WebSVN – HelenOS-historic – Blame – /kernel/trunk/genarch/src/mm/page_ht.c

Rev	Author	Line No.	Line
684	jermar	1	/*
		2	* Copyright (C) 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
		29	#include <genarch/mm/page_ht.h>
		30	#include <mm/page.h>
		31	#include <mm/frame.h>
699	jermar	32	#include <mm/heap.h>
755	jermar	33	#include <mm/as.h>
687	jermar	34	#include <arch/mm/asid.h>
684	jermar	35	#include <arch/types.h>
		36	#include <typedefs.h>
		37	#include <arch/asm.h>
746	jermar	38	#include <synch/spinlock.h>
		39	#include <arch.h>
699	jermar	40	#include <debug.h>
756	jermar	41	#include <memstr.h>
684	jermar	42
746	jermar	43	/**
756	jermar	44	* This lock protects the page hash table.
746	jermar	45	*/
		46	SPINLOCK_INITIALIZE(page_ht_lock);
		47
		48	/**
		49	* Page hash table pointer.
		50	* The page hash table may be accessed only when page_ht_lock is held.
		51	*/
		52	pte_t *page_ht = NULL;
		53
756	jermar	54	static void ht_mapping_insert(as_t *as, __address page, __address frame, int flags);
		55	static pte_t ht_mapping_find(as_t as, __address page);
684	jermar	56
		57	page_operations_t page_ht_operations = {
		58	.mapping_insert = ht_mapping_insert,
757	jermar	59	.mapping_find = ht_mapping_find
684	jermar	60	};
		61
		62	/** Map page to frame using page hash table.
		63	*
		64	* Map virtual address 'page' to physical address 'frame'
756	jermar	65	* using 'flags'.
684	jermar	66	*
756	jermar	67	* The address space must be locked and interruptsmust be disabled.
		68	*
		69	* @param as Address space to which page belongs.
684	jermar	70	* @param page Virtual address of the page to be mapped.
		71	* @param frame Physical address of memory frame to which the mapping is done.
		72	* @param flags Flags to be used for mapping.
		73	*/
756	jermar	74	void ht_mapping_insert(as_t *as, __address page, __address frame, int flags)
684	jermar	75	{
746	jermar	76	pte_t t, u;
		77	ipl_t ipl;
699	jermar	78
746	jermar	79	ipl = interrupts_disable();
		80	spinlock_lock(&page_ht_lock);
755	jermar	81
		82	t = HT_HASH(page, as->asid);
699	jermar	83	if (!HT_SLOT_EMPTY(t)) {
746	jermar	84
		85	/*
		86	* The slot is occupied.
		87	* Walk through the collision chain and append the mapping to its end.
		88	*/
		89
		90	do {
		91	u = t;
755	jermar	92	if (HT_COMPARE(page, as->asid, t)) {
746	jermar	93	/*
		94	* Nothing to do,
		95	* the record is already there.
		96	*/
		97	spinlock_unlock(&page_ht_lock);
		98	interrupts_restore(ipl);
		99	return;
		100	}
		101	} while ((t = HT_GET_NEXT(t)));
		102
		103	t = (pte_t ) malloc(sizeof(pte_t)); / FIXME: use slab allocator for this */
		104	if (!t)
		105	panic("could not allocate memory\n");
		106
		107	HT_SET_NEXT(u, t);
699	jermar	108	}
746	jermar	109
755	jermar	110	HT_SET_RECORD(t, page, as->asid, frame, flags);
746	jermar	111	HT_SET_NEXT(t, NULL);
		112
		113	spinlock_unlock(&page_ht_lock);
		114	interrupts_restore(ipl);
684	jermar	115	}
		116
		117	/** Find mapping for virtual page in page hash table.
		118	*
		119	* Find mapping for virtual page.
		120	*
756	jermar	121	* The address space must be locked and interrupts must be disabled.
746	jermar	122	*
756	jermar	123	* @param as Address space to wich page belongs.
684	jermar	124	* @param page Virtual page.
		125	*
699	jermar	126	* @return NULL if there is no such mapping; requested mapping otherwise.
684	jermar	127	*/
756	jermar	128	pte_t ht_mapping_find(as_t as, __address page)
684	jermar	129	{
699	jermar	130	pte_t *t;
		131
746	jermar	132	spinlock_lock(&page_ht_lock);
755	jermar	133	t = HT_HASH(page, as->asid);
746	jermar	134	if (!HT_SLOT_EMPTY(t)) {
755	jermar	135	while (!HT_COMPARE(page, as->asid, t) && HT_GET_NEXT(t))
746	jermar	136	t = HT_GET_NEXT(t);
755	jermar	137	t = HT_COMPARE(page, as->asid, t) ? t : NULL;
746	jermar	138	} else {
		139	t = NULL;
		140	}
		141	spinlock_unlock(&page_ht_lock);
		142	return t;
		143	}
		144
		145	/** Invalidate page hash table.
		146	*
		147	* Interrupts must be disabled.
		148	*/
		149	void ht_invalidate_all(void)
		150	{
		151	pte_t t, u;
		152	int i;
699	jermar	153
746	jermar	154	spinlock_lock(&page_ht_lock);
		155	for (i = 0; i < HT_ENTRIES; i++) {
		156	if (!HT_SLOT_EMPTY(&page_ht[i])) {
		157	t = HT_GET_NEXT(&page_ht[i]);
		158	while (t) {
		159	u = t;
		160	t = HT_GET_NEXT(t);
		161	free(u); /* FIXME: use slab allocator for this */
		162	}
		163	HT_INVALIDATE_SLOT(&page_ht[i]);
		164	}
		165	}
		166	spinlock_unlock(&page_ht_lock);
684	jermar	167	}

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