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

• Lines: 541
• Date: Tue Nov 28 17:33:24 2000
• Orig file: v2.2.17/drivers/char/drm/dma.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/dma.c linux/drivers/char/drm/dma.c
@@ -0,0 +1,540 @@
+/* dma.c -- DMA IOCTL and function support -*- linux-c -*-
+ * Created: Fri Mar 19 14:30:16 1999 by faith@precisioninsight.com
+ *
+ * Copyright 1999, 2000 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@valinuxa.com>
+ *
+ */
+
+#define __NO_VERSION__
+#include "drmP.h"
+
+#include <linux/interrupt.h>	/* For task queue support */
+
+void drm_dma_setup(drm_device_t *dev)
+{
+	int i;
+	
+	dev->dma = drm_alloc(sizeof(*dev->dma), DRM_MEM_DRIVER);
+	memset(dev->dma, 0, sizeof(*dev->dma));
+	for (i = 0; i <= DRM_MAX_ORDER; i++)
+		memset(&dev->dma->bufs[i], 0, sizeof(dev->dma->bufs[0]));
+}
+
+void drm_dma_takedown(drm_device_t *dev)
+{
+	drm_device_dma_t  *dma = dev->dma;
+	int		  i, j;
+
+	if (!dma) return;
+	
+				/* Clear dma buffers */
+	for (i = 0; i <= DRM_MAX_ORDER; i++) {
+		if (dma->bufs[i].seg_count) {
+			DRM_DEBUG("order %d: buf_count = %d,"
+				  " seg_count = %d\n",
+				  i,
+				  dma->bufs[i].buf_count,
+				  dma->bufs[i].seg_count);
+			for (j = 0; j < dma->bufs[i].seg_count; j++) {
+				drm_free_pages(dma->bufs[i].seglist[j],
+					       dma->bufs[i].page_order,
+					       DRM_MEM_DMA);
+			}
+			drm_free(dma->bufs[i].seglist,
+				 dma->bufs[i].seg_count
+				 * sizeof(*dma->bufs[0].seglist),
+				 DRM_MEM_SEGS);
+		}
+	   	if(dma->bufs[i].buf_count) {
+		   	for(j = 0; j < dma->bufs[i].buf_count; j++) {
+			   if(dma->bufs[i].buflist[j].dev_private) {
+			      drm_free(dma->bufs[i].buflist[j].dev_private,
+				       dma->bufs[i].buflist[j].dev_priv_size,
+				       DRM_MEM_BUFS);
+			   }
+			}
+		   	drm_free(dma->bufs[i].buflist,
+				 dma->bufs[i].buf_count *
+				 sizeof(*dma->bufs[0].buflist),
+				 DRM_MEM_BUFS);
+		   	drm_freelist_destroy(&dma->bufs[i].freelist);
+		}
+	}
+	
+	if (dma->buflist) {
+		drm_free(dma->buflist,
+			 dma->buf_count * sizeof(*dma->buflist),
+			 DRM_MEM_BUFS);
+	}
+
+	if (dma->pagelist) {
+		drm_free(dma->pagelist,
+			 dma->page_count * sizeof(*dma->pagelist),
+			 DRM_MEM_PAGES);
+	}
+	drm_free(dev->dma, sizeof(*dev->dma), DRM_MEM_DRIVER);
+	dev->dma = NULL;
+}
+
+#if DRM_DMA_HISTOGRAM
+/* This is slow, but is useful for debugging. */
+int drm_histogram_slot(unsigned long count)
+{
+	int value = DRM_DMA_HISTOGRAM_INITIAL;
+	int slot;
+
+	for (slot = 0;
+	     slot < DRM_DMA_HISTOGRAM_SLOTS;
+	     ++slot, value = DRM_DMA_HISTOGRAM_NEXT(value)) {
+		if (count < value) return slot;
+	}
+	return DRM_DMA_HISTOGRAM_SLOTS - 1;
+}
+
+void drm_histogram_compute(drm_device_t *dev, drm_buf_t *buf)
+{
+	cycles_t queued_to_dispatched;
+	cycles_t dispatched_to_completed;
+	cycles_t completed_to_freed;
+	int	 q2d, d2c, c2f, q2c, q2f;
+	
+	if (buf->time_queued) {
+		queued_to_dispatched	= (buf->time_dispatched
+					   - buf->time_queued);
+		dispatched_to_completed = (buf->time_completed
+					   - buf->time_dispatched);
+		completed_to_freed	= (buf->time_freed
+					   - buf->time_completed);
+
+		q2d = drm_histogram_slot(queued_to_dispatched);
+		d2c = drm_histogram_slot(dispatched_to_completed);
+		c2f = drm_histogram_slot(completed_to_freed);
+
+		q2c = drm_histogram_slot(queued_to_dispatched
+					 + dispatched_to_completed);
+		q2f = drm_histogram_slot(queued_to_dispatched
+					 + dispatched_to_completed
+					 + completed_to_freed);
+		
+		atomic_inc(&dev->histo.total);
+		atomic_inc(&dev->histo.queued_to_dispatched[q2d]);
+		atomic_inc(&dev->histo.dispatched_to_completed[d2c]);
+		atomic_inc(&dev->histo.completed_to_freed[c2f]);
+		
+		atomic_inc(&dev->histo.queued_to_completed[q2c]);
+		atomic_inc(&dev->histo.queued_to_freed[q2f]);
+
+	}
+	buf->time_queued     = 0;
+	buf->time_dispatched = 0;
+	buf->time_completed  = 0;
+	buf->time_freed	     = 0;
+}
+#endif
+
+void drm_free_buffer(drm_device_t *dev, drm_buf_t *buf)
+{
+	drm_device_dma_t *dma = dev->dma;
+
+	if (!buf) return;
+	
+	buf->waiting  = 0;
+	buf->pending  = 0;
+	buf->pid      = 0;
+	buf->used     = 0;
+#if DRM_DMA_HISTOGRAM
+	buf->time_completed = get_cycles();
+#endif
+	if (waitqueue_active(&buf->dma_wait)) {
+		wake_up_interruptible(&buf->dma_wait);
+	} else {
+				/* If processes are waiting, the last one
+				   to wake will put the buffer on the free
+				   list.  If no processes are waiting, we
+				   put the buffer on the freelist here. */
+		drm_freelist_put(dev, &dma->bufs[buf->order].freelist, buf);
+	}
+}
+
+void drm_reclaim_buffers(drm_device_t *dev, pid_t pid)
+{
+	drm_device_dma_t *dma = dev->dma;
+	int		 i;
+
+	if (!dma) return;
+	for (i = 0; i < dma->buf_count; i++) {
+		if (dma->buflist[i]->pid == pid) {
+			switch (dma->buflist[i]->list) {
+			case DRM_LIST_NONE:
+				drm_free_buffer(dev, dma->buflist[i]);
+				break;
+			case DRM_LIST_WAIT:
+				dma->buflist[i]->list = DRM_LIST_RECLAIM;
+				break;
+			default:
+				/* Buffer already on hardware. */
+				break;
+			}
+		}
+	}
+}
+
+int drm_context_switch(drm_device_t *dev, int old, int new)
+{
+	char	    buf[64];
+	drm_queue_t *q;
+
+	atomic_inc(&dev->total_ctx);
+
+	if (test_and_set_bit(0, &dev->context_flag)) {
+		DRM_ERROR("Reentering -- FIXME\n");
+		return -EBUSY;
+	}
+
+#if DRM_DMA_HISTOGRAM
+	dev->ctx_start = get_cycles();
+#endif
+	
+	DRM_DEBUG("Context switch from %d to %d\n", old, new);
+
+	if (new >= dev->queue_count) {
+		clear_bit(0, &dev->context_flag);
+		return -EINVAL;
+	}
+
+	if (new == dev->last_context) {
+		clear_bit(0, &dev->context_flag);
+		return 0;
+	}
+	
+	q = dev->queuelist[new];
+	atomic_inc(&q->use_count);
+	if (atomic_read(&q->use_count) == 1) {
+		atomic_dec(&q->use_count);
+		clear_bit(0, &dev->context_flag);
+		return -EINVAL;
+	}
+
+	if (drm_flags & DRM_FLAG_NOCTX) {
+		drm_context_switch_complete(dev, new);
+	} else {
+		sprintf(buf, "C %d %d\n", old, new);
+		drm_write_string(dev, buf);
+	}
+	
+	atomic_dec(&q->use_count);
+	
+	return 0;
+}
+
+int drm_context_switch_complete(drm_device_t *dev, int new)
+{
+	drm_device_dma_t *dma = dev->dma;
+	
+	dev->last_context = new;  /* PRE/POST: This is the _only_ writer. */
+	dev->last_switch  = jiffies;
+	
+	if (!_DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock)) {
+		DRM_ERROR("Lock isn't held after context switch\n");
+	}
+
+	if (!dma || !(dma->next_buffer && dma->next_buffer->while_locked)) {
+		if (drm_lock_free(dev, &dev->lock.hw_lock->lock,
+				  DRM_KERNEL_CONTEXT)) {
+			DRM_ERROR("Cannot free lock\n");
+		}
+	}
+	
+#if DRM_DMA_HISTOGRAM
+	atomic_inc(&dev->histo.ctx[drm_histogram_slot(get_cycles()
+						      - dev->ctx_start)]);
+		   
+#endif
+	clear_bit(0, &dev->context_flag);
+	wake_up_interruptible(&dev->context_wait);
+	
+	return 0;
+}
+
+void drm_clear_next_buffer(drm_device_t *dev)
+{
+	drm_device_dma_t *dma = dev->dma;
+	
+	dma->next_buffer = NULL;
+	if (dma->next_queue && !DRM_BUFCOUNT(&dma->next_queue->waitlist)) {
+		wake_up_interruptible(&dma->next_queue->flush_queue);
+	}
+	dma->next_queue	 = NULL;
+}
+
+
+int drm_select_queue(drm_device_t *dev, void (*wrapper)(unsigned long))
+{
+	int	   i;
+	int	   candidate = -1;
+	int	   j	     = jiffies;
+
+	if (!dev) {
+		DRM_ERROR("No device\n");
+		return -1;
+	}
+	if (!dev->queuelist || !dev->queuelist[DRM_KERNEL_CONTEXT]) {
+				/* This only happens between the time the
+				   interrupt is initialized and the time
+				   the queues are initialized. */
+		return -1;
+	}
+
+				/* Doing "while locked" DMA? */
+	if (DRM_WAITCOUNT(dev, DRM_KERNEL_CONTEXT)) {
+		return DRM_KERNEL_CONTEXT;
+	}
+
+				/* If there are buffers on the last_context
+				   queue, and we have not been executing
+				   this context very long, continue to
+				   execute this context. */
+	if (dev->last_switch <= j
+	    && dev->last_switch + DRM_TIME_SLICE > j
+	    && DRM_WAITCOUNT(dev, dev->last_context)) {
+		return dev->last_context;
+	}
+
+				/* Otherwise, find a candidate */
+	for (i = dev->last_checked + 1; i < dev->queue_count; i++) {
+		if (DRM_WAITCOUNT(dev, i)) {
+			candidate = dev->last_checked = i;
+			break;
+		}
+	}
+
+	if (candidate < 0) {
+		for (i = 0; i < dev->queue_count; i++) {
+			if (DRM_WAITCOUNT(dev, i)) {
+				candidate = dev->last_checked = i;
+				break;
+			}
+		}
+	}
+
+	if (wrapper
+	    && candidate >= 0
+	    && candidate != dev->last_context
+	    && dev->last_switch <= j
+	    && dev->last_switch + DRM_TIME_SLICE > j) {
+		if (dev->timer.expires != dev->last_switch + DRM_TIME_SLICE) {
+			del_timer(&dev->timer);
+			dev->timer.function = wrapper;
+			dev->timer.data	    = (unsigned long)dev;
+			dev->timer.expires  = dev->last_switch+DRM_TIME_SLICE;
+			add_timer(&dev->timer);
+		}
+		return -1;
+	}
+
+	return candidate;
+}
+
+
+int drm_dma_enqueue(drm_device_t *dev, drm_dma_t *d)
+{
+	int		  i;
+	drm_queue_t	  *q;
+	drm_buf_t	  *buf;
+	int		  idx;
+	int		  while_locked = 0;
+	drm_device_dma_t  *dma = dev->dma;
+	DECLARE_WAITQUEUE(entry, current);
+
+	DRM_DEBUG("%d\n", d->send_count);
+
+	if (d->flags & _DRM_DMA_WHILE_LOCKED) {
+		int context = dev->lock.hw_lock->lock;
+		
+		if (!_DRM_LOCK_IS_HELD(context)) {
+			DRM_ERROR("No lock held during \"while locked\""
+				  " request\n");
+			return -EINVAL;
+		}
+		if (d->context != _DRM_LOCKING_CONTEXT(context)
+		    && _DRM_LOCKING_CONTEXT(context) != DRM_KERNEL_CONTEXT) {
+			DRM_ERROR("Lock held by %d while %d makes"
+				  " \"while locked\" request\n",
+				  _DRM_LOCKING_CONTEXT(context),
+				  d->context);
+			return -EINVAL;
+		}
+		q = dev->queuelist[DRM_KERNEL_CONTEXT];
+		while_locked = 1;
+	} else {
+		q = dev->queuelist[d->context];
+	}
+
+
+	atomic_inc(&q->use_count);
+	if (atomic_read(&q->block_write)) {
+		add_wait_queue(&q->write_queue, &entry);
+		atomic_inc(&q->block_count);
+		for (;;) {
+			current->state = TASK_INTERRUPTIBLE;
+			if (!atomic_read(&q->block_write)) break;
+			schedule();
+			if (signal_pending(current)) {
+				atomic_dec(&q->use_count);
+				return -EINTR;
+			}
+		}
+		atomic_dec(&q->block_count);
+		current->state = TASK_RUNNING;
+		remove_wait_queue(&q->write_queue, &entry);
+	}
+	
+	for (i = 0; i < d->send_count; i++) {
+		idx = d->send_indices[i];
+		if (idx < 0 || idx >= dma->buf_count) {
+			atomic_dec(&q->use_count);
+			DRM_ERROR("Index %d (of %d max)\n",
+				  d->send_indices[i], dma->buf_count - 1);
+			return -EINVAL;
+		}
+		buf = dma->buflist[ idx ];
+		if (buf->pid != current->pid) {
+			atomic_dec(&q->use_count);
+			DRM_ERROR("Process %d using buffer owned by %d\n",
+				  current->pid, buf->pid);
+			return -EINVAL;
+		}
+		if (buf->list != DRM_LIST_NONE) {
+			atomic_dec(&q->use_count);
+			DRM_ERROR("Process %d using buffer %d on list %d\n",
+				  current->pid, buf->idx, buf->list);
+		}
+		buf->used	  = d->send_sizes[i];
+		buf->while_locked = while_locked;
+		buf->context	  = d->context;
+		if (!buf->used) {
+			DRM_ERROR("Queueing 0 length buffer\n");
+		}
+		if (buf->pending) {
+			atomic_dec(&q->use_count);
+			DRM_ERROR("Queueing pending buffer:"
+				  " buffer %d, offset %d\n",
+				  d->send_indices[i], i);
+			return -EINVAL;
+		}
+		if (buf->waiting) {
+			atomic_dec(&q->use_count);
+			DRM_ERROR("Queueing waiting buffer:"
+				  " buffer %d, offset %d\n",
+				  d->send_indices[i], i);
+			return -EINVAL;
+		}
+		buf->waiting = 1;
+		if (atomic_read(&q->use_count) == 1
+		    || atomic_read(&q->finalization)) {
+			drm_free_buffer(dev, buf);
+		} else {
+			drm_waitlist_put(&q->waitlist, buf);
+			atomic_inc(&q->total_queued);
+		}
+	}
+	atomic_dec(&q->use_count);
+	
+	return 0;
+}
+
+static int drm_dma_get_buffers_of_order(drm_device_t *dev, drm_dma_t *d,
+					int order)
+{
+	int		  i;
+	drm_buf_t	  *buf;
+	drm_device_dma_t  *dma = dev->dma;
+	
+	for (i = d->granted_count; i < d->request_count; i++) {
+		buf = drm_freelist_get(&dma->bufs[order].freelist,
+				       d->flags & _DRM_DMA_WAIT);
+		if (!buf) break;
+		if (buf->pending || buf->waiting) {
+			DRM_ERROR("Free buffer %d in use by %d (w%d, p%d)\n",
+				  buf->idx,
+				  buf->pid,
+				  buf->waiting,
+				  buf->pending);
+		}
+		buf->pid     = current->pid;
+		copy_to_user_ret(&d->request_indices[i],
+				 &buf->idx,
+				 sizeof(buf->idx),
+				 -EFAULT);
+		copy_to_user_ret(&d->request_sizes[i],
+				 &buf->total,
+				 sizeof(buf->total),
+				 -EFAULT);
+		++d->granted_count;
+	}
+	return 0;
+}
+
+
+int drm_dma_get_buffers(drm_device_t *dev, drm_dma_t *dma)
+{
+	int		  order;
+	int		  retcode = 0;
+	int		  tmp_order;
+	
+	order = drm_order(dma->request_size);
+
+	dma->granted_count = 0;
+	retcode		   = drm_dma_get_buffers_of_order(dev, dma, order);
+
+	if (dma->granted_count < dma->request_count
+	    && (dma->flags & _DRM_DMA_SMALLER_OK)) {
+		for (tmp_order = order - 1;
+		     !retcode
+			     && dma->granted_count < dma->request_count
+			     && tmp_order >= DRM_MIN_ORDER;
+		     --tmp_order) {
+			
+			retcode = drm_dma_get_buffers_of_order(dev, dma,
+							       tmp_order);
+		}
+	}
+
+	if (dma->granted_count < dma->request_count
+	    && (dma->flags & _DRM_DMA_LARGER_OK)) {
+		for (tmp_order = order + 1;
+		     !retcode
+			     && dma->granted_count < dma->request_count
+			     && tmp_order <= DRM_MAX_ORDER;
+		     ++tmp_order) {
+			
+			retcode = drm_dma_get_buffers_of_order(dev, dma,
+							       tmp_order);
+		}
+	}
+	return 0;
+}