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path: root/bsd/drm_sysctl.h
AgeCommit message (Collapse)Author
2003-10-24Don't try to use dev->dma_lock unless dma is initialized (dev->dma != NULL)Eric Anholt
in bufs_info sysctl handler. dev->dma and dev->dma_lock existence are protected by DRM_LOCK(). Fixes panic on sysctl hw.dri when the device is uninitialied (when you aren't in X).
2003-10-22Fix warning about static DRM(bufs_info) defined but not used in theEric Anholt
!__HAVE_DMA case.
2003-10-20Fix the possibility of sleeping with locks held in sysctls by copying theEric Anholt
data into temporary variables with the lock held then outputting to sysctls with the lock released. Rearranged a little extra code to aid this. Note that drm_memory_debug.h hasn't had this fix applied, but I consider that code to be just about dead anyway.
2003-10-19- SMPng lock the DRM. This is only partial -- there are a few code pathsEric Anholt
used by root (the X Server) which are not locked. However, it should deal with lost-IRQ issues on -current which I think people have been experiencing but I am unable to reproduce (though I understand why they would occur, because of a bug of mine). Note that most of the locking (DRM_LOCK()/UNLOCK()) is all covered by Giant still, so it doesn't matter yet. - Remove locking on FreeBSD-stable and NetBSD. These are covered by the fact that there is no reentrancy of the kernel except by interrupts, which are locked using spldrm()/splx() instead.
2003-10-03Stylistic preparation for SMPng locking work: DRM_LOCK/DRM_UNLOCK have sideEric Anholt
effects, so make them look like functions (add parenthesis).
2003-10-02Add an MIT-style copyright, assigned to myself, to these files. I thinkEric Anholt
I've touched enough of the code here, and there was no previous copyright. Do some drive-by style fixes while I'm here.
2003-08-19- Remove $FreeBSD$ tags as they weren't too useful and merges are now beingEric Anholt
done through perforce. - Add copyright headers to drm_os_*bsd.h, still need to research the other copyright-less files better.
2003-04-26Fix formatting of hw.dri sysctl.Eric Anholt
2003-04-26Missed files in the last commit: Remove memory debugging sysctl unlessEric Anholt
MEMORY_DEBUG is set.
2003-04-25Merge from FreeBSD-current.Eric Anholt
2003-04-24Remove more gamma DMA infrastructure. Most of this code was copied straightEric Anholt
from linux, so it could be added back if some driver needed it in the future.
2003-04-24Remove DRM_DMA_HISTOGRAM and associated code.Eric Anholt
2003-03-29Remove dead vma code and remove the unused devstate struct definition.Eric Anholt
2003-03-11Merge back from FreeBSD-current, adding FreeBSD ID tags to aid futureEric Anholt
merging. Also includes an update to radeon PCI IDs.
2003-02-21Merge from bsd-4-0-0-branch.Eric Anholt
2002-09-29warnings cleanupEric Anholt
2002-07-05merged bsd-3-0-0-branchAlan Hourihane
2002-01-27Import of XFree86 4.2.0David Dawes
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/* xf86drmHash.c -- Small hash table support for integer -> integer mapping
 * Created: Sun Apr 18 09:35:45 1999 by faith@precisioninsight.com
 *
 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * Authors: Rickard E. (Rik) Faith <faith@valinux.com>
 *
 * DESCRIPTION
 *
 * This file contains a straightforward implementation of a fixed-sized
 * hash table using self-organizing linked lists [Knuth73, pp. 398-399] for
 * collision resolution.  There are two potentially interesting things
 * about this implementation:
 *
 * 1) The table is power-of-two sized.  Prime sized tables are more
 * traditional, but do not have a significant advantage over power-of-two
 * sized table, especially when double hashing is not used for collision
 * resolution.
 *
 * 2) The hash computation uses a table of random integers [Hanson97,
 * pp. 39-41].
 *
 * FUTURE ENHANCEMENTS
 *
 * With a table size of 512, the current implementation is sufficient for a
 * few hundred keys.  Since this is well above the expected size of the
 * tables for which this implementation was designed, the implementation of
 * dynamic hash tables was postponed until the need arises.  A common (and
 * naive) approach to dynamic hash table implementation simply creates a
 * new hash table when necessary, rehashes all the data into the new table,
 * and destroys the old table.  The approach in [Larson88] is superior in
 * two ways: 1) only a portion of the table is expanded when needed,
 * distributing the expansion cost over several insertions, and 2) portions
 * of the table can be locked, enabling a scalable thread-safe
 * implementation.
 *
 * REFERENCES
 *
 * [Hanson97] David R. Hanson.  C Interfaces and Implementations:
 * Techniques for Creating Reusable Software.  Reading, Massachusetts:
 * Addison-Wesley, 1997.
 *
 * [Knuth73] Donald E. Knuth. The Art of Computer Programming.  Volume 3:
 * Sorting and Searching.  Reading, Massachusetts: Addison-Wesley, 1973.
 *
 * [Larson88] Per-Ake Larson. "Dynamic Hash Tables".  CACM 31(4), April
 * 1988, pp. 446-457.
 *
 */

#include <stdio.h>
#include <stdlib.h>

#define HASH_MAIN 0

#if !HASH_MAIN
# include "xf86drm.h"
#endif

#define HASH_MAGIC 0xdeadbeef
#define HASH_DEBUG 0
#define HASH_SIZE  512		/* Good for about 100 entries */
				/* If you change this value, you probably
                                   have to change the HashHash hashing
                                   function! */

#if HASH_MAIN
#define HASH_ALLOC malloc
#define HASH_FREE  free
#define HASH_RANDOM_DECL
#define HASH_RANDOM_INIT(seed)  srandom(seed)
#define HASH_RANDOM             random()
#define HASH_RANDOM_DESTROY
#else
#define HASH_ALLOC drmMalloc
#define HASH_FREE  drmFree
#define HASH_RANDOM_DECL        void *state
#define HASH_RANDOM_INIT(seed)  state = drmRandomCreate(seed)
#define HASH_RANDOM             drmRandom(state)
#define HASH_RANDOM_DESTROY     drmRandomDestroy(state)

#endif

typedef struct HashBucket {
    unsigned long     key;
    void              *value;
    struct HashBucket *next;
} HashBucket, *HashBucketPtr;

typedef struct HashTable {
    unsigned long    magic;
    unsigned long    entries;
    unsigned long    hits;	/* At top of linked list */
    unsigned long    partials;	/* Not at top of linked list */
    unsigned long    misses;	/* Not in table */
    HashBucketPtr    buckets[HASH_SIZE];
    int              p0;
    HashBucketPtr    p1;
} HashTable, *HashTablePtr;

#if HASH_MAIN
extern void *drmHashCreate(void);
extern int  drmHashDestroy(void *t);
extern int  drmHashLookup(void *t, unsigned long key, unsigned long *value);
extern int  drmHashInsert(void *t, unsigned long key, unsigned long value);
extern int  drmHashDelete(void *t, unsigned long key);
#endif

static unsigned long HashHash(unsigned long key)
{
    unsigned long        hash = 0;
    unsigned long        tmp  = key;
    static int           init = 0;
    static unsigned long scatter[256];
    int                  i;

    if (!init) {
	HASH_RANDOM_DECL;
	HASH_RANDOM_INIT(37);
	for (i = 0; i < 256; i++) scatter[i] = HASH_RANDOM;
	HASH_RANDOM_DESTROY;
	++init;
    }

    while (tmp) {
	hash = (hash << 1) + scatter[tmp & 0xff];
	tmp >>= 8;
    }

    hash %= HASH_SIZE;
#if HASH_DEBUG
    printf( "Hash(%d) = %d\n", key, hash);
#endif
    return hash;
}

void *drmHashCreate(void)
{
    HashTablePtr table;
    int          i;

    table           = HASH_ALLOC(sizeof(*table));
    if (!table) return NULL;
    table->magic    = HASH_MAGIC;
    table->entries  = 0;
    table->hits     = 0;
    table->partials = 0;
    table->misses   = 0;

    for (i = 0; i < HASH_SIZE; i++) table->buckets[i] = NULL;
    return table;
}

int drmHashDestroy(void *t)
{
    HashTablePtr  table = (HashTablePtr)t;
    HashBucketPtr bucket;
    HashBucketPtr next;
    int           i;

    if (table->magic != HASH_MAGIC) return -1; /* Bad magic */

    for (i = 0; i < HASH_SIZE; i++) {
	for (bucket = table->buckets[i]; bucket;) {
	    next = bucket->next;
	    HASH_FREE(bucket);
	    bucket = next;
	}
    }
    HASH_FREE(table);
    return 0;
}

/* Find the bucket and organize the list so that this bucket is at the
   top. */

static HashBucketPtr HashFind(HashTablePtr table,
			      unsigned long key, unsigned long *h)
{
    unsigned long hash = HashHash(key);
    HashBucketPtr prev = NULL;
    HashBucketPtr bucket;

    if (h) *h = hash;

    for (bucket = table->buckets[hash]; bucket; bucket = bucket->next) {
	if (bucket->key == key) {
	    if (prev) {
				/* Organize */
		prev->next           = bucket->next;
		bucket->next         = table->buckets[hash];
		table->buckets[hash] = bucket;
		++table->partials;
	    } else {
		++table->hits;
	    }
	    return bucket;
	}
	prev = bucket;
    }
    ++table->misses;
    return NULL;
}

int drmHashLookup(void *t, unsigned long key, void **value)
{
    HashTablePtr  table = (HashTablePtr)t;
    HashBucketPtr bucket;

    if (!table || table->magic != HASH_MAGIC) return -1; /* Bad magic */

    bucket = HashFind(table, key, NULL);
    if (!bucket) return 1;	/* Not found */
    *value = bucket->value;
    return 0;			/* Found */
}

int drmHashInsert(void *t, unsigned long key, void *value)
{
    HashTablePtr  table = (HashTablePtr)t;
    HashBucketPtr bucket;
    unsigned long hash;

    if (table->magic != HASH_MAGIC) return -1; /* Bad magic */

    if (HashFind(table, key, &hash)) return 1; /* Already in table */

    bucket               = HASH_ALLOC(sizeof(*bucket));
    if (!bucket) return -1;	/* Error */
    bucket->key          = key;
    bucket->value        = value;
    bucket->next         = table->buckets[hash];
    table->buckets[hash] = bucket;
#if HASH_DEBUG
    printf("Inserted %d at %d/%p\n", key, hash, bucket);
#endif
    return 0;			/* Added to table */
}

int drmHashDelete(void *t, unsigned long key)
{
    HashTablePtr  table = (HashTablePtr)t;
    unsigned long hash;
    HashBucketPtr bucket;

    if (table->magic != HASH_MAGIC) return -1; /* Bad magic */

    bucket = HashFind(table, key, &hash);

    if (!bucket) return 1;	/* Not found */

    table->buckets[hash] = bucket->next;
    HASH_FREE(bucket);
    return 0;
}

int drmHashNext(void *t, unsigned long *key, void **value)
{
    HashTablePtr  table = (HashTablePtr)t;

    while (table->p0 < HASH_SIZE) {
	if (table->p1) {
	    *key       = table->p1->key;
	    *value     = table->p1->value;
	    table->p1  = table->p1->next;
	    return 1;
	}
	table->p1 = table->buckets[table->p0];
	++table->p0;
    }
    return 0;
}

int drmHashFirst(void *t, unsigned long *key, void **value)
{
    HashTablePtr  table = (HashTablePtr)t;

    if (table->magic != HASH_MAGIC) return -1; /* Bad magic */

    table->p0 = 0;
    table->p1 = table->buckets[0];
    return drmHashNext(table, key, value);
}

#if HASH_MAIN
#define DIST_LIMIT 10
static int dist[DIST_LIMIT];

static void clear_dist(void) {
    int i;

    for (i = 0; i < DIST_LIMIT; i++) dist[i] = 0;
}

static int count_entries(HashBucketPtr bucket)
{
    int count = 0;

    for (; bucket; bucket = bucket->next) ++count;
    return count;
}

static void update_dist(int count)
{
    if (count >= DIST_LIMIT) ++dist[DIST_LIMIT-1];
    else                     ++dist[count];
}

static void compute_dist(HashTablePtr table)
{
    int           i;
    HashBucketPtr bucket;

    printf("Entries = %ld, hits = %ld, partials = %ld, misses = %ld\n",
	   table->entries, table->hits, table->partials, table->misses);
    clear_dist();
    for (i = 0; i < HASH_SIZE; i++) {
	bucket = table->buckets[i];
	update_dist(count_entries(bucket));
    }
    for (i = 0; i < DIST_LIMIT; i++) {
	if (i != DIST_LIMIT-1) printf("%5d %10d\n", i, dist[i]);
	else                   printf("other %10d\n", dist[i]);
    }
}

static void check_table(HashTablePtr table,
			unsigned long key, unsigned long value)
{
    unsigned long retval  = 0;
    int           retcode = drmHashLookup(table, key, &retval);

    switch (retcode) {
    case -1:
	printf("Bad magic = 0x%08lx:"
	       " key = %lu, expected = %lu, returned = %lu\n",
	       table->magic, key, value, retval);
	break;
    case 1:
	printf("Not found: key = %lu, expected = %lu returned = %lu\n",
	       key, value, retval);
	break;
    case 0:
	if (value != retval)
	    printf("Bad value: key = %lu, expected = %lu, returned = %lu\n",
		   key, value, retval);
	break;
    default:
	printf("Bad retcode = %d: key = %lu, expected = %lu, returned = %lu\n",
	       retcode, key, value, retval);
	break;
    }
}

int main(void)
{
    HashTablePtr table;
    int          i;

    printf("\n***** 256 consecutive integers ****\n");
    table = drmHashCreate();
    for (i = 0; i < 256; i++) drmHashInsert(table, i, i);
    for (i = 0; i < 256; i++) check_table(table, i, i);
    for (i = 256; i >= 0; i--) check_table(table, i, i);
    compute_dist(table);
    drmHashDestroy(table);

    printf("\n***** 1024 consecutive integers ****\n");
    table = drmHashCreate();
    for (i = 0; i < 1024; i++) drmHashInsert(table, i, i);
    for (i = 0; i < 1024; i++) check_table(table, i, i);
    for (i = 1024; i >= 0; i--) check_table(table, i, i);
    compute_dist(table);
    drmHashDestroy(table);

    printf("\n***** 1024 consecutive page addresses (4k pages) ****\n");
    table = drmHashCreate();
    for (i = 0; i < 1024; i++) drmHashInsert(table, i*4096, i);
    for (i = 0; i < 1024; i++) check_table(table, i*4096, i);
    for (i = 1024; i >= 0; i--) check_table(table, i*4096, i);
    compute_dist(table);
    drmHashDestroy(table);

    printf("\n***** 1024 random integers ****\n");
    table = drmHashCreate();
    srandom(0xbeefbeef);
    for (i = 0; i < 1024; i++) drmHashInsert(table, random(), i);
    srandom(0xbeefbeef);
    for (i = 0; i < 1024; i++) check_table(table, random(), i);
    srandom(0xbeefbeef);
    for (i = 0; i < 1024; i++) check_table(table, random(), i);
    compute_dist(table);
    drmHashDestroy(table);

    printf("\n***** 5000 random integers ****\n");
    table = drmHashCreate();
    srandom(0xbeefbeef);
    for (i = 0; i < 5000; i++) drmHashInsert(table, random(), i);
    srandom(0xbeefbeef);
    for (i = 0; i < 5000; i++) check_table(table, random(), i);
    srandom(0xbeefbeef);
    for (i = 0; i < 5000; i++) check_table(table, random(), i);
    compute_dist(table);
    drmHashDestroy(table);

    return 0;
}
#endif
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