patch-2.2.18 linux/drivers/char/drm/lists.c

• Lines: 231
• Date: Tue Nov 28 17:33:24 2000
• Orig file: v2.2.17/drivers/char/drm/lists.c
• Orig date: Thu Jan 1 01:00:00 1970

diff -u --new-file --recursive --exclude-from /usr/src/exclude v2.2.17/drivers/char/drm/lists.c linux/drivers/char/drm/lists.c
@@ -0,0 +1,230 @@
+/* lists.c -- Buffer list handling routines -*- linux-c -*-
+ * Created: Mon Apr 19 20:54:22 1999 by faith@precisioninsight.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
+ * 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>
+ *
+ */
+
+#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->lock      = SPIN_LOCK_UNLOCKED;
+	++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_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;
+	
+	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;
+	}
+		
+	DRM_DEBUG("Count = %d, wfh = %d\n",
+		  atomic_read(&bl->count), atomic_read(&bl->wfh));
+	return drm_freelist_try(bl);
+}