/* drm_lists.h -- Buffer list handling routines -*- linux-c -*-
* Created: Mon Apr 19 20:54:22 1999 by faith@valinux.com
*
* Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
* 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
* VA LINUX SYSTEMS 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>
* Gareth Hughes <gareth@valinux.com>
*/
#include "drmP.h"
int DRM(waitlist_create)(drm_waitlist_t *bl, int count)
{
if (bl->count) return -EINVAL;
bl->bufs = DRM(alloc)((bl->count + 2) * sizeof(*bl->bufs),
DRM_MEM_BUFLISTS);
if(!bl->bufs) return -ENOMEM;
memset(bl->bufs, 0, sizeof(*bl->bufs));
bl->count = count;
bl->rp = bl->bufs;
bl->wp = bl->bufs;
bl->end = &bl->bufs[bl->count+1];
spin_lock_init(&bl->write_lock);
spin_lock_init(&bl->read_lock);
return 0;
}
int DRM(waitlist_destroy)(drm_waitlist_t *bl)
{
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);
if (!left) {
DRM_ERROR("Overflow while adding buffer %d from filp %p\n",
buf->idx, buf->filp);
return -EINVAL;
}
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);
return buf;
}
int DRM(freelist_create)(drm_freelist_t *bl, int count)
{
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);
spin_lock_init(&bl->lock);
++bl->initialized;
return 0;
}
int DRM(freelist_destroy)(drm_freelist_t *bl)
{
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_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);
}
if (!bl) return 1;
buf->list = DRM_LIST_FREE;
spin_lock(&bl->lock);
buf->next = bl->next;
bl->next = buf;
spin_unlock(&bl->lock);
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 *buf;
if (!bl) return NULL;
/* Get buffer */
spin_lock(&bl->lock);
if (!bl->next) {
spin_unlock(&bl->lock);
return NULL;
}
buf = bl->next;
bl->next = bl->next->next;
spin_unlock(&bl->lock);
atomic_dec(&bl->count);
buf->next = NULL;
buf->list = DRM_LIST_NONE;
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)) {
if (block) {
add_wait_queue(&bl->waiting, &entry);
for (;;) {
current->state = TASK_INTERRUPTIBLE;
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;
}
return DRM(freelist_try)(bl);
}
