[unix-history] / sys / kern / subr_rlist.c

/*
 * Copyright (c) 1992 William F. Jolitz, TeleMuse
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This software is a component of "386BSD" developed by 
	William F. Jolitz, TeleMuse.
 * 4. Neither the name of the developer nor the name "386BSD"
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS A COMPONENT OF 386BSD DEVELOPED BY WILLIAM F. JOLITZ 
 * AND IS INTENDED FOR RESEARCH AND EDUCATIONAL PURPOSES ONLY. THIS 
 * SOFTWARE SHOULD NOT BE CONSIDERED TO BE A COMMERCIAL PRODUCT. 
 * THE DEVELOPER URGES THAT USERS WHO REQUIRE A COMMERCIAL PRODUCT 
 * NOT MAKE USE THIS WORK.
 *
 * FOR USERS WHO WISH TO UNDERSTAND THE 386BSD SYSTEM DEVELOPED
 * BY WILLIAM F. JOLITZ, WE RECOMMEND THE USER STUDY WRITTEN 
 * REFERENCES SUCH AS THE  "PORTING UNIX TO THE 386" SERIES 
 * (BEGINNING JANUARY 1991 "DR. DOBBS JOURNAL", USA AND BEGINNING 
 * JUNE 1991 "UNIX MAGAZIN", GERMANY) BY WILLIAM F. JOLITZ AND 
 * LYNNE GREER JOLITZ, AS WELL AS OTHER BOOKS ON UNIX AND THE 
 * ON-LINE 386BSD USER MANUAL BEFORE USE. A BOOK DISCUSSING THE INTERNALS 
 * OF 386BSD ENTITLED "386BSD FROM THE INSIDE OUT" WILL BE AVAILABLE LATE 1992.
 *
 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPER ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE DEVELOPER BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	$Id$
 */

#include "param.h"
#include "systm.h"
#include "cdefs.h"
#include "malloc.h"
#include "rlist.h"
#include "vm/vm.h"
#include "vm/vm_map.h"

extern vm_map_t kernel_map;

/*
 * Resource lists.
 */

#define RLIST_MIN 128
static int rlist_count=0;
static struct rlist *rlfree;
int rlist_active;

static struct rlist *
rlist_malloc()
{
	struct rlist *rl;
	int i;
	while( rlist_count < RLIST_MIN) {
		extern vm_map_t kmem_map;
		int s = splhigh();
		rl = (struct rlist *)kmem_malloc(kmem_map, NBPG, 0);
		splx(s);
		if( !rl)
			break;
		
		for(i=0;i<(NBPG/(sizeof *rl));i++) {
			rl->rl_next = rlfree;
			rlfree = rl;
			rlist_count++;
			rl++;
		}
	}

	if( (rl = rlfree) == 0 )
		panic("Cannot get an rlist entry");
		
	--rlist_count;
	rlfree = rl->rl_next;
	return rl;
}

inline static void
rlist_mfree( struct rlist *rl)
{
	rl->rl_next = rlfree;
	rlfree = rl;
	++rlist_count;
}
	

/*
 * Add space to a resource list. Used to either
 * initialize a list or return free space to it.
 */
void
rlist_free (rlp, start, end)
	register struct rlist **rlp;
	unsigned start, end;
{
	struct rlist *head;
	register struct rlist *olp = 0;
	int s;

	s = splhigh();
	while( rlist_active)
		tsleep((caddr_t)&rlist_active, PSWP, "rlistf", 0);
	rlist_active = 1;
	splx(s);

	head = *rlp;

loop:
	/* if nothing here, insert (tail of list) */
	if (*rlp == 0) {
		*rlp = rlist_malloc();
		(*rlp)->rl_start = start;
		(*rlp)->rl_end = end;
		(*rlp)->rl_next = 0;
		rlist_active = 0;
		wakeup((caddr_t)&rlist_active);
		return;
	}

	/* if new region overlaps something currently present, panic */
	if (start >= (*rlp)->rl_start && start <= (*rlp)->rl_end)  {
		printf("Frag %d:%d, ent %d:%d ", start, end,
			(*rlp)->rl_start, (*rlp)->rl_end);
		panic("overlapping front rlist_free: freed twice?");
	}
	if (end >= (*rlp)->rl_start && end <= (*rlp)->rl_end) {
		printf("Frag %d:%d, ent %d:%d ", start, end,
			(*rlp)->rl_start, (*rlp)->rl_end);
		panic("overlapping tail rlist_free: freed twice?");
	}

	/* are we adjacent to this element? (in front) */
	if (end+1 == (*rlp)->rl_start) {
		/* coalesce */
		(*rlp)->rl_start = start;
		goto scan;
	}

	/* are we before this element? */
	if (end < (*rlp)->rl_start) {
		register struct rlist *nlp;

		nlp = rlist_malloc();
		nlp->rl_start = start;
		nlp->rl_end = end;
		nlp->rl_next = *rlp;
		/*
		 * If the new element is in front of the list,
		 * adjust *rlp, else don't.
		 */
		if( olp) {
			olp->rl_next = nlp;
		} else {
			*rlp = nlp;
		}
		rlist_active = 0;
		wakeup((caddr_t)&rlist_active);
		return;
	}

	/* are we adjacent to this element? (at tail) */
	if ((*rlp)->rl_end + 1 == start) {
		/* coalesce */
		(*rlp)->rl_end = end;
		goto scan;
	}

	/* are we after this element */
	if (start  > (*rlp)->rl_end) {
		olp = *rlp;
		rlp = &((*rlp)->rl_next);
		goto loop;
	} else
		panic("rlist_free: can't happen");

scan:
	/* can we coalesce list now that we've filled a void? */
	{
		register struct rlist *lp, *lpn;

		for (lp = head; lp->rl_next ;) { 
			lpn = lp->rl_next;

			/* coalesce ? */
			if (lp->rl_end + 1 == lpn->rl_start) {
				lp->rl_end = lpn->rl_end;
				lp->rl_next = lpn->rl_next;
				rlist_mfree(lpn);
			} else
				lp = lp->rl_next;
		}
	}
	rlist_active = 0;
	wakeup((caddr_t)&rlist_active);
}

/*
 * Obtain a region of desired size from a resource list.
 * If nothing available of that size, return 0. Otherwise,
 * return a value of 1 and set resource start location with
 * "*loc". (Note: loc can be zero if we don't wish the value)
 */
int rlist_alloc (rlp, size, loc)
	struct rlist **rlp;
	unsigned size, *loc;
{
	register struct rlist *lp;
	int s;
	register struct rlist *olp = 0;

	s = splhigh();
	while( rlist_active)
		tsleep((caddr_t)&rlist_active, PSWP, "rlista", 0);
	rlist_active = 1;
	splx(s);

	/* walk list, allocating first thing that's big enough (first fit) */
	for (; *rlp; rlp = &((*rlp)->rl_next))
		if(size <= (*rlp)->rl_end - (*rlp)->rl_start + 1) {

			/* hand it to the caller */
			if (loc) *loc = (*rlp)->rl_start;
			(*rlp)->rl_start += size;

			/* did we eat this element entirely? */
			if ((*rlp)->rl_start > (*rlp)->rl_end) {
				lp = (*rlp)->rl_next;
				rlist_mfree(*rlp);
				/*
				 * if the deleted element was in fromt
				 * of the list, adjust *rlp, else don't.
				 */
				if (olp) {
					olp->rl_next = lp;
				} else {
					*rlp = lp;
				}
			}

			rlist_active = 0;
			wakeup((caddr_t)&rlist_active);
			return (1);
		} else {
			olp = *rlp;
		}

	rlist_active = 0;
	wakeup((caddr_t)&rlist_active);
	/* nothing in list that's big enough */
	return (0);
}

/*
 * Finished with this resource list, reclaim all space and
 * mark it as being empty.
 */
void
rlist_destroy (rlp)
	struct rlist **rlp;
{
	struct rlist *lp, *nlp;

	lp = *rlp;
	*rlp = 0;
	for (; lp; lp = nlp) {
		nlp = lp->rl_next;
		rlist_mfree(lp);
	}
}
Commit	Line	Data
15637ed4 RG	1	/*
	2	* Copyright (c) 1992 William F. Jolitz, TeleMuse
	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	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This software is a component of "386BSD" developed by
	16	William F. Jolitz, TeleMuse.
	17	* 4. Neither the name of the developer nor the name "386BSD"
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS A COMPONENT OF 386BSD DEVELOPED BY WILLIAM F. JOLITZ
	22	* AND IS INTENDED FOR RESEARCH AND EDUCATIONAL PURPOSES ONLY. THIS
	23	* SOFTWARE SHOULD NOT BE CONSIDERED TO BE A COMMERCIAL PRODUCT.
	24	* THE DEVELOPER URGES THAT USERS WHO REQUIRE A COMMERCIAL PRODUCT
	25	* NOT MAKE USE THIS WORK.
	26	*
	27	* FOR USERS WHO WISH TO UNDERSTAND THE 386BSD SYSTEM DEVELOPED
	28	* BY WILLIAM F. JOLITZ, WE RECOMMEND THE USER STUDY WRITTEN
	29	* REFERENCES SUCH AS THE "PORTING UNIX TO THE 386" SERIES
	30	* (BEGINNING JANUARY 1991 "DR. DOBBS JOURNAL", USA AND BEGINNING
	31	* JUNE 1991 "UNIX MAGAZIN", GERMANY) BY WILLIAM F. JOLITZ AND
	32	* LYNNE GREER JOLITZ, AS WELL AS OTHER BOOKS ON UNIX AND THE
	33	* ON-LINE 386BSD USER MANUAL BEFORE USE. A BOOK DISCUSSING THE INTERNALS
	34	* OF 386BSD ENTITLED "386BSD FROM THE INSIDE OUT" WILL BE AVAILABLE LATE 1992.
	35	*
	36	* THIS SOFTWARE IS PROVIDED BY THE DEVELOPER ``AS IS'' AND
	37	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	38	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	39	* ARE DISCLAIMED. IN NO EVENT SHALL THE DEVELOPER BE LIABLE
	40	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	41	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	42	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	43	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	44	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	45	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	46	* SUCH DAMAGE.
	47	*
736d20f2	48	* $Id$
15637ed4	49	*/
15637ed4	50
fde1aeb2 GW	51	#include "param.h"
fde1aeb2 GW	52	#include "systm.h"
736d20f2	53	#include "cdefs.h"
fde1aeb2	54	#include "malloc.h"
15637ed4	55	#include "rlist.h"
736d20f2 DG	56	#include "vm/vm.h"
	57	#include "vm/vm_map.h"
	58
	59	extern vm_map_t kernel_map;
15637ed4 RG	60
	61	/*
	62	* Resource lists.
	63	*/
	64
736d20f2 DG	65	#define RLIST_MIN 128
	66	static int rlist_count=0;
	67	static struct rlist *rlfree;
	68	int rlist_active;
	69
	70	static struct rlist *
	71	rlist_malloc()
	72	{
	73	struct rlist *rl;
	74	int i;
	75	while( rlist_count < RLIST_MIN) {
	76	extern vm_map_t kmem_map;
	77	int s = splhigh();
	78	rl = (struct rlist *)kmem_malloc(kmem_map, NBPG, 0);
	79	splx(s);
	80	if( !rl)
	81	break;
	82
	83	for(i=0;i<(NBPG/(sizeof *rl));i++) {
	84	rl->rl_next = rlfree;
	85	rlfree = rl;
	86	rlist_count++;
	87	rl++;
	88	}
	89	}
	90
	91	if( (rl = rlfree) == 0 )
	92	panic("Cannot get an rlist entry");
	93
	94	--rlist_count;
	95	rlfree = rl->rl_next;
	96	return rl;
	97	}
	98
	99	inline static void
	100	rlist_mfree( struct rlist *rl)
	101	{
	102	rl->rl_next = rlfree;
	103	rlfree = rl;
	104	++rlist_count;
	105	}
	106
	107
15637ed4 RG	108	/*
	109	* Add space to a resource list. Used to either
	110	* initialize a list or return free space to it.
	111	*/
4c45483e	112	void
15637ed4	113	rlist_free (rlp, start, end)
4c45483e GW	114	register struct rlist **rlp;
	115	unsigned start, end;
	116	{
15637ed4	117	struct rlist *head;
736d20f2 DG	118	register struct rlist *olp = 0;
	119	int s;
	120
	121	s = splhigh();
	122	while( rlist_active)
	123	tsleep((caddr_t)&rlist_active, PSWP, "rlistf", 0);
	124	rlist_active = 1;
	125	splx(s);
15637ed4 RG	126
	127	head = *rlp;
	128
	129	loop:
	130	/* if nothing here, insert (tail of list) */
	131	if (*rlp == 0) {
736d20f2	132	*rlp = rlist_malloc();
15637ed4 RG	133	(*rlp)->rl_start = start;
	134	(*rlp)->rl_end = end;
	135	(*rlp)->rl_next = 0;
736d20f2 DG	136	rlist_active = 0;
736d20f2 DG	137	wakeup((caddr_t)&rlist_active);
15637ed4 RG	138	return;
	139	}
	140
	141	/* if new region overlaps something currently present, panic */
	142	if (start >= (rlp)->rl_start && start <= (rlp)->rl_end) {
	143	printf("Frag %d:%d, ent %d:%d ", start, end,
	144	(rlp)->rl_start, (rlp)->rl_end);
	145	panic("overlapping front rlist_free: freed twice?");
	146	}
	147	if (end >= (rlp)->rl_start && end <= (rlp)->rl_end) {
	148	printf("Frag %d:%d, ent %d:%d ", start, end,
	149	(rlp)->rl_start, (rlp)->rl_end);
	150	panic("overlapping tail rlist_free: freed twice?");
	151	}
	152
	153	/* are we adjacent to this element? (in front) */
	154	if (end+1 == (*rlp)->rl_start) {
	155	/* coalesce */
	156	(*rlp)->rl_start = start;
	157	goto scan;
	158	}
	159
	160	/* are we before this element? */
	161	if (end < (*rlp)->rl_start) {
	162	register struct rlist *nlp;
	163
736d20f2	164	nlp = rlist_malloc();
15637ed4 RG	165	nlp->rl_start = start;
	166	nlp->rl_end = end;
	167	nlp->rl_next = *rlp;
736d20f2 DG	168	/*
	169	* If the new element is in front of the list,
	170	* adjust *rlp, else don't.
	171	*/
	172	if( olp) {
	173	olp->rl_next = nlp;
	174	} else {
	175	*rlp = nlp;
	176	}
	177	rlist_active = 0;
	178	wakeup((caddr_t)&rlist_active);
15637ed4 RG	179	return;
	180	}
	181
	182	/* are we adjacent to this element? (at tail) */
	183	if ((*rlp)->rl_end + 1 == start) {
	184	/* coalesce */
	185	(*rlp)->rl_end = end;
	186	goto scan;
	187	}
	188
	189	/* are we after this element */
	190	if (start > (*rlp)->rl_end) {
736d20f2	191	olp = *rlp;
15637ed4 RG	192	rlp = &((*rlp)->rl_next);
	193	goto loop;
	194	} else
	195	panic("rlist_free: can't happen");
	196
	197	scan:
	198	/* can we coalesce list now that we've filled a void? */
	199	{
	200	register struct rlist lp, lpn;
	201
	202	for (lp = head; lp->rl_next ;) {
	203	lpn = lp->rl_next;
	204
	205	/* coalesce ? */
	206	if (lp->rl_end + 1 == lpn->rl_start) {
	207	lp->rl_end = lpn->rl_end;
	208	lp->rl_next = lpn->rl_next;
736d20f2	209	rlist_mfree(lpn);
15637ed4 RG	210	} else
	211	lp = lp->rl_next;
	212	}
	213	}
736d20f2 DG	214	rlist_active = 0;
736d20f2 DG	215	wakeup((caddr_t)&rlist_active);
15637ed4 RG	216	}
	217
	218	/*
	219	* Obtain a region of desired size from a resource list.
	220	* If nothing available of that size, return 0. Otherwise,
	221	* return a value of 1 and set resource start location with
	222	* "*loc". (Note: loc can be zero if we don't wish the value)
	223	*/
	224	int rlist_alloc (rlp, size, loc)
736d20f2 DG	225	struct rlist **rlp;
	226	unsigned size, *loc;
	227	{
15637ed4	228	register struct rlist *lp;
736d20f2 DG	229	int s;
736d20f2 DG	230	register struct rlist *olp = 0;
15637ed4	231
736d20f2 DG	232	s = splhigh();
	233	while( rlist_active)
	234	tsleep((caddr_t)&rlist_active, PSWP, "rlista", 0);
	235	rlist_active = 1;
	236	splx(s);
15637ed4 RG	237
	238	/* walk list, allocating first thing that's big enough (first fit) */
	239	for (; rlp; rlp = &((rlp)->rl_next))
	240	if(size <= (rlp)->rl_end - (rlp)->rl_start + 1) {
	241
	242	/* hand it to the caller */
	243	if (loc) loc = (rlp)->rl_start;
	244	(*rlp)->rl_start += size;
	245
	246	/* did we eat this element entirely? */
	247	if ((rlp)->rl_start > (rlp)->rl_end) {
	248	lp = (*rlp)->rl_next;
736d20f2 DG	249	rlist_mfree(*rlp);
	250	/*
	251	* if the deleted element was in fromt
	252	* of the list, adjust *rlp, else don't.
	253	*/
	254	if (olp) {
	255	olp->rl_next = lp;
	256	} else {
	257	*rlp = lp;
	258	}
15637ed4 RG	259	}
15637ed4 RG	260
736d20f2 DG	261	rlist_active = 0;
736d20f2 DG	262	wakeup((caddr_t)&rlist_active);
15637ed4	263	return (1);
736d20f2 DG	264	} else {
736d20f2 DG	265	olp = *rlp;
15637ed4 RG	266	}
15637ed4 RG	267
736d20f2 DG	268	rlist_active = 0;
736d20f2 DG	269	wakeup((caddr_t)&rlist_active);
15637ed4 RG	270	/* nothing in list that's big enough */
	271	return (0);
	272	}
	273
	274	/*
	275	* Finished with this resource list, reclaim all space and
	276	* mark it as being empty.
	277	*/
4c45483e	278	void
15637ed4	279	rlist_destroy (rlp)
4c45483e GW	280	struct rlist **rlp;
4c45483e GW	281	{
15637ed4 RG	282	struct rlist lp, nlp;
	283
	284	lp = *rlp;
	285	*rlp = 0;
	286	for (; lp; lp = nlp) {
	287	nlp = lp->rl_next;
736d20f2	288	rlist_mfree(lp);
15637ed4 RG	289	}
15637ed4 RG	290	}