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

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/mm/as.c – Rev 2170