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>
		60	#include <synch/spinlock.h>
1380	jermar	61	#include <synch/mutex.h>
788	jermar	62	#include <adt/list.h>
1147	jermar	63	#include <adt/btree.h>
1235	jermar	64	#include <proc/task.h>
1288	jermar	65	#include <proc/thread.h>
1235	jermar	66	#include <arch/asm.h>
703	jermar	67	#include <panic.h>
		68	#include <debug.h>
1235	jermar	69	#include <print.h>
703	jermar	70	#include <memstr.h>
1070	jermar	71	#include <macros.h>
703	jermar	72	#include <arch.h>
1235	jermar	73	#include <errno.h>
		74	#include <config.h>
1387	jermar	75	#include <align.h>
1235	jermar	76	#include <arch/types.h>
1288	jermar	77	#include <syscall/copy.h>
		78	#include <arch/interrupt.h>
703	jermar	79
2009	jermar	80	#ifdef CONFIG_VIRT_IDX_DCACHE
		81	#include <arch/mm/cache.h>
		82	#endif /* CONFIG_VIRT_IDX_DCACHE */
		83
2125	decky	84	#ifndef __OBJC__
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;
2125	decky	90	#endif
703	jermar	91
1890	jermar	92	/**
		93	* Slab for as_t objects.
		94	*/
		95	static slab_cache_t *as_slab;
		96
2087	jermar	97	/**
		98	* This lock protects inactive_as_with_asid_head list. It must be acquired
		99	* before as_t mutex.
		100	*/
1415	jermar	101	SPINLOCK_INITIALIZE(inactive_as_with_asid_lock);
823	jermar	102
		103	/**
		104	* This list contains address spaces that are not active on any
		105	* processor and that have valid ASID.
		106	*/
		107	LIST_INITIALIZE(inactive_as_with_asid_head);
		108
757	jermar	109	/** Kernel address space. */
		110	as_t *AS_KERNEL = NULL;
		111
1235	jermar	112	static int area_flags_to_page_flags(int aflags);
1780	jermar	113	static as_area_t find_area_and_lock(as_t as, uintptr_t va);
2087	jermar	114	static bool check_area_conflicts(as_t *as, uintptr_t va, size_t size,
		115	as_area_t *avoid_area);
1409	jermar	116	static void sh_info_remove_reference(share_info_t *sh_info);
703	jermar	117
1891	jermar	118	static int as_constructor(void *obj, int flags)
		119	{
		120	as_t as = (as_t ) obj;
		121	int rc;
		122
		123	link_initialize(&as->inactive_as_with_asid_link);
		124	mutex_initialize(&as->lock);
		125
		126	rc = as_constructor_arch(as, flags);
		127
		128	return rc;
		129	}
		130
		131	static int as_destructor(void *obj)
		132	{
		133	as_t as = (as_t ) obj;
		134
		135	return as_destructor_arch(as);
		136	}
		137
756	jermar	138	/** Initialize address space subsystem. */
		139	void as_init(void)
		140	{
		141	as_arch_init();
1890	jermar	142
1891	jermar	143	as_slab = slab_cache_create("as_slab", sizeof(as_t), 0,
2087	jermar	144	as_constructor, as_destructor, SLAB_CACHE_MAGDEFERRED);
1890	jermar	145
789	palkovsky	146	AS_KERNEL = as_create(FLAG_AS_KERNEL);
1383	decky	147	if (!AS_KERNEL)
		148	panic("can't create kernel address space\n");
		149
756	jermar	150	}
		151
757	jermar	152	/** Create address space.
		153	*
		154	* @param flags Flags that influence way in wich the address space is created.
		155	*/
756	jermar	156	as_t *as_create(int flags)
703	jermar	157	{
		158	as_t *as;
		159
1890	jermar	160	as = (as_t *) slab_alloc(as_slab, 0);
1891	jermar	161	(void) as_create_arch(as, 0);
		162
1147	jermar	163	btree_create(&as->as_area_btree);
822	palkovsky	164
		165	if (flags & FLAG_AS_KERNEL)
		166	as->asid = ASID_KERNEL;
		167	else
		168	as->asid = ASID_INVALID;
		169
1468	jermar	170	as->refcount = 0;
1415	jermar	171	as->cpu_refcount = 0;
2089	decky	172	#ifdef AS_PAGE_TABLE
2106	jermar	173	as->genarch.page_table = page_table_create(flags);
2089	decky	174	#else
		175	page_table_create(flags);
		176	#endif
703	jermar	177
		178	return as;
		179	}
		180
1468	jermar	181	/** Destroy adress space.
		182	*
2087	jermar	183	* When there are no tasks referencing this address space (i.e. its refcount is
		184	* zero), the address space can be destroyed.
1468	jermar	185	*/
		186	void as_destroy(as_t *as)
973	palkovsky	187	{
1468	jermar	188	ipl_t ipl;
1594	jermar	189	bool cond;
973	palkovsky	190
1468	jermar	191	ASSERT(as->refcount == 0);
		192
		193	/*
		194	* Since there is no reference to this area,
		195	* it is safe not to lock its mutex.
		196	*/
		197	ipl = interrupts_disable();
		198	spinlock_lock(&inactive_as_with_asid_lock);
1587	jermar	199	if (as->asid != ASID_INVALID && as != AS_KERNEL) {
1594	jermar	200	if (as != AS && as->cpu_refcount == 0)
1587	jermar	201	list_remove(&as->inactive_as_with_asid_link);
1468	jermar	202	asid_put(as->asid);
		203	}
		204	spinlock_unlock(&inactive_as_with_asid_lock);
		205
		206	/*
		207	* Destroy address space areas of the address space.
1954	jermar	208	* The B+tree must be walked carefully because it is
1594	jermar	209	* also being destroyed.
1468	jermar	210	*/
1594	jermar	211	for (cond = true; cond; ) {
1468	jermar	212	btree_node_t *node;
1594	jermar	213
		214	ASSERT(!list_empty(&as->as_area_btree.leaf_head));
2087	jermar	215	node = list_get_instance(as->as_area_btree.leaf_head.next,
		216	btree_node_t, leaf_link);
1594	jermar	217
		218	if ((cond = node->keys)) {
		219	as_area_destroy(as, node->key[0]);
		220	}
1468	jermar	221	}
1495	jermar	222
1483	jermar	223	btree_destroy(&as->as_area_btree);
2089	decky	224	#ifdef AS_PAGE_TABLE
2106	jermar	225	page_table_destroy(as->genarch.page_table);
2089	decky	226	#else
		227	page_table_destroy(NULL);
		228	#endif
1468	jermar	229
		230	interrupts_restore(ipl);
		231
1890	jermar	232	slab_free(as_slab, as);
973	palkovsky	233	}
		234
703	jermar	235	/** Create address space area of common attributes.
		236	*
		237	* The created address space area is added to the target address space.
		238	*
		239	* @param as Target address space.
1239	jermar	240	* @param flags Flags of the area memory.
1048	jermar	241	* @param size Size of area.
703	jermar	242	* @param base Base address of area.
1239	jermar	243	* @param attrs Attributes of the area.
1409	jermar	244	* @param backend Address space area backend. NULL if no backend is used.
		245	* @param backend_data NULL or a pointer to an array holding two void *.
703	jermar	246	*
		247	* @return Address space area on success or NULL on failure.
		248	*/
2069	jermar	249	as_area_t *
		250	as_area_create(as_t *as, int flags, size_t size, uintptr_t base, int attrs,
1424	jermar	251	mem_backend_t backend, mem_backend_data_t backend_data)
703	jermar	252	{
		253	ipl_t ipl;
		254	as_area_t *a;
		255
		256	if (base % PAGE_SIZE)
1048	jermar	257	return NULL;
		258
1233	jermar	259	if (!size)
		260	return NULL;
		261
1048	jermar	262	/* Writeable executable areas are not supported. */
		263	if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
		264	return NULL;
703	jermar	265
		266	ipl = interrupts_disable();
1380	jermar	267	mutex_lock(&as->lock);
703	jermar	268
1048	jermar	269	if (!check_area_conflicts(as, base, size, NULL)) {
1380	jermar	270	mutex_unlock(&as->lock);
1048	jermar	271	interrupts_restore(ipl);
		272	return NULL;
		273	}
703	jermar	274
822	palkovsky	275	a = (as_area_t *) malloc(sizeof(as_area_t), 0);
703	jermar	276
1380	jermar	277	mutex_initialize(&a->lock);
822	palkovsky	278
1424	jermar	279	a->as = as;
1026	jermar	280	a->flags = flags;
1239	jermar	281	a->attributes = attrs;
1048	jermar	282	a->pages = SIZE2FRAMES(size);
822	palkovsky	283	a->base = base;
1409	jermar	284	a->sh_info = NULL;
		285	a->backend = backend;
1424	jermar	286	if (backend_data)
		287	a->backend_data = *backend_data;
		288	else
2087	jermar	289	memsetb((uintptr_t) &a->backend_data, sizeof(a->backend_data),
		290	0);
1424	jermar	291
1387	jermar	292	btree_create(&a->used_space);
822	palkovsky	293
1147	jermar	294	btree_insert(&as->as_area_btree, base, (void *) a, NULL);
822	palkovsky	295
1380	jermar	296	mutex_unlock(&as->lock);
703	jermar	297	interrupts_restore(ipl);
704	jermar	298
703	jermar	299	return a;
		300	}
		301
1235	jermar	302	/** Find address space area and change it.
		303	*
		304	* @param as Address space.
2087	jermar	305	* @param address Virtual address belonging to the area to be changed. Must be
		306	* page-aligned.
1235	jermar	307	* @param size New size of the virtual memory block starting at address.
		308	* @param flags Flags influencing the remap operation. Currently unused.
		309	*
1306	jermar	310	* @return Zero on success or a value from @ref errno.h otherwise.
1235	jermar	311	*/
1780	jermar	312	int as_area_resize(as_t *as, uintptr_t address, size_t size, int flags)
1235	jermar	313	{
1306	jermar	314	as_area_t *area;
1235	jermar	315	ipl_t ipl;
		316	size_t pages;
		317
		318	ipl = interrupts_disable();
1380	jermar	319	mutex_lock(&as->lock);
1235	jermar	320
		321	/*
		322	* Locate the area.
		323	*/
		324	area = find_area_and_lock(as, address);
		325	if (!area) {
1380	jermar	326	mutex_unlock(&as->lock);
1235	jermar	327	interrupts_restore(ipl);
1306	jermar	328	return ENOENT;
1235	jermar	329	}
		330
1424	jermar	331	if (area->backend == &phys_backend) {
1235	jermar	332	/*
		333	* Remapping of address space areas associated
		334	* with memory mapped devices is not supported.
		335	*/
1380	jermar	336	mutex_unlock(&area->lock);
		337	mutex_unlock(&as->lock);
1235	jermar	338	interrupts_restore(ipl);
1306	jermar	339	return ENOTSUP;
1235	jermar	340	}
1409	jermar	341	if (area->sh_info) {
		342	/*
		343	* Remapping of shared address space areas
		344	* is not supported.
		345	*/
		346	mutex_unlock(&area->lock);
		347	mutex_unlock(&as->lock);
		348	interrupts_restore(ipl);
		349	return ENOTSUP;
		350	}
1235	jermar	351
		352	pages = SIZE2FRAMES((address - area->base) + size);
		353	if (!pages) {
		354	/*
		355	* Zero size address space areas are not allowed.
		356	*/
1380	jermar	357	mutex_unlock(&area->lock);
		358	mutex_unlock(&as->lock);
1235	jermar	359	interrupts_restore(ipl);
1306	jermar	360	return EPERM;
1235	jermar	361	}
		362
		363	if (pages < area->pages) {
1403	jermar	364	bool cond;
1780	jermar	365	uintptr_t start_free = area->base + pages*PAGE_SIZE;
1235	jermar	366
		367	/*
		368	* Shrinking the area.
		369	* No need to check for overlaps.
		370	*/
1403	jermar	371
		372	/*
1436	jermar	373	* Start TLB shootdown sequence.
		374	*/
2087	jermar	375	tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base +
		376	pages * PAGE_SIZE, area->pages - pages);
1436	jermar	377
		378	/*
1403	jermar	379	* Remove frames belonging to used space starting from
		380	* the highest addresses downwards until an overlap with
		381	* the resized address space area is found. Note that this
		382	* is also the right way to remove part of the used_space
		383	* B+tree leaf list.
		384	*/
		385	for (cond = true; cond;) {
		386	btree_node_t *node;
		387
		388	ASSERT(!list_empty(&area->used_space.leaf_head));
2087	jermar	389	node =
		390	list_get_instance(area->used_space.leaf_head.prev,
		391	btree_node_t, leaf_link);
1403	jermar	392	if ((cond = (bool) node->keys)) {
1780	jermar	393	uintptr_t b = node->key[node->keys - 1];
2087	jermar	394	count_t c =
		395	(count_t) node->value[node->keys - 1];
1403	jermar	396	int i = 0;
1235	jermar	397
2087	jermar	398	if (overlaps(b, c * PAGE_SIZE, area->base,
		399	pages*PAGE_SIZE)) {
1403	jermar	400
2087	jermar	401	if (b + c * PAGE_SIZE <= start_free) {
1403	jermar	402	/*
2087	jermar	403	* The whole interval fits
		404	* completely in the resized
		405	* address space area.
1403	jermar	406	*/
		407	break;
		408	}
		409
		410	/*
2087	jermar	411	* Part of the interval corresponding
		412	* to b and c overlaps with the resized
		413	* address space area.
1403	jermar	414	*/
		415
		416	cond = false; /* we are almost done */
		417	i = (start_free - b) >> PAGE_WIDTH;
2087	jermar	418	if (!used_space_remove(area, start_free,
		419	c - i))
		420	panic("Could not remove used "
		421	"space.\n");
1403	jermar	422	} else {
		423	/*
2087	jermar	424	* The interval of used space can be
		425	* completely removed.
1403	jermar	426	*/
		427	if (!used_space_remove(area, b, c))
2087	jermar	428	panic("Could not remove used "
		429	"space.\n");
1403	jermar	430	}
		431
		432	for (; i < c; i++) {
		433	pte_t *pte;
		434
		435	page_table_lock(as, false);
2087	jermar	436	pte = page_mapping_find(as, b +
		437	i * PAGE_SIZE);
		438	ASSERT(pte && PTE_VALID(pte) &&
		439	PTE_PRESENT(pte));
		440	if (area->backend &&
		441	area->backend->frame_free) {
1424	jermar	442	area->backend->frame_free(area,
2087	jermar	443	b + i * PAGE_SIZE,
		444	PTE_GET_FRAME(pte));
1409	jermar	445	}
2087	jermar	446	page_mapping_remove(as, b +
		447	i * PAGE_SIZE);
1403	jermar	448	page_table_unlock(as, false);
		449	}
1235	jermar	450	}
		451	}
1436	jermar	452
1235	jermar	453	/*
1436	jermar	454	* Finish TLB shootdown sequence.
1235	jermar	455	*/
2087	jermar	456	tlb_invalidate_pages(as->asid, area->base + pages * PAGE_SIZE,
		457	area->pages - pages);
1235	jermar	458	tlb_shootdown_finalize();
1889	jermar	459
		460	/*
		461	* Invalidate software translation caches (e.g. TSB on sparc64).
		462	*/
2087	jermar	463	as_invalidate_translation_cache(as, area->base +
		464	pages * PAGE_SIZE, area->pages - pages);
1235	jermar	465	} else {
		466	/*
		467	* Growing the area.
		468	* Check for overlaps with other address space areas.
		469	*/
2087	jermar	470	if (!check_area_conflicts(as, address, pages * PAGE_SIZE,
		471	area)) {
1380	jermar	472	mutex_unlock(&area->lock);
		473	mutex_unlock(&as->lock);
1235	jermar	474	interrupts_restore(ipl);
1306	jermar	475	return EADDRNOTAVAIL;
1235	jermar	476	}
		477	}
		478
		479	area->pages = pages;
		480
1380	jermar	481	mutex_unlock(&area->lock);
		482	mutex_unlock(&as->lock);
1235	jermar	483	interrupts_restore(ipl);
		484
1306	jermar	485	return 0;
1235	jermar	486	}
		487
1306	jermar	488	/** Destroy address space area.
		489	*
		490	* @param as Address space.
		491	* @param address Address withing the area to be deleted.
		492	*
		493	* @return Zero on success or a value from @ref errno.h on failure.
		494	*/
1780	jermar	495	int as_area_destroy(as_t *as, uintptr_t address)
1306	jermar	496	{
		497	as_area_t *area;
1780	jermar	498	uintptr_t base;
1495	jermar	499	link_t *cur;
1306	jermar	500	ipl_t ipl;
		501
		502	ipl = interrupts_disable();
1380	jermar	503	mutex_lock(&as->lock);
1306	jermar	504
		505	area = find_area_and_lock(as, address);
		506	if (!area) {
1380	jermar	507	mutex_unlock(&as->lock);
1306	jermar	508	interrupts_restore(ipl);
		509	return ENOENT;
		510	}
		511
1403	jermar	512	base = area->base;
		513
1411	jermar	514	/*
1436	jermar	515	* Start TLB shootdown sequence.
		516	*/
1889	jermar	517	tlb_shootdown_start(TLB_INVL_PAGES, as->asid, area->base, area->pages);
1436	jermar	518
		519	/*
1411	jermar	520	* Visit only the pages mapped by used_space B+tree.
		521	*/
2087	jermar	522	for (cur = area->used_space.leaf_head.next;
		523	cur != &area->used_space.leaf_head; cur = cur->next) {
1411	jermar	524	btree_node_t *node;
1495	jermar	525	int i;
1403	jermar	526
1495	jermar	527	node = list_get_instance(cur, btree_node_t, leaf_link);
		528	for (i = 0; i < node->keys; i++) {
1780	jermar	529	uintptr_t b = node->key[i];
1495	jermar	530	count_t j;
1411	jermar	531	pte_t *pte;
1403	jermar	532
1495	jermar	533	for (j = 0; j < (count_t) node->value[i]; j++) {
1411	jermar	534	page_table_lock(as, false);
2087	jermar	535	pte = page_mapping_find(as, b + j * PAGE_SIZE);
		536	ASSERT(pte && PTE_VALID(pte) &&
		537	PTE_PRESENT(pte));
		538	if (area->backend &&
		539	area->backend->frame_free) {
		540	area->backend->frame_free(area, b +
		541	j * PAGE_SIZE, PTE_GET_FRAME(pte));
1403	jermar	542	}
2087	jermar	543	page_mapping_remove(as, b + j * PAGE_SIZE);
1411	jermar	544	page_table_unlock(as, false);
1306	jermar	545	}
		546	}
		547	}
1403	jermar	548
1306	jermar	549	/*
1436	jermar	550	* Finish TLB shootdown sequence.
1306	jermar	551	*/
1889	jermar	552	tlb_invalidate_pages(as->asid, area->base, area->pages);
1306	jermar	553	tlb_shootdown_finalize();
1436	jermar	554
1889	jermar	555	/*
2087	jermar	556	* Invalidate potential software translation caches (e.g. TSB on
		557	* sparc64).
1889	jermar	558	*/
		559	as_invalidate_translation_cache(as, area->base, area->pages);
		560
1436	jermar	561	btree_destroy(&area->used_space);
1306	jermar	562
1309	jermar	563	area->attributes \|= AS_AREA_ATTR_PARTIAL;
1409	jermar	564
		565	if (area->sh_info)
		566	sh_info_remove_reference(area->sh_info);
		567
1380	jermar	568	mutex_unlock(&area->lock);
1306	jermar	569
		570	/*
		571	* Remove the empty area from address space.
		572	*/
1889	jermar	573	btree_remove(&as->as_area_btree, base, NULL);
1306	jermar	574
1309	jermar	575	free(area);
		576
1889	jermar	577	mutex_unlock(&as->lock);
1306	jermar	578	interrupts_restore(ipl);
		579	return 0;
		580	}
		581
1413	jermar	582	/** Share address space area with another or the same address space.
1235	jermar	583	*
1424	jermar	584	* Address space area mapping is shared with a new address space area.
		585	* If the source address space area has not been shared so far,
		586	* a new sh_info is created. The new address space area simply gets the
		587	* sh_info of the source area. The process of duplicating the
		588	* mapping is done through the backend share function.
1413	jermar	589	*
1417	jermar	590	* @param src_as Pointer to source address space.
1239	jermar	591	* @param src_base Base address of the source address space area.
1417	jermar	592	* @param acc_size Expected size of the source area.
1428	palkovsky	593	* @param dst_as Pointer to destination address space.
1417	jermar	594	* @param dst_base Target base address.
		595	* @param dst_flags_mask Destination address space area flags mask.
1235	jermar	596	*
2007	jermar	597	* @return Zero on success or ENOENT if there is no such task or if there is no
		598	* such address space area, EPERM if there was a problem in accepting the area
		599	* or ENOMEM if there was a problem in allocating destination address space
		600	* area. ENOTSUP is returned if the address space area backend does not support
2015	jermar	601	* sharing or if the kernel detects an attempt to create an illegal address
		602	* alias.
1235	jermar	603	*/
1780	jermar	604	int as_area_share(as_t *src_as, uintptr_t src_base, size_t acc_size,
		605	as_t *dst_as, uintptr_t dst_base, int dst_flags_mask)
1235	jermar	606	{
		607	ipl_t ipl;
1239	jermar	608	int src_flags;
		609	size_t src_size;
		610	as_area_t src_area, dst_area;
1413	jermar	611	share_info_t *sh_info;
1424	jermar	612	mem_backend_t *src_backend;
		613	mem_backend_data_t src_backend_data;
1434	palkovsky	614
1235	jermar	615	ipl = interrupts_disable();
1380	jermar	616	mutex_lock(&src_as->lock);
1329	palkovsky	617	src_area = find_area_and_lock(src_as, src_base);
1239	jermar	618	if (!src_area) {
1238	jermar	619	/*
		620	* Could not find the source address space area.
		621	*/
1380	jermar	622	mutex_unlock(&src_as->lock);
1238	jermar	623	interrupts_restore(ipl);
		624	return ENOENT;
		625	}
2007	jermar	626
1424	jermar	627	if (!src_area->backend \|\| !src_area->backend->share) {
1413	jermar	628	/*
1851	jermar	629	* There is no backend or the backend does not
1424	jermar	630	* know how to share the area.
1413	jermar	631	*/
		632	mutex_unlock(&src_area->lock);
		633	mutex_unlock(&src_as->lock);
		634	interrupts_restore(ipl);
		635	return ENOTSUP;
		636	}
		637
1239	jermar	638	src_size = src_area->pages * PAGE_SIZE;
		639	src_flags = src_area->flags;
1424	jermar	640	src_backend = src_area->backend;
		641	src_backend_data = src_area->backend_data;
1544	palkovsky	642
		643	/* Share the cacheable flag from the original mapping */
		644	if (src_flags & AS_AREA_CACHEABLE)
		645	dst_flags_mask \|= AS_AREA_CACHEABLE;
		646
2087	jermar	647	if (src_size != acc_size \|\|
		648	(src_flags & dst_flags_mask) != dst_flags_mask) {
1413	jermar	649	mutex_unlock(&src_area->lock);
		650	mutex_unlock(&src_as->lock);
1235	jermar	651	interrupts_restore(ipl);
		652	return EPERM;
		653	}
1413	jermar	654
2015	jermar	655	#ifdef CONFIG_VIRT_IDX_DCACHE
		656	if (!(dst_flags_mask & AS_AREA_EXEC)) {
		657	if (PAGE_COLOR(src_area->base) != PAGE_COLOR(dst_base)) {
		658	/*
		659	* Refuse to create an illegal address alias.
		660	*/
		661	mutex_unlock(&src_area->lock);
		662	mutex_unlock(&src_as->lock);
		663	interrupts_restore(ipl);
		664	return ENOTSUP;
		665	}
		666	}
		667	#endif /* CONFIG_VIRT_IDX_DCACHE */
		668
1235	jermar	669	/*
1413	jermar	670	* Now we are committed to sharing the area.
1954	jermar	671	* First, prepare the area for sharing.
1413	jermar	672	* Then it will be safe to unlock it.
		673	*/
		674	sh_info = src_area->sh_info;
		675	if (!sh_info) {
		676	sh_info = (share_info_t *) malloc(sizeof(share_info_t), 0);
		677	mutex_initialize(&sh_info->lock);
		678	sh_info->refcount = 2;
		679	btree_create(&sh_info->pagemap);
		680	src_area->sh_info = sh_info;
		681	} else {
		682	mutex_lock(&sh_info->lock);
		683	sh_info->refcount++;
		684	mutex_unlock(&sh_info->lock);
		685	}
		686
1424	jermar	687	src_area->backend->share(src_area);
1413	jermar	688
		689	mutex_unlock(&src_area->lock);
		690	mutex_unlock(&src_as->lock);
		691
		692	/*
1239	jermar	693	* Create copy of the source address space area.
		694	* The destination area is created with AS_AREA_ATTR_PARTIAL
		695	* attribute set which prevents race condition with
		696	* preliminary as_page_fault() calls.
1417	jermar	697	* The flags of the source area are masked against dst_flags_mask
		698	* to support sharing in less privileged mode.
1235	jermar	699	*/
1461	palkovsky	700	dst_area = as_area_create(dst_as, dst_flags_mask, src_size, dst_base,
2087	jermar	701	AS_AREA_ATTR_PARTIAL, src_backend, &src_backend_data);
1239	jermar	702	if (!dst_area) {
1235	jermar	703	/*
		704	* Destination address space area could not be created.
		705	*/
1413	jermar	706	sh_info_remove_reference(sh_info);
		707
1235	jermar	708	interrupts_restore(ipl);
		709	return ENOMEM;
		710	}
2009	jermar	711
1235	jermar	712	/*
1239	jermar	713	* Now the destination address space area has been
		714	* fully initialized. Clear the AS_AREA_ATTR_PARTIAL
1413	jermar	715	* attribute and set the sh_info.
1239	jermar	716	*/
2009	jermar	717	mutex_lock(&dst_as->lock);
1380	jermar	718	mutex_lock(&dst_area->lock);
1239	jermar	719	dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
1413	jermar	720	dst_area->sh_info = sh_info;
1380	jermar	721	mutex_unlock(&dst_area->lock);
2009	jermar	722	mutex_unlock(&dst_as->lock);
		723
1235	jermar	724	interrupts_restore(ipl);
		725
		726	return 0;
		727	}
		728
1423	jermar	729	/** Check access mode for address space area.
		730	*
		731	* The address space area must be locked prior to this call.
		732	*
		733	* @param area Address space area.
		734	* @param access Access mode.
		735	*
		736	* @return False if access violates area's permissions, true otherwise.
		737	*/
		738	bool as_area_check_access(as_area_t *area, pf_access_t access)
		739	{
		740	int flagmap[] = {
		741	[PF_ACCESS_READ] = AS_AREA_READ,
		742	[PF_ACCESS_WRITE] = AS_AREA_WRITE,
		743	[PF_ACCESS_EXEC] = AS_AREA_EXEC
		744	};
		745
		746	if (!(area->flags & flagmap[access]))
		747	return false;
		748
		749	return true;
		750	}
		751
703	jermar	752	/** Handle page fault within the current address space.
		753	*
1409	jermar	754	* This is the high-level page fault handler. It decides
		755	* whether the page fault can be resolved by any backend
		756	* and if so, it invokes the backend to resolve the page
		757	* fault.
		758	*
703	jermar	759	* Interrupts are assumed disabled.
		760	*
		761	* @param page Faulting page.
1411	jermar	762	* @param access Access mode that caused the fault (i.e. read/write/exec).
1288	jermar	763	* @param istate Pointer to interrupted state.
703	jermar	764	*
1409	jermar	765	* @return AS_PF_FAULT on page fault, AS_PF_OK on success or AS_PF_DEFER if the
		766	* fault was caused by copy_to_uspace() or copy_from_uspace().
703	jermar	767	*/
1780	jermar	768	int as_page_fault(uintptr_t page, pf_access_t access, istate_t *istate)
703	jermar	769	{
1044	jermar	770	pte_t *pte;
977	jermar	771	as_area_t *area;
703	jermar	772
1380	jermar	773	if (!THREAD)
1409	jermar	774	return AS_PF_FAULT;
1380	jermar	775
703	jermar	776	ASSERT(AS);
1044	jermar	777
1380	jermar	778	mutex_lock(&AS->lock);
977	jermar	779	area = find_area_and_lock(AS, page);
703	jermar	780	if (!area) {
		781	/*
		782	* No area contained mapping for 'page'.
		783	* Signal page fault to low-level handler.
		784	*/
1380	jermar	785	mutex_unlock(&AS->lock);
1288	jermar	786	goto page_fault;
703	jermar	787	}
		788
1239	jermar	789	if (area->attributes & AS_AREA_ATTR_PARTIAL) {
		790	/*
		791	* The address space area is not fully initialized.
		792	* Avoid possible race by returning error.
		793	*/
1380	jermar	794	mutex_unlock(&area->lock);
		795	mutex_unlock(&AS->lock);
1288	jermar	796	goto page_fault;
1239	jermar	797	}
		798
1424	jermar	799	if (!area->backend \|\| !area->backend->page_fault) {
1409	jermar	800	/*
		801	* The address space area is not backed by any backend
		802	* or the backend cannot handle page faults.
		803	*/
		804	mutex_unlock(&area->lock);
		805	mutex_unlock(&AS->lock);
		806	goto page_fault;
		807	}
1179	jermar	808
1044	jermar	809	page_table_lock(AS, false);
		810
703	jermar	811	/*
1044	jermar	812	* To avoid race condition between two page faults
		813	* on the same address, we need to make sure
		814	* the mapping has not been already inserted.
		815	*/
		816	if ((pte = page_mapping_find(AS, page))) {
		817	if (PTE_PRESENT(pte)) {
1423	jermar	818	if (((access == PF_ACCESS_READ) && PTE_READABLE(pte)) \|\|
2087	jermar	819	(access == PF_ACCESS_WRITE && PTE_WRITABLE(pte)) \|\|
		820	(access == PF_ACCESS_EXEC && PTE_EXECUTABLE(pte))) {
1423	jermar	821	page_table_unlock(AS, false);
		822	mutex_unlock(&area->lock);
		823	mutex_unlock(&AS->lock);
		824	return AS_PF_OK;
		825	}
1044	jermar	826	}
		827	}
1409	jermar	828
1044	jermar	829	/*
1409	jermar	830	* Resort to the backend page fault handler.
703	jermar	831	*/
1424	jermar	832	if (area->backend->page_fault(area, page, access) != AS_PF_OK) {
1409	jermar	833	page_table_unlock(AS, false);
		834	mutex_unlock(&area->lock);
		835	mutex_unlock(&AS->lock);
		836	goto page_fault;
		837	}
703	jermar	838
1044	jermar	839	page_table_unlock(AS, false);
1380	jermar	840	mutex_unlock(&area->lock);
		841	mutex_unlock(&AS->lock);
1288	jermar	842	return AS_PF_OK;
		843
		844	page_fault:
		845	if (THREAD->in_copy_from_uspace) {
		846	THREAD->in_copy_from_uspace = false;
2087	jermar	847	istate_set_retaddr(istate,
		848	(uintptr_t) &memcpy_from_uspace_failover_address);
1288	jermar	849	} else if (THREAD->in_copy_to_uspace) {
		850	THREAD->in_copy_to_uspace = false;
2087	jermar	851	istate_set_retaddr(istate,
		852	(uintptr_t) &memcpy_to_uspace_failover_address);
1288	jermar	853	} else {
		854	return AS_PF_FAULT;
		855	}
		856
		857	return AS_PF_DEFER;
703	jermar	858	}
		859
823	jermar	860	/** Switch address spaces.
703	jermar	861	*
1380	jermar	862	* Note that this function cannot sleep as it is essentially a part of
1415	jermar	863	* scheduling. Sleeping here would lead to deadlock on wakeup.
1380	jermar	864	*
823	jermar	865	* @param old Old address space or NULL.
		866	* @param new New address space.
703	jermar	867	*/
2106	jermar	868	void as_switch(as_t old_as, as_t new_as)
703	jermar	869	{
		870	ipl_t ipl;
823	jermar	871	bool needs_asid = false;
703	jermar	872
		873	ipl = interrupts_disable();
1415	jermar	874	spinlock_lock(&inactive_as_with_asid_lock);
703	jermar	875
		876	/*
823	jermar	877	* First, take care of the old address space.
		878	*/
2106	jermar	879	if (old_as) {
		880	mutex_lock_active(&old_as->lock);
		881	ASSERT(old_as->cpu_refcount);
		882	if((--old_as->cpu_refcount == 0) && (old_as != AS_KERNEL)) {
823	jermar	883	/*
		884	* The old address space is no longer active on
		885	* any processor. It can be appended to the
		886	* list of inactive address spaces with assigned
		887	* ASID.
		888	*/
2106	jermar	889	ASSERT(old_as->asid != ASID_INVALID);
		890	list_append(&old_as->inactive_as_with_asid_link,
2087	jermar	891	&inactive_as_with_asid_head);
823	jermar	892	}
2106	jermar	893	mutex_unlock(&old_as->lock);
1890	jermar	894
		895	/*
		896	* Perform architecture-specific tasks when the address space
		897	* is being removed from the CPU.
		898	*/
2106	jermar	899	as_deinstall_arch(old_as);
823	jermar	900	}
		901
		902	/*
		903	* Second, prepare the new address space.
		904	*/
2106	jermar	905	mutex_lock_active(&new_as->lock);
		906	if ((new_as->cpu_refcount++ == 0) && (new_as != AS_KERNEL)) {
		907	if (new_as->asid != ASID_INVALID) {
		908	list_remove(&new_as->inactive_as_with_asid_link);
2087	jermar	909	} else {
		910	/*
2106	jermar	911	* Defer call to asid_get() until new_as->lock is released.
2087	jermar	912	*/
		913	needs_asid = true;
		914	}
823	jermar	915	}
2106	jermar	916	#ifdef AS_PAGE_TABLE
		917	SET_PTL0_ADDRESS(new_as->genarch.page_table);
		918	#endif
		919	mutex_unlock(&new_as->lock);
823	jermar	920
		921	if (needs_asid) {
		922	/*
		923	* Allocation of new ASID was deferred
		924	* until now in order to avoid deadlock.
		925	*/
		926	asid_t asid;
		927
		928	asid = asid_get();
2106	jermar	929	mutex_lock_active(&new_as->lock);
		930	new_as->asid = asid;
		931	mutex_unlock(&new_as->lock);
823	jermar	932	}
1415	jermar	933	spinlock_unlock(&inactive_as_with_asid_lock);
823	jermar	934	interrupts_restore(ipl);
		935
		936	/*
703	jermar	937	* Perform architecture-specific steps.
727	jermar	938	* (e.g. write ASID to hardware register etc.)
703	jermar	939	*/
2106	jermar	940	as_install_arch(new_as);
703	jermar	941
2106	jermar	942	AS = new_as;
703	jermar	943	}
754	jermar	944
1235	jermar	945	/** Convert address space area flags to page flags.
754	jermar	946	*
1235	jermar	947	* @param aflags Flags of some address space area.
754	jermar	948	*
1235	jermar	949	* @return Flags to be passed to page_mapping_insert().
754	jermar	950	*/
1235	jermar	951	int area_flags_to_page_flags(int aflags)
754	jermar	952	{
		953	int flags;
		954
1178	jermar	955	flags = PAGE_USER \| PAGE_PRESENT;
754	jermar	956
1235	jermar	957	if (aflags & AS_AREA_READ)
1026	jermar	958	flags \|= PAGE_READ;
		959
1235	jermar	960	if (aflags & AS_AREA_WRITE)
1026	jermar	961	flags \|= PAGE_WRITE;
		962
1235	jermar	963	if (aflags & AS_AREA_EXEC)
1026	jermar	964	flags \|= PAGE_EXEC;
		965
1424	jermar	966	if (aflags & AS_AREA_CACHEABLE)
1178	jermar	967	flags \|= PAGE_CACHEABLE;
		968
754	jermar	969	return flags;
		970	}
756	jermar	971
1235	jermar	972	/** Compute flags for virtual address translation subsytem.
		973	*
		974	* The address space area must be locked.
		975	* Interrupts must be disabled.
		976	*
		977	* @param a Address space area.
		978	*
		979	* @return Flags to be used in page_mapping_insert().
		980	*/
1409	jermar	981	int as_area_get_flags(as_area_t *a)
1235	jermar	982	{
		983	return area_flags_to_page_flags(a->flags);
		984	}
		985
756	jermar	986	/** Create page table.
		987	*
		988	* Depending on architecture, create either address space
		989	* private or global page table.
		990	*
		991	* @param flags Flags saying whether the page table is for kernel address space.
		992	*
		993	* @return First entry of the page table.
		994	*/
		995	pte_t *page_table_create(int flags)
		996	{
2125	decky	997	#ifdef __OBJC__
		998	return [as_t page_table_create: flags];
		999	#else
		1000	ASSERT(as_operations);
		1001	ASSERT(as_operations->page_table_create);
		1002
		1003	return as_operations->page_table_create(flags);
		1004	#endif
756	jermar	1005	}
977	jermar	1006
1468	jermar	1007	/** Destroy page table.
		1008	*
		1009	* Destroy page table in architecture specific way.
		1010	*
		1011	* @param page_table Physical address of PTL0.
		1012	*/
		1013	void page_table_destroy(pte_t *page_table)
		1014	{
2125	decky	1015	#ifdef __OBJC__
		1016	return [as_t page_table_destroy: page_table];
		1017	#else
		1018	ASSERT(as_operations);
		1019	ASSERT(as_operations->page_table_destroy);
		1020
		1021	as_operations->page_table_destroy(page_table);
		1022	#endif
1468	jermar	1023	}
		1024
1044	jermar	1025	/** Lock page table.
		1026	*
		1027	* This function should be called before any page_mapping_insert(),
		1028	* page_mapping_remove() and page_mapping_find().
		1029	*
		1030	* Locking order is such that address space areas must be locked
		1031	* prior to this call. Address space can be locked prior to this
		1032	* call in which case the lock argument is false.
		1033	*
		1034	* @param as Address space.
1248	jermar	1035	* @param lock If false, do not attempt to lock as->lock.
1044	jermar	1036	*/
		1037	void page_table_lock(as_t *as, bool lock)
		1038	{
2125	decky	1039	#ifdef __OBJC__
		1040	[as page_table_lock: lock];
		1041	#else
1044	jermar	1042	ASSERT(as_operations);
		1043	ASSERT(as_operations->page_table_lock);
2125	decky	1044
1044	jermar	1045	as_operations->page_table_lock(as, lock);
2125	decky	1046	#endif
1044	jermar	1047	}
		1048
		1049	/** Unlock page table.
		1050	*
		1051	* @param as Address space.
1248	jermar	1052	* @param unlock If false, do not attempt to unlock as->lock.
1044	jermar	1053	*/
		1054	void page_table_unlock(as_t *as, bool unlock)
		1055	{
2125	decky	1056	#ifdef __OBJC__
		1057	[as page_table_unlock: unlock];
		1058	#else
1044	jermar	1059	ASSERT(as_operations);
		1060	ASSERT(as_operations->page_table_unlock);
2125	decky	1061
1044	jermar	1062	as_operations->page_table_unlock(as, unlock);
2125	decky	1063	#endif
1044	jermar	1064	}
		1065
977	jermar	1066
		1067	/** Find address space area and lock it.
		1068	*
		1069	* The address space must be locked and interrupts must be disabled.
		1070	*
		1071	* @param as Address space.
		1072	* @param va Virtual address.
		1073	*
2087	jermar	1074	* @return Locked address space area containing va on success or NULL on
		1075	* failure.
977	jermar	1076	*/
1780	jermar	1077	as_area_t find_area_and_lock(as_t as, uintptr_t va)
977	jermar	1078	{
		1079	as_area_t *a;
1147	jermar	1080	btree_node_t leaf, lnode;
		1081	int i;
977	jermar	1082
1147	jermar	1083	a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
		1084	if (a) {
		1085	/* va is the base address of an address space area */
1380	jermar	1086	mutex_lock(&a->lock);
1147	jermar	1087	return a;
		1088	}
		1089
		1090	/*
1150	jermar	1091	* Search the leaf node and the righmost record of its left neighbour
1147	jermar	1092	* to find out whether this is a miss or va belongs to an address
		1093	* space area found there.
		1094	*/
		1095
		1096	/* First, search the leaf node itself. */
		1097	for (i = 0; i < leaf->keys; i++) {
		1098	a = (as_area_t *) leaf->value[i];
1380	jermar	1099	mutex_lock(&a->lock);
1147	jermar	1100	if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
		1101	return a;
		1102	}
1380	jermar	1103	mutex_unlock(&a->lock);
1147	jermar	1104	}
977	jermar	1105
1147	jermar	1106	/*
1150	jermar	1107	* Second, locate the left neighbour and test its last record.
1148	jermar	1108	* Because of its position in the B+tree, it must have base < va.
1147	jermar	1109	*/
2087	jermar	1110	lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf);
		1111	if (lnode) {
1147	jermar	1112	a = (as_area_t *) lnode->value[lnode->keys - 1];
1380	jermar	1113	mutex_lock(&a->lock);
1147	jermar	1114	if (va < a->base + a->pages * PAGE_SIZE) {
1048	jermar	1115	return a;
1147	jermar	1116	}
1380	jermar	1117	mutex_unlock(&a->lock);
977	jermar	1118	}
		1119
		1120	return NULL;
		1121	}
1048	jermar	1122
		1123	/** Check area conflicts with other areas.
		1124	*
		1125	* The address space must be locked and interrupts must be disabled.
		1126	*
		1127	* @param as Address space.
		1128	* @param va Starting virtual address of the area being tested.
		1129	* @param size Size of the area being tested.
		1130	* @param avoid_area Do not touch this area.
		1131	*
		1132	* @return True if there is no conflict, false otherwise.
		1133	*/
2087	jermar	1134	bool check_area_conflicts(as_t *as, uintptr_t va, size_t size,
		1135	as_area_t *avoid_area)
1048	jermar	1136	{
		1137	as_area_t *a;
1147	jermar	1138	btree_node_t leaf, node;
		1139	int i;
1048	jermar	1140
1070	jermar	1141	/*
		1142	* We don't want any area to have conflicts with NULL page.
		1143	*/
		1144	if (overlaps(va, size, NULL, PAGE_SIZE))
		1145	return false;
		1146
1147	jermar	1147	/*
		1148	* The leaf node is found in O(log n), where n is proportional to
		1149	* the number of address space areas belonging to as.
		1150	* The check for conflicts is then attempted on the rightmost
1150	jermar	1151	* record in the left neighbour, the leftmost record in the right
		1152	* neighbour and all records in the leaf node itself.
1147	jermar	1153	*/
1048	jermar	1154
1147	jermar	1155	if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
		1156	if (a != avoid_area)
		1157	return false;
		1158	}
		1159
		1160	/* First, check the two border cases. */
1150	jermar	1161	if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	1162	a = (as_area_t *) node->value[node->keys - 1];
1380	jermar	1163	mutex_lock(&a->lock);
1147	jermar	1164	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1165	mutex_unlock(&a->lock);
1147	jermar	1166	return false;
		1167	}
1380	jermar	1168	mutex_unlock(&a->lock);
1147	jermar	1169	}
2087	jermar	1170	node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf);
		1171	if (node) {
1147	jermar	1172	a = (as_area_t *) node->value[0];
1380	jermar	1173	mutex_lock(&a->lock);
1147	jermar	1174	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1175	mutex_unlock(&a->lock);
1147	jermar	1176	return false;
		1177	}
1380	jermar	1178	mutex_unlock(&a->lock);
1147	jermar	1179	}
		1180
		1181	/* Second, check the leaf node. */
		1182	for (i = 0; i < leaf->keys; i++) {
		1183	a = (as_area_t *) leaf->value[i];
		1184
1048	jermar	1185	if (a == avoid_area)
		1186	continue;
1147	jermar	1187
1380	jermar	1188	mutex_lock(&a->lock);
1147	jermar	1189	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1190	mutex_unlock(&a->lock);
1147	jermar	1191	return false;
		1192	}
1380	jermar	1193	mutex_unlock(&a->lock);
1048	jermar	1194	}
		1195
1070	jermar	1196	/*
		1197	* So far, the area does not conflict with other areas.
		1198	* Check if it doesn't conflict with kernel address space.
		1199	*/
		1200	if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
		1201	return !overlaps(va, size,
2087	jermar	1202	KERNEL_ADDRESS_SPACE_START,
		1203	KERNEL_ADDRESS_SPACE_END - KERNEL_ADDRESS_SPACE_START);
1070	jermar	1204	}
		1205
1048	jermar	1206	return true;
		1207	}
1235	jermar	1208
1380	jermar	1209	/** Return size of the address space area with given base. */
1780	jermar	1210	size_t as_get_size(uintptr_t base)
1329	palkovsky	1211	{
		1212	ipl_t ipl;
		1213	as_area_t *src_area;
		1214	size_t size;
		1215
		1216	ipl = interrupts_disable();
		1217	src_area = find_area_and_lock(AS, base);
		1218	if (src_area){
		1219	size = src_area->pages * PAGE_SIZE;
1380	jermar	1220	mutex_unlock(&src_area->lock);
1329	palkovsky	1221	} else {
		1222	size = 0;
		1223	}
		1224	interrupts_restore(ipl);
		1225	return size;
		1226	}
		1227
1387	jermar	1228	/** Mark portion of address space area as used.
		1229	*
		1230	* The address space area must be already locked.
		1231	*
		1232	* @param a Address space area.
		1233	* @param page First page to be marked.
		1234	* @param count Number of page to be marked.
		1235	*
		1236	* @return 0 on failure and 1 on success.
		1237	*/
1780	jermar	1238	int used_space_insert(as_area_t *a, uintptr_t page, count_t count)
1387	jermar	1239	{
		1240	btree_node_t leaf, node;
		1241	count_t pages;
		1242	int i;
		1243
		1244	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1245	ASSERT(count);
		1246
		1247	pages = (count_t) btree_search(&a->used_space, page, &leaf);
		1248	if (pages) {
		1249	/*
		1250	* We hit the beginning of some used space.
		1251	*/
		1252	return 0;
		1253	}
		1254
1437	jermar	1255	if (!leaf->keys) {
		1256	btree_insert(&a->used_space, page, (void *) count, leaf);
		1257	return 1;
		1258	}
		1259
1387	jermar	1260	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1261	if (node) {
2087	jermar	1262	uintptr_t left_pg = node->key[node->keys - 1];
		1263	uintptr_t right_pg = leaf->key[0];
		1264	count_t left_cnt = (count_t) node->value[node->keys - 1];
		1265	count_t right_cnt = (count_t) leaf->value[0];
1387	jermar	1266
		1267	/*
		1268	* Examine the possibility that the interval fits
		1269	* somewhere between the rightmost interval of
		1270	* the left neigbour and the first interval of the leaf.
		1271	*/
		1272
		1273	if (page >= right_pg) {
		1274	/* Do nothing. */
2087	jermar	1275	} else if (overlaps(page, count * PAGE_SIZE, left_pg,
		1276	left_cnt * PAGE_SIZE)) {
1387	jermar	1277	/* The interval intersects with the left interval. */
		1278	return 0;
2087	jermar	1279	} else if (overlaps(page, count * PAGE_SIZE, right_pg,
		1280	right_cnt * PAGE_SIZE)) {
1387	jermar	1281	/* The interval intersects with the right interval. */
		1282	return 0;
2087	jermar	1283	} else if ((page == left_pg + left_cnt * PAGE_SIZE) &&
		1284	(page + count * PAGE_SIZE == right_pg)) {
		1285	/*
		1286	* The interval can be added by merging the two already
		1287	* present intervals.
		1288	*/
1403	jermar	1289	node->value[node->keys - 1] += count + right_cnt;
1387	jermar	1290	btree_remove(&a->used_space, right_pg, leaf);
		1291	return 1;
2087	jermar	1292	} else if (page == left_pg + left_cnt * PAGE_SIZE) {
		1293	/*
		1294	* The interval can be added by simply growing the left
		1295	* interval.
		1296	*/
1403	jermar	1297	node->value[node->keys - 1] += count;
1387	jermar	1298	return 1;
2087	jermar	1299	} else if (page + count * PAGE_SIZE == right_pg) {
1387	jermar	1300	/*
2087	jermar	1301	* The interval can be addded by simply moving base of
		1302	* the right interval down and increasing its size
		1303	* accordingly.
1387	jermar	1304	*/
1403	jermar	1305	leaf->value[0] += count;
1387	jermar	1306	leaf->key[0] = page;
		1307	return 1;
		1308	} else {
		1309	/*
		1310	* The interval is between both neigbouring intervals,
		1311	* but cannot be merged with any of them.
		1312	*/
2087	jermar	1313	btree_insert(&a->used_space, page, (void *) count,
		1314	leaf);
1387	jermar	1315	return 1;
		1316	}
		1317	} else if (page < leaf->key[0]) {
1780	jermar	1318	uintptr_t right_pg = leaf->key[0];
1387	jermar	1319	count_t right_cnt = (count_t) leaf->value[0];
		1320
		1321	/*
2087	jermar	1322	* Investigate the border case in which the left neighbour does
		1323	* not exist but the interval fits from the left.
1387	jermar	1324	*/
		1325
2087	jermar	1326	if (overlaps(page, count * PAGE_SIZE, right_pg,
		1327	right_cnt * PAGE_SIZE)) {
1387	jermar	1328	/* The interval intersects with the right interval. */
		1329	return 0;
2087	jermar	1330	} else if (page + count * PAGE_SIZE == right_pg) {
1387	jermar	1331	/*
2087	jermar	1332	* The interval can be added by moving the base of the
		1333	* right interval down and increasing its size
		1334	* accordingly.
1387	jermar	1335	*/
		1336	leaf->key[0] = page;
1403	jermar	1337	leaf->value[0] += count;
1387	jermar	1338	return 1;
		1339	} else {
		1340	/*
		1341	* The interval doesn't adjoin with the right interval.
		1342	* It must be added individually.
		1343	*/
2087	jermar	1344	btree_insert(&a->used_space, page, (void *) count,
		1345	leaf);
1387	jermar	1346	return 1;
		1347	}
		1348	}
		1349
		1350	node = btree_leaf_node_right_neighbour(&a->used_space, leaf);
		1351	if (node) {
2087	jermar	1352	uintptr_t left_pg = leaf->key[leaf->keys - 1];
		1353	uintptr_t right_pg = node->key[0];
		1354	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1355	count_t right_cnt = (count_t) node->value[0];
1387	jermar	1356
		1357	/*
		1358	* Examine the possibility that the interval fits
		1359	* somewhere between the leftmost interval of
		1360	* the right neigbour and the last interval of the leaf.
		1361	*/
		1362
		1363	if (page < left_pg) {
		1364	/* Do nothing. */
2087	jermar	1365	} else if (overlaps(page, count * PAGE_SIZE, left_pg,
		1366	left_cnt * PAGE_SIZE)) {
1387	jermar	1367	/* The interval intersects with the left interval. */
		1368	return 0;
2087	jermar	1369	} else if (overlaps(page, count * PAGE_SIZE, right_pg,
		1370	right_cnt * PAGE_SIZE)) {
1387	jermar	1371	/* The interval intersects with the right interval. */
		1372	return 0;
2087	jermar	1373	} else if ((page == left_pg + left_cnt * PAGE_SIZE) &&
		1374	(page + count * PAGE_SIZE == right_pg)) {
		1375	/*
		1376	* The interval can be added by merging the two already
		1377	* present intervals.
		1378	* */
1403	jermar	1379	leaf->value[leaf->keys - 1] += count + right_cnt;
1387	jermar	1380	btree_remove(&a->used_space, right_pg, node);
		1381	return 1;
2087	jermar	1382	} else if (page == left_pg + left_cnt * PAGE_SIZE) {
		1383	/*
		1384	* The interval can be added by simply growing the left
		1385	* interval.
		1386	* */
1403	jermar	1387	leaf->value[leaf->keys - 1] += count;
1387	jermar	1388	return 1;
2087	jermar	1389	} else if (page + count * PAGE_SIZE == right_pg) {
1387	jermar	1390	/*
2087	jermar	1391	* The interval can be addded by simply moving base of
		1392	* the right interval down and increasing its size
		1393	* accordingly.
1387	jermar	1394	*/
1403	jermar	1395	node->value[0] += count;
1387	jermar	1396	node->key[0] = page;
		1397	return 1;
		1398	} else {
		1399	/*
		1400	* The interval is between both neigbouring intervals,
		1401	* but cannot be merged with any of them.
		1402	*/
2087	jermar	1403	btree_insert(&a->used_space, page, (void *) count,
		1404	leaf);
1387	jermar	1405	return 1;
		1406	}
		1407	} else if (page >= leaf->key[leaf->keys - 1]) {
1780	jermar	1408	uintptr_t left_pg = leaf->key[leaf->keys - 1];
1387	jermar	1409	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1410
		1411	/*
2087	jermar	1412	* Investigate the border case in which the right neighbour
		1413	* does not exist but the interval fits from the right.
1387	jermar	1414	*/
		1415
2087	jermar	1416	if (overlaps(page, count * PAGE_SIZE, left_pg,
		1417	left_cnt * PAGE_SIZE)) {
1403	jermar	1418	/* The interval intersects with the left interval. */
1387	jermar	1419	return 0;
2087	jermar	1420	} else if (left_pg + left_cnt * PAGE_SIZE == page) {
		1421	/*
		1422	* The interval can be added by growing the left
		1423	* interval.
		1424	*/
1403	jermar	1425	leaf->value[leaf->keys - 1] += count;
1387	jermar	1426	return 1;
		1427	} else {
		1428	/*
		1429	* The interval doesn't adjoin with the left interval.
		1430	* It must be added individually.
		1431	*/
2087	jermar	1432	btree_insert(&a->used_space, page, (void *) count,
		1433	leaf);
1387	jermar	1434	return 1;
		1435	}
		1436	}
		1437
		1438	/*
2087	jermar	1439	* Note that if the algorithm made it thus far, the interval can fit
		1440	* only between two other intervals of the leaf. The two border cases
		1441	* were already resolved.
1387	jermar	1442	*/
		1443	for (i = 1; i < leaf->keys; i++) {
		1444	if (page < leaf->key[i]) {
2087	jermar	1445	uintptr_t left_pg = leaf->key[i - 1];
		1446	uintptr_t right_pg = leaf->key[i];
		1447	count_t left_cnt = (count_t) leaf->value[i - 1];
		1448	count_t right_cnt = (count_t) leaf->value[i];
1387	jermar	1449
		1450	/*
		1451	* The interval fits between left_pg and right_pg.
		1452	*/
		1453
2087	jermar	1454	if (overlaps(page, count * PAGE_SIZE, left_pg,
		1455	left_cnt * PAGE_SIZE)) {
		1456	/*
		1457	* The interval intersects with the left
		1458	* interval.
		1459	*/
1387	jermar	1460	return 0;
2087	jermar	1461	} else if (overlaps(page, count * PAGE_SIZE, right_pg,
		1462	right_cnt * PAGE_SIZE)) {
		1463	/*
		1464	* The interval intersects with the right
		1465	* interval.
		1466	*/
1387	jermar	1467	return 0;
2087	jermar	1468	} else if ((page == left_pg + left_cnt * PAGE_SIZE) &&
		1469	(page + count * PAGE_SIZE == right_pg)) {
		1470	/*
		1471	* The interval can be added by merging the two
		1472	* already present intervals.
		1473	*/
1403	jermar	1474	leaf->value[i - 1] += count + right_cnt;
1387	jermar	1475	btree_remove(&a->used_space, right_pg, leaf);
		1476	return 1;
2087	jermar	1477	} else if (page == left_pg + left_cnt * PAGE_SIZE) {
		1478	/*
		1479	* The interval can be added by simply growing
		1480	* the left interval.
		1481	*/
1403	jermar	1482	leaf->value[i - 1] += count;
1387	jermar	1483	return 1;
2087	jermar	1484	} else if (page + count * PAGE_SIZE == right_pg) {
1387	jermar	1485	/*
2087	jermar	1486	* The interval can be addded by simply moving
		1487	* base of the right interval down and
		1488	* increasing its size accordingly.
1387	jermar	1489	*/
1403	jermar	1490	leaf->value[i] += count;
1387	jermar	1491	leaf->key[i] = page;
		1492	return 1;
		1493	} else {
		1494	/*
2087	jermar	1495	* The interval is between both neigbouring
		1496	* intervals, but cannot be merged with any of
		1497	* them.
1387	jermar	1498	*/
2087	jermar	1499	btree_insert(&a->used_space, page,
		1500	(void *) count, leaf);
1387	jermar	1501	return 1;
		1502	}
		1503	}
		1504	}
		1505
2087	jermar	1506	panic("Inconsistency detected while adding %d pages of used space at "
		1507	"%p.\n", count, page);
1387	jermar	1508	}
		1509
		1510	/** Mark portion of address space area as unused.
		1511	*
		1512	* The address space area must be already locked.
		1513	*
		1514	* @param a Address space area.
		1515	* @param page First page to be marked.
		1516	* @param count Number of page to be marked.
		1517	*
		1518	* @return 0 on failure and 1 on success.
		1519	*/
1780	jermar	1520	int used_space_remove(as_area_t *a, uintptr_t page, count_t count)
1387	jermar	1521	{
		1522	btree_node_t leaf, node;
		1523	count_t pages;
		1524	int i;
		1525
		1526	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1527	ASSERT(count);
		1528
		1529	pages = (count_t) btree_search(&a->used_space, page, &leaf);
		1530	if (pages) {
		1531	/*
		1532	* We are lucky, page is the beginning of some interval.
		1533	*/
		1534	if (count > pages) {
		1535	return 0;
		1536	} else if (count == pages) {
		1537	btree_remove(&a->used_space, page, leaf);
1403	jermar	1538	return 1;
1387	jermar	1539	} else {
		1540	/*
		1541	* Find the respective interval.
		1542	* Decrease its size and relocate its start address.
		1543	*/
		1544	for (i = 0; i < leaf->keys; i++) {
		1545	if (leaf->key[i] == page) {
2087	jermar	1546	leaf->key[i] += count * PAGE_SIZE;
1403	jermar	1547	leaf->value[i] -= count;
1387	jermar	1548	return 1;
		1549	}
		1550	}
		1551	goto error;
		1552	}
		1553	}
		1554
		1555	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1556	if (node && page < leaf->key[0]) {
1780	jermar	1557	uintptr_t left_pg = node->key[node->keys - 1];
1387	jermar	1558	count_t left_cnt = (count_t) node->value[node->keys - 1];
		1559
2087	jermar	1560	if (overlaps(left_pg, left_cnt * PAGE_SIZE, page,
		1561	count * PAGE_SIZE)) {
		1562	if (page + count * PAGE_SIZE ==
		1563	left_pg + left_cnt * PAGE_SIZE) {
1387	jermar	1564	/*
2087	jermar	1565	* The interval is contained in the rightmost
		1566	* interval of the left neighbour and can be
		1567	* removed by updating the size of the bigger
		1568	* interval.
1387	jermar	1569	*/
1403	jermar	1570	node->value[node->keys - 1] -= count;
1387	jermar	1571	return 1;
2087	jermar	1572	} else if (page + count * PAGE_SIZE <
		1573	left_pg + left_cnt*PAGE_SIZE) {
1403	jermar	1574	count_t new_cnt;
1387	jermar	1575
		1576	/*
2087	jermar	1577	* The interval is contained in the rightmost
		1578	* interval of the left neighbour but its
		1579	* removal requires both updating the size of
		1580	* the original interval and also inserting a
		1581	* new interval.
1387	jermar	1582	*/
2087	jermar	1583	new_cnt = ((left_pg + left_cnt * PAGE_SIZE) -
		1584	(page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1403	jermar	1585	node->value[node->keys - 1] -= count + new_cnt;
2087	jermar	1586	btree_insert(&a->used_space, page +
		1587	count * PAGE_SIZE, (void *) new_cnt, leaf);
1387	jermar	1588	return 1;
		1589	}
		1590	}
		1591	return 0;
		1592	} else if (page < leaf->key[0]) {
		1593	return 0;
		1594	}
		1595
		1596	if (page > leaf->key[leaf->keys - 1]) {
1780	jermar	1597	uintptr_t left_pg = leaf->key[leaf->keys - 1];
1387	jermar	1598	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1599
2087	jermar	1600	if (overlaps(left_pg, left_cnt * PAGE_SIZE, page,
		1601	count * PAGE_SIZE)) {
		1602	if (page + count * PAGE_SIZE ==
		1603	left_pg + left_cnt * PAGE_SIZE) {
1387	jermar	1604	/*
2087	jermar	1605	* The interval is contained in the rightmost
		1606	* interval of the leaf and can be removed by
		1607	* updating the size of the bigger interval.
1387	jermar	1608	*/
1403	jermar	1609	leaf->value[leaf->keys - 1] -= count;
1387	jermar	1610	return 1;
2087	jermar	1611	} else if (page + count * PAGE_SIZE < left_pg +
		1612	left_cnt * PAGE_SIZE) {
1403	jermar	1613	count_t new_cnt;
1387	jermar	1614
		1615	/*
2087	jermar	1616	* The interval is contained in the rightmost
		1617	* interval of the leaf but its removal
		1618	* requires both updating the size of the
		1619	* original interval and also inserting a new
		1620	* interval.
1387	jermar	1621	*/
2087	jermar	1622	new_cnt = ((left_pg + left_cnt * PAGE_SIZE) -
		1623	(page + count * PAGE_SIZE)) >> PAGE_WIDTH;
1403	jermar	1624	leaf->value[leaf->keys - 1] -= count + new_cnt;
2087	jermar	1625	btree_insert(&a->used_space, page +
		1626	count * PAGE_SIZE, (void *) new_cnt, leaf);
1387	jermar	1627	return 1;
		1628	}
		1629	}
		1630	return 0;
		1631	}
		1632
		1633	/*
		1634	* The border cases have been already resolved.
		1635	* Now the interval can be only between intervals of the leaf.
		1636	*/
		1637	for (i = 1; i < leaf->keys - 1; i++) {
		1638	if (page < leaf->key[i]) {
1780	jermar	1639	uintptr_t left_pg = leaf->key[i - 1];
1387	jermar	1640	count_t left_cnt = (count_t) leaf->value[i - 1];
		1641
		1642	/*
2087	jermar	1643	* Now the interval is between intervals corresponding
		1644	* to (i - 1) and i.
1387	jermar	1645	*/
2087	jermar	1646	if (overlaps(left_pg, left_cnt * PAGE_SIZE, page,
		1647	count * PAGE_SIZE)) {
		1648	if (page + count * PAGE_SIZE ==
		1649	left_pg + left_cnt*PAGE_SIZE) {
1387	jermar	1650	/*
2087	jermar	1651	* The interval is contained in the
		1652	* interval (i - 1) of the leaf and can
		1653	* be removed by updating the size of
		1654	* the bigger interval.
1387	jermar	1655	*/
1403	jermar	1656	leaf->value[i - 1] -= count;
1387	jermar	1657	return 1;
2087	jermar	1658	} else if (page + count * PAGE_SIZE <
		1659	left_pg + left_cnt * PAGE_SIZE) {
1403	jermar	1660	count_t new_cnt;
1387	jermar	1661
		1662	/*
2087	jermar	1663	* The interval is contained in the
		1664	* interval (i - 1) of the leaf but its
		1665	* removal requires both updating the
		1666	* size of the original interval and
1387	jermar	1667	* also inserting a new interval.
		1668	*/
2087	jermar	1669	new_cnt = ((left_pg +
		1670	left_cnt * PAGE_SIZE) -
		1671	(page + count * PAGE_SIZE)) >>
		1672	PAGE_WIDTH;
1403	jermar	1673	leaf->value[i - 1] -= count + new_cnt;
2087	jermar	1674	btree_insert(&a->used_space, page +
		1675	count * PAGE_SIZE, (void *) new_cnt,
		1676	leaf);
1387	jermar	1677	return 1;
		1678	}
		1679	}
		1680	return 0;
		1681	}
		1682	}
		1683
		1684	error:
2087	jermar	1685	panic("Inconsistency detected while removing %d pages of used space "
		1686	"from %p.\n", count, page);
1387	jermar	1687	}
		1688
1409	jermar	1689	/** Remove reference to address space area share info.
		1690	*
		1691	* If the reference count drops to 0, the sh_info is deallocated.
		1692	*
		1693	* @param sh_info Pointer to address space area share info.
		1694	*/
		1695	void sh_info_remove_reference(share_info_t *sh_info)
		1696	{
		1697	bool dealloc = false;
		1698
		1699	mutex_lock(&sh_info->lock);
		1700	ASSERT(sh_info->refcount);
		1701	if (--sh_info->refcount == 0) {
		1702	dealloc = true;
1495	jermar	1703	link_t *cur;
1409	jermar	1704
		1705	/*
		1706	* Now walk carefully the pagemap B+tree and free/remove
		1707	* reference from all frames found there.
		1708	*/
2087	jermar	1709	for (cur = sh_info->pagemap.leaf_head.next;
		1710	cur != &sh_info->pagemap.leaf_head; cur = cur->next) {
1409	jermar	1711	btree_node_t *node;
1495	jermar	1712	int i;
1409	jermar	1713
1495	jermar	1714	node = list_get_instance(cur, btree_node_t, leaf_link);
		1715	for (i = 0; i < node->keys; i++)
1780	jermar	1716	frame_free((uintptr_t) node->value[i]);
1409	jermar	1717	}
		1718
		1719	}
		1720	mutex_unlock(&sh_info->lock);
		1721
		1722	if (dealloc) {
		1723	btree_destroy(&sh_info->pagemap);
		1724	free(sh_info);
		1725	}
		1726	}
		1727
1235	jermar	1728	/*
		1729	* Address space related syscalls.
		1730	*/
		1731
		1732	/** Wrapper for as_area_create(). */
1780	jermar	1733	unative_t sys_as_area_create(uintptr_t address, size_t size, int flags)
1235	jermar	1734	{
2087	jermar	1735	if (as_area_create(AS, flags \| AS_AREA_CACHEABLE, size, address,
		1736	AS_AREA_ATTR_NONE, &anon_backend, NULL))
1780	jermar	1737	return (unative_t) address;
1235	jermar	1738	else
1780	jermar	1739	return (unative_t) -1;
1235	jermar	1740	}
		1741
1793	jermar	1742	/** Wrapper for as_area_resize(). */
1780	jermar	1743	unative_t sys_as_area_resize(uintptr_t address, size_t size, int flags)
1235	jermar	1744	{
1780	jermar	1745	return (unative_t) as_area_resize(AS, address, size, 0);
1235	jermar	1746	}
		1747
1793	jermar	1748	/** Wrapper for as_area_destroy(). */
1780	jermar	1749	unative_t sys_as_area_destroy(uintptr_t address)
1306	jermar	1750	{
1780	jermar	1751	return (unative_t) as_area_destroy(AS, address);
1306	jermar	1752	}
1702	cejka	1753
1914	jermar	1754	/** Print out information about address space.
		1755	*
		1756	* @param as Address space.
		1757	*/
		1758	void as_print(as_t *as)
		1759	{
		1760	ipl_t ipl;
		1761
		1762	ipl = interrupts_disable();
		1763	mutex_lock(&as->lock);
		1764
		1765	/* print out info about address space areas */
		1766	link_t *cur;
2087	jermar	1767	for (cur = as->as_area_btree.leaf_head.next;
		1768	cur != &as->as_area_btree.leaf_head; cur = cur->next) {
		1769	btree_node_t *node;
1914	jermar	1770
2087	jermar	1771	node = list_get_instance(cur, btree_node_t, leaf_link);
		1772
1914	jermar	1773	int i;
		1774	for (i = 0; i < node->keys; i++) {
1915	jermar	1775	as_area_t *area = node->value[i];
1914	jermar	1776
		1777	mutex_lock(&area->lock);
		1778	printf("as_area: %p, base=%p, pages=%d (%p - %p)\n",
2087	jermar	1779	area, area->base, area->pages, area->base,
		1780	area->base + area->pages*PAGE_SIZE);
1914	jermar	1781	mutex_unlock(&area->lock);
		1782	}
		1783	}
		1784
		1785	mutex_unlock(&as->lock);
		1786	interrupts_restore(ipl);
		1787	}
		1788
1757	jermar	1789	/** @}
1702	cejka	1790	*/

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/mm/as.c – Rev 2125