drm/linux/lists.c

246 lines
6.7 KiB
C

/* lists.c -- Buffer list handling routines -*- linux-c -*-
* Created: Mon Apr 19 20:54:22 1999 by faith@precisioninsight.com
* Revised: Mon Dec 6 16:04:44 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.
*
* $PI: xc/programs/Xserver/hw/xfree86/os-support/linux/drm/kernel/lists.c,v 1.3 1999/08/20 15:07:02 faith Exp $
* $XFree86: xc/programs/Xserver/hw/xfree86/os-support/linux/drm/kernel/lists.c,v 1.1 1999/09/25 14:38:01 dawes Exp $
*
*/
#define __NO_VERSION__
#include "drmP.h"
int drm_waitlist_create(drm_waitlist_t *bl, int count)
{
DRM_DEBUG("%d\n", count);
if (bl->count) return -EINVAL;
bl->count = count;
bl->bufs = drm_alloc((bl->count + 2) * sizeof(*bl->bufs),
DRM_MEM_BUFLISTS);
bl->rp = bl->bufs;
bl->wp = bl->bufs;
bl->end = &bl->bufs[bl->count+1];
bl->write_lock = SPIN_LOCK_UNLOCKED;
bl->read_lock = SPIN_LOCK_UNLOCKED;
return 0;
}
int drm_waitlist_destroy(drm_waitlist_t *bl)
{
DRM_DEBUG("\n");
if (bl->rp != bl->wp) return -EINVAL;
if (bl->bufs) drm_free(bl->bufs,
(bl->count + 2) * sizeof(*bl->bufs),
DRM_MEM_BUFLISTS);
bl->count = 0;
bl->bufs = NULL;
bl->rp = NULL;
bl->wp = NULL;
bl->end = NULL;
return 0;
}
int drm_waitlist_put(drm_waitlist_t *bl, drm_buf_t *buf)
{
int left;
unsigned long flags;
left = DRM_LEFTCOUNT(bl);
DRM_DEBUG("put %d (%d left, rp = %p, wp = %p)\n",
buf->idx, left, bl->rp, bl->wp);
if (!left) {
DRM_ERROR("Overflow while adding buffer %d from pid %d\n",
buf->idx, buf->pid);
return -EINVAL;
}
#if DRM_DMA_HISTOGRAM
buf->time_queued = get_cycles();
#endif
buf->list = DRM_LIST_WAIT;
spin_lock_irqsave(&bl->write_lock, flags);
*bl->wp = buf;
if (++bl->wp >= bl->end) bl->wp = bl->bufs;
spin_unlock_irqrestore(&bl->write_lock, flags);
return 0;
}
drm_buf_t *drm_waitlist_get(drm_waitlist_t *bl)
{
drm_buf_t *buf;
unsigned long flags;
spin_lock_irqsave(&bl->read_lock, flags);
buf = *bl->rp;
if (bl->rp == bl->wp) {
spin_unlock_irqrestore(&bl->read_lock, flags);
return NULL;
}
if (++bl->rp >= bl->end) bl->rp = bl->bufs;
spin_unlock_irqrestore(&bl->read_lock, flags);
DRM_DEBUG("get %d\n", buf->idx);
return buf;
}
int drm_freelist_create(drm_freelist_t *bl, int count)
{
DRM_DEBUG("\n");
atomic_set(&bl->count, 0);
bl->next = NULL;
init_waitqueue_head(&bl->waiting);
bl->low_mark = 0;
bl->high_mark = 0;
atomic_set(&bl->wfh, 0);
++bl->initialized;
return 0;
}
int drm_freelist_destroy(drm_freelist_t *bl)
{
DRM_DEBUG("\n");
atomic_set(&bl->count, 0);
bl->next = NULL;
return 0;
}
int drm_freelist_put(drm_device_t *dev, drm_freelist_t *bl, drm_buf_t *buf)
{
drm_buf_t *old, *prev;
int count = 0;
drm_device_dma_t *dma = dev->dma;
if (!dma) {
DRM_ERROR("No DMA support\n");
return 1;
}
if (buf->waiting || buf->pending || buf->list == DRM_LIST_FREE) {
DRM_ERROR("Freed buffer %d: w%d, p%d, l%d\n",
buf->idx, buf->waiting, buf->pending, buf->list);
}
DRM_DEBUG("%d, count = %d, wfh = %d, w%d, p%d\n",
buf->idx, atomic_read(&bl->count), atomic_read(&bl->wfh),
buf->waiting, buf->pending);
if (!bl) return 1;
#if DRM_DMA_HISTOGRAM
buf->time_freed = get_cycles();
drm_histogram_compute(dev, buf);
#endif
buf->list = DRM_LIST_FREE;
do {
old = bl->next;
buf->next = old;
prev = cmpxchg(&bl->next, old, buf);
if (++count > DRM_LOOPING_LIMIT) {
DRM_ERROR("Looping\n");
return 1;
}
} while (prev != old);
atomic_inc(&bl->count);
if (atomic_read(&bl->count) > dma->buf_count) {
DRM_ERROR("%d of %d buffers free after addition of %d\n",
atomic_read(&bl->count), dma->buf_count, buf->idx);
return 1;
}
/* Check for high water mark */
if (atomic_read(&bl->wfh) && atomic_read(&bl->count)>=bl->high_mark) {
atomic_set(&bl->wfh, 0);
wake_up_interruptible(&bl->waiting);
}
return 0;
}
static drm_buf_t *drm_freelist_try(drm_freelist_t *bl)
{
drm_buf_t *old, *new, *prev;
drm_buf_t *buf;
int count = 0;
if (!bl) return NULL;
/* Get buffer */
do {
old = bl->next;
if (!old) return NULL;
new = bl->next->next;
prev = cmpxchg(&bl->next, old, new);
if (++count > DRM_LOOPING_LIMIT) {
DRM_ERROR("Looping\n");
return NULL;
}
} while (prev != old);
atomic_dec(&bl->count);
buf = old;
buf->next = NULL;
buf->list = DRM_LIST_NONE;
DRM_DEBUG("%d, count = %d, wfh = %d, w%d, p%d\n",
buf->idx, atomic_read(&bl->count), atomic_read(&bl->wfh),
buf->waiting, buf->pending);
if (buf->waiting || buf->pending) {
DRM_ERROR("Free buffer %d: w%d, p%d, l%d\n",
buf->idx, buf->waiting, buf->pending, buf->list);
}
return buf;
}
drm_buf_t *drm_freelist_get(drm_freelist_t *bl, int block)
{
drm_buf_t *buf = NULL;
DECLARE_WAITQUEUE(entry, current);
if (!bl || !bl->initialized) return NULL;
/* Check for low water mark */
if (atomic_read(&bl->count) <= bl->low_mark) /* Became low */
atomic_set(&bl->wfh, 1);
if (atomic_read(&bl->wfh)) {
DRM_DEBUG("Block = %d, count = %d, wfh = %d\n",
block, atomic_read(&bl->count),
atomic_read(&bl->wfh));
if (block) {
add_wait_queue(&bl->waiting, &entry);
current->state = TASK_INTERRUPTIBLE;
for (;;) {
if (!atomic_read(&bl->wfh)
&& (buf = drm_freelist_try(bl))) break;
schedule();
if (signal_pending(current)) break;
}
current->state = TASK_RUNNING;
remove_wait_queue(&bl->waiting, &entry);
}
return buf;
}
DRM_DEBUG("Count = %d, wfh = %d\n",
atomic_read(&bl->count), atomic_read(&bl->wfh));
return drm_freelist_try(bl);
}