}
		367
1424	jermar	368	if (area->backend == &phys_backend) {
1235	jermar	369	/*
		370	* Remapping of address space areas associated
		371	* with memory mapped devices is not supported.
		372	*/
1380	jermar	373	mutex_unlock(&area->lock);
		374	mutex_unlock(&as->lock);
1235	jermar	375	interrupts_restore(ipl);
1306	jermar	376	return ENOTSUP;
1235	jermar	377	}
1409	jermar	378	if (area->sh_info) {
		379	/*
		380	* Remapping of shared address space areas
		381	* is not supported.
		382	*/
		383	mutex_unlock(&area->lock);
		384	mutex_unlock(&as->lock);
		385	interrupts_restore(ipl);
		386	return ENOTSUP;
		387	}
1235	jermar	388
		389	pages = SIZE2FRAMES((address - area->base) + size);
		390	if (!pages) {
		391	/*
		392	* Zero size address space areas are not allowed.
		393	*/
1380	jermar	394	mutex_unlock(&area->lock);
		395	mutex_unlock(&as->lock);
1235	jermar	396	interrupts_restore(ipl);
1306	jermar	397	return EPERM;
1235	jermar	398	}
		399
		400	if (pages < area->pages) {
1403	jermar	401	bool cond;
1780	jermar	402	uintptr_t start_free = area->base + pages*PAGE_SIZE;
1235	jermar	403
		404	/*
		405	* Shrinking the area.
		406	* No need to check for overlaps.
		407	*/
1403	jermar	408
		409	/*
1436	jermar	410	* Start TLB shootdown sequence.
		411	*/
2087	jermar	412	tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base +
		413	pages * PAGE_SIZE, area->pages - pages);
1436	jermar	414
		415	/*
1403	jermar	416	* Remove frames belonging to used space starting from
		417	* the highest addresses downwards until an overlap with
		418	* the resized address space area is found. Note that this
		419	* is also the right way to remove part of the used_space
		420	* B+tree leaf list.
		421	*/
		422	for (cond = true; cond;) {
		423	btree_node_t *node;
		424
		425	ASSERT(!list_empty(&area->used_space.leaf_head));
2087	jermar	426	node =
		427	list_get_instance(area->used_space.leaf_head.prev,
		428	btree_node_t, leaf_link);
1403	jermar	429	if ((cond = (bool) node->keys)) {
1780	jermar	430	uintptr_t b = node->key[node->keys - 1];
2087	jermar	431	count_t c =
		432	(count_t) node->value[node->keys - 1];
2745	decky	433	unsigned int i = 0;
1235	jermar	434
2087	jermar	435	if (overlaps(b, c * PAGE_SIZE, area->base,
2133	jermar	436	pages * PAGE_SIZE)) {
1403	jermar	437
2087	jermar	438	if (b + c * PAGE_SIZE <= start_free) {
1403	jermar	439	/*
2087	jermar	440	* The whole interval fits
		441	* completely in the resized
		442	* address space area.
1403	jermar	443	*/
		444	break;
		445	}
		446
		447	/*
2087	jermar	448	* Part of the interval corresponding
		449	* to b and c overlaps with the resized
		450	* address space area.
1403	jermar	451	*/
		452
		453	cond = false; /* we are almost done */
		454	i = (start_free - b) >> PAGE_WIDTH;
3057	decky	455	if (!used_space_remove(area, start_free, c - i))
		456	panic("Could not remove used space.\n");
1403	jermar	457	} else {
		458	/*
2087	jermar	459	* The interval of used space can be
		460	* completely removed.
1403	jermar	461	*/
		462	if (!used_space_remove(area, b, c))
3057	decky	463	panic("Could not remove used space.\n");
1403	jermar	464	}
		465
		466	for (; i < c; i++) {
		467	pte_t *pte;
		468
		469	page_table_lock(as, false);
2087	jermar	470	pte = page_mapping_find(as, b +
		471	i * PAGE_SIZE);
		472	ASSERT(pte && PTE_VALID(pte) &&
		473	PTE_PRESENT(pte));
		474	if (area->backend &&
		475	area->backend->frame_free) {
1424	jermar	476	area->backend->frame_free(area,
2087	jermar	477	b + i * PAGE_SIZE,
		478	PTE_GET_FRAME(pte));
1409	jermar	479	}
2087	jermar	480	page_mapping_remove(as, b +
		481	i * PAGE_SIZE);
1403	jermar	482	page_table_unlock(as, false);
		483	}
1235	jermar	484	}
		485	}
1436	jermar	486
1235	jermar	487	/*
1436	jermar	488	* Finish TLB shootdown sequence.
1235	jermar	489	*/
2183	jermar	490
2087	jermar	491	tlb_invalidate_pages(as->asid, area->base + pages * PAGE_SIZE,
		492	area->pages - pages);
1889	jermar	493	/*
		494	* Invalidate software translation caches (e.g. TSB on sparc64).
		495	*/
2087	jermar	496	as_invalidate_translation_cache(as, area->base +
		497	pages * PAGE_SIZE, area->pages - pages);
2183	jermar	498	tlb_shootdown_finalize();
		499
1235	jermar	500	} else {
		501	/*
		502	* Growing the area.
		503	* Check for overlaps with other address space areas.
		504	*/
2087	jermar	505	if (!check_area_conflicts(as, address, pages * PAGE_SIZE,
		506	area)) {
1380	jermar	507	mutex_unlock(&area->lock);
		508	mutex_unlock(&as->lock);
1235	jermar	509	interrupts_restore(ipl);
1306	jermar	510	return EADDRNOTAVAIL;
1235	jermar	511	}
		512	}
		513
		514	area->pages = pages;
		515
1380	jermar	516	mutex_unlock(&area->lock);
		517	mutex_unlock(&as->lock);
1235	jermar	518	interrupts_restore(ipl);
		519
1306	jermar	520	return 0;
1235	jermar	521	}
		522
1306	jermar	523	/** Destroy address space area.
		524	*
		525	* @param as Address space.
		526	* @param address Address withing the area to be deleted.
		527	*
		528	* @return Zero on success or a value from @ref errno.h on failure.
		529	*/
1780	jermar	530	int as_area_destroy(as_t *as, uintptr_t address)
1306	jermar	531	{
		532	as_area_t *area;
1780	jermar	533	uintptr_t base;
1495	jermar	534	link_t *cur;
1306	jermar	535	ipl_t ipl;
		536
		537	ipl = interrupts_disable();
1380	jermar	538	mutex_lock(&as->lock);
1306	jermar	539
		540	area = find_area_and_lock(as, address);
		541	if (!area) {
1380	jermar	542	mutex_unlock(&as->lock);
1306	jermar	543	interrupts_restore(ipl);
		544	return ENOENT;
		545	}
		546
1403	jermar	547	base = area->base;
		548
1411	jermar	549	/*
1436	jermar	550	* Start TLB shootdown sequence.
		551	*/
1889	jermar	552	tlb_shootdown_start(TLB_INVL_PAGES, as->asid, area->base, area->pages);
1436	jermar	553
		554	/*
1411	jermar	555	* Visit only the pages mapped by used_space B+tree.
		556	*/
2087	jermar	557	for (cur = area->used_space.leaf_head.next;
		558	cur != &area->used_space.leaf_head; cur = cur->next) {
1411	jermar	559	btree_node_t *node;
2745	decky	560	unsigned int i;
1403	jermar	561
1495	jermar	562	node = list_get_instance(cur, btree_node_t, leaf_link);
		563	for (i = 0; i < node->keys; i++) {
1780	jermar	564	uintptr_t b = node->key[i];
1495	jermar	565	count_t j;
1411	jermar	566	pte_t *pte;
1403	jermar	567
1495	jermar	568	for (j = 0; j < (count_t) node->value[i]; j++) {
1411	jermar	569	page_table_lock(as, false);
2087	jermar	570	pte = page_mapping_find(as, b + j * PAGE_SIZE);
		571	ASSERT(pte && PTE_VALID(pte) &&
		572	PTE_PRESENT(pte));
		573	if (area->backend &&
		574	area->backend->frame_free) {
		575	area->backend->frame_free(area, b +
2133	jermar	576	j * PAGE_SIZE, PTE_GET_FRAME(pte));
1403	jermar	577	}
2087	jermar	578	page_mapping_remove(as, b + j * PAGE_SIZE);
1411	jermar	579	page_table_unlock(as, false);
1306	jermar	580	}
		581	}
		582	}
1403	jermar	583
1306	jermar	584	/*
1436	jermar	585	* Finish TLB shootdown sequence.
1306	jermar	586	*/
2183	jermar	587
1889	jermar	588	tlb_invalidate_pages(as->asid, area->base, area->pages);
		589	/*
2087	jermar	590	* Invalidate potential software translation caches (e.g. TSB on
		591	* sparc64).
1889	jermar	592	*/
		593	as_invalidate_translation_cache(as, area->base, area->pages);
2183	jermar	594	tlb_shootdown_finalize();
1889	jermar	595
1436	jermar	596	btree_destroy(&area->used_space);
1306	jermar	597
1309	jermar	598	area->attributes \|= AS_AREA_ATTR_PARTIAL;
1409	jermar	599
		600	if (area->sh_info)
		601	sh_info_remove_reference(area->sh_info);
		602
1380	jermar	603	mutex_unlock(&area->lock);
1306	jermar	604
		605	/*
		606	* Remove the empty area from address space.
		607	*/
1889	jermar	608	btree_remove(&as->as_area_btree, base, NULL);
1306	jermar	609
1309	jermar	610	free(area);
		611
1889	jermar	612	mutex_unlock(&as->lock);
1306	jermar	613	interrupts_restore(ipl);
		614	return 0;
		615	}
		616
1413	jermar	617	/** Share address space area with another or the same address space.
1235	jermar	618	*
1424	jermar	619	* Address space area mapping is shared with a new address space area.
		620	* If the source address space area has not been shared so far,
		621	* a new sh_info is created. The new address space area simply gets the
		622	* sh_info of the source area. The process of duplicating the
		623	* mapping is done through the backend share function.
1413	jermar	624	*
1417	jermar	625	* @param src_as Pointer to source address space.
1239	jermar	626	* @param src_base Base address of the source address space area.
1417	jermar	627	* @param acc_size Expected size of the source area.
1428	palkovsky	628	* @param dst_as Pointer to destination address space.
1417	jermar	629	* @param dst_base Target base address.
		630	* @param dst_flags_mask Destination address space area flags mask.
1235	jermar	631	*
2007	jermar	632	* @return Zero on success or ENOENT if there is no such task or if there is no
		633	* such address space area, EPERM if there was a problem in accepting the area
		634	* or ENOMEM if there was a problem in allocating destination address space
		635	* area. ENOTSUP is returned if the address space area backend does not support
2141	jermar	636	* sharing.
1235	jermar	637	*/
1780	jermar	638	int as_area_share(as_t *src_as, uintptr_t src_base, size_t acc_size,
2647	jermar	639	as_t *dst_as, uintptr_t dst_base, int dst_flags_mask)
1235	jermar	640	{
		641	ipl_t ipl;
1239	jermar	642	int src_flags;
		643	size_t src_size;
		644	as_area_t src_area, dst_area;
1413	jermar	645	share_info_t *sh_info;
1424	jermar	646	mem_backend_t *src_backend;
		647	mem_backend_data_t src_backend_data;
1434	palkovsky	648
1235	jermar	649	ipl = interrupts_disable();
1380	jermar	650	mutex_lock(&src_as->lock);
1329	palkovsky	651	src_area = find_area_and_lock(src_as, src_base);
1239	jermar	652	if (!src_area) {
1238	jermar	653	/*
		654	* Could not find the source address space area.
		655	*/
1380	jermar	656	mutex_unlock(&src_as->lock);
1238	jermar	657	interrupts_restore(ipl);
		658	return ENOENT;
		659	}
2007	jermar	660
1424	jermar	661	if (!src_area->backend \|\| !src_area->backend->share) {
1413	jermar	662	/*
1851	jermar	663	* There is no backend or the backend does not
1424	jermar	664	* know how to share the area.
1413	jermar	665	*/
		666	mutex_unlock(&src_area->lock);
		667	mutex_unlock(&src_as->lock);
		668	interrupts_restore(ipl);
		669	return ENOTSUP;
		670	}
		671
1239	jermar	672	src_size = src_area->pages * PAGE_SIZE;
		673	src_flags = src_area->flags;
1424	jermar	674	src_backend = src_area->backend;
		675	src_backend_data = src_area->backend_data;
1544	palkovsky	676
		677	/* Share the cacheable flag from the original mapping */
		678	if (src_flags & AS_AREA_CACHEABLE)
		679	dst_flags_mask \|= AS_AREA_CACHEABLE;
		680
2087	jermar	681	if (src_size != acc_size \|\|
		682	(src_flags & dst_flags_mask) != dst_flags_mask) {
1413	jermar	683	mutex_unlock(&src_area->lock);
		684	mutex_unlock(&src_as->lock);
1235	jermar	685	interrupts_restore(ipl);
		686	return EPERM;
		687	}
1413	jermar	688
1235	jermar	689	/*
1413	jermar	690	* Now we are committed to sharing the area.
1954	jermar	691	* First, prepare the area for sharing.
1413	jermar	692	* Then it will be safe to unlock it.
		693	*/
		694	sh_info = src_area->sh_info;
		695	if (!sh_info) {
		696	sh_info = (share_info_t *) malloc(sizeof(share_info_t), 0);
3186	jermar	697	mutex_initialize(&sh_info->lock, MUTEX_PASSIVE);
1413	jermar	698	sh_info->refcount = 2;
		699	btree_create(&sh_info->pagemap);
		700	src_area->sh_info = sh_info;
2647	jermar	701	/*
		702	* Call the backend to setup sharing.
		703	*/
		704	src_area->backend->share(src_area);
1413	jermar	705	} else {
		706	mutex_lock(&sh_info->lock);
		707	sh_info->refcount++;
		708	mutex_unlock(&sh_info->lock);
		709	}
		710
		711	mutex_unlock(&src_area->lock);
		712	mutex_unlock(&src_as->lock);
		713
		714	/*
1239	jermar	715	* Create copy of the source address space area.
		716	* The destination area is created with AS_AREA_ATTR_PARTIAL
		717	* attribute set which prevents race condition with
		718	* preliminary as_page_fault() calls.
1417	jermar	719	* The flags of the source area are masked against dst_flags_mask
		720	* to support sharing in less privileged mode.
1235	jermar	721	*/
1461	palkovsky	722	dst_area = as_area_create(dst_as, dst_flags_mask, src_size, dst_base,
2087	jermar	723	AS_AREA_ATTR_PARTIAL, src_backend, &src_backend_data);
1239	jermar	724	if (!dst_area) {
1235	jermar	725	/*
		726	* Destination address space area could not be created.
		727	*/
1413	jermar	728	sh_info_remove_reference(sh_info);
		729
1235	jermar	730	interrupts_restore(ipl);
		731	return ENOMEM;
		732	}
2009	jermar	733
1235	jermar	734	/*
1239	jermar	735	* Now the destination address space area has been
		736	* fully initialized. Clear the AS_AREA_ATTR_PARTIAL
1413	jermar	737	* attribute and set the sh_info.
1239	jermar	738	*/
2009	jermar	739	mutex_lock(&dst_as->lock);
1380	jermar	740	mutex_lock(&dst_area->lock);
1239	jermar	741	dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
1413	jermar	742	dst_area->sh_info = sh_info;
1380	jermar	743	mutex_unlock(&dst_area->lock);
2009	jermar	744	mutex_unlock(&dst_as->lock);
		745
1235	jermar	746	interrupts_restore(ipl);
		747
		748	return 0;
		749	}
		750
1423	jermar	751	/** Check access mode for address space area.
		752	*
		753	* The address space area must be locked prior to this call.
		754	*
		755	* @param area Address space area.
		756	* @param access Access mode.
		757	*
		758	* @return False if access violates area's permissions, true otherwise.
		759	*/
		760	bool as_area_check_access(as_area_t *area, pf_access_t access)
		761	{
		762	int flagmap[] = {
		763	[PF_ACCESS_READ] = AS_AREA_READ,
		764	[PF_ACCESS_WRITE] = AS_AREA_WRITE,
		765	[PF_ACCESS_EXEC] = AS_AREA_EXEC
		766	};
		767
		768	if (!(area->flags & flagmap[access]))
		769	return false;
		770
		771	return true;
		772	}
		773
3222	svoboda	774	/** Change adress area flags.
		775	*
		776	* The idea is to have the same data, but with a different access mode.
		777	* This is needed e.g. for writing code into memory and then executing it.
		778	* In order for this to work properly, this may copy the data
		779	* into private anonymous memory (unless it's already there).
		780	*
		781	* @param as Address space.
		782	* @param flags Flags of the area memory.
		783	* @param address Address withing the area to be changed.
		784	*
		785	* @return Zero on success or a value from @ref errno.h on failure.
		786	*/
		787	int as_area_change_flags(as_t *as, int flags, uintptr_t address)
		788	{
		789	as_area_t *area;
		790	uintptr_t base;
		791	link_t *cur;
		792	ipl_t ipl;
		793	int page_flags;
		794	uintptr_t *old_frame;
		795	index_t frame_idx;
		796	count_t used_pages;
		797
		798	/* Flags for the new memory mapping */
		799	page_flags = area_flags_to_page_flags(flags);
		800
		801	ipl = interrupts_disable();
		802	mutex_lock(&as->lock);
		803
		804	area = find_area_and_lock(as, address);
		805	if (!area) {
		806	mutex_unlock(&as->lock);
		807	interrupts_restore(ipl);
		808	return ENOENT;
		809	}
		810
		811	if (area->sh_info \|\| area->backend != &anon_backend) {
		812	/* Copying shared areas not supported yet */
		813	/* Copying non-anonymous memory not supported yet */
		814	mutex_unlock(&area->lock);
		815	mutex_unlock(&as->lock);
		816	interrupts_restore(ipl);
		817	return ENOTSUP;
		818	}
		819
		820	base = area->base;
		821
		822	/*
		823	* Compute total number of used pages in the used_space B+tree
		824	*/
		825	used_pages = 0;
		826
		827	for (cur = area->used_space.leaf_head.next;
		828	cur != &area->used_space.leaf_head; cur = cur->next) {
		829	btree_node_t *node;
		830	unsigned int i;
		831
		832	node = list_get_instance(cur, btree_node_t, leaf_link);
		833	for (i = 0; i < node->keys; i++) {
		834	used_pages += (count_t) node->value[i];
		835	}
		836	}
		837
		838	/* An array for storing frame numbers */
		839	old_frame = malloc(used_pages * sizeof(uintptr_t), 0);
		840
		841	/*
		842	* Start TLB shootdown sequence.
		843	*/
		844	tlb_shootdown_start(TLB_INVL_PAGES, as->asid, area->base, area->pages);
		845
		846	/*
		847	* Remove used pages from page tables and remember their frame
		848	* numbers.
		849	*/
		850	frame_idx = 0;
		851
		852	for (cur = area->used_space.leaf_head.next;
		853	cur != &area->used_space.leaf_head; cur = cur->next) {
		854	btree_node_t *node;
		855	unsigned int i;
		856
		857	node = list_get_instance(cur, btree_node_t, leaf_link);
		858	for (i = 0; i < node->keys; i++) {
		859	uintptr_t b = node->key[i];
		860	count_t j;
		861	pte_t *pte;
		862
		863	for (j = 0; j < (count_t) node->value[i]; j++) {
		864	page_table_lock(as, false);
		865	pte = page_mapping_find(as, b + j * PAGE_SIZE);
		866	ASSERT(pte && PTE_VALID(pte) &&
		867	PTE_PRESENT(pte));
		868	old_frame[frame_idx++] = PTE_GET_FRAME(pte);
		869
		870	/* Remove old mapping */
		871	page_mapping_remove(as, b + j * PAGE_SIZE);
		872	page_table_unlock(as, false);
		873	}
		874	}
		875	}
		876
		877	/*
		878	* Finish TLB shootdown sequence.
		879	*/
		880
		881	tlb_invalidate_pages(as->asid, area->base, area->pages);
		882	/*
		883	* Invalidate potential software translation caches (e.g. TSB on
		884	* sparc64).
		885	*/
		886	as_invalidate_translation_cache(as, area->base, area->pages);
		887	tlb_shootdown_finalize();
		888
		889	/*
		890	* Map pages back in with new flags. This step is kept separate
		891	* so that there's no instant when the memory area could be
		892	* accesed with both the old and the new flags at once.
		893	*/
		894	frame_idx = 0;
		895
		896	for (cur = area->used_space.leaf_head.next;
		897	cur != &area->used_space.leaf_head; cur = cur->next) {
		898	btree_node_t *node;
		899	unsigned int i;
		900
		901	node = list_get_instance(cur, btree_node_t, leaf_link);
		902	for (i = 0; i < node->keys; i++) {
		903	uintptr_t b = node->key[i];
		904	count_t j;
		905
		906	for (j = 0; j < (count_t) node->value[i]; j++) {
		907	page_table_lock(as, false);
		908
		909	/* Insert the new mapping */
		910	page_mapping_insert(as, b + j * PAGE_SIZE,
		911	old_frame[frame_idx++], page_flags);
		912
		913	page_table_unlock(as, false);
		914	}
		915	}
		916	}
		917
		918	free(old_frame);
		919
		920	mutex_unlock(&area->lock);
		921	mutex_unlock(&as->lock);
		922	interrupts_restore(ipl);
		923
		924	return 0;
		925	}
		926
		927
703	jermar	928	/** Handle page fault within the current address space.
		929	*
1409	jermar	930	* This is the high-level page fault handler. It decides
		931	* whether the page fault can be resolved by any backend
		932	* and if so, it invokes the backend to resolve the page
		933	* fault.
		934	*
703	jermar	935	* Interrupts are assumed disabled.
		936	*
		937	* @param page Faulting page.
1411	jermar	938	* @param access Access mode that caused the fault (i.e. read/write/exec).
1288	jermar	939	* @param istate Pointer to interrupted state.
703	jermar	940	*
1409	jermar	941	* @return AS_PF_FAULT on page fault, AS_PF_OK on success or AS_PF_DEFER if the
		942	* fault was caused by copy_to_uspace() or copy_from_uspace().
703	jermar	943	*/
1780	jermar	944	int as_page_fault(uintptr_t page, pf_access_t access, istate_t *istate)
703	jermar	945	{
1044	jermar	946	pte_t *pte;
977	jermar	947	as_area_t *area;
703	jermar	948
1380	jermar	949	if (!THREAD)
1409	jermar	950	return AS_PF_FAULT;
1380	jermar	951
703	jermar	952	ASSERT(AS);
1044	jermar	953
1380	jermar	954	mutex_lock(&AS->lock);
977	jermar	955	area = find_area_and_lock(AS, page);
703	jermar	956	if (!area) {
		957	/*
		958	* No area contained mapping for 'page'.
		959	* Signal page fault to low-level handler.
		960	*/
1380	jermar	961	mutex_unlock(&AS->lock);
1288	jermar	962	goto page_fault;
703	jermar	963	}
		964
1239	jermar	965	if (area->attributes & AS_AREA_ATTR_PARTIAL) {
		966	/*
		967	* The address space area is not fully initialized.
		968	* Avoid possible race by returning error.
		969	*/
1380	jermar	970	mutex_unlock(&area->lock);
		971	mutex_unlock(&AS->lock);
1288	jermar	972	goto page_fault;
1239	jermar	973	}
		974
1424	jermar	975	if (!area->backend \|\| !area->backend->page_fault) {
1409	jermar	976	/*
		977	* The address space area is not backed by any backend
		978	* or the backend cannot handle page faults.
		979	*/
		980	mutex_unlock(&area->lock);
		981	mutex_unlock(&AS->lock);
		982	goto page_fault;
		983	}
1179	jermar	984
1044	jermar	985	page_table_lock(AS, false);
		986
703	jermar	987	/*
1044	jermar	988	* To avoid race condition between two page faults
		989	* on the same address, we need to make sure
		990	* the mapping has not been already inserted.
		991	*/
		992	if ((pte = page_mapping_find(AS, page))) {
		993	if (PTE_PRESENT(pte)) {
1423	jermar	994	if (((access == PF_ACCESS_READ) && PTE_READABLE(pte)) \|\|
2087	jermar	995	(access == PF_ACCESS_WRITE && PTE_WRITABLE(pte)) \|\|
		996	(access == PF_ACCESS_EXEC && PTE_EXECUTABLE(pte))) {
1423	jermar	997	page_table_unlock(AS, false);
		998	mutex_unlock(&area->lock);
		999	mutex_unlock(&AS->lock);
		1000	return AS_PF_OK;
		1001	}
1044	jermar	1002	}
		1003	}
1409	jermar	1004
1044	jermar	1005	/*
1409	jermar	1006	* Resort to the backend page fault handler.
703	jermar	1007	*/
1424	jermar	1008	if (area->backend->page_fault(area, page, access) != AS_PF_OK) {
1409	jermar	1009	page_table_unlock(AS, false);
		1010	mutex_unlock(&area->lock);
		1011	mutex_unlock(&AS->lock);
		1012	goto page_fault;
		1013	}
703	jermar	1014
1044	jermar	1015	page_table_unlock(AS, false);
1380	jermar	1016	mutex_unlock(&area->lock);
		1017	mutex_unlock(&AS->lock);
1288	jermar	1018	return AS_PF_OK;
		1019
		1020	page_fault:
		1021	if (THREAD->in_copy_from_uspace) {
		1022	THREAD->in_copy_from_uspace = false;
2087	jermar	1023	istate_set_retaddr(istate,
		1024	(uintptr_t) &memcpy_from_uspace_failover_address);
1288	jermar	1025	} else if (THREAD->in_copy_to_uspace) {
		1026	THREAD->in_copy_to_uspace = false;
2087	jermar	1027	istate_set_retaddr(istate,
		1028	(uintptr_t) &memcpy_to_uspace_failover_address);
1288	jermar	1029	} else {
		1030	return AS_PF_FAULT;
		1031	}
		1032
		1033	return AS_PF_DEFER;
703	jermar	1034	}
		1035
823	jermar	1036	/** Switch address spaces.
703	jermar	1037	*
1380	jermar	1038	* Note that this function cannot sleep as it is essentially a part of
2170	jermar	1039	* scheduling. Sleeping here would lead to deadlock on wakeup. Another
		1040	* thing which is forbidden in this context is locking the address space.
1380	jermar	1041	*
2183	jermar	1042	* When this function is enetered, no spinlocks may be held.
		1043	*
823	jermar	1044	* @param old Old address space or NULL.
		1045	* @param new New address space.
703	jermar	1046	*/
2106	jermar	1047	void as_switch(as_t old_as, as_t new_as)
703	jermar	1048	{
2183	jermar	1049	DEADLOCK_PROBE_INIT(p_asidlock);
		1050	preemption_disable();
		1051	retry:
		1052	(void) interrupts_disable();
		1053	if (!spinlock_trylock(&asidlock)) {
		1054	/*
		1055	* Avoid deadlock with TLB shootdown.
		1056	* We can enable interrupts here because
		1057	* preemption is disabled. We should not be
		1058	* holding any other lock.
		1059	*/
		1060	(void) interrupts_enable();
		1061	DEADLOCK_PROBE(p_asidlock, DEADLOCK_THRESHOLD);
		1062	goto retry;
		1063	}
		1064	preemption_enable();
703	jermar	1065
		1066	/*
823	jermar	1067	* First, take care of the old address space.
		1068	*/
2106	jermar	1069	if (old_as) {
		1070	ASSERT(old_as->cpu_refcount);
		1071	if((--old_as->cpu_refcount == 0) && (old_as != AS_KERNEL)) {
823	jermar	1072	/*
		1073	* The old address space is no longer active on
		1074	* any processor. It can be appended to the
		1075	* list of inactive address spaces with assigned
		1076	* ASID.
		1077	*/
2141	jermar	1078	ASSERT(old_as->asid != ASID_INVALID);
		1079	list_append(&old_as->inactive_as_with_asid_link,
		1080	&inactive_as_with_asid_head);
823	jermar	1081	}
1890	jermar	1082
		1083	/*
		1084	* Perform architecture-specific tasks when the address space
		1085	* is being removed from the CPU.
		1086	*/
2106	jermar	1087	as_deinstall_arch(old_as);
823	jermar	1088	}
		1089
		1090	/*
		1091	* Second, prepare the new address space.
		1092	*/
2106	jermar	1093	if ((new_as->cpu_refcount++ == 0) && (new_as != AS_KERNEL)) {
2170	jermar	1094	if (new_as->asid != ASID_INVALID)
2106	jermar	1095	list_remove(&new_as->inactive_as_with_asid_link);
2170	jermar	1096	else
		1097	new_as->asid = asid_get();
823	jermar	1098	}
2106	jermar	1099	#ifdef AS_PAGE_TABLE
		1100	SET_PTL0_ADDRESS(new_as->genarch.page_table);
		1101	#endif
823	jermar	1102
		1103	/*
703	jermar	1104	* Perform architecture-specific steps.
727	jermar	1105	* (e.g. write ASID to hardware register etc.)
703	jermar	1106	*/
2106	jermar	1107	as_install_arch(new_as);
2170	jermar	1108
		1109	spinlock_unlock(&asidlock);
703	jermar	1110
2106	jermar	1111	AS = new_as;
703	jermar	1112	}
754	jermar	1113
1235	jermar	1114	/** Convert address space area flags to page flags.
754	jermar	1115	*
1235	jermar	1116	* @param aflags Flags of some address space area.
754	jermar	1117	*
1235	jermar	1118	* @return Flags to be passed to page_mapping_insert().
754	jermar	1119	*/
1235	jermar	1120	int area_flags_to_page_flags(int aflags)
754	jermar	1121	{
		1122	int flags;
		1123
1178	jermar	1124	flags = PAGE_USER \| PAGE_PRESENT;
754	jermar	1125
1235	jermar	1126	if (aflags & AS_AREA_READ)
1026	jermar	1127	flags \|= PAGE_READ;
		1128
1235	jermar	1129	if (aflags & AS_AREA_WRITE)
1026	jermar	1130	flags \|= PAGE_WRITE;
		1131
1235	jermar	1132	if (aflags & AS_AREA_EXEC)
1026	jermar	1133	flags \|= PAGE_EXEC;
		1134
1424	jermar	1135	if (aflags & AS_AREA_CACHEABLE)
1178	jermar	1136	flags \|= PAGE_CACHEABLE;
		1137
754	jermar	1138	return flags;
		1139	}
756	jermar	1140
1235	jermar	1141	/** Compute flags for virtual address translation subsytem.
		1142	*
		1143	* The address space area must be locked.
		1144	* Interrupts must be disabled.
		1145	*
		1146	* @param a Address space area.
		1147	*
		1148	* @return Flags to be used in page_mapping_insert().
		1149	*/
1409	jermar	1150	int as_area_get_flags(as_area_t *a)
1235	jermar	1151	{
		1152	return area_flags_to_page_flags(a->flags);
		1153	}
		1154
756	jermar	1155	/** Create page table.
		1156	*
		1157	* Depending on architecture, create either address space
		1158	* private or global page table.
		1159	*
		1160	* @param flags Flags saying whether the page table is for kernel address space.
		1161	*
		1162	* @return First entry of the page table.
		1163	*/
		1164	pte_t *page_table_create(int flags)
		1165	{
2125	decky	1166	#ifdef __OBJC__
		1167	return [as_t page_table_create: flags];
		1168	#else
		1169	ASSERT(as_operations);
		1170	ASSERT(as_operations->page_table_create);
		1171
		1172	return as_operations->page_table_create(flags);
		1173	#endif
756	jermar	1174	}
977	jermar	1175
1468	jermar	1176	/** Destroy page table.
		1177	*
		1178	* Destroy page table in architecture specific way.
		1179	*
		1180	* @param page_table Physical address of PTL0.
		1181	*/
		1182	void page_table_destroy(pte_t *page_table)
		1183	{
2125	decky	1184	#ifdef __OBJC__
		1185	return [as_t page_table_destroy: page_table];
		1186	#else
		1187	ASSERT(as_operations);
		1188	ASSERT(as_operations->page_table_destroy);
		1189
		1190	as_operations->page_table_destroy(page_table);
		1191	#endif
1468	jermar	1192	}
		1193
1044	jermar	1194	/** Lock page table.
		1195	*
		1196	* This function should be called before any page_mapping_insert(),
		1197	* page_mapping_remove() and page_mapping_find().
		1198	*
		1199	* Locking order is such that address space areas must be locked
		1200	* prior to this call. Address space can be locked prior to this
		1201	* call in which case the lock argument is false.
		1202	*
		1203	* @param as Address space.
1248	jermar	1204	* @param lock If false, do not attempt to lock as->lock.
1044	jermar	1205	*/
		1206	void page_table_lock(as_t *as, bool lock)
		1207	{
2125	decky	1208	#ifdef __OBJC__
		1209	[as page_table_lock: lock];
		1210	#else
1044	jermar	1211	ASSERT(as_operations);
		1212	ASSERT(as_operations->page_table_lock);
2125	decky	1213
1044	jermar	1214	as_operations->page_table_lock(as, lock);
2125	decky	1215	#endif
1044	jermar	1216	}
		1217
		1218	/** Unlock page table.
		1219	*
		1220	* @param as Address space.
1248	jermar	1221	* @param unlock If false, do not attempt to unlock as->lock.
1044	jermar	1222	*/
		1223	void page_table_unlock(as_t *as, bool unlock)
		1224	{
2125	decky	1225	#ifdef __OBJC__
		1226	[as page_table_unlock: unlock];
		1227	#else
1044	jermar	1228	ASSERT(as_operations);
		1229	ASSERT(as_operations->page_table_unlock);
2125	decky	1230
1044	jermar	1231	as_operations->page_table_unlock(as, unlock);
2125	decky	1232	#endif
1044	jermar	1233	}
		1234
977	jermar	1235
		1236	/** Find address space area and lock it.
		1237	*
		1238	* The address space must be locked and interrupts must be disabled.
		1239	*
		1240	* @param as Address space.
		1241	* @param va Virtual address.
		1242	*
2087	jermar	1243	* @return Locked address space area containing va on success or NULL on
		1244	* failure.
977	jermar	1245	*/
1780	jermar	1246	as_area_t find_area_and_lock(as_t as, uintptr_t va)
977	jermar	1247	{
		1248	as_area_t *a;
1147	jermar	1249	btree_node_t leaf, lnode;
2745	decky	1250	unsigned int i;
977	jermar	1251
1147	jermar	1252	a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
		1253	if (a) {
		1254	/* va is the base address of an address space area */
1380	jermar	1255	mutex_lock(&a->lock);
1147	jermar	1256	return a;
		1257	}
		1258
		1259	/*
1150	jermar	1260	* Search the leaf node and the righmost record of its left neighbour
1147	jermar	1261	* to find out whether this is a miss or va belongs to an address
		1262	* space area found there.
		1263	*/
		1264
		1265	/* First, search the leaf node itself. */
		1266	for (i = 0; i < leaf->keys; i++) {
		1267	a = (as_area_t *) leaf->value[i];
1380	jermar	1268	mutex_lock(&a->lock);
1147	jermar	1269	if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
		1270	return a;
		1271	}
1380	jermar	1272	mutex_unlock(&a->lock);
1147	jermar	1273	}
977	jermar	1274
1147	jermar	1275	/*
1150	jermar	1276	* Second, locate the left neighbour and test its last record.
1148	jermar	1277	* Because of its position in the B+tree, it must have base < va.
1147	jermar	1278	*/
2087	jermar	1279	lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf);
		1280	if (lnode) {
1147	jermar	1281	a = (as_area_t *) lnode->value[lnode->keys - 1];
1380	jermar	1282	mutex_lock(&a->lock);
1147	jermar	1283	if (va < a->base + a->pages * PAGE_SIZE) {
1048	jermar	1284	return a;
1147	jermar	1285	}
1380	jermar	1286	mutex_unlock(&a->lock);
977	jermar	1287	}
		1288
		1289	return NULL;
		1290	}
1048	jermar	1291
		1292	/** Check area conflicts with other areas.
		1293	*
		1294	* The address space must be locked and interrupts must be disabled.
		1295	*
		1296	* @param as Address space.
		1297	* @param va Starting virtual address of the area being tested.
		1298	* @param size Size of the area being tested.
		1299	* @param avoid_area Do not touch this area.
		1300	*
		1301	* @return True if there is no conflict, false otherwise.
		1302	*/
2087	jermar	1303	bool check_area_conflicts(as_t *as, uintptr_t va, size_t size,
		1304	as_area_t *avoid_area)
1048	jermar	1305	{
		1306	as_area_t *a;
1147	jermar	1307	btree_node_t leaf, node;
2745	decky	1308	unsigned int i;
1048	jermar	1309
1070	jermar	1310	/*
		1311	* We don't want any area to have conflicts with NULL page.
		1312	*/
		1313	if (overlaps(va, size, NULL, PAGE_SIZE))
		1314	return false;
		1315
1147	jermar	1316	/*
		1317	* The leaf node is found in O(log n), where n is proportional to
		1318	* the number of address space areas belonging to as.
		1319	* The check for conflicts is then attempted on the rightmost
1150	jermar	1320	* record in the left neighbour, the leftmost record in the right
		1321	* neighbour and all records in the leaf node itself.
1147	jermar	1322	*/
1048	jermar	1323
1147	jermar	1324	if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
		1325	if (a != avoid_area)
		1326	return false;
		1327	}
		1328
		1329	/* First, check the two border cases. */
1150	jermar	1330	if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	1331	a = (as_area_t *) node->value[node->keys - 1];
1380	jermar	1332	mutex_lock(&a->lock);
1147	jermar	1333	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1334	mutex_unlock(&a->lock);
1147	jermar	1335	return false;
		1336	}
1380	jermar	1337	mutex_unlock(&a->lock);
1147	jermar	1338	}
2087	jermar	1339	node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf);
		1340	if (node) {
1147	jermar	1341	a = (as_area_t *) node->value[0];
1380	jermar	1342	mutex_lock(&a->lock);
1147	jermar	1343	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1344	mutex_unlock(&a->lock);
1147	jermar	1345	return false;
		1346	}
1380	jermar	1347	mutex_unlock(&a->lock);
1147	jermar	1348	}
		1349
		1350	/* Second, check the leaf node. */
		1351	for (i = 0; i < leaf->keys; i++) {
		1352	a = (as_area_t *) leaf->value[i];
		1353
1048	jermar	1354	if (a == avoid_area)
		1355	continue;
1147	jermar	1356
1380	jermar	1357	mutex_lock(&a->lock);
1147	jermar	1358	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1359	mutex_unlock(&a->lock);
1147	jermar	1360	return false;
		1361	}
1380	jermar	1362	mutex_unlock(&a->lock);
1048	jermar	1363	}
		1364
1070	jermar	1365	/*
		1366	* So far, the area does not conflict with other areas.
		1367	* Check if it doesn't conflict with kernel address space.
		1368	*/
		1369	if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
		1370	return !overlaps(va, size,
2087	jermar	1371	KERNEL_ADDRESS_SPACE_START,
		1372	KERNEL_ADDRESS_SPACE_END - KERNEL_ADDRESS_SPACE_START);
1070	jermar	1373	}
		1374
1048	jermar	1375	return true;
		1376	}
1235	jermar	1377
2556	jermar	1378	/** Return size of the address space area with given base.
		1379	*
		1380	* @param base Arbitrary address insede the address space area.
		1381	*
		1382	* @return Size of the address space area in bytes or zero if it
		1383	* does not exist.
		1384	*/
		1385	size_t as_area_get_size(uintptr_t base)
1329	palkovsky	1386	{
		1387	ipl_t ipl;
		1388	as_area_t *src_area;
		1389	size_t size;
		1390
		1391	ipl = interrupts_disable();
		1392	src_area = find_area_and_lock(AS, base);
		1393	if (src_area){
		1394	size = src_area->pages * PAGE_SIZE;
1380	jermar	1395	mutex_unlock(&src_area->lock);
1329	palkovsky	1396	} else {
		1397	size = 0;
		1398	}
		1399	interrupts_restore(ipl);
		1400	return size;
		1401	}
		1402
1387	jermar	1403	/** Mark portion of address space area as used.
		1404	*
		1405	* The address space area must be already locked.
		1406	*
		1407	* @param a Address space area.
		1408	* @param page First page to be marked.
		1409	* @param count Number of page to be marked.
		1410	*
		1411	* @return 0 on failure and 1 on success.
		1412	*/
1780	jermar	1413	int used_space_insert(as_area_t *a, uintptr_t page, count_t count)
1387	jermar	1414	{
		1415	btree_node_t leaf, node;
		1416	count_t pages;
2745	decky	1417	unsigned int i;
1387	jermar	1418
		1419	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1420	ASSERT(count);
		1421
		1422	pages = (count_t) btree_search(&a->used_space, page, &leaf);
		1423	if (pages) {
		1424	/*
		1425	* We hit the beginning of some used space.
		1426	*/
		1427	return 0;
		1428	}
		1429
1437	jermar	1430	if (!leaf->keys) {
		1431	btree_insert(&a->used_space, page, (void *) count, leaf);
		1432	return 1;
		1433	}
		1434
1387	jermar	1435	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1436	if (node) {
2087	jermar	1437	uintptr_t left_pg = node->key[node->keys - 1];
		1438	uintptr_t right_pg = leaf->key[0];
		1439	count_t left_cnt = (count_t) node->value[node->keys - 1];
		1440	count_t right_cnt = (count_t) leaf->value[0];
1387	jermar	1441
		1442	/*
		1443	* Examine the possibility that the interval fits
		1444	* somewhere between the rightmost interval of
		1445	* the left neigbour and the first interval of the leaf.
		1446	*/
		1447
		1448	if (page >= right_pg) {
		1449	/* Do nothing. */
2087	jermar	1450	} else if (overlaps(page, count * PAGE_SIZE, left_pg,
		1451	left_cnt * PAGE_SIZE)) {
1387	jermar	1452	/* The interval intersects with the left interval. */
		1453	return 0;
2087	jermar	1454	} else if (overlaps(page, count * PAGE_SIZE, right_pg,
		1455	right_cnt * PAGE_SIZE)) {
1387	jermar	1456	/* The interval intersects with the right interval. */
		1457	return 0;
2087	jermar	1458	} else if ((page == left_pg + left_cnt * PAGE_SIZE) &&
		1459	(page + count * PAGE_SIZE == right_pg)) {
		1460	/*
		1461	* The interval can be added by merging the two already
		1462	* present intervals.
		1463	*/
1403	jermar	1464	node->value[node->keys - 1] += count + right_cnt;
1387	jermar	1465	btree_remove(&a->used_space, right_pg, leaf);
		1466	return 1;
2087	jermar	1467	} else if (page == left_pg + left_cnt * PAGE_SIZE) {
		1468	/*
		1469	* The interval can be added by simply growing the left
		1470	* interval.
		1471	*/
1403	jermar	1472	node->value[node->keys - 1] += count;
1387	jermar	1473	return 1;
2087	jermar	1474	} else if (page + count * PAGE_SIZE == right_pg) {
1387	jermar	1475	/*
2087	jermar	1476	* The interval can be addded by simply moving base of
		1477	* the right interval down and increasing its size
		1478	* accordingly.
1387	jermar	1479	*/
1403	jermar	1480	leaf->value[0] += count;
1387	jermar	1481	leaf->key[0] = page;
		1482	return 1;
		1483	} else {
		1484	/*
		1485	* The interval is between both neigbouring intervals,
		1486	* but cannot be merged with any of them.
		1487	*/
2087	jermar	1488	btree_insert(&a->used_space, page, (void *) count,
		1489	leaf);
1387	jermar	1490	return 1;
		1491	}
		1492	} else if (page < leaf->key[0]) {
1780	jermar	1493	uintptr_t right_pg = leaf->key[0];
1387	jermar	1494	count_t right_cnt = (count_t) leaf->value[0];
		1495
		1496	/*
2087	jermar	1497	* Investigate the border case in which the left neighbour does
		1498	* not exist but the interval fits from the left.
1387	jermar	1499	*/
		1500
2087	jermar	1501	if (overlaps(page, count * PAGE_SIZE, right_pg,
		1502	right_cnt * PAGE_SIZE)) {
1387	jermar	1503	/* The interval intersects with the right interval. */
		1504	return 0;
2087	jermar	1505	} else if (page + count * PAGE_SIZE == right_pg) {
1387	jermar	1506	/*
2087	jermar	1507	* The interval can be added by moving the base of the
		1508	* right interval down and increasing its size
		1509	* accordingly.
1387	jermar	1510	*/
		1511	leaf->key[0] = page;
1403	jermar	1512	leaf->value[0] += count;
1387	jermar	1513	return 1;
		1514	} else {
		1515	/*
		1516	* The interval doesn't adjoin with the right interval.
		1517	* It must be added individually.
		1518	*/
2087	jermar	1519	btree_insert(&a->used_space, page, (void *) count,
		1520	leaf);
1387	jermar	1521	return 1;
		1522	}
		1523	}
		1524
		1525	node = btree_leaf_node_right_neighbour(&a->used_space, leaf);
		1526	if (node) {
2087	jermar	1527	uintptr_t left_pg = leaf->key[leaf->keys - 1];
		1528	uintptr_t right_pg = node->key[0];
		1529	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1530	count_t right_cnt = (count_t) node->value[0];
1387	jermar	1531
		1532	/*
		1533	* Examine the possibility that the interval fits
		1534	* somewhere between the leftmost interval of
		1535	* the right neigbour and the last interval of the leaf.
		1536	*/
		1537
		1538	if (page < left_pg) {
		1539	/* Do nothing. */
2087	jermar	1540	} else if (overlaps(page, count * PAGE_SIZE, left_pg,
		1541	left_cnt * PAGE_SIZE)) {
1387	jermar	1542	/* The interval intersects with the left interval. */
		1543	return 0;
2087	jermar	1544	} else if (overlaps(page, count * PAGE_SIZE, right_pg,
		1545	right_cnt * PAGE_SIZE)) {
1387	jermar	1546	/* The interval intersects with the right interval. */
		1547	return 0;
2087	jermar	1548	} else if ((page == left_pg + left_cnt * PAGE_SIZE) &&
		1549	(page + count * PAGE_SIZE == right_pg)) {
		1550	/*
		1551	* The interval can be added by merging the two already
		1552	* present intervals.
		1553	* */
1403	jermar	1554	leaf->value[leaf->keys - 1] += count + right_cnt;
1387	jermar	1555	btree_remove(&a->used_space, right_pg, node);
		1556	return 1;
2087	jermar	1557	} else if (page == left_pg + left_cnt * PAGE_SIZE) {
		1558	/*
		1559	* The interval can be added by simply growing the left
		1560	* interval.
		1561	* */
1403	jermar	1562	leaf->value[leaf->keys - 1] += count;
1387	jermar	1563	return 1;
2087	jermar	1564	} else if (page + count * PAGE_SIZE == right_pg) {
1387	jermar	1565	/*
2087	jermar	1566	* The interval can be addded by simply moving base of
		1567	* the right interval down and increasing its size
		1568	* accordingly.
1387	jermar	1569	*/
1403	jermar	1570	node->value[0] += count;
1387	jermar	1571	node->key[0] = page;
		1572	return 1;
		1573	} else {
		1574	/*
		1575	* The interval is between both neigbouring intervals,
		1576	* but cannot be merged with any of them.
		1577	*/
2087	jermar	1578	btree_insert(&a->used_space, page, (void *) count,
		1579	leaf);
1387	jermar	1580	return 1;
		1581	}
		1582	} else if (page >= leaf->key[leaf->keys - 1]) {
1780	jermar	1583	uintptr_t left_pg = leaf->key[leaf->keys - 1];
1387	jermar	1584	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1585
		1586	/*
2087	jermar	1587	* Investigate the border case in which the right neighbour
		1588	* does not exist but the interval fits from the right.
1387	jermar	1589	*/
		1590
2087	jermar	1591	if (overlaps(page, count * PAGE_SIZE, left_pg,
		1592	left_cnt * PAGE_SIZE)) {
1403	jermar	1593	/* The interval intersects with the left interval. */
1387	jermar	1594	return 0;
2087	jermar	1595	} else if (left_pg + left_cnt * PAGE_SIZE == page) {
		1596	/*
		1597	* The interval can be added by growing the left
		1598	* interval.
		1599	*/
1403	jermar	1600	leaf->value[leaf->keys - 1] += count;
1387	jermar	1601	return 1;
		1602	} else {
		1603	/*
		1604	* The interval doesn't adjoin with the left interval.
		1605	* It must be added individually.
		1606	*/
2087	jermar	1607	btree_insert(&a->used_space, page, (void *) count,
		1608	leaf);
1387	jermar	1609	return 1;
		1610	}
		1611	}
		1612
		1613	/*
2087	jermar	1614	* Note that if the algorithm made it thus far, the interval can fit
		1615	* only between two other intervals of the leaf. The two border cases
		1616	* were already resolved.
1387	jermar	1617	*/
		1618	for (i = 1; i < leaf->keys; i++) {
		1619	if (page < leaf->key[i]) {
2087	jermar	1620	uintptr_t left_pg = leaf->key[i - 1];
		1621	uintptr_t right_pg = leaf->key[i];
		1622	count_t left_cnt = (count_t) leaf->value[i - 1];
		1623	count_t right_cnt = (count_t) leaf->value[i];
1387	jermar	1624
		1625	/*
		1626	* The interval fits between left_pg and right_pg.
		1627	*/
		1628
2087	jermar	1629	if (overlaps(page, count * PAGE_SIZE, left_pg,
		1630	left_cnt * PAGE_SIZE)) {
		1631	/*
		1632	* The interval intersects with the left
		1633	* interval.
		1634	*/
1387	jermar	1635	return 0;
2087	jermar	1636	} else if (overlaps(page, count * PAGE_SIZE, right_pg,
		1637	right_cnt * PAGE_SIZE)) {
		1638	/*
		1639	* The interval intersects with the right
		1640	* interval.
		1641	*/
1387	jermar	1642	return 0;
2087	jermar	1643	} else if ((page == left_pg + left_cnt * PAGE_SIZE) &&
		1644	(page + count * PAGE_SIZE == right_pg)) {
		1645	/*
		1646	* The interval can be added by merging the two
		1647	* already present intervals.
		1648	*/
1403	jermar	1649	leaf->value[i - 1] += count + right_cnt;
1387	jermar	1650	btree_remove(&a->used_space, right_pg, leaf);
		1651	return 1;
2087	jermar	1652	} else if (page == left_pg + left_cnt * PAGE_SIZE) {
		1653	/*
		1654	* The interval can be added by simply growing
		1655	* the left interval.
		1656	*/
1403	jermar	1657	leaf->value[i - 1] += count;
1387	jermar	1658	return 1;
2087	jermar	1659	} else if (page + count * PAGE_SIZE == right_pg) {
1387	jermar	1660	/*
2087	jermar	1661	* The interval can be addded by simply moving
		1662	* base of the right interval down and
		1663	* increasing its size accordingly.
1387	jermar	1664	*/
1403	jermar	1665	leaf->value[i] += count;
1387	jermar	1666	leaf->key[i] = page;
		1667	return 1;
		1668	} else {
		1669	/*
2087	jermar	1670	* The interval is between both neigbouring
		1671	* intervals, but cannot be merged with any of
		1672	* them.
1387	jermar	1673	*/
2087	jermar	1674	btree_insert(&a->used_space, page,
		1675	(void *) count, leaf);
1387	jermar	1676	return 1;
		1677	}
		1678	}
		1679	}
		1680
3057	decky	1681	panic("Inconsistency detected while adding %" PRIc " pages of used space at "
2087	jermar	1682	"%p.\n", count, page);
1387	jermar	1683	}
		1684
		1685	/** Mark portion of address space area as unused.
		1686	*
		1687	* The address space area must be already locked.
		1688	*
		1689	* @param a Address space area.
		1690	* @param page First page to be marked.
		1691	* @param count Number of page to be marked.
		1692	*
		1693	* @return 0 on failure and 1 on success.
		1694	*/
1780	jermar	1695	int used_space_remove(as_area_t *a, uintptr_t page, count_t count)
1387	jermar	1696	{
		1697	btree_node_t leaf, node;
		1698	count_t pages;
2745	decky	1699	unsigned int i;
1387	jermar	1700
		1701	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1702	ASSERT(count);
		1703
		1704	pages = (count_t) btree_search(&a->used_space, page, &leaf);
		1705	if (pages) {
		1706	/*
		1707	* We are lucky, page is the beginning of some interval.
		1708	*/
		1709	if (count > pages) {
		1710	return 0;
		1711	} else if (count == pages) {
		1712	btree_remove(&a->used_space, page, leaf);
1403	jermar	1713	return 1;
1387	jermar	1714	} else {
		1715	/*
		1716	* Find the respective interval.
		1717	* Decrease its size and relocate its start address.
		1718	*/
		1719	for (i = 0; i < leaf->keys; i++) {
		1720	if (leaf->key[i] == page) {
2087	jermar	1721	leaf->key[i] += count * PAGE_SIZE;
1403	jermar	1722	leaf->value[i] -= count;
1387	jermar	1723	return 1;
		1724	}
		1725	}
		1726	goto error;
		1727	}
		1728	}
		1729
		1730	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1731	if (node && page < leaf->key[0]) {
1780	jermar	1732	uintptr_t left_pg = node->key[node->keys - 1];
1387	jermar	1733	count_t left_cnt = (count_t) node->value[node->keys - 1];
		1734
2087	jermar	1735	if (overlaps(left_pg, left_cnt * PAGE_SIZE, page,
		1736	count * PAGE_SIZE)) {
		1737	if (page + count * PAGE_SIZE ==
		1738	left_pg + left_cnt * PAGE_SIZE) {
1387	jermar	1739	/*
2087	jermar	1740	* The interval is contained in the rightmost
		1741	* interval of the left neighbour and can be
		1742	* removed by updating the size of the bigger
		1743	* interval.
1387	jermar	1744	*/
1403	jermar	1745	node->value[node->keys - 1] -= count;
1387	jermar	1746	return 1;
2087	jermar	1747	} else if (page + count * PAGE_SIZE <
		1748	left_pg + left_cnt*PAGE_SIZE) {
1403	jermar	1749	count_t new_cnt;
1387	jermar	1750
		1751	/*
2087	jermar	1752	* The interval is contained in the rightmost
		1753	* interval of the left neighbour but its
		1754	* removal requires both updating the size of
		1755	* the original interval and also inserting a
		1756	* new interval.
1387	jermar	1757	*/
2087	jermar	1758	new_cnt = ((left_pg + left_cnt * PAGE_SIZE) -
		1759	(page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1403	jermar	1760	node->value[node->keys - 1] -= count + new_cnt;
2087	jermar	1761	btree_insert(&a->used_space, page +
		1762	count * PAGE_SIZE, (void *) new_cnt, leaf);
1387	jermar	1763	return 1;
		1764	}
		1765	}
		1766	return 0;
		1767	} else if (page < leaf->key[0]) {
		1768	return 0;
		1769	}
		1770
		1771	if (page > leaf->key[leaf->keys - 1]) {
1780	jermar	1772	uintptr_t left_pg = leaf->key[leaf->keys - 1];
1387	jermar	1773	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1774
2087	jermar	1775	if (overlaps(left_pg, left_cnt * PAGE_SIZE, page,
		1776	count * PAGE_SIZE)) {
		1777	if (page + count * PAGE_SIZE ==
		1778	left_pg + left_cnt * PAGE_SIZE) {
1387	jermar	1779	/*
2087	jermar	1780	* The interval is contained in the rightmost
		1781	* interval of the leaf and can be removed by
		1782	* updating the size of the bigger interval.
1387	jermar	1783	*/
1403	jermar	1784	leaf->value[leaf->keys - 1] -= count;
1387	jermar	1785	return 1;
2087	jermar	1786	} else if (page + count * PAGE_SIZE < left_pg +
		1787	left_cnt * PAGE_SIZE) {
1403	jermar	1788	count_t new_cnt;
1387	jermar	1789
		1790	/*
2087	jermar	1791	* The interval is contained in the rightmost
		1792	* interval of the leaf but its removal
		1793	* requires both updating the size of the
		1794	* original interval and also inserting a new
		1795	* interval.
1387	jermar	1796	*/
2087	jermar	1797	new_cnt = ((left_pg + left_cnt * PAGE_SIZE) -
		1798	(page + count * PAGE_SIZE)) >> PAGE_WIDTH;
1403	jermar	1799	leaf->value[leaf->keys - 1] -= count + new_cnt;
2087	jermar	1800	btree_insert(&a->used_space, page +
		1801	count * PAGE_SIZE, (void *) new_cnt, leaf);
1387	jermar	1802	return 1;
		1803	}
		1804	}
		1805	return 0;
		1806	}
		1807
		1808	/*
		1809	* The border cases have been already resolved.
		1810	* Now the interval can be only between intervals of the leaf.
		1811	*/
		1812	for (i = 1; i < leaf->keys - 1; i++) {
		1813	if (page < leaf->key[i]) {
1780	jermar	1814	uintptr_t left_pg = leaf->key[i - 1];
1387	jermar	1815	count_t left_cnt = (count_t) leaf->value[i - 1];
		1816
		1817	/*
2087	jermar	1818	* Now the interval is between intervals corresponding
		1819	* to (i - 1) and i.
1387	jermar	1820	*/
2087	jermar	1821	if (overlaps(left_pg, left_cnt * PAGE_SIZE, page,
		1822	count * PAGE_SIZE)) {
		1823	if (page + count * PAGE_SIZE ==
		1824	left_pg + left_cnt*PAGE_SIZE) {
1387	jermar	1825	/*
2087	jermar	1826	* The interval is contained in the
		1827	* interval (i - 1) of the leaf and can
		1828	* be removed by updating the size of
		1829	* the bigger interval.
1387	jermar	1830	*/
1403	jermar	1831	leaf->value[i - 1] -= count;
1387	jermar	1832	return 1;
2087	jermar	1833	} else if (page + count * PAGE_SIZE <
		1834	left_pg + left_cnt * PAGE_SIZE) {
1403	jermar	1835	count_t new_cnt;
1387	jermar	1836
		1837	/*
2087	jermar	1838	* The interval is contained in the
		1839	* interval (i - 1) of the leaf but its
		1840	* removal requires both updating the
		1841	* size of the original interval and
1387	jermar	1842	* also inserting a new interval.
		1843	*/
2087	jermar	1844	new_cnt = ((left_pg +
		1845	left_cnt * PAGE_SIZE) -
		1846	(page + count * PAGE_SIZE)) >>
		1847	PAGE_WIDTH;
1403	jermar	1848	leaf->value[i - 1] -= count + new_cnt;
2087	jermar	1849	btree_insert(&a->used_space, page +
		1850	count * PAGE_SIZE, (void *) new_cnt,
		1851	leaf);
1387	jermar	1852	return 1;
		1853	}
		1854	}
		1855	return 0;
		1856	}
		1857	}
		1858
		1859	error:
3057	decky	1860	panic("Inconsistency detected while removing %" PRIc " pages of used space "
2087	jermar	1861	"from %p.\n", count, page);
1387	jermar	1862	}
		1863
1409	jermar	1864	/** Remove reference to address space area share info.
		1865	*
		1866	* If the reference count drops to 0, the sh_info is deallocated.
		1867	*
		1868	* @param sh_info Pointer to address space area share info.
		1869	*/
		1870	void sh_info_remove_reference(share_info_t *sh_info)
		1871	{
		1872	bool dealloc = false;
		1873
		1874	mutex_lock(&sh_info->lock);
		1875	ASSERT(sh_info->refcount);
		1876	if (--sh_info->refcount == 0) {
		1877	dealloc = true;
1495	jermar	1878	link_t *cur;
1409	jermar	1879
		1880	/*
		1881	* Now walk carefully the pagemap B+tree and free/remove
		1882	* reference from all frames found there.
		1883	*/
2087	jermar	1884	for (cur = sh_info->pagemap.leaf_head.next;
		1885	cur != &sh_info->pagemap.leaf_head; cur = cur->next) {
1409	jermar	1886	btree_node_t *node;
2745	decky	1887	unsigned int i;
1409	jermar	1888
1495	jermar	1889	node = list_get_instance(cur, btree_node_t, leaf_link);
		1890	for (i = 0; i < node->keys; i++)
1780	jermar	1891	frame_free((uintptr_t) node->value[i]);
1409	jermar	1892	}
		1893
		1894	}
		1895	mutex_unlock(&sh_info->lock);
		1896
		1897	if (dealloc) {
		1898	btree_destroy(&sh_info->pagemap);
		1899	free(sh_info);
		1900	}
		1901	}
		1902
1235	jermar	1903	/*
		1904	* Address space related syscalls.
		1905	*/
		1906
		1907	/** Wrapper for as_area_create(). */
1780	jermar	1908	unative_t sys_as_area_create(uintptr_t address, size_t size, int flags)
1235	jermar	1909	{
2087	jermar	1910	if (as_area_create(AS, flags \| AS_AREA_CACHEABLE, size, address,
		1911	AS_AREA_ATTR_NONE, &anon_backend, NULL))
1780	jermar	1912	return (unative_t) address;
1235	jermar	1913	else
1780	jermar	1914	return (unative_t) -1;
1235	jermar	1915	}
		1916
1793	jermar	1917	/** Wrapper for as_area_resize(). */
1780	jermar	1918	unative_t sys_as_area_resize(uintptr_t address, size_t size, int flags)
1235	jermar	1919	{
1780	jermar	1920	return (unative_t) as_area_resize(AS, address, size, 0);
1235	jermar	1921	}
		1922
3222	svoboda	1923	/** Wrapper for as_area_change_flags(). */
		1924	unative_t sys_as_area_change_flags(uintptr_t address, int flags)
		1925	{
		1926	return (unative_t) as_area_change_flags(AS, flags, address);
		1927	}
		1928
1793	jermar	1929	/** Wrapper for as_area_destroy(). */
1780	jermar	1930	unative_t sys_as_area_destroy(uintptr_t address)
1306	jermar	1931	{
1780	jermar	1932	return (unative_t) as_area_destroy(AS, address);
1306	jermar	1933	}
1702	cejka	1934
1914	jermar	1935	/** Print out information about address space.
		1936	*
		1937	* @param as Address space.
		1938	*/
		1939	void as_print(as_t *as)
		1940	{
		1941	ipl_t ipl;
		1942
		1943	ipl = interrupts_disable();
		1944	mutex_lock(&as->lock);
		1945
		1946	/* print out info about address space areas */
		1947	link_t *cur;
2087	jermar	1948	for (cur = as->as_area_btree.leaf_head.next;
		1949	cur != &as->as_area_btree.leaf_head; cur = cur->next) {
		1950	btree_node_t *node;
1914	jermar	1951
2087	jermar	1952	node = list_get_instance(cur, btree_node_t, leaf_link);
		1953
2745	decky	1954	unsigned int i;
1914	jermar	1955	for (i = 0; i < node->keys; i++) {
1915	jermar	1956	as_area_t *area = node->value[i];
1914	jermar	1957
		1958	mutex_lock(&area->lock);
3057	decky	1959	printf("as_area: %p, base=%p, pages=%" PRIc " (%p - %p)\n",
2087	jermar	1960	area, area->base, area->pages, area->base,
3057	decky	1961	area->base + FRAMES2SIZE(area->pages));
1914	jermar	1962	mutex_unlock(&area->lock);
		1963	}
		1964	}
		1965
		1966	mutex_unlock(&as->lock);
		1967	interrupts_restore(ipl);
		1968	}
		1969
1757	jermar	1970	/** @}
1702	cejka	1971	*/

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/mm/as.c – Rev 3222