WebSVN – HelenOS-historic – Blame – /kernel/trunk/generic/src/mm/as.c

Rev	Author	Line No.	Line
703	jermar	1	/*
		2	* Copyright (C) 2001-2006 Jakub Jermar
		3	* All rights reserved.
		4	*
		5	* Redistribution and use in source and binary forms, with or without
		6	* modification, are permitted provided that the following conditions
		7	* are met:
		8	*
		9	* - Redistributions of source code must retain the above copyright
		10	* notice, this list of conditions and the following disclaimer.
		11	* - Redistributions in binary form must reproduce the above copyright
		12	* notice, this list of conditions and the following disclaimer in the
		13	* documentation and/or other materials provided with the distribution.
		14	* - The name of the author may not be used to endorse or promote products
		15	* derived from this software without specific prior written permission.
		16	*
		17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
		18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
		19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
		20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
		21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
		22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
		23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
		24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
		25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
		26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
		27	*/
		28
1705	cejka	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
		42	* create address space and create, resize and share
		43	* address space areas.
		44	*
		45	* @see page.c
		46	*
703	jermar	47	*/
		48
		49	#include <mm/as.h>
756	jermar	50	#include <arch/mm/as.h>
703	jermar	51	#include <mm/page.h>
		52	#include <mm/frame.h>
814	palkovsky	53	#include <mm/slab.h>
703	jermar	54	#include <mm/tlb.h>
		55	#include <arch/mm/page.h>
		56	#include <genarch/mm/page_pt.h>
1108	jermar	57	#include <genarch/mm/page_ht.h>
727	jermar	58	#include <mm/asid.h>
703	jermar	59	#include <arch/mm/asid.h>
		60	#include <synch/spinlock.h>
1380	jermar	61	#include <synch/mutex.h>
788	jermar	62	#include <adt/list.h>
1147	jermar	63	#include <adt/btree.h>
1235	jermar	64	#include <proc/task.h>
1288	jermar	65	#include <proc/thread.h>
1235	jermar	66	#include <arch/asm.h>
703	jermar	67	#include <panic.h>
		68	#include <debug.h>
1235	jermar	69	#include <print.h>
703	jermar	70	#include <memstr.h>
1070	jermar	71	#include <macros.h>
703	jermar	72	#include <arch.h>
1235	jermar	73	#include <errno.h>
		74	#include <config.h>
1387	jermar	75	#include <align.h>
1235	jermar	76	#include <arch/types.h>
		77	#include <typedefs.h>
1288	jermar	78	#include <syscall/copy.h>
		79	#include <arch/interrupt.h>
703	jermar	80
756	jermar	81	as_operations_t *as_operations = NULL;
703	jermar	82
1415	jermar	83	/** This lock protects inactive_as_with_asid_head list. It must be acquired before as_t mutex. */
		84	SPINLOCK_INITIALIZE(inactive_as_with_asid_lock);
823	jermar	85
		86	/**
		87	* This list contains address spaces that are not active on any
		88	* processor and that have valid ASID.
		89	*/
		90	LIST_INITIALIZE(inactive_as_with_asid_head);
		91
757	jermar	92	/** Kernel address space. */
		93	as_t *AS_KERNEL = NULL;
		94
1235	jermar	95	static int area_flags_to_page_flags(int aflags);
977	jermar	96	static as_area_t find_area_and_lock(as_t as, __address va);
1048	jermar	97	static bool check_area_conflicts(as_t as, __address va, size_t size, as_area_t avoid_area);
1409	jermar	98	static void sh_info_remove_reference(share_info_t *sh_info);
703	jermar	99
756	jermar	100	/** Initialize address space subsystem. */
		101	void as_init(void)
		102	{
		103	as_arch_init();
789	palkovsky	104	AS_KERNEL = as_create(FLAG_AS_KERNEL);
1383	decky	105	if (!AS_KERNEL)
		106	panic("can't create kernel address space\n");
		107
756	jermar	108	}
		109
757	jermar	110	/** Create address space.
		111	*
		112	* @param flags Flags that influence way in wich the address space is created.
		113	*/
756	jermar	114	as_t *as_create(int flags)
703	jermar	115	{
		116	as_t *as;
		117
822	palkovsky	118	as = (as_t *) malloc(sizeof(as_t), 0);
823	jermar	119	link_initialize(&as->inactive_as_with_asid_link);
1380	jermar	120	mutex_initialize(&as->lock);
1147	jermar	121	btree_create(&as->as_area_btree);
822	palkovsky	122
		123	if (flags & FLAG_AS_KERNEL)
		124	as->asid = ASID_KERNEL;
		125	else
		126	as->asid = ASID_INVALID;
		127
1468	jermar	128	as->refcount = 0;
1415	jermar	129	as->cpu_refcount = 0;
822	palkovsky	130	as->page_table = page_table_create(flags);
703	jermar	131
		132	return as;
		133	}
		134
1468	jermar	135	/** Destroy adress space.
		136	*
		137	* When there are no tasks referencing this address space (i.e. its refcount is zero),
		138	* the address space can be destroyed.
		139	*/
		140	void as_destroy(as_t *as)
973	palkovsky	141	{
1468	jermar	142	ipl_t ipl;
1594	jermar	143	bool cond;
973	palkovsky	144
1468	jermar	145	ASSERT(as->refcount == 0);
		146
		147	/*
		148	* Since there is no reference to this area,
		149	* it is safe not to lock its mutex.
		150	*/
		151	ipl = interrupts_disable();
		152	spinlock_lock(&inactive_as_with_asid_lock);
1587	jermar	153	if (as->asid != ASID_INVALID && as != AS_KERNEL) {
1594	jermar	154	if (as != AS && as->cpu_refcount == 0)
1587	jermar	155	list_remove(&as->inactive_as_with_asid_link);
1468	jermar	156	asid_put(as->asid);
		157	}
		158	spinlock_unlock(&inactive_as_with_asid_lock);
		159
		160	/*
		161	* Destroy address space areas of the address space.
1594	jermar	162	* The B+tee must be walked carefully because it is
		163	* also being destroyed.
1468	jermar	164	*/
1594	jermar	165	for (cond = true; cond; ) {
1468	jermar	166	btree_node_t *node;
1594	jermar	167
		168	ASSERT(!list_empty(&as->as_area_btree.leaf_head));
		169	node = list_get_instance(as->as_area_btree.leaf_head.next, btree_node_t, leaf_link);
		170
		171	if ((cond = node->keys)) {
		172	as_area_destroy(as, node->key[0]);
		173	}
1468	jermar	174	}
1495	jermar	175
1483	jermar	176	btree_destroy(&as->as_area_btree);
1468	jermar	177	page_table_destroy(as->page_table);
		178
		179	interrupts_restore(ipl);
		180
973	palkovsky	181	free(as);
		182	}
		183
703	jermar	184	/** Create address space area of common attributes.
		185	*
		186	* The created address space area is added to the target address space.
		187	*
		188	* @param as Target address space.
1239	jermar	189	* @param flags Flags of the area memory.
1048	jermar	190	* @param size Size of area.
703	jermar	191	* @param base Base address of area.
1239	jermar	192	* @param attrs Attributes of the area.
1409	jermar	193	* @param backend Address space area backend. NULL if no backend is used.
		194	* @param backend_data NULL or a pointer to an array holding two void *.
703	jermar	195	*
		196	* @return Address space area on success or NULL on failure.
		197	*/
1409	jermar	198	as_area_t as_area_create(as_t as, int flags, size_t size, __address base, int attrs,
1424	jermar	199	mem_backend_t backend, mem_backend_data_t backend_data)
703	jermar	200	{
		201	ipl_t ipl;
		202	as_area_t *a;
		203
		204	if (base % PAGE_SIZE)
1048	jermar	205	return NULL;
		206
1233	jermar	207	if (!size)
		208	return NULL;
		209
1048	jermar	210	/* Writeable executable areas are not supported. */
		211	if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
		212	return NULL;
703	jermar	213
		214	ipl = interrupts_disable();
1380	jermar	215	mutex_lock(&as->lock);
703	jermar	216
1048	jermar	217	if (!check_area_conflicts(as, base, size, NULL)) {
1380	jermar	218	mutex_unlock(&as->lock);
1048	jermar	219	interrupts_restore(ipl);
		220	return NULL;
		221	}
703	jermar	222
822	palkovsky	223	a = (as_area_t *) malloc(sizeof(as_area_t), 0);
703	jermar	224
1380	jermar	225	mutex_initialize(&a->lock);
822	palkovsky	226
1424	jermar	227	a->as = as;
1026	jermar	228	a->flags = flags;
1239	jermar	229	a->attributes = attrs;
1048	jermar	230	a->pages = SIZE2FRAMES(size);
822	palkovsky	231	a->base = base;
1409	jermar	232	a->sh_info = NULL;
		233	a->backend = backend;
1424	jermar	234	if (backend_data)
		235	a->backend_data = *backend_data;
		236	else
		237	memsetb((__address) &a->backend_data, sizeof(a->backend_data), 0);
		238
1387	jermar	239	btree_create(&a->used_space);
822	palkovsky	240
1147	jermar	241	btree_insert(&as->as_area_btree, base, (void *) a, NULL);
822	palkovsky	242
1380	jermar	243	mutex_unlock(&as->lock);
703	jermar	244	interrupts_restore(ipl);
704	jermar	245
703	jermar	246	return a;
		247	}
		248
1235	jermar	249	/** Find address space area and change it.
		250	*
		251	* @param as Address space.
		252	* @param address Virtual address belonging to the area to be changed. Must be page-aligned.
		253	* @param size New size of the virtual memory block starting at address.
		254	* @param flags Flags influencing the remap operation. Currently unused.
		255	*
1306	jermar	256	* @return Zero on success or a value from @ref errno.h otherwise.
1235	jermar	257	*/
1306	jermar	258	int as_area_resize(as_t *as, __address address, size_t size, int flags)
1235	jermar	259	{
1306	jermar	260	as_area_t *area;
1235	jermar	261	ipl_t ipl;
		262	size_t pages;
		263
		264	ipl = interrupts_disable();
1380	jermar	265	mutex_lock(&as->lock);
1235	jermar	266
		267	/*
		268	* Locate the area.
		269	*/
		270	area = find_area_and_lock(as, address);
		271	if (!area) {
1380	jermar	272	mutex_unlock(&as->lock);
1235	jermar	273	interrupts_restore(ipl);
1306	jermar	274	return ENOENT;
1235	jermar	275	}
		276
1424	jermar	277	if (area->backend == &phys_backend) {
1235	jermar	278	/*
		279	* Remapping of address space areas associated
		280	* with memory mapped devices is not supported.
		281	*/
1380	jermar	282	mutex_unlock(&area->lock);
		283	mutex_unlock(&as->lock);
1235	jermar	284	interrupts_restore(ipl);
1306	jermar	285	return ENOTSUP;
1235	jermar	286	}
1409	jermar	287	if (area->sh_info) {
		288	/*
		289	* Remapping of shared address space areas
		290	* is not supported.
		291	*/
		292	mutex_unlock(&area->lock);
		293	mutex_unlock(&as->lock);
		294	interrupts_restore(ipl);
		295	return ENOTSUP;
		296	}
1235	jermar	297
		298	pages = SIZE2FRAMES((address - area->base) + size);
		299	if (!pages) {
		300	/*
		301	* Zero size address space areas are not allowed.
		302	*/
1380	jermar	303	mutex_unlock(&area->lock);
		304	mutex_unlock(&as->lock);
1235	jermar	305	interrupts_restore(ipl);
1306	jermar	306	return EPERM;
1235	jermar	307	}
		308
		309	if (pages < area->pages) {
1403	jermar	310	bool cond;
		311	__address start_free = area->base + pages*PAGE_SIZE;
1235	jermar	312
		313	/*
		314	* Shrinking the area.
		315	* No need to check for overlaps.
		316	*/
1403	jermar	317
		318	/*
1436	jermar	319	* Start TLB shootdown sequence.
		320	*/
		321	tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
		322
		323	/*
1403	jermar	324	* Remove frames belonging to used space starting from
		325	* the highest addresses downwards until an overlap with
		326	* the resized address space area is found. Note that this
		327	* is also the right way to remove part of the used_space
		328	* B+tree leaf list.
		329	*/
		330	for (cond = true; cond;) {
		331	btree_node_t *node;
		332
		333	ASSERT(!list_empty(&area->used_space.leaf_head));
		334	node = list_get_instance(area->used_space.leaf_head.prev, btree_node_t, leaf_link);
		335	if ((cond = (bool) node->keys)) {
		336	__address b = node->key[node->keys - 1];
		337	count_t c = (count_t) node->value[node->keys - 1];
		338	int i = 0;
1235	jermar	339
1403	jermar	340	if (overlaps(b, cPAGE_SIZE, area->base, pagesPAGE_SIZE)) {
		341
		342	if (b + c*PAGE_SIZE <= start_free) {
		343	/*
		344	* The whole interval fits completely
		345	* in the resized address space area.
		346	*/
		347	break;
		348	}
		349
		350	/*
		351	* Part of the interval corresponding to b and c
		352	* overlaps with the resized address space area.
		353	*/
		354
		355	cond = false; /* we are almost done */
		356	i = (start_free - b) >> PAGE_WIDTH;
		357	if (!used_space_remove(area, start_free, c - i))
		358	panic("Could not remove used space.");
		359	} else {
		360	/*
		361	* The interval of used space can be completely removed.
		362	*/
		363	if (!used_space_remove(area, b, c))
		364	panic("Could not remove used space.\n");
		365	}
		366
		367	for (; i < c; i++) {
		368	pte_t *pte;
		369
		370	page_table_lock(as, false);
		371	pte = page_mapping_find(as, b + i*PAGE_SIZE);
		372	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424	jermar	373	if (area->backend && area->backend->frame_free) {
		374	area->backend->frame_free(area,
1409	jermar	375	b + i*PAGE_SIZE, PTE_GET_FRAME(pte));
		376	}
1403	jermar	377	page_mapping_remove(as, b + i*PAGE_SIZE);
		378	page_table_unlock(as, false);
		379	}
1235	jermar	380	}
		381	}
1436	jermar	382
1235	jermar	383	/*
1436	jermar	384	* Finish TLB shootdown sequence.
1235	jermar	385	*/
		386	tlb_invalidate_pages(AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
		387	tlb_shootdown_finalize();
		388	} else {
		389	/*
		390	* Growing the area.
		391	* Check for overlaps with other address space areas.
		392	*/
		393	if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {
1380	jermar	394	mutex_unlock(&area->lock);
		395	mutex_unlock(&as->lock);
1235	jermar	396	interrupts_restore(ipl);
1306	jermar	397	return EADDRNOTAVAIL;
1235	jermar	398	}
		399	}
		400
		401	area->pages = pages;
		402
1380	jermar	403	mutex_unlock(&area->lock);
		404	mutex_unlock(&as->lock);
1235	jermar	405	interrupts_restore(ipl);
		406
1306	jermar	407	return 0;
1235	jermar	408	}
		409
1306	jermar	410	/** Destroy address space area.
		411	*
		412	* @param as Address space.
		413	* @param address Address withing the area to be deleted.
		414	*
		415	* @return Zero on success or a value from @ref errno.h on failure.
		416	*/
		417	int as_area_destroy(as_t *as, __address address)
		418	{
		419	as_area_t *area;
		420	__address base;
1495	jermar	421	link_t *cur;
1306	jermar	422	ipl_t ipl;
		423
		424	ipl = interrupts_disable();
1380	jermar	425	mutex_lock(&as->lock);
1306	jermar	426
		427	area = find_area_and_lock(as, address);
		428	if (!area) {
1380	jermar	429	mutex_unlock(&as->lock);
1306	jermar	430	interrupts_restore(ipl);
		431	return ENOENT;
		432	}
		433
1403	jermar	434	base = area->base;
		435
1411	jermar	436	/*
1436	jermar	437	* Start TLB shootdown sequence.
		438	*/
		439	tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages);
		440
		441	/*
1411	jermar	442	* Visit only the pages mapped by used_space B+tree.
		443	*/
1495	jermar	444	for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {
1411	jermar	445	btree_node_t *node;
1495	jermar	446	int i;
1403	jermar	447
1495	jermar	448	node = list_get_instance(cur, btree_node_t, leaf_link);
		449	for (i = 0; i < node->keys; i++) {
		450	__address b = node->key[i];
		451	count_t j;
1411	jermar	452	pte_t *pte;
1403	jermar	453
1495	jermar	454	for (j = 0; j < (count_t) node->value[i]; j++) {
1411	jermar	455	page_table_lock(as, false);
1495	jermar	456	pte = page_mapping_find(as, b + j*PAGE_SIZE);
1411	jermar	457	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424	jermar	458	if (area->backend && area->backend->frame_free) {
		459	area->backend->frame_free(area,
1495	jermar	460	b + j*PAGE_SIZE, PTE_GET_FRAME(pte));
1403	jermar	461	}
1495	jermar	462	page_mapping_remove(as, b + j*PAGE_SIZE);
1411	jermar	463	page_table_unlock(as, false);
1306	jermar	464	}
		465	}
		466	}
1403	jermar	467
1306	jermar	468	/*
1436	jermar	469	* Finish TLB shootdown sequence.
1306	jermar	470	*/
		471	tlb_invalidate_pages(AS->asid, area->base, area->pages);
		472	tlb_shootdown_finalize();
1436	jermar	473
		474	btree_destroy(&area->used_space);
1306	jermar	475
1309	jermar	476	area->attributes \|= AS_AREA_ATTR_PARTIAL;
1409	jermar	477
		478	if (area->sh_info)
		479	sh_info_remove_reference(area->sh_info);
		480
1380	jermar	481	mutex_unlock(&area->lock);
1306	jermar	482
		483	/*
		484	* Remove the empty area from address space.
		485	*/
		486	btree_remove(&AS->as_area_btree, base, NULL);
		487
1309	jermar	488	free(area);
		489
1380	jermar	490	mutex_unlock(&AS->lock);
1306	jermar	491	interrupts_restore(ipl);
		492	return 0;
		493	}
		494
1413	jermar	495	/** Share address space area with another or the same address space.
1235	jermar	496	*
1424	jermar	497	* Address space area mapping is shared with a new address space area.
		498	* If the source address space area has not been shared so far,
		499	* a new sh_info is created. The new address space area simply gets the
		500	* sh_info of the source area. The process of duplicating the
		501	* mapping is done through the backend share function.
1413	jermar	502	*
1417	jermar	503	* @param src_as Pointer to source address space.
1239	jermar	504	* @param src_base Base address of the source address space area.
1417	jermar	505	* @param acc_size Expected size of the source area.
1428	palkovsky	506	* @param dst_as Pointer to destination address space.
1417	jermar	507	* @param dst_base Target base address.
		508	* @param dst_flags_mask Destination address space area flags mask.
1235	jermar	509	*
1306	jermar	510	* @return Zero on success or ENOENT if there is no such task or
1235	jermar	511	* if there is no such address space area,
		512	* EPERM if there was a problem in accepting the area or
		513	* ENOMEM if there was a problem in allocating destination
1413	jermar	514	* address space area. ENOTSUP is returned if an attempt
		515	* to share non-anonymous address space area is detected.
1235	jermar	516	*/
1413	jermar	517	int as_area_share(as_t *src_as, __address src_base, size_t acc_size,
1428	palkovsky	518	as_t *dst_as, __address dst_base, int dst_flags_mask)
1235	jermar	519	{
		520	ipl_t ipl;
1239	jermar	521	int src_flags;
		522	size_t src_size;
		523	as_area_t src_area, dst_area;
1413	jermar	524	share_info_t *sh_info;
1424	jermar	525	mem_backend_t *src_backend;
		526	mem_backend_data_t src_backend_data;
1434	palkovsky	527
1235	jermar	528	ipl = interrupts_disable();
1380	jermar	529	mutex_lock(&src_as->lock);
1329	palkovsky	530	src_area = find_area_and_lock(src_as, src_base);
1239	jermar	531	if (!src_area) {
1238	jermar	532	/*
		533	* Could not find the source address space area.
		534	*/
1380	jermar	535	mutex_unlock(&src_as->lock);
1238	jermar	536	interrupts_restore(ipl);
		537	return ENOENT;
		538	}
1413	jermar	539
1424	jermar	540	if (!src_area->backend \|\| !src_area->backend->share) {
1413	jermar	541	/*
1424	jermar	542	* There is now backend or the backend does not
		543	* know how to share the area.
1413	jermar	544	*/
		545	mutex_unlock(&src_area->lock);
		546	mutex_unlock(&src_as->lock);
		547	interrupts_restore(ipl);
		548	return ENOTSUP;
		549	}
		550
1239	jermar	551	src_size = src_area->pages * PAGE_SIZE;
		552	src_flags = src_area->flags;
1424	jermar	553	src_backend = src_area->backend;
		554	src_backend_data = src_area->backend_data;
1544	palkovsky	555
		556	/* Share the cacheable flag from the original mapping */
		557	if (src_flags & AS_AREA_CACHEABLE)
		558	dst_flags_mask \|= AS_AREA_CACHEABLE;
		559
1461	palkovsky	560	if (src_size != acc_size \|\| (src_flags & dst_flags_mask) != dst_flags_mask) {
1413	jermar	561	mutex_unlock(&src_area->lock);
		562	mutex_unlock(&src_as->lock);
1235	jermar	563	interrupts_restore(ipl);
		564	return EPERM;
		565	}
1413	jermar	566
1235	jermar	567	/*
1413	jermar	568	* Now we are committed to sharing the area.
		569	* First prepare the area for sharing.
		570	* Then it will be safe to unlock it.
		571	*/
		572	sh_info = src_area->sh_info;
		573	if (!sh_info) {
		574	sh_info = (share_info_t *) malloc(sizeof(share_info_t), 0);
		575	mutex_initialize(&sh_info->lock);
		576	sh_info->refcount = 2;
		577	btree_create(&sh_info->pagemap);
		578	src_area->sh_info = sh_info;
		579	} else {
		580	mutex_lock(&sh_info->lock);
		581	sh_info->refcount++;
		582	mutex_unlock(&sh_info->lock);
		583	}
		584
1424	jermar	585	src_area->backend->share(src_area);
1413	jermar	586
		587	mutex_unlock(&src_area->lock);
		588	mutex_unlock(&src_as->lock);
		589
		590	/*
1239	jermar	591	* Create copy of the source address space area.
		592	* The destination area is created with AS_AREA_ATTR_PARTIAL
		593	* attribute set which prevents race condition with
		594	* preliminary as_page_fault() calls.
1417	jermar	595	* The flags of the source area are masked against dst_flags_mask
		596	* to support sharing in less privileged mode.
1235	jermar	597	*/
1461	palkovsky	598	dst_area = as_area_create(dst_as, dst_flags_mask, src_size, dst_base,
1424	jermar	599	AS_AREA_ATTR_PARTIAL, src_backend, &src_backend_data);
1239	jermar	600	if (!dst_area) {
1235	jermar	601	/*
		602	* Destination address space area could not be created.
		603	*/
1413	jermar	604	sh_info_remove_reference(sh_info);
		605
1235	jermar	606	interrupts_restore(ipl);
		607	return ENOMEM;
		608	}
		609
		610	/*
1239	jermar	611	* Now the destination address space area has been
		612	* fully initialized. Clear the AS_AREA_ATTR_PARTIAL
1413	jermar	613	* attribute and set the sh_info.
1239	jermar	614	*/
1380	jermar	615	mutex_lock(&dst_area->lock);
1239	jermar	616	dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
1413	jermar	617	dst_area->sh_info = sh_info;
1380	jermar	618	mutex_unlock(&dst_area->lock);
1235	jermar	619
		620	interrupts_restore(ipl);
		621
		622	return 0;
		623	}
		624
1423	jermar	625	/** Check access mode for address space area.
		626	*
		627	* The address space area must be locked prior to this call.
		628	*
		629	* @param area Address space area.
		630	* @param access Access mode.
		631	*
		632	* @return False if access violates area's permissions, true otherwise.
		633	*/
		634	bool as_area_check_access(as_area_t *area, pf_access_t access)
		635	{
		636	int flagmap[] = {
		637	[PF_ACCESS_READ] = AS_AREA_READ,
		638	[PF_ACCESS_WRITE] = AS_AREA_WRITE,
		639	[PF_ACCESS_EXEC] = AS_AREA_EXEC
		640	};
		641
		642	if (!(area->flags & flagmap[access]))
		643	return false;
		644
		645	return true;
		646	}
		647
703	jermar	648	/** Handle page fault within the current address space.
		649	*
1409	jermar	650	* This is the high-level page fault handler. It decides
		651	* whether the page fault can be resolved by any backend
		652	* and if so, it invokes the backend to resolve the page
		653	* fault.
		654	*
703	jermar	655	* Interrupts are assumed disabled.
		656	*
		657	* @param page Faulting page.
1411	jermar	658	* @param access Access mode that caused the fault (i.e. read/write/exec).
1288	jermar	659	* @param istate Pointer to interrupted state.
703	jermar	660	*
1409	jermar	661	* @return AS_PF_FAULT on page fault, AS_PF_OK on success or AS_PF_DEFER if the
		662	* fault was caused by copy_to_uspace() or copy_from_uspace().
703	jermar	663	*/
1411	jermar	664	int as_page_fault(__address page, pf_access_t access, istate_t *istate)
703	jermar	665	{
1044	jermar	666	pte_t *pte;
977	jermar	667	as_area_t *area;
703	jermar	668
1380	jermar	669	if (!THREAD)
1409	jermar	670	return AS_PF_FAULT;
1380	jermar	671
703	jermar	672	ASSERT(AS);
1044	jermar	673
1380	jermar	674	mutex_lock(&AS->lock);
977	jermar	675	area = find_area_and_lock(AS, page);
703	jermar	676	if (!area) {
		677	/*
		678	* No area contained mapping for 'page'.
		679	* Signal page fault to low-level handler.
		680	*/
1380	jermar	681	mutex_unlock(&AS->lock);
1288	jermar	682	goto page_fault;
703	jermar	683	}
		684
1239	jermar	685	if (area->attributes & AS_AREA_ATTR_PARTIAL) {
		686	/*
		687	* The address space area is not fully initialized.
		688	* Avoid possible race by returning error.
		689	*/
1380	jermar	690	mutex_unlock(&area->lock);
		691	mutex_unlock(&AS->lock);
1288	jermar	692	goto page_fault;
1239	jermar	693	}
		694
1424	jermar	695	if (!area->backend \|\| !area->backend->page_fault) {
1409	jermar	696	/*
		697	* The address space area is not backed by any backend
		698	* or the backend cannot handle page faults.
		699	*/
		700	mutex_unlock(&area->lock);
		701	mutex_unlock(&AS->lock);
		702	goto page_fault;
		703	}
1179	jermar	704
1044	jermar	705	page_table_lock(AS, false);
		706
703	jermar	707	/*
1044	jermar	708	* To avoid race condition between two page faults
		709	* on the same address, we need to make sure
		710	* the mapping has not been already inserted.
		711	*/
		712	if ((pte = page_mapping_find(AS, page))) {
		713	if (PTE_PRESENT(pte)) {
1423	jermar	714	if (((access == PF_ACCESS_READ) && PTE_READABLE(pte)) \|\|
		715	(access == PF_ACCESS_WRITE && PTE_WRITABLE(pte)) \|\|
		716	(access == PF_ACCESS_EXEC && PTE_EXECUTABLE(pte))) {
		717	page_table_unlock(AS, false);
		718	mutex_unlock(&area->lock);
		719	mutex_unlock(&AS->lock);
		720	return AS_PF_OK;
		721	}
1044	jermar	722	}
		723	}
1409	jermar	724
1044	jermar	725	/*
1409	jermar	726	* Resort to the backend page fault handler.
703	jermar	727	*/
1424	jermar	728	if (area->backend->page_fault(area, page, access) != AS_PF_OK) {
1409	jermar	729	page_table_unlock(AS, false);
		730	mutex_unlock(&area->lock);
		731	mutex_unlock(&AS->lock);
		732	goto page_fault;
		733	}
703	jermar	734
1044	jermar	735	page_table_unlock(AS, false);
1380	jermar	736	mutex_unlock(&area->lock);
		737	mutex_unlock(&AS->lock);
1288	jermar	738	return AS_PF_OK;
		739
		740	page_fault:
		741	if (THREAD->in_copy_from_uspace) {
		742	THREAD->in_copy_from_uspace = false;
		743	istate_set_retaddr(istate, (__address) &memcpy_from_uspace_failover_address);
		744	} else if (THREAD->in_copy_to_uspace) {
		745	THREAD->in_copy_to_uspace = false;
		746	istate_set_retaddr(istate, (__address) &memcpy_to_uspace_failover_address);
		747	} else {
		748	return AS_PF_FAULT;
		749	}
		750
		751	return AS_PF_DEFER;
703	jermar	752	}
		753
823	jermar	754	/** Switch address spaces.
703	jermar	755	*
1380	jermar	756	* Note that this function cannot sleep as it is essentially a part of
1415	jermar	757	* scheduling. Sleeping here would lead to deadlock on wakeup.
1380	jermar	758	*
823	jermar	759	* @param old Old address space or NULL.
		760	* @param new New address space.
703	jermar	761	*/
823	jermar	762	void as_switch(as_t old, as_t new)
703	jermar	763	{
		764	ipl_t ipl;
823	jermar	765	bool needs_asid = false;
703	jermar	766
		767	ipl = interrupts_disable();
1415	jermar	768	spinlock_lock(&inactive_as_with_asid_lock);
703	jermar	769
		770	/*
823	jermar	771	* First, take care of the old address space.
		772	*/
		773	if (old) {
1380	jermar	774	mutex_lock_active(&old->lock);
1415	jermar	775	ASSERT(old->cpu_refcount);
		776	if((--old->cpu_refcount == 0) && (old != AS_KERNEL)) {
823	jermar	777	/*
		778	* The old address space is no longer active on
		779	* any processor. It can be appended to the
		780	* list of inactive address spaces with assigned
		781	* ASID.
		782	*/
		783	ASSERT(old->asid != ASID_INVALID);
		784	list_append(&old->inactive_as_with_asid_link, &inactive_as_with_asid_head);
		785	}
1380	jermar	786	mutex_unlock(&old->lock);
823	jermar	787	}
		788
		789	/*
		790	* Second, prepare the new address space.
		791	*/
1380	jermar	792	mutex_lock_active(&new->lock);
1415	jermar	793	if ((new->cpu_refcount++ == 0) && (new != AS_KERNEL)) {
823	jermar	794	if (new->asid != ASID_INVALID)
		795	list_remove(&new->inactive_as_with_asid_link);
		796	else
		797	needs_asid = true; /* defer call to asid_get() until new->lock is released */
		798	}
		799	SET_PTL0_ADDRESS(new->page_table);
1380	jermar	800	mutex_unlock(&new->lock);
823	jermar	801
		802	if (needs_asid) {
		803	/*
		804	* Allocation of new ASID was deferred
		805	* until now in order to avoid deadlock.
		806	*/
		807	asid_t asid;
		808
		809	asid = asid_get();
1380	jermar	810	mutex_lock_active(&new->lock);
823	jermar	811	new->asid = asid;
1380	jermar	812	mutex_unlock(&new->lock);
823	jermar	813	}
1415	jermar	814	spinlock_unlock(&inactive_as_with_asid_lock);
823	jermar	815	interrupts_restore(ipl);
		816
		817	/*
703	jermar	818	* Perform architecture-specific steps.
727	jermar	819	* (e.g. write ASID to hardware register etc.)
703	jermar	820	*/
823	jermar	821	as_install_arch(new);
703	jermar	822
823	jermar	823	AS = new;
703	jermar	824	}
754	jermar	825
1235	jermar	826	/** Convert address space area flags to page flags.
754	jermar	827	*
1235	jermar	828	* @param aflags Flags of some address space area.
754	jermar	829	*
1235	jermar	830	* @return Flags to be passed to page_mapping_insert().
754	jermar	831	*/
1235	jermar	832	int area_flags_to_page_flags(int aflags)
754	jermar	833	{
		834	int flags;
		835
1178	jermar	836	flags = PAGE_USER \| PAGE_PRESENT;
754	jermar	837
1235	jermar	838	if (aflags & AS_AREA_READ)
1026	jermar	839	flags \|= PAGE_READ;
		840
1235	jermar	841	if (aflags & AS_AREA_WRITE)
1026	jermar	842	flags \|= PAGE_WRITE;
		843
1235	jermar	844	if (aflags & AS_AREA_EXEC)
1026	jermar	845	flags \|= PAGE_EXEC;
		846
1424	jermar	847	if (aflags & AS_AREA_CACHEABLE)
1178	jermar	848	flags \|= PAGE_CACHEABLE;
		849
754	jermar	850	return flags;
		851	}
756	jermar	852
1235	jermar	853	/** Compute flags for virtual address translation subsytem.
		854	*
		855	* The address space area must be locked.
		856	* Interrupts must be disabled.
		857	*
		858	* @param a Address space area.
		859	*
		860	* @return Flags to be used in page_mapping_insert().
		861	*/
1409	jermar	862	int as_area_get_flags(as_area_t *a)
1235	jermar	863	{
		864	return area_flags_to_page_flags(a->flags);
		865	}
		866
756	jermar	867	/** Create page table.
		868	*
		869	* Depending on architecture, create either address space
		870	* private or global page table.
		871	*
		872	* @param flags Flags saying whether the page table is for kernel address space.
		873	*
		874	* @return First entry of the page table.
		875	*/
		876	pte_t *page_table_create(int flags)
		877	{
		878	ASSERT(as_operations);
		879	ASSERT(as_operations->page_table_create);
		880
		881	return as_operations->page_table_create(flags);
		882	}
977	jermar	883
1468	jermar	884	/** Destroy page table.
		885	*
		886	* Destroy page table in architecture specific way.
		887	*
		888	* @param page_table Physical address of PTL0.
		889	*/
		890	void page_table_destroy(pte_t *page_table)
		891	{
		892	ASSERT(as_operations);
		893	ASSERT(as_operations->page_table_destroy);
		894
		895	as_operations->page_table_destroy(page_table);
		896	}
		897
1044	jermar	898	/** Lock page table.
		899	*
		900	* This function should be called before any page_mapping_insert(),
		901	* page_mapping_remove() and page_mapping_find().
		902	*
		903	* Locking order is such that address space areas must be locked
		904	* prior to this call. Address space can be locked prior to this
		905	* call in which case the lock argument is false.
		906	*
		907	* @param as Address space.
1248	jermar	908	* @param lock If false, do not attempt to lock as->lock.
1044	jermar	909	*/
		910	void page_table_lock(as_t *as, bool lock)
		911	{
		912	ASSERT(as_operations);
		913	ASSERT(as_operations->page_table_lock);
		914
		915	as_operations->page_table_lock(as, lock);
		916	}
		917
		918	/** Unlock page table.
		919	*
		920	* @param as Address space.
1248	jermar	921	* @param unlock If false, do not attempt to unlock as->lock.
1044	jermar	922	*/
		923	void page_table_unlock(as_t *as, bool unlock)
		924	{
		925	ASSERT(as_operations);
		926	ASSERT(as_operations->page_table_unlock);
		927
		928	as_operations->page_table_unlock(as, unlock);
		929	}
		930
977	jermar	931
		932	/** Find address space area and lock it.
		933	*
		934	* The address space must be locked and interrupts must be disabled.
		935	*
		936	* @param as Address space.
		937	* @param va Virtual address.
		938	*
		939	* @return Locked address space area containing va on success or NULL on failure.
		940	*/
		941	as_area_t find_area_and_lock(as_t as, __address va)
		942	{
		943	as_area_t *a;
1147	jermar	944	btree_node_t leaf, lnode;
		945	int i;
977	jermar	946
1147	jermar	947	a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
		948	if (a) {
		949	/* va is the base address of an address space area */
1380	jermar	950	mutex_lock(&a->lock);
1147	jermar	951	return a;
		952	}
		953
		954	/*
1150	jermar	955	* Search the leaf node and the righmost record of its left neighbour
1147	jermar	956	* to find out whether this is a miss or va belongs to an address
		957	* space area found there.
		958	*/
		959
		960	/* First, search the leaf node itself. */
		961	for (i = 0; i < leaf->keys; i++) {
		962	a = (as_area_t *) leaf->value[i];
1380	jermar	963	mutex_lock(&a->lock);
1147	jermar	964	if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
		965	return a;
		966	}
1380	jermar	967	mutex_unlock(&a->lock);
1147	jermar	968	}
977	jermar	969
1147	jermar	970	/*
1150	jermar	971	* Second, locate the left neighbour and test its last record.
1148	jermar	972	* Because of its position in the B+tree, it must have base < va.
1147	jermar	973	*/
1150	jermar	974	if ((lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	975	a = (as_area_t *) lnode->value[lnode->keys - 1];
1380	jermar	976	mutex_lock(&a->lock);
1147	jermar	977	if (va < a->base + a->pages * PAGE_SIZE) {
1048	jermar	978	return a;
1147	jermar	979	}
1380	jermar	980	mutex_unlock(&a->lock);
977	jermar	981	}
		982
		983	return NULL;
		984	}
1048	jermar	985
		986	/** Check area conflicts with other areas.
		987	*
		988	* The address space must be locked and interrupts must be disabled.
		989	*
		990	* @param as Address space.
		991	* @param va Starting virtual address of the area being tested.
		992	* @param size Size of the area being tested.
		993	* @param avoid_area Do not touch this area.
		994	*
		995	* @return True if there is no conflict, false otherwise.
		996	*/
		997	bool check_area_conflicts(as_t as, __address va, size_t size, as_area_t avoid_area)
		998	{
		999	as_area_t *a;
1147	jermar	1000	btree_node_t leaf, node;
		1001	int i;
1048	jermar	1002
1070	jermar	1003	/*
		1004	* We don't want any area to have conflicts with NULL page.
		1005	*/
		1006	if (overlaps(va, size, NULL, PAGE_SIZE))
		1007	return false;
		1008
1147	jermar	1009	/*
		1010	* The leaf node is found in O(log n), where n is proportional to
		1011	* the number of address space areas belonging to as.
		1012	* The check for conflicts is then attempted on the rightmost
1150	jermar	1013	* record in the left neighbour, the leftmost record in the right
		1014	* neighbour and all records in the leaf node itself.
1147	jermar	1015	*/
1048	jermar	1016
1147	jermar	1017	if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
		1018	if (a != avoid_area)
		1019	return false;
		1020	}
		1021
		1022	/* First, check the two border cases. */
1150	jermar	1023	if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	1024	a = (as_area_t *) node->value[node->keys - 1];
1380	jermar	1025	mutex_lock(&a->lock);
1147	jermar	1026	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1027	mutex_unlock(&a->lock);
1147	jermar	1028	return false;
		1029	}
1380	jermar	1030	mutex_unlock(&a->lock);
1147	jermar	1031	}
1150	jermar	1032	if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	1033	a = (as_area_t *) node->value[0];
1380	jermar	1034	mutex_lock(&a->lock);
1147	jermar	1035	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1036	mutex_unlock(&a->lock);
1147	jermar	1037	return false;
		1038	}
1380	jermar	1039	mutex_unlock(&a->lock);
1147	jermar	1040	}
		1041
		1042	/* Second, check the leaf node. */
		1043	for (i = 0; i < leaf->keys; i++) {
		1044	a = (as_area_t *) leaf->value[i];
		1045
1048	jermar	1046	if (a == avoid_area)
		1047	continue;
1147	jermar	1048
1380	jermar	1049	mutex_lock(&a->lock);
1147	jermar	1050	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1051	mutex_unlock(&a->lock);
1147	jermar	1052	return false;
		1053	}
1380	jermar	1054	mutex_unlock(&a->lock);
1048	jermar	1055	}
		1056
1070	jermar	1057	/*
		1058	* So far, the area does not conflict with other areas.
		1059	* Check if it doesn't conflict with kernel address space.
		1060	*/
		1061	if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
		1062	return !overlaps(va, size,
		1063	KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START);
		1064	}
		1065
1048	jermar	1066	return true;
		1067	}
1235	jermar	1068
1380	jermar	1069	/** Return size of the address space area with given base. */
1329	palkovsky	1070	size_t as_get_size(__address base)
		1071	{
		1072	ipl_t ipl;
		1073	as_area_t *src_area;
		1074	size_t size;
		1075
		1076	ipl = interrupts_disable();
		1077	src_area = find_area_and_lock(AS, base);
		1078	if (src_area){
		1079	size = src_area->pages * PAGE_SIZE;
1380	jermar	1080	mutex_unlock(&src_area->lock);
1329	palkovsky	1081	} else {
		1082	size = 0;
		1083	}
		1084	interrupts_restore(ipl);
		1085	return size;
		1086	}
		1087
1387	jermar	1088	/** Mark portion of address space area as used.
		1089	*
		1090	* The address space area must be already locked.
		1091	*
		1092	* @param a Address space area.
		1093	* @param page First page to be marked.
		1094	* @param count Number of page to be marked.
		1095	*
		1096	* @return 0 on failure and 1 on success.
		1097	*/
		1098	int used_space_insert(as_area_t *a, __address page, count_t count)
		1099	{
		1100	btree_node_t leaf, node;
		1101	count_t pages;
		1102	int i;
		1103
		1104	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1105	ASSERT(count);
		1106
		1107	pages = (count_t) btree_search(&a->used_space, page, &leaf);
		1108	if (pages) {
		1109	/*
		1110	* We hit the beginning of some used space.
		1111	*/
		1112	return 0;
		1113	}
		1114
1437	jermar	1115	if (!leaf->keys) {
		1116	btree_insert(&a->used_space, page, (void *) count, leaf);
		1117	return 1;
		1118	}
		1119
1387	jermar	1120	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1121	if (node) {
		1122	__address left_pg = node->key[node->keys - 1], right_pg = leaf->key[0];
		1123	count_t left_cnt = (count_t) node->value[node->keys - 1], right_cnt = (count_t) leaf->value[0];
		1124
		1125	/*
		1126	* Examine the possibility that the interval fits
		1127	* somewhere between the rightmost interval of
		1128	* the left neigbour and the first interval of the leaf.
		1129	*/
		1130
		1131	if (page >= right_pg) {
		1132	/* Do nothing. */
		1133	} else if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1134	/* The interval intersects with the left interval. */
		1135	return 0;
		1136	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1137	/* The interval intersects with the right interval. */
		1138	return 0;
		1139	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1140	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1141	node->value[node->keys - 1] += count + right_cnt;
1387	jermar	1142	btree_remove(&a->used_space, right_pg, leaf);
		1143	return 1;
		1144	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1145	/* The interval can be added by simply growing the left interval. */
1403	jermar	1146	node->value[node->keys - 1] += count;
1387	jermar	1147	return 1;
		1148	} else if (page + count*PAGE_SIZE == right_pg) {
		1149	/*
		1150	* The interval can be addded by simply moving base of the right
		1151	* interval down and increasing its size accordingly.
		1152	*/
1403	jermar	1153	leaf->value[0] += count;
1387	jermar	1154	leaf->key[0] = page;
		1155	return 1;
		1156	} else {
		1157	/*
		1158	* The interval is between both neigbouring intervals,
		1159	* but cannot be merged with any of them.
		1160	*/
		1161	btree_insert(&a->used_space, page, (void *) count, leaf);
		1162	return 1;
		1163	}
		1164	} else if (page < leaf->key[0]) {
		1165	__address right_pg = leaf->key[0];
		1166	count_t right_cnt = (count_t) leaf->value[0];
		1167
		1168	/*
		1169	* Investigate the border case in which the left neighbour does not
		1170	* exist but the interval fits from the left.
		1171	*/
		1172
		1173	if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1174	/* The interval intersects with the right interval. */
		1175	return 0;
		1176	} else if (page + count*PAGE_SIZE == right_pg) {
		1177	/*
		1178	* The interval can be added by moving the base of the right interval down
		1179	* and increasing its size accordingly.
		1180	*/
		1181	leaf->key[0] = page;
1403	jermar	1182	leaf->value[0] += count;
1387	jermar	1183	return 1;
		1184	} else {
		1185	/*
		1186	* The interval doesn't adjoin with the right interval.
		1187	* It must be added individually.
		1188	*/
		1189	btree_insert(&a->used_space, page, (void *) count, leaf);
		1190	return 1;
		1191	}
		1192	}
		1193
		1194	node = btree_leaf_node_right_neighbour(&a->used_space, leaf);
		1195	if (node) {
		1196	__address left_pg = leaf->key[leaf->keys - 1], right_pg = node->key[0];
		1197	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1], right_cnt = (count_t) node->value[0];
		1198
		1199	/*
		1200	* Examine the possibility that the interval fits
		1201	* somewhere between the leftmost interval of
		1202	* the right neigbour and the last interval of the leaf.
		1203	*/
		1204
		1205	if (page < left_pg) {
		1206	/* Do nothing. */
		1207	} else if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1208	/* The interval intersects with the left interval. */
		1209	return 0;
		1210	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1211	/* The interval intersects with the right interval. */
		1212	return 0;
		1213	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1214	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1215	leaf->value[leaf->keys - 1] += count + right_cnt;
1387	jermar	1216	btree_remove(&a->used_space, right_pg, node);
		1217	return 1;
		1218	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1219	/* The interval can be added by simply growing the left interval. */
1403	jermar	1220	leaf->value[leaf->keys - 1] += count;
1387	jermar	1221	return 1;
		1222	} else if (page + count*PAGE_SIZE == right_pg) {
		1223	/*
		1224	* The interval can be addded by simply moving base of the right
		1225	* interval down and increasing its size accordingly.
		1226	*/
1403	jermar	1227	node->value[0] += count;
1387	jermar	1228	node->key[0] = page;
		1229	return 1;
		1230	} else {
		1231	/*
		1232	* The interval is between both neigbouring intervals,
		1233	* but cannot be merged with any of them.
		1234	*/
		1235	btree_insert(&a->used_space, page, (void *) count, leaf);
		1236	return 1;
		1237	}
		1238	} else if (page >= leaf->key[leaf->keys - 1]) {
		1239	__address left_pg = leaf->key[leaf->keys - 1];
		1240	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1241
		1242	/*
		1243	* Investigate the border case in which the right neighbour does not
		1244	* exist but the interval fits from the right.
		1245	*/
		1246
		1247	if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
1403	jermar	1248	/* The interval intersects with the left interval. */
1387	jermar	1249	return 0;
		1250	} else if (left_pg + left_cnt*PAGE_SIZE == page) {
		1251	/* The interval can be added by growing the left interval. */
1403	jermar	1252	leaf->value[leaf->keys - 1] += count;
1387	jermar	1253	return 1;
		1254	} else {
		1255	/*
		1256	* The interval doesn't adjoin with the left interval.
		1257	* It must be added individually.
		1258	*/
		1259	btree_insert(&a->used_space, page, (void *) count, leaf);
		1260	return 1;
		1261	}
		1262	}
		1263
		1264	/*
		1265	* Note that if the algorithm made it thus far, the interval can fit only
		1266	* between two other intervals of the leaf. The two border cases were already
		1267	* resolved.
		1268	*/
		1269	for (i = 1; i < leaf->keys; i++) {
		1270	if (page < leaf->key[i]) {
		1271	__address left_pg = leaf->key[i - 1], right_pg = leaf->key[i];
		1272	count_t left_cnt = (count_t) leaf->value[i - 1], right_cnt = (count_t) leaf->value[i];
		1273
		1274	/*
		1275	* The interval fits between left_pg and right_pg.
		1276	*/
		1277
		1278	if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1279	/* The interval intersects with the left interval. */
		1280	return 0;
		1281	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1282	/* The interval intersects with the right interval. */
		1283	return 0;
		1284	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1285	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1286	leaf->value[i - 1] += count + right_cnt;
1387	jermar	1287	btree_remove(&a->used_space, right_pg, leaf);
		1288	return 1;
		1289	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1290	/* The interval can be added by simply growing the left interval. */
1403	jermar	1291	leaf->value[i - 1] += count;
1387	jermar	1292	return 1;
		1293	} else if (page + count*PAGE_SIZE == right_pg) {
		1294	/*
		1295	* The interval can be addded by simply moving base of the right
		1296	* interval down and increasing its size accordingly.
		1297	*/
1403	jermar	1298	leaf->value[i] += count;
1387	jermar	1299	leaf->key[i] = page;
		1300	return 1;
		1301	} else {
		1302	/*
		1303	* The interval is between both neigbouring intervals,
		1304	* but cannot be merged with any of them.
		1305	*/
		1306	btree_insert(&a->used_space, page, (void *) count, leaf);
		1307	return 1;
		1308	}
		1309	}
		1310	}
		1311
1735	decky	1312	panic("Inconsistency detected while adding %d pages of used space at %p.\n", count, page);
1387	jermar	1313	}
		1314
		1315	/** Mark portion of address space area as unused.
		1316	*
		1317	* The address space area must be already locked.
		1318	*
		1319	* @param a Address space area.
		1320	* @param page First page to be marked.
		1321	* @param count Number of page to be marked.
		1322	*
		1323	* @return 0 on failure and 1 on success.
		1324	*/
		1325	int used_space_remove(as_area_t *a, __address page, count_t count)
		1326	{
		1327	btree_node_t leaf, node;
		1328	count_t pages;
		1329	int i;
		1330
		1331	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1332	ASSERT(count);
		1333
		1334	pages = (count_t) btree_search(&a->used_space, page, &leaf);
		1335	if (pages) {
		1336	/*
		1337	* We are lucky, page is the beginning of some interval.
		1338	*/
		1339	if (count > pages) {
		1340	return 0;
		1341	} else if (count == pages) {
		1342	btree_remove(&a->used_space, page, leaf);
1403	jermar	1343	return 1;
1387	jermar	1344	} else {
		1345	/*
		1346	* Find the respective interval.
		1347	* Decrease its size and relocate its start address.
		1348	*/
		1349	for (i = 0; i < leaf->keys; i++) {
		1350	if (leaf->key[i] == page) {
		1351	leaf->key[i] += count*PAGE_SIZE;
1403	jermar	1352	leaf->value[i] -= count;
1387	jermar	1353	return 1;
		1354	}
		1355	}
		1356	goto error;
		1357	}
		1358	}
		1359
		1360	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1361	if (node && page < leaf->key[0]) {
		1362	__address left_pg = node->key[node->keys - 1];
		1363	count_t left_cnt = (count_t) node->value[node->keys - 1];
		1364
		1365	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1366	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1367	/*
		1368	* The interval is contained in the rightmost interval
		1369	* of the left neighbour and can be removed by
		1370	* updating the size of the bigger interval.
		1371	*/
1403	jermar	1372	node->value[node->keys - 1] -= count;
1387	jermar	1373	return 1;
		1374	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1375	count_t new_cnt;
1387	jermar	1376
		1377	/*
		1378	* The interval is contained in the rightmost interval
		1379	* of the left neighbour but its removal requires
		1380	* both updating the size of the original interval and
		1381	* also inserting a new interval.
		1382	*/
1403	jermar	1383	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1384	node->value[node->keys - 1] -= count + new_cnt;
1387	jermar	1385	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1386	return 1;
		1387	}
		1388	}
		1389	return 0;
		1390	} else if (page < leaf->key[0]) {
		1391	return 0;
		1392	}
		1393
		1394	if (page > leaf->key[leaf->keys - 1]) {
		1395	__address left_pg = leaf->key[leaf->keys - 1];
		1396	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1397
		1398	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1399	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1400	/*
		1401	* The interval is contained in the rightmost interval
		1402	* of the leaf and can be removed by updating the size
		1403	* of the bigger interval.
		1404	*/
1403	jermar	1405	leaf->value[leaf->keys - 1] -= count;
1387	jermar	1406	return 1;
		1407	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1408	count_t new_cnt;
1387	jermar	1409
		1410	/*
		1411	* The interval is contained in the rightmost interval
		1412	* of the leaf but its removal requires both updating
		1413	* the size of the original interval and
		1414	* also inserting a new interval.
		1415	*/
1403	jermar	1416	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1417	leaf->value[leaf->keys - 1] -= count + new_cnt;
1387	jermar	1418	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1419	return 1;
		1420	}
		1421	}
		1422	return 0;
		1423	}
		1424
		1425	/*
		1426	* The border cases have been already resolved.
		1427	* Now the interval can be only between intervals of the leaf.
		1428	*/
		1429	for (i = 1; i < leaf->keys - 1; i++) {
		1430	if (page < leaf->key[i]) {
		1431	__address left_pg = leaf->key[i - 1];
		1432	count_t left_cnt = (count_t) leaf->value[i - 1];
		1433
		1434	/*
		1435	* Now the interval is between intervals corresponding to (i - 1) and i.
		1436	*/
		1437	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1438	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1439	/*
		1440	* The interval is contained in the interval (i - 1)
		1441	* of the leaf and can be removed by updating the size
		1442	* of the bigger interval.
		1443	*/
1403	jermar	1444	leaf->value[i - 1] -= count;
1387	jermar	1445	return 1;
		1446	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1447	count_t new_cnt;
1387	jermar	1448
		1449	/*
		1450	* The interval is contained in the interval (i - 1)
		1451	* of the leaf but its removal requires both updating
		1452	* the size of the original interval and
		1453	* also inserting a new interval.
		1454	*/
1403	jermar	1455	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1456	leaf->value[i - 1] -= count + new_cnt;
1387	jermar	1457	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1458	return 1;
		1459	}
		1460	}
		1461	return 0;
		1462	}
		1463	}
		1464
		1465	error:
1735	decky	1466	panic("Inconsistency detected while removing %d pages of used space from %p.\n", count, page);
1387	jermar	1467	}
		1468
1409	jermar	1469	/** Remove reference to address space area share info.
		1470	*
		1471	* If the reference count drops to 0, the sh_info is deallocated.
		1472	*
		1473	* @param sh_info Pointer to address space area share info.
		1474	*/
		1475	void sh_info_remove_reference(share_info_t *sh_info)
		1476	{
		1477	bool dealloc = false;
		1478
		1479	mutex_lock(&sh_info->lock);
		1480	ASSERT(sh_info->refcount);
		1481	if (--sh_info->refcount == 0) {
		1482	dealloc = true;
1495	jermar	1483	link_t *cur;
1409	jermar	1484
		1485	/*
		1486	* Now walk carefully the pagemap B+tree and free/remove
		1487	* reference from all frames found there.
		1488	*/
1495	jermar	1489	for (cur = sh_info->pagemap.leaf_head.next; cur != &sh_info->pagemap.leaf_head; cur = cur->next) {
1409	jermar	1490	btree_node_t *node;
1495	jermar	1491	int i;
1409	jermar	1492
1495	jermar	1493	node = list_get_instance(cur, btree_node_t, leaf_link);
		1494	for (i = 0; i < node->keys; i++)
		1495	frame_free(ADDR2PFN((__address) node->value[i]));
1409	jermar	1496	}
		1497
		1498	}
		1499	mutex_unlock(&sh_info->lock);
		1500
		1501	if (dealloc) {
		1502	btree_destroy(&sh_info->pagemap);
		1503	free(sh_info);
		1504	}
		1505	}
		1506
1235	jermar	1507	/*
		1508	* Address space related syscalls.
		1509	*/
		1510
		1511	/** Wrapper for as_area_create(). */
		1512	__native sys_as_area_create(__address address, size_t size, int flags)
		1513	{
1424	jermar	1514	if (as_area_create(AS, flags \| AS_AREA_CACHEABLE, size, address, AS_AREA_ATTR_NONE, &anon_backend, NULL))
1235	jermar	1515	return (__native) address;
		1516	else
		1517	return (__native) -1;
		1518	}
		1519
		1520	/** Wrapper for as_area_resize. */
		1521	__native sys_as_area_resize(__address address, size_t size, int flags)
		1522	{
1306	jermar	1523	return (__native) as_area_resize(AS, address, size, 0);
1235	jermar	1524	}
		1525
1306	jermar	1526	/** Wrapper for as_area_destroy. */
		1527	__native sys_as_area_destroy(__address address)
		1528	{
		1529	return (__native) as_area_destroy(AS, address);
		1530	}
1702	cejka	1531
		1532	/** @}
		1533	*/
		1534

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(root)/kernel/trunk/generic/src/mm/as.c – Rev 1735