WebSVN – HelenOS – Blame – /branches/rcu/kernel/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
1248	jermar	29	/**
		30	* @file as.c
		31	* @brief Address space related functions.
		32	*
703	jermar	33	* This file contains address space manipulation functions.
		34	* Roughly speaking, this is a higher-level client of
		35	* Virtual Address Translation (VAT) subsystem.
1248	jermar	36	*
		37	* Functionality provided by this file allows one to
		38	* create address space and create, resize and share
		39	* address space areas.
		40	*
		41	* @see page.c
		42	*
703	jermar	43	*/
		44
		45	#include <mm/as.h>
756	jermar	46	#include <arch/mm/as.h>
703	jermar	47	#include <mm/page.h>
		48	#include <mm/frame.h>
814	palkovsky	49	#include <mm/slab.h>
703	jermar	50	#include <mm/tlb.h>
		51	#include <arch/mm/page.h>
		52	#include <genarch/mm/page_pt.h>
1108	jermar	53	#include <genarch/mm/page_ht.h>
727	jermar	54	#include <mm/asid.h>
703	jermar	55	#include <arch/mm/asid.h>
		56	#include <synch/spinlock.h>
1380	jermar	57	#include <synch/mutex.h>
788	jermar	58	#include <adt/list.h>
1147	jermar	59	#include <adt/btree.h>
1235	jermar	60	#include <proc/task.h>
1288	jermar	61	#include <proc/thread.h>
1235	jermar	62	#include <arch/asm.h>
703	jermar	63	#include <panic.h>
		64	#include <debug.h>
1235	jermar	65	#include <print.h>
703	jermar	66	#include <memstr.h>
1070	jermar	67	#include <macros.h>
703	jermar	68	#include <arch.h>
1235	jermar	69	#include <errno.h>
		70	#include <config.h>
1387	jermar	71	#include <align.h>
1235	jermar	72	#include <arch/types.h>
		73	#include <typedefs.h>
1288	jermar	74	#include <syscall/copy.h>
		75	#include <arch/interrupt.h>
703	jermar	76
756	jermar	77	as_operations_t *as_operations = NULL;
703	jermar	78
1415	jermar	79	/** This lock protects inactive_as_with_asid_head list. It must be acquired before as_t mutex. */
		80	SPINLOCK_INITIALIZE(inactive_as_with_asid_lock);
823	jermar	81
		82	/**
		83	* This list contains address spaces that are not active on any
		84	* processor and that have valid ASID.
		85	*/
		86	LIST_INITIALIZE(inactive_as_with_asid_head);
		87
757	jermar	88	/** Kernel address space. */
		89	as_t *AS_KERNEL = NULL;
		90
1235	jermar	91	static int area_flags_to_page_flags(int aflags);
977	jermar	92	static as_area_t find_area_and_lock(as_t as, __address va);
1048	jermar	93	static bool check_area_conflicts(as_t as, __address va, size_t size, as_area_t avoid_area);
1409	jermar	94	static void sh_info_remove_reference(share_info_t *sh_info);
703	jermar	95
756	jermar	96	/** Initialize address space subsystem. */
		97	void as_init(void)
		98	{
		99	as_arch_init();
789	palkovsky	100	AS_KERNEL = as_create(FLAG_AS_KERNEL);
1383	decky	101	if (!AS_KERNEL)
		102	panic("can't create kernel address space\n");
		103
756	jermar	104	}
		105
757	jermar	106	/** Create address space.
		107	*
		108	* @param flags Flags that influence way in wich the address space is created.
		109	*/
756	jermar	110	as_t *as_create(int flags)
703	jermar	111	{
		112	as_t *as;
		113
822	palkovsky	114	as = (as_t *) malloc(sizeof(as_t), 0);
823	jermar	115	link_initialize(&as->inactive_as_with_asid_link);
1380	jermar	116	mutex_initialize(&as->lock);
1147	jermar	117	btree_create(&as->as_area_btree);
822	palkovsky	118
		119	if (flags & FLAG_AS_KERNEL)
		120	as->asid = ASID_KERNEL;
		121	else
		122	as->asid = ASID_INVALID;
		123
1468	jermar	124	as->refcount = 0;
1415	jermar	125	as->cpu_refcount = 0;
822	palkovsky	126	as->page_table = page_table_create(flags);
703	jermar	127
		128	return as;
		129	}
		130
1468	jermar	131	/** Destroy adress space.
		132	*
		133	* When there are no tasks referencing this address space (i.e. its refcount is zero),
		134	* the address space can be destroyed.
		135	*/
		136	void as_destroy(as_t *as)
973	palkovsky	137	{
1468	jermar	138	ipl_t ipl;
		139	bool cond;
973	palkovsky	140
1468	jermar	141	ASSERT(as->refcount == 0);
		142
		143	/*
		144	* Since there is no reference to this area,
		145	* it is safe not to lock its mutex.
		146	*/
		147
		148	ipl = interrupts_disable();
		149	spinlock_lock(&inactive_as_with_asid_lock);
		150	if (as->asid != ASID_INVALID && as->asid != ASID_KERNEL) {
		151	list_remove(&as->inactive_as_with_asid_link);
		152	asid_put(as->asid);
		153	}
		154	spinlock_unlock(&inactive_as_with_asid_lock);
		155
		156	/*
		157	* Destroy address space areas of the address space.
		158	*/
		159	for (cond = true; cond; ) {
		160	btree_node_t *node;
		161
		162	ASSERT(!list_empty(&as->as_area_btree.leaf_head));
		163	node = list_get_instance(&as->as_area_btree.leaf_head.next, btree_node_t, leaf_link);
		164	if ((cond = node->keys)) {
		165	as_area_destroy(as, node->key[0]);
		166	btree_remove(&as->as_area_btree, node->key[0], node);
		167	}
		168	}
		169
		170	page_table_destroy(as->page_table);
		171
		172	interrupts_restore(ipl);
		173
973	palkovsky	174	free(as);
		175	}
		176
703	jermar	177	/** Create address space area of common attributes.
		178	*
		179	* The created address space area is added to the target address space.
		180	*
		181	* @param as Target address space.
1239	jermar	182	* @param flags Flags of the area memory.
1048	jermar	183	* @param size Size of area.
703	jermar	184	* @param base Base address of area.
1239	jermar	185	* @param attrs Attributes of the area.
1409	jermar	186	* @param backend Address space area backend. NULL if no backend is used.
		187	* @param backend_data NULL or a pointer to an array holding two void *.
703	jermar	188	*
		189	* @return Address space area on success or NULL on failure.
		190	*/
1409	jermar	191	as_area_t as_area_create(as_t as, int flags, size_t size, __address base, int attrs,
1424	jermar	192	mem_backend_t backend, mem_backend_data_t backend_data)
703	jermar	193	{
		194	ipl_t ipl;
		195	as_area_t *a;
		196
		197	if (base % PAGE_SIZE)
1048	jermar	198	return NULL;
		199
1233	jermar	200	if (!size)
		201	return NULL;
		202
1048	jermar	203	/* Writeable executable areas are not supported. */
		204	if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
		205	return NULL;
703	jermar	206
		207	ipl = interrupts_disable();
1380	jermar	208	mutex_lock(&as->lock);
703	jermar	209
1048	jermar	210	if (!check_area_conflicts(as, base, size, NULL)) {
1380	jermar	211	mutex_unlock(&as->lock);
1048	jermar	212	interrupts_restore(ipl);
		213	return NULL;
		214	}
703	jermar	215
822	palkovsky	216	a = (as_area_t *) malloc(sizeof(as_area_t), 0);
703	jermar	217
1380	jermar	218	mutex_initialize(&a->lock);
822	palkovsky	219
1424	jermar	220	a->as = as;
1026	jermar	221	a->flags = flags;
1239	jermar	222	a->attributes = attrs;
1048	jermar	223	a->pages = SIZE2FRAMES(size);
822	palkovsky	224	a->base = base;
1409	jermar	225	a->sh_info = NULL;
		226	a->backend = backend;
1424	jermar	227	if (backend_data)
		228	a->backend_data = *backend_data;
		229	else
		230	memsetb((__address) &a->backend_data, sizeof(a->backend_data), 0);
		231
1387	jermar	232	btree_create(&a->used_space);
822	palkovsky	233
1147	jermar	234	btree_insert(&as->as_area_btree, base, (void *) a, NULL);
822	palkovsky	235
1380	jermar	236	mutex_unlock(&as->lock);
703	jermar	237	interrupts_restore(ipl);
704	jermar	238
703	jermar	239	return a;
		240	}
		241
1235	jermar	242	/** Find address space area and change it.
		243	*
		244	* @param as Address space.
		245	* @param address Virtual address belonging to the area to be changed. Must be page-aligned.
		246	* @param size New size of the virtual memory block starting at address.
		247	* @param flags Flags influencing the remap operation. Currently unused.
		248	*
1306	jermar	249	* @return Zero on success or a value from @ref errno.h otherwise.
1235	jermar	250	*/
1306	jermar	251	int as_area_resize(as_t *as, __address address, size_t size, int flags)
1235	jermar	252	{
1306	jermar	253	as_area_t *area;
1235	jermar	254	ipl_t ipl;
		255	size_t pages;
		256
		257	ipl = interrupts_disable();
1380	jermar	258	mutex_lock(&as->lock);
1235	jermar	259
		260	/*
		261	* Locate the area.
		262	*/
		263	area = find_area_and_lock(as, address);
		264	if (!area) {
1380	jermar	265	mutex_unlock(&as->lock);
1235	jermar	266	interrupts_restore(ipl);
1306	jermar	267	return ENOENT;
1235	jermar	268	}
		269
1424	jermar	270	if (area->backend == &phys_backend) {
1235	jermar	271	/*
		272	* Remapping of address space areas associated
		273	* with memory mapped devices is not supported.
		274	*/
1380	jermar	275	mutex_unlock(&area->lock);
		276	mutex_unlock(&as->lock);
1235	jermar	277	interrupts_restore(ipl);
1306	jermar	278	return ENOTSUP;
1235	jermar	279	}
1409	jermar	280	if (area->sh_info) {
		281	/*
		282	* Remapping of shared address space areas
		283	* is not supported.
		284	*/
		285	mutex_unlock(&area->lock);
		286	mutex_unlock(&as->lock);
		287	interrupts_restore(ipl);
		288	return ENOTSUP;
		289	}
1235	jermar	290
		291	pages = SIZE2FRAMES((address - area->base) + size);
		292	if (!pages) {
		293	/*
		294	* Zero size address space areas are not allowed.
		295	*/
1380	jermar	296	mutex_unlock(&area->lock);
		297	mutex_unlock(&as->lock);
1235	jermar	298	interrupts_restore(ipl);
1306	jermar	299	return EPERM;
1235	jermar	300	}
		301
		302	if (pages < area->pages) {
1403	jermar	303	bool cond;
		304	__address start_free = area->base + pages*PAGE_SIZE;
1235	jermar	305
		306	/*
		307	* Shrinking the area.
		308	* No need to check for overlaps.
		309	*/
1403	jermar	310
		311	/*
1436	jermar	312	* Start TLB shootdown sequence.
		313	*/
		314	tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
		315
		316	/*
1403	jermar	317	* Remove frames belonging to used space starting from
		318	* the highest addresses downwards until an overlap with
		319	* the resized address space area is found. Note that this
		320	* is also the right way to remove part of the used_space
		321	* B+tree leaf list.
		322	*/
		323	for (cond = true; cond;) {
		324	btree_node_t *node;
		325
		326	ASSERT(!list_empty(&area->used_space.leaf_head));
		327	node = list_get_instance(area->used_space.leaf_head.prev, btree_node_t, leaf_link);
		328	if ((cond = (bool) node->keys)) {
		329	__address b = node->key[node->keys - 1];
		330	count_t c = (count_t) node->value[node->keys - 1];
		331	int i = 0;
1235	jermar	332
1403	jermar	333	if (overlaps(b, cPAGE_SIZE, area->base, pagesPAGE_SIZE)) {
		334
		335	if (b + c*PAGE_SIZE <= start_free) {
		336	/*
		337	* The whole interval fits completely
		338	* in the resized address space area.
		339	*/
		340	break;
		341	}
		342
		343	/*
		344	* Part of the interval corresponding to b and c
		345	* overlaps with the resized address space area.
		346	*/
		347
		348	cond = false; /* we are almost done */
		349	i = (start_free - b) >> PAGE_WIDTH;
		350	if (!used_space_remove(area, start_free, c - i))
		351	panic("Could not remove used space.");
		352	} else {
		353	/*
		354	* The interval of used space can be completely removed.
		355	*/
		356	if (!used_space_remove(area, b, c))
		357	panic("Could not remove used space.\n");
		358	}
		359
		360	for (; i < c; i++) {
		361	pte_t *pte;
		362
		363	page_table_lock(as, false);
		364	pte = page_mapping_find(as, b + i*PAGE_SIZE);
		365	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424	jermar	366	if (area->backend && area->backend->frame_free) {
		367	area->backend->frame_free(area,
1409	jermar	368	b + i*PAGE_SIZE, PTE_GET_FRAME(pte));
		369	}
1403	jermar	370	page_mapping_remove(as, b + i*PAGE_SIZE);
		371	page_table_unlock(as, false);
		372	}
1235	jermar	373	}
		374	}
1436	jermar	375
1235	jermar	376	/*
1436	jermar	377	* Finish TLB shootdown sequence.
1235	jermar	378	*/
		379	tlb_invalidate_pages(AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
		380	tlb_shootdown_finalize();
		381	} else {
		382	/*
		383	* Growing the area.
		384	* Check for overlaps with other address space areas.
		385	*/
		386	if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {
1380	jermar	387	mutex_unlock(&area->lock);
		388	mutex_unlock(&as->lock);
1235	jermar	389	interrupts_restore(ipl);
1306	jermar	390	return EADDRNOTAVAIL;
1235	jermar	391	}
		392	}
		393
		394	area->pages = pages;
		395
1380	jermar	396	mutex_unlock(&area->lock);
		397	mutex_unlock(&as->lock);
1235	jermar	398	interrupts_restore(ipl);
		399
1306	jermar	400	return 0;
1235	jermar	401	}
		402
1306	jermar	403	/** Destroy address space area.
		404	*
		405	* @param as Address space.
		406	* @param address Address withing the area to be deleted.
		407	*
		408	* @return Zero on success or a value from @ref errno.h on failure.
		409	*/
		410	int as_area_destroy(as_t *as, __address address)
		411	{
		412	as_area_t *area;
		413	__address base;
		414	ipl_t ipl;
1411	jermar	415	bool cond;
1306	jermar	416
		417	ipl = interrupts_disable();
1380	jermar	418	mutex_lock(&as->lock);
1306	jermar	419
		420	area = find_area_and_lock(as, address);
		421	if (!area) {
1380	jermar	422	mutex_unlock(&as->lock);
1306	jermar	423	interrupts_restore(ipl);
		424	return ENOENT;
		425	}
		426
1403	jermar	427	base = area->base;
		428
1411	jermar	429	/*
1436	jermar	430	* Start TLB shootdown sequence.
		431	*/
		432	tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages);
		433
		434	/*
1411	jermar	435	* Visit only the pages mapped by used_space B+tree.
		436	* Note that we must be very careful when walking the tree
		437	* leaf list and removing used space as the leaf list changes
		438	* unpredictibly after each remove. The solution is to actually
		439	* not walk the tree at all, but to remove items from the head
		440	* of the leaf list until there are some keys left.
		441	*/
		442	for (cond = true; cond;) {
		443	btree_node_t *node;
1403	jermar	444
1411	jermar	445	ASSERT(!list_empty(&area->used_space.leaf_head));
		446	node = list_get_instance(area->used_space.leaf_head.next, btree_node_t, leaf_link);
		447	if ((cond = (bool) node->keys)) {
		448	__address b = node->key[0];
		449	count_t i;
		450	pte_t *pte;
1403	jermar	451
1411	jermar	452	for (i = 0; i < (count_t) node->value[0]; i++) {
		453	page_table_lock(as, false);
		454	pte = page_mapping_find(as, b + i*PAGE_SIZE);
		455	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424	jermar	456	if (area->backend && area->backend->frame_free) {
		457	area->backend->frame_free(area,
1411	jermar	458	b + i*PAGE_SIZE, PTE_GET_FRAME(pte));
1403	jermar	459	}
1411	jermar	460	page_mapping_remove(as, b + i*PAGE_SIZE);
		461	page_table_unlock(as, false);
1306	jermar	462	}
1411	jermar	463	if (!used_space_remove(area, b, i))
		464	panic("Could not remove used space.\n");
1306	jermar	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;
1413	jermar	555
1461	palkovsky	556	if (src_size != acc_size \|\| (src_flags & dst_flags_mask) != dst_flags_mask) {
1413	jermar	557	mutex_unlock(&src_area->lock);
		558	mutex_unlock(&src_as->lock);
1235	jermar	559	interrupts_restore(ipl);
		560	return EPERM;
		561	}
1413	jermar	562
1235	jermar	563	/*
1413	jermar	564	* Now we are committed to sharing the area.
		565	* First prepare the area for sharing.
		566	* Then it will be safe to unlock it.
		567	*/
		568	sh_info = src_area->sh_info;
		569	if (!sh_info) {
		570	sh_info = (share_info_t *) malloc(sizeof(share_info_t), 0);
		571	mutex_initialize(&sh_info->lock);
		572	sh_info->refcount = 2;
		573	btree_create(&sh_info->pagemap);
		574	src_area->sh_info = sh_info;
		575	} else {
		576	mutex_lock(&sh_info->lock);
		577	sh_info->refcount++;
		578	mutex_unlock(&sh_info->lock);
		579	}
		580
1424	jermar	581	src_area->backend->share(src_area);
1413	jermar	582
		583	mutex_unlock(&src_area->lock);
		584	mutex_unlock(&src_as->lock);
		585
		586	/*
1239	jermar	587	* Create copy of the source address space area.
		588	* The destination area is created with AS_AREA_ATTR_PARTIAL
		589	* attribute set which prevents race condition with
		590	* preliminary as_page_fault() calls.
1417	jermar	591	* The flags of the source area are masked against dst_flags_mask
		592	* to support sharing in less privileged mode.
1235	jermar	593	*/
1461	palkovsky	594	dst_area = as_area_create(dst_as, dst_flags_mask, src_size, dst_base,
1424	jermar	595	AS_AREA_ATTR_PARTIAL, src_backend, &src_backend_data);
1239	jermar	596	if (!dst_area) {
1235	jermar	597	/*
		598	* Destination address space area could not be created.
		599	*/
1413	jermar	600	sh_info_remove_reference(sh_info);
		601
1235	jermar	602	interrupts_restore(ipl);
		603	return ENOMEM;
		604	}
		605
		606	/*
1239	jermar	607	* Now the destination address space area has been
		608	* fully initialized. Clear the AS_AREA_ATTR_PARTIAL
1413	jermar	609	* attribute and set the sh_info.
1239	jermar	610	*/
1380	jermar	611	mutex_lock(&dst_area->lock);
1239	jermar	612	dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
1413	jermar	613	dst_area->sh_info = sh_info;
1380	jermar	614	mutex_unlock(&dst_area->lock);
1235	jermar	615
		616	interrupts_restore(ipl);
		617
		618	return 0;
		619	}
		620
1423	jermar	621	/** Check access mode for address space area.
		622	*
		623	* The address space area must be locked prior to this call.
		624	*
		625	* @param area Address space area.
		626	* @param access Access mode.
		627	*
		628	* @return False if access violates area's permissions, true otherwise.
		629	*/
		630	bool as_area_check_access(as_area_t *area, pf_access_t access)
		631	{
		632	int flagmap[] = {
		633	[PF_ACCESS_READ] = AS_AREA_READ,
		634	[PF_ACCESS_WRITE] = AS_AREA_WRITE,
		635	[PF_ACCESS_EXEC] = AS_AREA_EXEC
		636	};
		637
		638	if (!(area->flags & flagmap[access]))
		639	return false;
		640
		641	return true;
		642	}
		643
703	jermar	644	/** Handle page fault within the current address space.
		645	*
1409	jermar	646	* This is the high-level page fault handler. It decides
		647	* whether the page fault can be resolved by any backend
		648	* and if so, it invokes the backend to resolve the page
		649	* fault.
		650	*
703	jermar	651	* Interrupts are assumed disabled.
		652	*
		653	* @param page Faulting page.
1411	jermar	654	* @param access Access mode that caused the fault (i.e. read/write/exec).
1288	jermar	655	* @param istate Pointer to interrupted state.
703	jermar	656	*
1409	jermar	657	* @return AS_PF_FAULT on page fault, AS_PF_OK on success or AS_PF_DEFER if the
		658	* fault was caused by copy_to_uspace() or copy_from_uspace().
703	jermar	659	*/
1411	jermar	660	int as_page_fault(__address page, pf_access_t access, istate_t *istate)
703	jermar	661	{
1044	jermar	662	pte_t *pte;
977	jermar	663	as_area_t *area;
703	jermar	664
1380	jermar	665	if (!THREAD)
1409	jermar	666	return AS_PF_FAULT;
1380	jermar	667
703	jermar	668	ASSERT(AS);
1044	jermar	669
1380	jermar	670	mutex_lock(&AS->lock);
977	jermar	671	area = find_area_and_lock(AS, page);
703	jermar	672	if (!area) {
		673	/*
		674	* No area contained mapping for 'page'.
		675	* Signal page fault to low-level handler.
		676	*/
1380	jermar	677	mutex_unlock(&AS->lock);
1288	jermar	678	goto page_fault;
703	jermar	679	}
		680
1239	jermar	681	if (area->attributes & AS_AREA_ATTR_PARTIAL) {
		682	/*
		683	* The address space area is not fully initialized.
		684	* Avoid possible race by returning error.
		685	*/
1380	jermar	686	mutex_unlock(&area->lock);
		687	mutex_unlock(&AS->lock);
1288	jermar	688	goto page_fault;
1239	jermar	689	}
		690
1424	jermar	691	if (!area->backend \|\| !area->backend->page_fault) {
1409	jermar	692	/*
		693	* The address space area is not backed by any backend
		694	* or the backend cannot handle page faults.
		695	*/
		696	mutex_unlock(&area->lock);
		697	mutex_unlock(&AS->lock);
		698	goto page_fault;
		699	}
1179	jermar	700
1044	jermar	701	page_table_lock(AS, false);
		702
703	jermar	703	/*
1044	jermar	704	* To avoid race condition between two page faults
		705	* on the same address, we need to make sure
		706	* the mapping has not been already inserted.
		707	*/
		708	if ((pte = page_mapping_find(AS, page))) {
		709	if (PTE_PRESENT(pte)) {
1423	jermar	710	if (((access == PF_ACCESS_READ) && PTE_READABLE(pte)) \|\|
		711	(access == PF_ACCESS_WRITE && PTE_WRITABLE(pte)) \|\|
		712	(access == PF_ACCESS_EXEC && PTE_EXECUTABLE(pte))) {
		713	page_table_unlock(AS, false);
		714	mutex_unlock(&area->lock);
		715	mutex_unlock(&AS->lock);
		716	return AS_PF_OK;
		717	}
1044	jermar	718	}
		719	}
1409	jermar	720
1044	jermar	721	/*
1409	jermar	722	* Resort to the backend page fault handler.
703	jermar	723	*/
1424	jermar	724	if (area->backend->page_fault(area, page, access) != AS_PF_OK) {
1409	jermar	725	page_table_unlock(AS, false);
		726	mutex_unlock(&area->lock);
		727	mutex_unlock(&AS->lock);
		728	goto page_fault;
		729	}
703	jermar	730
1044	jermar	731	page_table_unlock(AS, false);
1380	jermar	732	mutex_unlock(&area->lock);
		733	mutex_unlock(&AS->lock);
1288	jermar	734	return AS_PF_OK;
		735
		736	page_fault:
		737	if (THREAD->in_copy_from_uspace) {
		738	THREAD->in_copy_from_uspace = false;
		739	istate_set_retaddr(istate, (__address) &memcpy_from_uspace_failover_address);
		740	} else if (THREAD->in_copy_to_uspace) {
		741	THREAD->in_copy_to_uspace = false;
		742	istate_set_retaddr(istate, (__address) &memcpy_to_uspace_failover_address);
		743	} else {
		744	return AS_PF_FAULT;
		745	}
		746
		747	return AS_PF_DEFER;
703	jermar	748	}
		749
823	jermar	750	/** Switch address spaces.
703	jermar	751	*
1380	jermar	752	* Note that this function cannot sleep as it is essentially a part of
1415	jermar	753	* scheduling. Sleeping here would lead to deadlock on wakeup.
1380	jermar	754	*
823	jermar	755	* @param old Old address space or NULL.
		756	* @param new New address space.
703	jermar	757	*/
823	jermar	758	void as_switch(as_t old, as_t new)
703	jermar	759	{
		760	ipl_t ipl;
823	jermar	761	bool needs_asid = false;
703	jermar	762
		763	ipl = interrupts_disable();
1415	jermar	764	spinlock_lock(&inactive_as_with_asid_lock);
703	jermar	765
		766	/*
823	jermar	767	* First, take care of the old address space.
		768	*/
		769	if (old) {
1380	jermar	770	mutex_lock_active(&old->lock);
1415	jermar	771	ASSERT(old->cpu_refcount);
		772	if((--old->cpu_refcount == 0) && (old != AS_KERNEL)) {
823	jermar	773	/*
		774	* The old address space is no longer active on
		775	* any processor. It can be appended to the
		776	* list of inactive address spaces with assigned
		777	* ASID.
		778	*/
		779	ASSERT(old->asid != ASID_INVALID);
		780	list_append(&old->inactive_as_with_asid_link, &inactive_as_with_asid_head);
		781	}
1380	jermar	782	mutex_unlock(&old->lock);
823	jermar	783	}
		784
		785	/*
		786	* Second, prepare the new address space.
		787	*/
1380	jermar	788	mutex_lock_active(&new->lock);
1415	jermar	789	if ((new->cpu_refcount++ == 0) && (new != AS_KERNEL)) {
823	jermar	790	if (new->asid != ASID_INVALID)
		791	list_remove(&new->inactive_as_with_asid_link);
		792	else
		793	needs_asid = true; /* defer call to asid_get() until new->lock is released */
		794	}
		795	SET_PTL0_ADDRESS(new->page_table);
1380	jermar	796	mutex_unlock(&new->lock);
823	jermar	797
		798	if (needs_asid) {
		799	/*
		800	* Allocation of new ASID was deferred
		801	* until now in order to avoid deadlock.
		802	*/
		803	asid_t asid;
		804
		805	asid = asid_get();
1380	jermar	806	mutex_lock_active(&new->lock);
823	jermar	807	new->asid = asid;
1380	jermar	808	mutex_unlock(&new->lock);
823	jermar	809	}
1415	jermar	810	spinlock_unlock(&inactive_as_with_asid_lock);
823	jermar	811	interrupts_restore(ipl);
		812
		813	/*
703	jermar	814	* Perform architecture-specific steps.
727	jermar	815	* (e.g. write ASID to hardware register etc.)
703	jermar	816	*/
823	jermar	817	as_install_arch(new);
703	jermar	818
823	jermar	819	AS = new;
703	jermar	820	}
754	jermar	821
1235	jermar	822	/** Convert address space area flags to page flags.
754	jermar	823	*
1235	jermar	824	* @param aflags Flags of some address space area.
754	jermar	825	*
1235	jermar	826	* @return Flags to be passed to page_mapping_insert().
754	jermar	827	*/
1235	jermar	828	int area_flags_to_page_flags(int aflags)
754	jermar	829	{
		830	int flags;
		831
1178	jermar	832	flags = PAGE_USER \| PAGE_PRESENT;
754	jermar	833
1235	jermar	834	if (aflags & AS_AREA_READ)
1026	jermar	835	flags \|= PAGE_READ;
		836
1235	jermar	837	if (aflags & AS_AREA_WRITE)
1026	jermar	838	flags \|= PAGE_WRITE;
		839
1235	jermar	840	if (aflags & AS_AREA_EXEC)
1026	jermar	841	flags \|= PAGE_EXEC;
		842
1424	jermar	843	if (aflags & AS_AREA_CACHEABLE)
1178	jermar	844	flags \|= PAGE_CACHEABLE;
		845
754	jermar	846	return flags;
		847	}
756	jermar	848
1235	jermar	849	/** Compute flags for virtual address translation subsytem.
		850	*
		851	* The address space area must be locked.
		852	* Interrupts must be disabled.
		853	*
		854	* @param a Address space area.
		855	*
		856	* @return Flags to be used in page_mapping_insert().
		857	*/
1409	jermar	858	int as_area_get_flags(as_area_t *a)
1235	jermar	859	{
		860	return area_flags_to_page_flags(a->flags);
		861	}
		862
756	jermar	863	/** Create page table.
		864	*
		865	* Depending on architecture, create either address space
		866	* private or global page table.
		867	*
		868	* @param flags Flags saying whether the page table is for kernel address space.
		869	*
		870	* @return First entry of the page table.
		871	*/
		872	pte_t *page_table_create(int flags)
		873	{
		874	ASSERT(as_operations);
		875	ASSERT(as_operations->page_table_create);
		876
		877	return as_operations->page_table_create(flags);
		878	}
977	jermar	879
1468	jermar	880	/** Destroy page table.
		881	*
		882	* Destroy page table in architecture specific way.
		883	*
		884	* @param page_table Physical address of PTL0.
		885	*/
		886	void page_table_destroy(pte_t *page_table)
		887	{
		888	ASSERT(as_operations);
		889	ASSERT(as_operations->page_table_destroy);
		890
		891	as_operations->page_table_destroy(page_table);
		892	}
		893
1044	jermar	894	/** Lock page table.
		895	*
		896	* This function should be called before any page_mapping_insert(),
		897	* page_mapping_remove() and page_mapping_find().
		898	*
		899	* Locking order is such that address space areas must be locked
		900	* prior to this call. Address space can be locked prior to this
		901	* call in which case the lock argument is false.
		902	*
		903	* @param as Address space.
1248	jermar	904	* @param lock If false, do not attempt to lock as->lock.
1044	jermar	905	*/
		906	void page_table_lock(as_t *as, bool lock)
		907	{
		908	ASSERT(as_operations);
		909	ASSERT(as_operations->page_table_lock);
		910
		911	as_operations->page_table_lock(as, lock);
		912	}
		913
		914	/** Unlock page table.
		915	*
		916	* @param as Address space.
1248	jermar	917	* @param unlock If false, do not attempt to unlock as->lock.
1044	jermar	918	*/
		919	void page_table_unlock(as_t *as, bool unlock)
		920	{
		921	ASSERT(as_operations);
		922	ASSERT(as_operations->page_table_unlock);
		923
		924	as_operations->page_table_unlock(as, unlock);
		925	}
		926
977	jermar	927
		928	/** Find address space area and lock it.
		929	*
		930	* The address space must be locked and interrupts must be disabled.
		931	*
		932	* @param as Address space.
		933	* @param va Virtual address.
		934	*
		935	* @return Locked address space area containing va on success or NULL on failure.
		936	*/
		937	as_area_t find_area_and_lock(as_t as, __address va)
		938	{
		939	as_area_t *a;
1147	jermar	940	btree_node_t leaf, lnode;
		941	int i;
977	jermar	942
1147	jermar	943	a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
		944	if (a) {
		945	/* va is the base address of an address space area */
1380	jermar	946	mutex_lock(&a->lock);
1147	jermar	947	return a;
		948	}
		949
		950	/*
1150	jermar	951	* Search the leaf node and the righmost record of its left neighbour
1147	jermar	952	* to find out whether this is a miss or va belongs to an address
		953	* space area found there.
		954	*/
		955
		956	/* First, search the leaf node itself. */
		957	for (i = 0; i < leaf->keys; i++) {
		958	a = (as_area_t *) leaf->value[i];
1380	jermar	959	mutex_lock(&a->lock);
1147	jermar	960	if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
		961	return a;
		962	}
1380	jermar	963	mutex_unlock(&a->lock);
1147	jermar	964	}
977	jermar	965
1147	jermar	966	/*
1150	jermar	967	* Second, locate the left neighbour and test its last record.
1148	jermar	968	* Because of its position in the B+tree, it must have base < va.
1147	jermar	969	*/
1150	jermar	970	if ((lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	971	a = (as_area_t *) lnode->value[lnode->keys - 1];
1380	jermar	972	mutex_lock(&a->lock);
1147	jermar	973	if (va < a->base + a->pages * PAGE_SIZE) {
1048	jermar	974	return a;
1147	jermar	975	}
1380	jermar	976	mutex_unlock(&a->lock);
977	jermar	977	}
		978
		979	return NULL;
		980	}
1048	jermar	981
		982	/** Check area conflicts with other areas.
		983	*
		984	* The address space must be locked and interrupts must be disabled.
		985	*
		986	* @param as Address space.
		987	* @param va Starting virtual address of the area being tested.
		988	* @param size Size of the area being tested.
		989	* @param avoid_area Do not touch this area.
		990	*
		991	* @return True if there is no conflict, false otherwise.
		992	*/
		993	bool check_area_conflicts(as_t as, __address va, size_t size, as_area_t avoid_area)
		994	{
		995	as_area_t *a;
1147	jermar	996	btree_node_t leaf, node;
		997	int i;
1048	jermar	998
1070	jermar	999	/*
		1000	* We don't want any area to have conflicts with NULL page.
		1001	*/
		1002	if (overlaps(va, size, NULL, PAGE_SIZE))
		1003	return false;
		1004
1147	jermar	1005	/*
		1006	* The leaf node is found in O(log n), where n is proportional to
		1007	* the number of address space areas belonging to as.
		1008	* The check for conflicts is then attempted on the rightmost
1150	jermar	1009	* record in the left neighbour, the leftmost record in the right
		1010	* neighbour and all records in the leaf node itself.
1147	jermar	1011	*/
1048	jermar	1012
1147	jermar	1013	if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
		1014	if (a != avoid_area)
		1015	return false;
		1016	}
		1017
		1018	/* First, check the two border cases. */
1150	jermar	1019	if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	1020	a = (as_area_t *) node->value[node->keys - 1];
1380	jermar	1021	mutex_lock(&a->lock);
1147	jermar	1022	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1023	mutex_unlock(&a->lock);
1147	jermar	1024	return false;
		1025	}
1380	jermar	1026	mutex_unlock(&a->lock);
1147	jermar	1027	}
1150	jermar	1028	if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) {
1147	jermar	1029	a = (as_area_t *) node->value[0];
1380	jermar	1030	mutex_lock(&a->lock);
1147	jermar	1031	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1032	mutex_unlock(&a->lock);
1147	jermar	1033	return false;
		1034	}
1380	jermar	1035	mutex_unlock(&a->lock);
1147	jermar	1036	}
		1037
		1038	/* Second, check the leaf node. */
		1039	for (i = 0; i < leaf->keys; i++) {
		1040	a = (as_area_t *) leaf->value[i];
		1041
1048	jermar	1042	if (a == avoid_area)
		1043	continue;
1147	jermar	1044
1380	jermar	1045	mutex_lock(&a->lock);
1147	jermar	1046	if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380	jermar	1047	mutex_unlock(&a->lock);
1147	jermar	1048	return false;
		1049	}
1380	jermar	1050	mutex_unlock(&a->lock);
1048	jermar	1051	}
		1052
1070	jermar	1053	/*
		1054	* So far, the area does not conflict with other areas.
		1055	* Check if it doesn't conflict with kernel address space.
		1056	*/
		1057	if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
		1058	return !overlaps(va, size,
		1059	KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START);
		1060	}
		1061
1048	jermar	1062	return true;
		1063	}
1235	jermar	1064
1380	jermar	1065	/** Return size of the address space area with given base. */
1329	palkovsky	1066	size_t as_get_size(__address base)
		1067	{
		1068	ipl_t ipl;
		1069	as_area_t *src_area;
		1070	size_t size;
		1071
		1072	ipl = interrupts_disable();
		1073	src_area = find_area_and_lock(AS, base);
		1074	if (src_area){
		1075	size = src_area->pages * PAGE_SIZE;
1380	jermar	1076	mutex_unlock(&src_area->lock);
1329	palkovsky	1077	} else {
		1078	size = 0;
		1079	}
		1080	interrupts_restore(ipl);
		1081	return size;
		1082	}
		1083
1387	jermar	1084	/** Mark portion of address space area as used.
		1085	*
		1086	* The address space area must be already locked.
		1087	*
		1088	* @param a Address space area.
		1089	* @param page First page to be marked.
		1090	* @param count Number of page to be marked.
		1091	*
		1092	* @return 0 on failure and 1 on success.
		1093	*/
		1094	int used_space_insert(as_area_t *a, __address page, count_t count)
		1095	{
		1096	btree_node_t leaf, node;
		1097	count_t pages;
		1098	int i;
		1099
		1100	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1101	ASSERT(count);
		1102
		1103	pages = (count_t) btree_search(&a->used_space, page, &leaf);
		1104	if (pages) {
		1105	/*
		1106	* We hit the beginning of some used space.
		1107	*/
		1108	return 0;
		1109	}
		1110
1437	jermar	1111	if (!leaf->keys) {
		1112	btree_insert(&a->used_space, page, (void *) count, leaf);
		1113	return 1;
		1114	}
		1115
1387	jermar	1116	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1117	if (node) {
		1118	__address left_pg = node->key[node->keys - 1], right_pg = leaf->key[0];
		1119	count_t left_cnt = (count_t) node->value[node->keys - 1], right_cnt = (count_t) leaf->value[0];
		1120
		1121	/*
		1122	* Examine the possibility that the interval fits
		1123	* somewhere between the rightmost interval of
		1124	* the left neigbour and the first interval of the leaf.
		1125	*/
		1126
		1127	if (page >= right_pg) {
		1128	/* Do nothing. */
		1129	} else if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1130	/* The interval intersects with the left interval. */
		1131	return 0;
		1132	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1133	/* The interval intersects with the right interval. */
		1134	return 0;
		1135	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1136	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1137	node->value[node->keys - 1] += count + right_cnt;
1387	jermar	1138	btree_remove(&a->used_space, right_pg, leaf);
		1139	return 1;
		1140	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1141	/* The interval can be added by simply growing the left interval. */
1403	jermar	1142	node->value[node->keys - 1] += count;
1387	jermar	1143	return 1;
		1144	} else if (page + count*PAGE_SIZE == right_pg) {
		1145	/*
		1146	* The interval can be addded by simply moving base of the right
		1147	* interval down and increasing its size accordingly.
		1148	*/
1403	jermar	1149	leaf->value[0] += count;
1387	jermar	1150	leaf->key[0] = page;
		1151	return 1;
		1152	} else {
		1153	/*
		1154	* The interval is between both neigbouring intervals,
		1155	* but cannot be merged with any of them.
		1156	*/
		1157	btree_insert(&a->used_space, page, (void *) count, leaf);
		1158	return 1;
		1159	}
		1160	} else if (page < leaf->key[0]) {
		1161	__address right_pg = leaf->key[0];
		1162	count_t right_cnt = (count_t) leaf->value[0];
		1163
		1164	/*
		1165	* Investigate the border case in which the left neighbour does not
		1166	* exist but the interval fits from the left.
		1167	*/
		1168
		1169	if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1170	/* The interval intersects with the right interval. */
		1171	return 0;
		1172	} else if (page + count*PAGE_SIZE == right_pg) {
		1173	/*
		1174	* The interval can be added by moving the base of the right interval down
		1175	* and increasing its size accordingly.
		1176	*/
		1177	leaf->key[0] = page;
1403	jermar	1178	leaf->value[0] += count;
1387	jermar	1179	return 1;
		1180	} else {
		1181	/*
		1182	* The interval doesn't adjoin with the right interval.
		1183	* It must be added individually.
		1184	*/
		1185	btree_insert(&a->used_space, page, (void *) count, leaf);
		1186	return 1;
		1187	}
		1188	}
		1189
		1190	node = btree_leaf_node_right_neighbour(&a->used_space, leaf);
		1191	if (node) {
		1192	__address left_pg = leaf->key[leaf->keys - 1], right_pg = node->key[0];
		1193	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1], right_cnt = (count_t) node->value[0];
		1194
		1195	/*
		1196	* Examine the possibility that the interval fits
		1197	* somewhere between the leftmost interval of
		1198	* the right neigbour and the last interval of the leaf.
		1199	*/
		1200
		1201	if (page < left_pg) {
		1202	/* Do nothing. */
		1203	} else if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1204	/* The interval intersects with the left interval. */
		1205	return 0;
		1206	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1207	/* The interval intersects with the right interval. */
		1208	return 0;
		1209	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1210	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1211	leaf->value[leaf->keys - 1] += count + right_cnt;
1387	jermar	1212	btree_remove(&a->used_space, right_pg, node);
		1213	return 1;
		1214	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1215	/* The interval can be added by simply growing the left interval. */
1403	jermar	1216	leaf->value[leaf->keys - 1] += count;
1387	jermar	1217	return 1;
		1218	} else if (page + count*PAGE_SIZE == right_pg) {
		1219	/*
		1220	* The interval can be addded by simply moving base of the right
		1221	* interval down and increasing its size accordingly.
		1222	*/
1403	jermar	1223	node->value[0] += count;
1387	jermar	1224	node->key[0] = page;
		1225	return 1;
		1226	} else {
		1227	/*
		1228	* The interval is between both neigbouring intervals,
		1229	* but cannot be merged with any of them.
		1230	*/
		1231	btree_insert(&a->used_space, page, (void *) count, leaf);
		1232	return 1;
		1233	}
		1234	} else if (page >= leaf->key[leaf->keys - 1]) {
		1235	__address left_pg = leaf->key[leaf->keys - 1];
		1236	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1237
		1238	/*
		1239	* Investigate the border case in which the right neighbour does not
		1240	* exist but the interval fits from the right.
		1241	*/
		1242
		1243	if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
1403	jermar	1244	/* The interval intersects with the left interval. */
1387	jermar	1245	return 0;
		1246	} else if (left_pg + left_cnt*PAGE_SIZE == page) {
		1247	/* The interval can be added by growing the left interval. */
1403	jermar	1248	leaf->value[leaf->keys - 1] += count;
1387	jermar	1249	return 1;
		1250	} else {
		1251	/*
		1252	* The interval doesn't adjoin with the left interval.
		1253	* It must be added individually.
		1254	*/
		1255	btree_insert(&a->used_space, page, (void *) count, leaf);
		1256	return 1;
		1257	}
		1258	}
		1259
		1260	/*
		1261	* Note that if the algorithm made it thus far, the interval can fit only
		1262	* between two other intervals of the leaf. The two border cases were already
		1263	* resolved.
		1264	*/
		1265	for (i = 1; i < leaf->keys; i++) {
		1266	if (page < leaf->key[i]) {
		1267	__address left_pg = leaf->key[i - 1], right_pg = leaf->key[i];
		1268	count_t left_cnt = (count_t) leaf->value[i - 1], right_cnt = (count_t) leaf->value[i];
		1269
		1270	/*
		1271	* The interval fits between left_pg and right_pg.
		1272	*/
		1273
		1274	if (overlaps(page, countPAGE_SIZE, left_pg, left_cntPAGE_SIZE)) {
		1275	/* The interval intersects with the left interval. */
		1276	return 0;
		1277	} else if (overlaps(page, countPAGE_SIZE, right_pg, right_cntPAGE_SIZE)) {
		1278	/* The interval intersects with the right interval. */
		1279	return 0;
		1280	} else if ((page == left_pg + left_cntPAGE_SIZE) && (page + countPAGE_SIZE == right_pg)) {
		1281	/* The interval can be added by merging the two already present intervals. */
1403	jermar	1282	leaf->value[i - 1] += count + right_cnt;
1387	jermar	1283	btree_remove(&a->used_space, right_pg, leaf);
		1284	return 1;
		1285	} else if (page == left_pg + left_cnt*PAGE_SIZE) {
		1286	/* The interval can be added by simply growing the left interval. */
1403	jermar	1287	leaf->value[i - 1] += count;
1387	jermar	1288	return 1;
		1289	} else if (page + count*PAGE_SIZE == right_pg) {
		1290	/*
		1291	* The interval can be addded by simply moving base of the right
		1292	* interval down and increasing its size accordingly.
		1293	*/
1403	jermar	1294	leaf->value[i] += count;
1387	jermar	1295	leaf->key[i] = page;
		1296	return 1;
		1297	} else {
		1298	/*
		1299	* The interval is between both neigbouring intervals,
		1300	* but cannot be merged with any of them.
		1301	*/
		1302	btree_insert(&a->used_space, page, (void *) count, leaf);
		1303	return 1;
		1304	}
		1305	}
		1306	}
		1307
		1308	panic("Inconsistency detected while adding %d pages of used space at %P.\n", count, page);
		1309	}
		1310
		1311	/** Mark portion of address space area as unused.
		1312	*
		1313	* The address space area must be already locked.
		1314	*
		1315	* @param a Address space area.
		1316	* @param page First page to be marked.
		1317	* @param count Number of page to be marked.
		1318	*
		1319	* @return 0 on failure and 1 on success.
		1320	*/
		1321	int used_space_remove(as_area_t *a, __address page, count_t count)
		1322	{
		1323	btree_node_t leaf, node;
		1324	count_t pages;
		1325	int i;
		1326
		1327	ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
		1328	ASSERT(count);
		1329
		1330	pages = (count_t) btree_search(&a->used_space, page, &leaf);
		1331	if (pages) {
		1332	/*
		1333	* We are lucky, page is the beginning of some interval.
		1334	*/
		1335	if (count > pages) {
		1336	return 0;
		1337	} else if (count == pages) {
		1338	btree_remove(&a->used_space, page, leaf);
1403	jermar	1339	return 1;
1387	jermar	1340	} else {
		1341	/*
		1342	* Find the respective interval.
		1343	* Decrease its size and relocate its start address.
		1344	*/
		1345	for (i = 0; i < leaf->keys; i++) {
		1346	if (leaf->key[i] == page) {
		1347	leaf->key[i] += count*PAGE_SIZE;
1403	jermar	1348	leaf->value[i] -= count;
1387	jermar	1349	return 1;
		1350	}
		1351	}
		1352	goto error;
		1353	}
		1354	}
		1355
		1356	node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
		1357	if (node && page < leaf->key[0]) {
		1358	__address left_pg = node->key[node->keys - 1];
		1359	count_t left_cnt = (count_t) node->value[node->keys - 1];
		1360
		1361	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1362	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1363	/*
		1364	* The interval is contained in the rightmost interval
		1365	* of the left neighbour and can be removed by
		1366	* updating the size of the bigger interval.
		1367	*/
1403	jermar	1368	node->value[node->keys - 1] -= count;
1387	jermar	1369	return 1;
		1370	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1371	count_t new_cnt;
1387	jermar	1372
		1373	/*
		1374	* The interval is contained in the rightmost interval
		1375	* of the left neighbour but its removal requires
		1376	* both updating the size of the original interval and
		1377	* also inserting a new interval.
		1378	*/
1403	jermar	1379	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1380	node->value[node->keys - 1] -= count + new_cnt;
1387	jermar	1381	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1382	return 1;
		1383	}
		1384	}
		1385	return 0;
		1386	} else if (page < leaf->key[0]) {
		1387	return 0;
		1388	}
		1389
		1390	if (page > leaf->key[leaf->keys - 1]) {
		1391	__address left_pg = leaf->key[leaf->keys - 1];
		1392	count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
		1393
		1394	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1395	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1396	/*
		1397	* The interval is contained in the rightmost interval
		1398	* of the leaf and can be removed by updating the size
		1399	* of the bigger interval.
		1400	*/
1403	jermar	1401	leaf->value[leaf->keys - 1] -= count;
1387	jermar	1402	return 1;
		1403	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1404	count_t new_cnt;
1387	jermar	1405
		1406	/*
		1407	* The interval is contained in the rightmost interval
		1408	* of the leaf but its removal requires both updating
		1409	* the size of the original interval and
		1410	* also inserting a new interval.
		1411	*/
1403	jermar	1412	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1413	leaf->value[leaf->keys - 1] -= count + new_cnt;
1387	jermar	1414	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1415	return 1;
		1416	}
		1417	}
		1418	return 0;
		1419	}
		1420
		1421	/*
		1422	* The border cases have been already resolved.
		1423	* Now the interval can be only between intervals of the leaf.
		1424	*/
		1425	for (i = 1; i < leaf->keys - 1; i++) {
		1426	if (page < leaf->key[i]) {
		1427	__address left_pg = leaf->key[i - 1];
		1428	count_t left_cnt = (count_t) leaf->value[i - 1];
		1429
		1430	/*
		1431	* Now the interval is between intervals corresponding to (i - 1) and i.
		1432	*/
		1433	if (overlaps(left_pg, left_cntPAGE_SIZE, page, countPAGE_SIZE)) {
		1434	if (page + countPAGE_SIZE == left_pg + left_cntPAGE_SIZE) {
		1435	/*
		1436	* The interval is contained in the interval (i - 1)
		1437	* of the leaf and can be removed by updating the size
		1438	* of the bigger interval.
		1439	*/
1403	jermar	1440	leaf->value[i - 1] -= count;
1387	jermar	1441	return 1;
		1442	} else if (page + countPAGE_SIZE < left_pg + left_cntPAGE_SIZE) {
1403	jermar	1443	count_t new_cnt;
1387	jermar	1444
		1445	/*
		1446	* The interval is contained in the interval (i - 1)
		1447	* of the leaf but its removal requires both updating
		1448	* the size of the original interval and
		1449	* also inserting a new interval.
		1450	*/
1403	jermar	1451	new_cnt = ((left_pg + left_cntPAGE_SIZE) - (page + countPAGE_SIZE)) >> PAGE_WIDTH;
		1452	leaf->value[i - 1] -= count + new_cnt;
1387	jermar	1453	btree_insert(&a->used_space, page + countPAGE_SIZE, (void ) new_cnt, leaf);
		1454	return 1;
		1455	}
		1456	}
		1457	return 0;
		1458	}
		1459	}
		1460
		1461	error:
		1462	panic("Inconsistency detected while removing %d pages of used space from %P.\n", count, page);
		1463	}
		1464
1409	jermar	1465	/** Remove reference to address space area share info.
		1466	*
		1467	* If the reference count drops to 0, the sh_info is deallocated.
		1468	*
		1469	* @param sh_info Pointer to address space area share info.
		1470	*/
		1471	void sh_info_remove_reference(share_info_t *sh_info)
		1472	{
		1473	bool dealloc = false;
		1474
		1475	mutex_lock(&sh_info->lock);
		1476	ASSERT(sh_info->refcount);
		1477	if (--sh_info->refcount == 0) {
		1478	dealloc = true;
		1479	bool cond;
		1480
		1481	/*
		1482	* Now walk carefully the pagemap B+tree and free/remove
		1483	* reference from all frames found there.
		1484	*/
		1485	for (cond = true; cond;) {
		1486	btree_node_t *node;
		1487
		1488	ASSERT(!list_empty(&sh_info->pagemap.leaf_head));
		1489	node = list_get_instance(sh_info->pagemap.leaf_head.next, btree_node_t, leaf_link);
		1490	if ((cond = node->keys)) {
		1491	frame_free(ADDR2PFN((__address) node->value[0]));
		1492	btree_remove(&sh_info->pagemap, node->key[0], node);
		1493	}
		1494	}
		1495
		1496	}
		1497	mutex_unlock(&sh_info->lock);
		1498
		1499	if (dealloc) {
		1500	btree_destroy(&sh_info->pagemap);
		1501	free(sh_info);
		1502	}
		1503	}
		1504
1235	jermar	1505	/*
		1506	* Address space related syscalls.
		1507	*/
		1508
		1509	/** Wrapper for as_area_create(). */
		1510	__native sys_as_area_create(__address address, size_t size, int flags)
		1511	{
1424	jermar	1512	if (as_area_create(AS, flags \| AS_AREA_CACHEABLE, size, address, AS_AREA_ATTR_NONE, &anon_backend, NULL))
1235	jermar	1513	return (__native) address;
		1514	else
		1515	return (__native) -1;
		1516	}
		1517
		1518	/** Wrapper for as_area_resize. */
		1519	__native sys_as_area_resize(__address address, size_t size, int flags)
		1520	{
1306	jermar	1521	return (__native) as_area_resize(AS, address, size, 0);
1235	jermar	1522	}
		1523
1306	jermar	1524	/** Wrapper for as_area_destroy. */
		1525	__native sys_as_area_destroy(__address address)
		1526	{
		1527	return (__native) as_area_destroy(AS, address);
		1528	}

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(root)/branches/rcu/kernel/generic/src/mm/as.c @ 3808 – Rev 1468