[unix-history] / usr / src / sys / kern / subr_rmap.c

/*	subr_rmap.c	4.8	82/10/21	*/

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/map.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/proc.h"
#include "../h/text.h"
#include "../h/kernel.h"

/*
 * Resource map handling routines.
 *
 * A resource map is an array of structures each
 * of which describes a segment of the address space of an available
 * resource.  The segments are described by their base address and
 * length, and sorted in address order.  Each resource map has a fixed
 * maximum number of segments allowed.  Resources are allocated
 * by taking part or all of one of the segments of the map.
 *
 * Returning of resources will require another segment if
 * the returned resources are not adjacent in the address
 * space to an existing segment.  If the return of a segment
 * would require a slot which is not available, then one of
 * the resource map segments is discarded after a warning is printed.
 * Returning of resources may also cause the map to collapse
 * by coalescing two existing segments and the returned space
 * into a single segment.  In this case the resource map is
 * made smaller by copying together to fill the resultant gap.
 *
 * N.B.: the current implementation uses a dense array and does
 * not admit the value ``0'' as a legal address, since that is used
 * as a delimiter.
 */

/*
 * Initialize map mp to have (mapsize-2) segments
 * and to be called ``name'', which we print if
 * the slots become so fragmented that we lose space.
 * The map itself is initialized with size elements free
 * starting at addr.
 */
rminit(mp, size, addr, name, mapsize)
	register struct map *mp;
	long size, addr;
	char *name;
	int mapsize;
{
	register struct mapent *ep = (struct mapent *)(mp+1);

	mp->m_name = name;
/* N.B.: WE ASSUME HERE THAT sizeof (struct map) == sizeof (struct mapent) */
	/*
	 * One of the mapsize slots is taken by the map structure,
	 * segments has size 0 and addr 0, and acts as a delimiter.
	 * We insure that we never use segments past the end of
	 * the array which is given by mp->m_limit.
	 * Instead, when excess segments occur we discard some resources.
	 */
	mp->m_limit = (struct mapent *)&mp[mapsize];
	/*
	 * Simulate a rmfree(), but with the option to
	 * call with size 0 and addr 0 when we just want
	 * to initialize without freeing.
	 */
	ep->m_size = size;
	ep->m_addr = addr;
}

/*
 * Allocate 'size' units from the given
 * map. Return the base of the allocated space.
 * In a map, the addresses are increasing and the
 * list is terminated by a 0 size.
 *
 * Algorithm is first-fit.
 *
 * This routine knows about the interleaving of the swapmap
 * and handles that.
 */
long
rmalloc(mp, size)
	register struct map *mp;
	long size;
{
	register struct mapent *ep = (struct mapent *)(mp+1);
	register int addr;
	register struct mapent *bp;
	swblk_t first, rest;

	if (size <= 0 || mp == swapmap && size > DMMAX)
		panic("rmalloc");
	/*
	 * Search for a piece of the resource map which has enough
	 * free space to accomodate the request.
	 */
	for (bp = ep; bp->m_size; bp++) {
		if (bp->m_size >= size) {
			/*
			 * If allocating from swapmap,
			 * then have to respect interleaving
			 * boundaries.
			 */
			if (mp == swapmap &&
			    (first = DMMAX - bp->m_addr%DMMAX) < bp->m_size) {
				if (bp->m_size - first < size)
					continue;
				addr = bp->m_addr + first;
				rest = bp->m_size - first - size;
				bp->m_size = first;
				if (rest)
					rmfree(swapmap, rest, addr+size);
				return (addr);
			}
			/*
			 * Allocate from the map.
			 * If there is no space left of the piece
			 * we allocated from, move the rest of
			 * the pieces to the left.
			 */
			addr = bp->m_addr;
			bp->m_addr += size;
			if ((bp->m_size -= size) == 0) {
				do {
					bp++;
					(bp-1)->m_addr = bp->m_addr;
				} while ((bp-1)->m_size = bp->m_size);
			}
			if (mp == swapmap && addr % CLSIZE)
				panic("rmalloc swapmap");
			return (addr);
		}
	}
	return (0);
}

/*
 * Free the previously allocated space at addr
 * of size units into the specified map.
 * Sort addr into map and combine on
 * one or both ends if possible.
 */
rmfree(mp, size, addr)
	struct map *mp;
	long size, addr;
{
	struct mapent *firstbp;
	register struct mapent *bp;
	register int t;

	/*
	 * Both address and size must be
	 * positive, or the protocol has broken down.
	 */
	if (addr <= 0 || size <= 0)
		goto badrmfree;
	/*
	 * Locate the piece of the map which starts after the
	 * returned space (or the end of the map).
	 */
	firstbp = bp = (struct mapent *)(mp + 1);
	for (; bp->m_addr <= addr && bp->m_size != 0; bp++)
		continue;
	/*
	 * If the piece on the left abuts us,
	 * then we should combine with it.
	 */
	if (bp > firstbp && (bp-1)->m_addr+(bp-1)->m_size >= addr) {
		/*
		 * Check no overlap (internal error).
		 */
		if ((bp-1)->m_addr+(bp-1)->m_size > addr)
			goto badrmfree;
		/*
		 * Add into piece on the left by increasing its size.
		 */
		(bp-1)->m_size += size;
		/*
		 * If the combined piece abuts the piece on
		 * the right now, compress it in also,
		 * by shifting the remaining pieces of the map over.
		 */
		if (bp->m_addr && addr+size >= bp->m_addr) {
			if (addr+size > bp->m_addr)
				goto badrmfree;
			(bp-1)->m_size += bp->m_size;
			while (bp->m_size) {
				bp++;
				(bp-1)->m_addr = bp->m_addr;
				(bp-1)->m_size = bp->m_size;
			}
		}
		goto done;
	}
	/*
	 * Don't abut on the left, check for abutting on
	 * the right.
	 */
	if (addr+size >= bp->m_addr && bp->m_size) {
		if (addr+size > bp->m_addr)
			goto badrmfree;
		bp->m_addr -= size;
		bp->m_size += size;
		goto done;
	}
	/*
	 * Don't abut at all.  Make a new entry
	 * and check for map overflow.
	 */
	do {
		t = bp->m_addr;
		bp->m_addr = addr;
		addr = t;
		t = bp->m_size;
		bp->m_size = size;
		bp++;
	} while (size = t);
	/*
	 * Segment at bp is to be the delimiter;
	 * If there is not room for it 
	 * then the table is too full
	 * and we must discard something.
	 */
	if (bp+1 > mp->m_limit) {
		/*
		 * Back bp up to last available segment.
		 * which contains a segment already and must
		 * be made into the delimiter.
		 * Discard second to last entry,
		 * since it is presumably smaller than the last
		 * and move the last entry back one.
		 */
		bp--;
		printf("%s: rmap ovflo, lost [%d,%d)\n", mp->m_name,
		    (bp-1)->m_addr, (bp-1)->m_addr+(bp-1)->m_size);
		bp[-1] = bp[0];
		bp[0].m_size = bp[0].m_addr = 0;
	}
done:
	/*
	 * THIS IS RIDICULOUS... IT DOESN'T BELONG HERE!
	 */
	if ((mp == kernelmap) && kmapwnt) {
		kmapwnt = 0;
		wakeup((caddr_t)kernelmap);
	}
	return;
badrmfree:
	panic("bad rmfree");
}

/*
 * Allocate 'size' units from the given map, starting at address 'addr'.
 * Return 'addr' if successful, 0 if not.
 * This may cause the creation or destruction of a resource map segment.
 *
 * This routine will return failure status if there is not enough room
 * for a required additional map segment.
 *
 * An attempt to use this on 'swapmap' will result in
 * a failure return.  This is due mainly to laziness and could be fixed
 * to do the right thing, although it probably will never be used.
 */
rmget(mp, size, addr)
	register struct map *mp;
{
	register struct mapent *ep = (struct mapent *)(mp+1);
	register struct mapent *bp, *bp2;

	if (size <= 0)
		panic("rmget");
	if (mp == swapmap)
		return (0);
	/*
	 * Look for a map segment containing the requested address.
	 * If none found, return failure.
	 */
	for (bp = ep; bp->m_size; bp++)
		if (bp->m_addr <= addr && bp->m_addr + bp->m_size > addr)
			break;
	if (bp->m_size == 0)
		return (0);

	/*
	 * If segment is too small, return failure.
	 * If big enough, allocate the block, compressing or expanding
	 * the map as necessary.
	 */
	if (bp->m_addr + bp->m_size < addr + size)
		return (0);
	if (bp->m_addr == addr)
		if (bp->m_addr + bp->m_size == addr + size) {
			/*
			 * Allocate entire segment and compress map
			 */
			bp2 = bp;
			while (bp2->m_size) {
				bp2++;
				(bp2-1)->m_addr = bp2->m_addr;
				(bp2-1)->m_size = bp2->m_size;
			}
		} else {
			/*
			 * Allocate first part of segment
			 */
			bp->m_addr += size;
			bp->m_size -= size;
		}
	else
		if (bp->m_addr + bp->m_size == addr + size) {
			/*
			 * Allocate last part of segment
			 */
			bp->m_size -= size;
		} else {
			/*
			 * Allocate from middle of segment, but only
			 * if table can be expanded.
			 */
			for (bp2=bp; bp2->m_size; bp2++)
				;
			if (bp2 == mp->m_limit)
				return (0);
			while (bp2 > bp) {
				(bp2+1)->m_addr = bp2->m_addr;
				(bp2+1)->m_size = bp2->m_size;
				bp2--;
			}
			(bp+1)->m_addr = addr + size;
			(bp+1)->m_size =
			    bp->m_addr + bp->m_size - (addr + size);
			bp->m_size = addr - bp->m_addr;
		}
	return (addr);
}
Commit	Line	Data
a29f7995	1	/* subr_rmap.c 4.8 82/10/21 */
2694e78a BJ	2
	3	#include "../h/param.h"
	4	#include "../h/systm.h"
	5	#include "../h/map.h"
	6	#include "../h/dir.h"
	7	#include "../h/user.h"
	8	#include "../h/proc.h"
2694e78a	9	#include "../h/text.h"
39d536e6	10	#include "../h/kernel.h"
2694e78a	11
b725a0ca BJ	12	/*
	13	* Resource map handling routines.
	14	*
	15	* A resource map is an array of structures each
	16	* of which describes a segment of the address space of an available
	17	* resource. The segments are described by their base address and
	18	* length, and sorted in address order. Each resource map has a fixed
	19	* maximum number of segments allowed. Resources are allocated
	20	* by taking part or all of one of the segments of the map.
	21	*
	22	* Returning of resources will require another segment if
	23	* the returned resources are not adjacent in the address
	24	* space to an existing segment. If the return of a segment
	25	* would require a slot which is not available, then one of
	26	* the resource map segments is discarded after a warning is printed.
	27	* Returning of resources may also cause the map to collapse
	28	* by coalescing two existing segments and the returned space
	29	* into a single segment. In this case the resource map is
	30	* made smaller by copying together to fill the resultant gap.
	31	*
	32	* N.B.: the current implementation uses a dense array and does
	33	* not admit the value ``0'' as a legal address, since that is used
	34	* as a delimiter.
	35	*/
	36
	37	/*
	38	* Initialize map mp to have (mapsize-2) segments
	39	* and to be called ``name'', which we print if
	40	* the slots become so fragmented that we lose space.
	41	* The map itself is initialized with size elements free
	42	* starting at addr.
	43	*/
	44	rminit(mp, size, addr, name, mapsize)
	45	register struct map *mp;
a29f7995	46	long size, addr;
b725a0ca BJ	47	char *name;
	48	int mapsize;
	49	{
	50	register struct mapent ep = (struct mapent )(mp+1);
	51
	52	mp->m_name = name;
	53	/* N.B.: WE ASSUME HERE THAT sizeof (struct map) == sizeof (struct mapent) */
	54	/*
	55	* One of the mapsize slots is taken by the map structure,
	56	* segments has size 0 and addr 0, and acts as a delimiter.
	57	* We insure that we never use segments past the end of
	58	* the array which is given by mp->m_limit.
	59	* Instead, when excess segments occur we discard some resources.
	60	*/
	61	mp->m_limit = (struct mapent *)&mp[mapsize];
	62	/*
	63	* Simulate a rmfree(), but with the option to
	64	* call with size 0 and addr 0 when we just want
	65	* to initialize without freeing.
	66	*/
	67	ep->m_size = size;
	68	ep->m_addr = addr;
	69	}
	70
2694e78a BJ	71	/*
2694e78a BJ	72	* Allocate 'size' units from the given
b725a0ca	73	* map. Return the base of the allocated space.
2694e78a BJ	74	* In a map, the addresses are increasing and the
2694e78a BJ	75	* list is terminated by a 0 size.
b725a0ca	76	*
2694e78a	77	* Algorithm is first-fit.
b725a0ca BJ	78	*
	79	* This routine knows about the interleaving of the swapmap
	80	* and handles that.
2694e78a	81	*/
39d536e6	82	long
b725a0ca BJ	83	rmalloc(mp, size)
b725a0ca BJ	84	register struct map *mp;
39d536e6	85	long size;
2694e78a	86	{
b725a0ca BJ	87	register struct mapent ep = (struct mapent )(mp+1);
	88	register int addr;
	89	register struct mapent *bp;
41888f16	90	swblk_t first, rest;
2694e78a	91
41888f16	92	if (size <= 0 \|\| mp == swapmap && size > DMMAX)
b725a0ca BJ	93	panic("rmalloc");
	94	/*
	95	* Search for a piece of the resource map which has enough
	96	* free space to accomodate the request.
	97	*/
	98	for (bp = ep; bp->m_size; bp++) {
2694e78a	99	if (bp->m_size >= size) {
b725a0ca BJ	100	/*
	101	* If allocating from swapmap,
	102	* then have to respect interleaving
	103	* boundaries.
	104	*/
41888f16 BJ	105	if (mp == swapmap &&
	106	(first = DMMAX - bp->m_addr%DMMAX) < bp->m_size) {
	107	if (bp->m_size - first < size)
	108	continue;
b725a0ca	109	addr = bp->m_addr + first;
41888f16 BJ	110	rest = bp->m_size - first - size;
	111	bp->m_size = first;
	112	if (rest)
b725a0ca BJ	113	rmfree(swapmap, rest, addr+size);
b725a0ca BJ	114	return (addr);
41888f16	115	}
b725a0ca BJ	116	/*
	117	* Allocate from the map.
	118	* If there is no space left of the piece
	119	* we allocated from, move the rest of
	120	* the pieces to the left.
	121	*/
	122	addr = bp->m_addr;
2694e78a BJ	123	bp->m_addr += size;
	124	if ((bp->m_size -= size) == 0) {
	125	do {
	126	bp++;
	127	(bp-1)->m_addr = bp->m_addr;
	128	} while ((bp-1)->m_size = bp->m_size);
	129	}
b725a0ca BJ	130	if (mp == swapmap && addr % CLSIZE)
	131	panic("rmalloc swapmap");
	132	return (addr);
2694e78a BJ	133	}
2694e78a BJ	134	}
b725a0ca	135	return (0);
2694e78a BJ	136	}
	137
	138	/*
b725a0ca	139	* Free the previously allocated space at addr
2694e78a	140	* of size units into the specified map.
b725a0ca	141	* Sort addr into map and combine on
2694e78a BJ	142	* one or both ends if possible.
2694e78a BJ	143	*/
b725a0ca BJ	144	rmfree(mp, size, addr)
b725a0ca BJ	145	struct map *mp;
39d536e6	146	long size, addr;
2694e78a	147	{
b725a0ca BJ	148	struct mapent *firstbp;
b725a0ca BJ	149	register struct mapent *bp;
2694e78a BJ	150	register int t;
2694e78a BJ	151
b725a0ca BJ	152	/*
	153	* Both address and size must be
	154	* positive, or the protocol has broken down.
	155	*/
	156	if (addr <= 0 \|\| size <= 0)
	157	goto badrmfree;
	158	/*
	159	* Locate the piece of the map which starts after the
	160	* returned space (or the end of the map).
	161	*/
	162	firstbp = bp = (struct mapent *)(mp + 1);
	163	for (; bp->m_addr <= addr && bp->m_size != 0; bp++)
2694e78a	164	continue;
b725a0ca BJ	165	/*
	166	* If the piece on the left abuts us,
	167	* then we should combine with it.
	168	*/
	169	if (bp > firstbp && (bp-1)->m_addr+(bp-1)->m_size >= addr) {
	170	/*
	171	* Check no overlap (internal error).
	172	*/
	173	if ((bp-1)->m_addr+(bp-1)->m_size > addr)
	174	goto badrmfree;
	175	/*
	176	* Add into piece on the left by increasing its size.
	177	*/
2694e78a	178	(bp-1)->m_size += size;
b725a0ca BJ	179	/*
	180	* If the combined piece abuts the piece on
	181	* the right now, compress it in also,
	182	* by shifting the remaining pieces of the map over.
	183	*/
	184	if (bp->m_addr && addr+size >= bp->m_addr) {
	185	if (addr+size > bp->m_addr)
	186	goto badrmfree;
2694e78a BJ	187	(bp-1)->m_size += bp->m_size;
	188	while (bp->m_size) {
	189	bp++;
	190	(bp-1)->m_addr = bp->m_addr;
	191	(bp-1)->m_size = bp->m_size;
	192	}
	193	}
b725a0ca BJ	194	goto done;
	195	}
	196	/*
	197	* Don't abut on the left, check for abutting on
	198	* the right.
	199	*/
	200	if (addr+size >= bp->m_addr && bp->m_size) {
	201	if (addr+size > bp->m_addr)
	202	goto badrmfree;
	203	bp->m_addr -= size;
	204	bp->m_size += size;
	205	goto done;
	206	}
	207	/*
	208	* Don't abut at all. Make a new entry
	209	* and check for map overflow.
	210	*/
	211	do {
	212	t = bp->m_addr;
	213	bp->m_addr = addr;
	214	addr = t;
	215	t = bp->m_size;
	216	bp->m_size = size;
	217	bp++;
	218	} while (size = t);
	219	/*
	220	* Segment at bp is to be the delimiter;
	221	* If there is not room for it
	222	* then the table is too full
	223	* and we must discard something.
	224	*/
	225	if (bp+1 > mp->m_limit) {
	226	/*
	227	* Back bp up to last available segment.
	228	* which contains a segment already and must
	229	* be made into the delimiter.
	230	* Discard second to last entry,
	231	* since it is presumably smaller than the last
	232	* and move the last entry back one.
	233	*/
	234	bp--;
f4c13170	235	printf("%s: rmap ovflo, lost [%d,%d)\n", mp->m_name,
b725a0ca BJ	236	(bp-1)->m_addr, (bp-1)->m_addr+(bp-1)->m_size);
	237	bp[-1] = bp[0];
	238	bp[0].m_size = bp[0].m_addr = 0;
2694e78a	239	}
b725a0ca BJ	240	done:
	241	/*
	242	* THIS IS RIDICULOUS... IT DOESN'T BELONG HERE!
	243	*/
2694e78a BJ	244	if ((mp == kernelmap) && kmapwnt) {
	245	kmapwnt = 0;
	246	wakeup((caddr_t)kernelmap);
	247	}
b725a0ca BJ	248	return;
	249	badrmfree:
	250	panic("bad rmfree");
2694e78a	251	}
1c1f6ecf BF	252
	253	/*
	254	* Allocate 'size' units from the given map, starting at address 'addr'.
	255	* Return 'addr' if successful, 0 if not.
	256	* This may cause the creation or destruction of a resource map segment.
	257	*
	258	* This routine will return failure status if there is not enough room
	259	* for a required additional map segment.
	260	*
	261	* An attempt to use this on 'swapmap' will result in
	262	* a failure return. This is due mainly to laziness and could be fixed
	263	* to do the right thing, although it probably will never be used.
	264	*/
	265	rmget(mp, size, addr)
	266	register struct map *mp;
	267	{
	268	register struct mapent ep = (struct mapent )(mp+1);
	269	register struct mapent bp, bp2;
	270
	271	if (size <= 0)
	272	panic("rmget");
	273	if (mp == swapmap)
	274	return (0);
	275	/*
	276	* Look for a map segment containing the requested address.
	277	* If none found, return failure.
	278	*/
	279	for (bp = ep; bp->m_size; bp++)
	280	if (bp->m_addr <= addr && bp->m_addr + bp->m_size > addr)
	281	break;
	282	if (bp->m_size == 0)
	283	return (0);
	284
	285	/*
	286	* If segment is too small, return failure.
	287	* If big enough, allocate the block, compressing or expanding
	288	* the map as necessary.
	289	*/
	290	if (bp->m_addr + bp->m_size < addr + size)
	291	return (0);
	292	if (bp->m_addr == addr)
	293	if (bp->m_addr + bp->m_size == addr + size) {
	294	/*
	295	* Allocate entire segment and compress map
	296	*/
	297	bp2 = bp;
	298	while (bp2->m_size) {
	299	bp2++;
	300	(bp2-1)->m_addr = bp2->m_addr;
	301	(bp2-1)->m_size = bp2->m_size;
	302	}
	303	} else {
	304	/*
	305	* Allocate first part of segment
	306	*/
	307	bp->m_addr += size;
	308	bp->m_size -= size;
	309	}
	310	else
	311	if (bp->m_addr + bp->m_size == addr + size) {
	312	/*
	313	* Allocate last part of segment
	314	*/
	315	bp->m_size -= size;
316	} else {
317	/*
318	* Allocate from middle of segment, but only
319	* if table can be expanded.
320	*/
321	for (bp2=bp; bp2->m_size; bp2++)
322	;
323	if (bp2 == mp->m_limit)
324	return (0);
325	while (bp2 > bp) {
326	(bp2+1)->m_addr = bp2->m_addr;
327	(bp2+1)->m_size = bp2->m_size;
328	bp2--;
329	}
330	(bp+1)->m_addr = addr + size;
331	(bp+1)->m_size =
332	bp->m_addr + bp->m_size - (addr + size);
333	bp->m_size = addr - bp->m_addr;
334	}
335	return (addr);
336	}