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

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diff -u --new-file --recursive --exclude-from /usr/src/exclude v2.2.17/drivers/char/drm/gamma_dma.c linux/drivers/char/drm/gamma_dma.c
@@ -0,0 +1,824 @@
+/* gamma_dma.c -- DMA support for GMX 2000 -*- linux-c -*-
+ * Created: Fri Mar 19 14:30:16 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"
+#include "gamma_drv.h"
+
+#include <linux/interrupt.h>	/* For task queue support */
+
+
+/* WARNING!!! MAGIC NUMBER!!!  The number of regions already added to the
+   kernel must be specified here.  Currently, the number is 2.	This must
+   match the order the X server uses for instantiating register regions ,
+   or must be passed in a new ioctl. */
+#define GAMMA_REG(reg)						   \
+	(2							   \
+	 + ((reg < 0x1000)					   \
+	    ? 0							   \
+	    : ((reg < 0x10000) ? 1 : ((reg < 0x11000) ? 2 : 3))))
+
+#define GAMMA_OFF(reg)						   \
+	((reg < 0x1000)						   \
+	 ? reg							   \
+	 : ((reg < 0x10000)					   \
+	    ? (reg - 0x1000)					   \
+	    : ((reg < 0x11000)					   \
+	       ? (reg - 0x10000)				   \
+	       : (reg - 0x11000))))
+
+#define GAMMA_BASE(reg)	 ((unsigned long)dev->maplist[GAMMA_REG(reg)]->handle)
+#define GAMMA_ADDR(reg)	 (GAMMA_BASE(reg) + GAMMA_OFF(reg))
+#define GAMMA_DEREF(reg) *(__volatile__ int *)GAMMA_ADDR(reg)
+#define GAMMA_READ(reg)	 GAMMA_DEREF(reg)
+#define GAMMA_WRITE(reg,val) do { GAMMA_DEREF(reg) = val; } while (0)
+
+#define GAMMA_BROADCASTMASK    0x9378
+#define GAMMA_COMMANDINTENABLE 0x0c48
+#define GAMMA_DMAADDRESS       0x0028
+#define GAMMA_DMACOUNT	       0x0030
+#define GAMMA_FILTERMODE       0x8c00
+#define GAMMA_GCOMMANDINTFLAGS 0x0c50
+#define GAMMA_GCOMMANDMODE     0x0c40
+#define GAMMA_GCOMMANDSTATUS   0x0c60
+#define GAMMA_GDELAYTIMER      0x0c38
+#define GAMMA_GDMACONTROL      0x0060
+#define GAMMA_GINTENABLE       0x0808
+#define GAMMA_GINTFLAGS	       0x0810
+#define GAMMA_INFIFOSPACE      0x0018
+#define GAMMA_OUTFIFOWORDS     0x0020
+#define GAMMA_OUTPUTFIFO       0x2000
+#define GAMMA_SYNC	       0x8c40
+#define GAMMA_SYNC_TAG	       0x0188
+
+static inline void gamma_dma_dispatch(drm_device_t *dev, unsigned long address,
+				      unsigned long length)
+{
+	GAMMA_WRITE(GAMMA_DMAADDRESS, virt_to_phys((void *)address));
+	while (GAMMA_READ(GAMMA_GCOMMANDSTATUS) != 4)
+		;
+	GAMMA_WRITE(GAMMA_DMACOUNT, length / 4);
+}
+
+static inline void gamma_dma_quiescent_single(drm_device_t *dev)
+{
+	while (GAMMA_READ(GAMMA_DMACOUNT))
+		;
+	while (GAMMA_READ(GAMMA_INFIFOSPACE) < 3)
+		;
+
+	GAMMA_WRITE(GAMMA_FILTERMODE, 1 << 10);
+	GAMMA_WRITE(GAMMA_SYNC, 0);
+	
+	do {
+		while (!GAMMA_READ(GAMMA_OUTFIFOWORDS))
+			;
+	} while (GAMMA_READ(GAMMA_OUTPUTFIFO) != GAMMA_SYNC_TAG);
+}
+
+static inline void gamma_dma_quiescent_dual(drm_device_t *dev)
+{
+	while (GAMMA_READ(GAMMA_DMACOUNT))
+		;
+	while (GAMMA_READ(GAMMA_INFIFOSPACE) < 3)
+		;
+
+	GAMMA_WRITE(GAMMA_BROADCASTMASK, 3);
+
+	GAMMA_WRITE(GAMMA_FILTERMODE, 1 << 10);
+	GAMMA_WRITE(GAMMA_SYNC, 0);
+	
+				/* Read from first MX */
+	do {
+		while (!GAMMA_READ(GAMMA_OUTFIFOWORDS))
+			;
+	} while (GAMMA_READ(GAMMA_OUTPUTFIFO) != GAMMA_SYNC_TAG);
+	
+				/* Read from second MX */
+	do {
+		while (!GAMMA_READ(GAMMA_OUTFIFOWORDS + 0x10000))
+			;
+	} while (GAMMA_READ(GAMMA_OUTPUTFIFO + 0x10000) != GAMMA_SYNC_TAG);
+}
+
+static inline void gamma_dma_ready(drm_device_t *dev)
+{
+	while (GAMMA_READ(GAMMA_DMACOUNT))
+		;
+}
+
+static inline int gamma_dma_is_ready(drm_device_t *dev)
+{
+	return !GAMMA_READ(GAMMA_DMACOUNT);
+}
+
+static void gamma_dma_service(int irq, void *device, struct pt_regs *regs)
+{
+	drm_device_t	 *dev = (drm_device_t *)device;
+	drm_device_dma_t *dma = dev->dma;
+	
+	atomic_inc(&dev->total_irq);
+	GAMMA_WRITE(GAMMA_GDELAYTIMER, 0xc350/2); /* 0x05S */
+	GAMMA_WRITE(GAMMA_GCOMMANDINTFLAGS, 8);
+	GAMMA_WRITE(GAMMA_GINTFLAGS, 0x2001);
+	if (gamma_dma_is_ready(dev)) {
+				/* Free previous buffer */
+		if (test_and_set_bit(0, &dev->dma_flag)) {
+			atomic_inc(&dma->total_missed_free);
+			return;
+		}
+		if (dma->this_buffer) {
+			drm_free_buffer(dev, dma->this_buffer);
+			dma->this_buffer = NULL;
+		}
+		clear_bit(0, &dev->dma_flag);
+
+				/* Dispatch new buffer */
+		queue_task(&dev->tq, &tq_immediate);
+		mark_bh(IMMEDIATE_BH);
+	}
+}
+
+/* Only called by gamma_dma_schedule. */
+static int gamma_do_dma(drm_device_t *dev, int locked)
+{
+	unsigned long	 address;
+	unsigned long	 length;
+	drm_buf_t	 *buf;
+	int		 retcode = 0;
+	drm_device_dma_t *dma = dev->dma;
+#if DRM_DMA_HISTOGRAM
+	cycles_t	 dma_start, dma_stop;
+#endif
+
+	if (test_and_set_bit(0, &dev->dma_flag)) {
+		atomic_inc(&dma->total_missed_dma);
+		return -EBUSY;
+	}
+	
+#if DRM_DMA_HISTOGRAM
+	dma_start = get_cycles();
+#endif
+
+	if (!dma->next_buffer) {
+		DRM_ERROR("No next_buffer\n");
+		clear_bit(0, &dev->dma_flag);
+		return -EINVAL;
+	}
+
+	buf	= dma->next_buffer;
+	address = (unsigned long)buf->address;
+	length	= buf->used;
+
+	DRM_DEBUG("context %d, buffer %d (%ld bytes)\n",
+		  buf->context, buf->idx, length);
+
+	if (buf->list == DRM_LIST_RECLAIM) {
+		drm_clear_next_buffer(dev);
+		drm_free_buffer(dev, buf);
+		clear_bit(0, &dev->dma_flag);
+		return -EINVAL;
+	}
+
+	if (!length) {
+		DRM_ERROR("0 length buffer\n");
+		drm_clear_next_buffer(dev);
+		drm_free_buffer(dev, buf);
+		clear_bit(0, &dev->dma_flag);
+		return 0;
+	}
+	
+	if (!gamma_dma_is_ready(dev)) {
+		clear_bit(0, &dev->dma_flag);
+		return -EBUSY;
+	}
+
+	if (buf->while_locked) {
+		if (!_DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock)) {
+			DRM_ERROR("Dispatching buffer %d from pid %d"
+				  " \"while locked\", but no lock held\n",
+				  buf->idx, buf->pid);
+		}
+	} else {
+		if (!locked && !drm_lock_take(&dev->lock.hw_lock->lock,
+					      DRM_KERNEL_CONTEXT)) {
+			atomic_inc(&dma->total_missed_lock);
+			clear_bit(0, &dev->dma_flag);
+			return -EBUSY;
+		}
+	}
+
+	if (dev->last_context != buf->context
+	    && !(dev->queuelist[buf->context]->flags
+		 & _DRM_CONTEXT_PRESERVED)) {
+				/* PRE: dev->last_context != buf->context */
+		if (drm_context_switch(dev, dev->last_context, buf->context)) {
+			drm_clear_next_buffer(dev);
+			drm_free_buffer(dev, buf);
+		}
+		retcode = -EBUSY;
+		goto cleanup;
+			
+				/* POST: we will wait for the context
+				   switch and will dispatch on a later call
+				   when dev->last_context == buf->context.
+				   NOTE WE HOLD THE LOCK THROUGHOUT THIS
+				   TIME! */
+	}
+
+	drm_clear_next_buffer(dev);
+	buf->pending	 = 1;
+	buf->waiting	 = 0;
+	buf->list	 = DRM_LIST_PEND;
+#if DRM_DMA_HISTOGRAM
+	buf->time_dispatched = get_cycles();
+#endif
+
+	gamma_dma_dispatch(dev, address, length);
+	drm_free_buffer(dev, dma->this_buffer);
+	dma->this_buffer = buf;
+
+	atomic_add(length, &dma->total_bytes);
+	atomic_inc(&dma->total_dmas);
+
+	if (!buf->while_locked && !dev->context_flag && !locked) {
+		if (drm_lock_free(dev, &dev->lock.hw_lock->lock,
+				  DRM_KERNEL_CONTEXT)) {
+			DRM_ERROR("\n");
+		}
+	}
+cleanup:
+
+	clear_bit(0, &dev->dma_flag);
+
+#if DRM_DMA_HISTOGRAM
+	dma_stop = get_cycles();
+	atomic_inc(&dev->histo.dma[drm_histogram_slot(dma_stop - dma_start)]);
+#endif
+
+	return retcode;
+}
+
+static void gamma_dma_schedule_timer_wrapper(unsigned long dev)
+{
+	gamma_dma_schedule((drm_device_t *)dev, 0);
+}
+
+static void gamma_dma_schedule_tq_wrapper(void *dev)
+{
+	gamma_dma_schedule(dev, 0);
+}
+
+int gamma_dma_schedule(drm_device_t *dev, int locked)
+{
+	int		 next;
+	drm_queue_t	 *q;
+	drm_buf_t	 *buf;
+	int		 retcode   = 0;
+	int		 processed = 0;
+	int		 missed;
+	int		 expire	   = 20;
+	drm_device_dma_t *dma	   = dev->dma;
+#if DRM_DMA_HISTOGRAM
+	cycles_t	 schedule_start;
+#endif
+
+	if (test_and_set_bit(0, &dev->interrupt_flag)) {
+				/* Not reentrant */
+		atomic_inc(&dma->total_missed_sched);
+		return -EBUSY;
+	}
+	missed = atomic_read(&dma->total_missed_sched);
+
+#if DRM_DMA_HISTOGRAM
+	schedule_start = get_cycles();
+#endif
+
+again:
+	if (dev->context_flag) {
+		clear_bit(0, &dev->interrupt_flag);
+		return -EBUSY;
+	}
+	if (dma->next_buffer) {
+				/* Unsent buffer that was previously
+				   selected, but that couldn't be sent
+				   because the lock could not be obtained
+				   or the DMA engine wasn't ready.  Try
+				   again. */
+		atomic_inc(&dma->total_tried);
+		if (!(retcode = gamma_do_dma(dev, locked))) {
+			atomic_inc(&dma->total_hit);
+			++processed;
+		}
+	} else {
+		do {
+			next = drm_select_queue(dev,
+					     gamma_dma_schedule_timer_wrapper);
+			if (next >= 0) {
+				q   = dev->queuelist[next];
+				buf = drm_waitlist_get(&q->waitlist);
+				dma->next_buffer = buf;
+				dma->next_queue	 = q;
+				if (buf && buf->list == DRM_LIST_RECLAIM) {
+					drm_clear_next_buffer(dev);
+					drm_free_buffer(dev, buf);
+				}
+			}
+		} while (next >= 0 && !dma->next_buffer);
+		if (dma->next_buffer) {
+			if (!(retcode = gamma_do_dma(dev, locked))) {
+				++processed;
+			}
+		}
+	}
+
+	if (--expire) {
+		if (missed != atomic_read(&dma->total_missed_sched)) {
+			atomic_inc(&dma->total_lost);
+			if (gamma_dma_is_ready(dev)) goto again;
+		}
+		if (processed && gamma_dma_is_ready(dev)) {
+			atomic_inc(&dma->total_lost);
+			processed = 0;
+			goto again;
+		}
+	}
+	
+	clear_bit(0, &dev->interrupt_flag);
+	
+#if DRM_DMA_HISTOGRAM
+	atomic_inc(&dev->histo.schedule[drm_histogram_slot(get_cycles()
+							   - schedule_start)]);
+#endif
+	return retcode;
+}
+
+static int gamma_dma_priority(drm_device_t *dev, drm_dma_t *d)
+{
+	unsigned long	  address;
+	unsigned long	  length;
+	int		  must_free = 0;
+	int		  retcode   = 0;
+	int		  i;
+	int		  idx;
+	drm_buf_t	  *buf;
+	drm_buf_t	  *last_buf = NULL;
+	drm_device_dma_t  *dma	    = dev->dma;
+	DECLARE_WAITQUEUE(entry, current);
+
+				/* Turn off interrupt handling */
+	while (test_and_set_bit(0, &dev->interrupt_flag)) {
+		schedule();
+		if (signal_pending(current)) return -EINTR;
+	}
+	if (!(d->flags & _DRM_DMA_WHILE_LOCKED)) {
+		while (!drm_lock_take(&dev->lock.hw_lock->lock,
+				      DRM_KERNEL_CONTEXT)) {
+			schedule();
+			if (signal_pending(current)) {
+				clear_bit(0, &dev->interrupt_flag);
+				return -EINTR;
+			}
+		}
+		++must_free;
+	}
+	atomic_inc(&dma->total_prio);
+
+	for (i = 0; i < d->send_count; i++) {
+		idx = d->send_indices[i];
+		if (idx < 0 || idx >= dma->buf_count) {
+			DRM_ERROR("Index %d (of %d max)\n",
+				  d->send_indices[i], dma->buf_count - 1);
+			continue;
+		}
+		buf = dma->buflist[ idx ];
+		if (buf->pid != current->pid) {
+			DRM_ERROR("Process %d using buffer owned by %d\n",
+				  current->pid, buf->pid);
+			retcode = -EINVAL;
+			goto cleanup;
+		}
+		if (buf->list != DRM_LIST_NONE) {
+			DRM_ERROR("Process %d using %d's buffer on list %d\n",
+				  current->pid, buf->pid, buf->list);
+			retcode = -EINVAL;
+			goto cleanup;
+		}
+				/* This isn't a race condition on
+				   buf->list, since our concern is the
+				   buffer reclaim during the time the
+				   process closes the /dev/drm? handle, so
+				   it can't also be doing DMA. */
+		buf->list	  = DRM_LIST_PRIO;
+		buf->used	  = d->send_sizes[i];
+		buf->context	  = d->context;
+		buf->while_locked = d->flags & _DRM_DMA_WHILE_LOCKED;
+		address		  = (unsigned long)buf->address;
+		length		  = buf->used;
+		if (!length) {
+			DRM_ERROR("0 length buffer\n");
+		}
+		if (buf->pending) {
+			DRM_ERROR("Sending pending buffer:"
+				  " buffer %d, offset %d\n",
+				  d->send_indices[i], i);
+			retcode = -EINVAL;
+			goto cleanup;
+		}
+		if (buf->waiting) {
+			DRM_ERROR("Sending waiting buffer:"
+				  " buffer %d, offset %d\n",
+				  d->send_indices[i], i);
+			retcode = -EINVAL;
+			goto cleanup;
+		}
+		buf->pending = 1;
+		
+		if (dev->last_context != buf->context
+		    && !(dev->queuelist[buf->context]->flags
+			 & _DRM_CONTEXT_PRESERVED)) {
+			add_wait_queue(&dev->context_wait, &entry);
+			current->state = TASK_INTERRUPTIBLE;
+				/* PRE: dev->last_context != buf->context */
+			drm_context_switch(dev, dev->last_context,
+					   buf->context);
+				/* POST: we will wait for the context
+				   switch and will dispatch on a later call
+				   when dev->last_context == buf->context.
+				   NOTE WE HOLD THE LOCK THROUGHOUT THIS
+				   TIME! */
+			schedule();
+			current->state = TASK_RUNNING;
+			remove_wait_queue(&dev->context_wait, &entry);
+			if (signal_pending(current)) {
+				retcode = -EINTR;
+				goto cleanup;
+			}
+			if (dev->last_context != buf->context) {
+				DRM_ERROR("Context mismatch: %d %d\n",
+					  dev->last_context,
+					  buf->context);
+			}
+		}
+
+#if DRM_DMA_HISTOGRAM
+		buf->time_queued     = get_cycles();
+		buf->time_dispatched = buf->time_queued;
+#endif
+		gamma_dma_dispatch(dev, address, length);
+		atomic_add(length, &dma->total_bytes);
+		atomic_inc(&dma->total_dmas);
+		
+		if (last_buf) {
+			drm_free_buffer(dev, last_buf);
+		}
+		last_buf = buf;
+	}
+
+
+cleanup:
+	if (last_buf) {
+		gamma_dma_ready(dev);
+		drm_free_buffer(dev, last_buf);
+	}
+	
+	if (must_free && !dev->context_flag) {
+		if (drm_lock_free(dev, &dev->lock.hw_lock->lock,
+				  DRM_KERNEL_CONTEXT)) {
+			DRM_ERROR("\n");
+		}
+	}
+	clear_bit(0, &dev->interrupt_flag);
+	return retcode;
+}
+
+static int gamma_dma_send_buffers(drm_device_t *dev, drm_dma_t *d)
+{
+	DECLARE_WAITQUEUE(entry, current);
+	drm_buf_t	  *last_buf = NULL;
+	int		  retcode   = 0;
+	drm_device_dma_t  *dma	    = dev->dma;
+
+	if (d->flags & _DRM_DMA_BLOCK) {
+		last_buf = dma->buflist[d->send_indices[d->send_count-1]];
+		add_wait_queue(&last_buf->dma_wait, &entry);
+	}
+	
+	if ((retcode = drm_dma_enqueue(dev, d))) {
+		if (d->flags & _DRM_DMA_BLOCK)
+			remove_wait_queue(&last_buf->dma_wait, &entry);
+		return retcode;
+	}
+	
+	gamma_dma_schedule(dev, 0);
+	
+	if (d->flags & _DRM_DMA_BLOCK) {
+		DRM_DEBUG("%d waiting\n", current->pid);
+		for (;;) {
+			current->state = TASK_INTERRUPTIBLE;
+			if (!last_buf->waiting
+			    && !last_buf->pending)
+				break; /* finished */
+			schedule();
+			if (signal_pending(current)) {
+				retcode = -EINTR; /* Can't restart */
+				break;
+			}
+		}
+		current->state = TASK_RUNNING;
+		DRM_DEBUG("%d running\n", current->pid);
+		remove_wait_queue(&last_buf->dma_wait, &entry);
+		if (!retcode
+		    || (last_buf->list==DRM_LIST_PEND && !last_buf->pending)) {
+			if (!waitqueue_active(&last_buf->dma_wait)) {
+				drm_free_buffer(dev, last_buf);
+			}
+		}
+		if (retcode) {
+			DRM_ERROR("ctx%d w%d p%d c%d i%d l%d %d/%d\n",
+				  d->context,
+				  last_buf->waiting,
+				  last_buf->pending,
+				  DRM_WAITCOUNT(dev, d->context),
+				  last_buf->idx,
+				  last_buf->list,
+				  last_buf->pid,
+				  current->pid);
+		}
+	}
+	return retcode;
+}
+
+int gamma_dma(struct inode *inode, struct file *filp, unsigned int cmd,
+	      unsigned long arg)
+{
+	drm_file_t	  *priv	    = filp->private_data;
+	drm_device_t	  *dev	    = priv->dev;
+	drm_device_dma_t  *dma	    = dev->dma;
+	int		  retcode   = 0;
+	drm_dma_t	  d;
+
+	copy_from_user_ret(&d, (drm_dma_t *)arg, sizeof(d), -EFAULT);
+	DRM_DEBUG("%d %d: %d send, %d req\n",
+		  current->pid, d.context, d.send_count, d.request_count);
+
+	if (d.context == DRM_KERNEL_CONTEXT || d.context >= dev->queue_slots) {
+		DRM_ERROR("Process %d using context %d\n",
+			  current->pid, d.context);
+		return -EINVAL;
+	}
+	if (d.send_count < 0 || d.send_count > dma->buf_count) {
+		DRM_ERROR("Process %d trying to send %d buffers (of %d max)\n",
+			  current->pid, d.send_count, dma->buf_count);
+		return -EINVAL;
+	}
+	if (d.request_count < 0 || d.request_count > dma->buf_count) {
+		DRM_ERROR("Process %d trying to get %d buffers (of %d max)\n",
+			  current->pid, d.request_count, dma->buf_count);
+		return -EINVAL;
+	}
+
+	if (d.send_count) {
+		if (d.flags & _DRM_DMA_PRIORITY)
+			retcode = gamma_dma_priority(dev, &d);
+		else 
+			retcode = gamma_dma_send_buffers(dev, &d);
+	}
+
+	d.granted_count = 0;
+
+	if (!retcode && d.request_count) {
+		retcode = drm_dma_get_buffers(dev, &d);
+	}
+
+	DRM_DEBUG("%d returning, granted = %d\n",
+		  current->pid, d.granted_count);
+	copy_to_user_ret((drm_dma_t *)arg, &d, sizeof(d), -EFAULT);
+
+	return retcode;
+}
+
+int gamma_irq_install(drm_device_t *dev, int irq)
+{
+	int retcode;
+
+	if (!irq)     return -EINVAL;
+	
+	down(&dev->struct_sem);
+	if (dev->irq) {
+		up(&dev->struct_sem);
+		return -EBUSY;
+	}
+	dev->irq = irq;
+	up(&dev->struct_sem);
+	
+	DRM_DEBUG("%d\n", irq);
+
+	dev->context_flag     = 0;
+	dev->interrupt_flag   = 0;
+	dev->dma_flag	      = 0;
+	
+	dev->dma->next_buffer = NULL;
+	dev->dma->next_queue  = NULL;
+	dev->dma->this_buffer = NULL;
+
+	dev->tq.next	      = NULL;
+	dev->tq.sync	      = 0;
+	dev->tq.routine	      = gamma_dma_schedule_tq_wrapper;
+	dev->tq.data	      = dev;
+
+
+				/* Before installing handler */
+	GAMMA_WRITE(GAMMA_GCOMMANDMODE, 0);
+	GAMMA_WRITE(GAMMA_GDMACONTROL, 0);
+	
+				/* Install handler */
+	if ((retcode = request_irq(dev->irq,
+				   gamma_dma_service,
+				   0,
+				   dev->devname,
+				   dev))) {
+		down(&dev->struct_sem);
+		dev->irq = 0;
+		up(&dev->struct_sem);
+		return retcode;
+	}
+
+				/* After installing handler */
+	GAMMA_WRITE(GAMMA_GINTENABLE,	    0x2001);
+	GAMMA_WRITE(GAMMA_COMMANDINTENABLE, 0x0008);
+	GAMMA_WRITE(GAMMA_GDELAYTIMER,	   0x39090);
+	
+	return 0;
+}
+
+int gamma_irq_uninstall(drm_device_t *dev)
+{
+	int irq;
+
+	down(&dev->struct_sem);
+	irq	 = dev->irq;
+	dev->irq = 0;
+	up(&dev->struct_sem);
+	
+	if (!irq) return -EINVAL;
+	
+	DRM_DEBUG("%d\n", irq);
+	
+	GAMMA_WRITE(GAMMA_GDELAYTIMER,	    0);
+	GAMMA_WRITE(GAMMA_COMMANDINTENABLE, 0);
+	GAMMA_WRITE(GAMMA_GINTENABLE,	    0);
+	free_irq(irq, dev);
+
+	return 0;
+}
+
+
+int gamma_control(struct inode *inode, struct file *filp, unsigned int cmd,
+		  unsigned long arg)
+{
+	drm_file_t	*priv	= filp->private_data;
+	drm_device_t	*dev	= priv->dev;
+	drm_control_t	ctl;
+	int		retcode;
+	
+	copy_from_user_ret(&ctl, (drm_control_t *)arg, sizeof(ctl), -EFAULT);
+	
+	switch (ctl.func) {
+	case DRM_INST_HANDLER:
+		if ((retcode = gamma_irq_install(dev, ctl.irq)))
+			return retcode;
+		break;
+	case DRM_UNINST_HANDLER:
+		if ((retcode = gamma_irq_uninstall(dev)))
+			return retcode;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+int gamma_lock(struct inode *inode, struct file *filp, unsigned int cmd,
+	       unsigned long arg)
+{
+	drm_file_t	  *priv	  = filp->private_data;
+	drm_device_t	  *dev	  = priv->dev;
+	DECLARE_WAITQUEUE(entry, current);
+	int		  ret	= 0;
+	drm_lock_t	  lock;
+	drm_queue_t	  *q;
+#if DRM_DMA_HISTOGRAM
+	cycles_t	  start;
+
+	dev->lck_start = start = get_cycles();
+#endif
+
+	copy_from_user_ret(&lock, (drm_lock_t *)arg, sizeof(lock), -EFAULT);
+
+	if (lock.context == DRM_KERNEL_CONTEXT) {
+		DRM_ERROR("Process %d using kernel context %d\n",
+			  current->pid, lock.context);
+		return -EINVAL;
+	}
+
+	DRM_DEBUG("%d (pid %d) requests lock (0x%08x), flags = 0x%08x\n",
+		  lock.context, current->pid, dev->lock.hw_lock->lock,
+		  lock.flags);
+
+	if (lock.context < 0 || lock.context >= dev->queue_count)
+		return -EINVAL;
+	q = dev->queuelist[lock.context];
+	
+	ret = drm_flush_block_and_flush(dev, lock.context, lock.flags);
+
+	if (!ret) {
+		if (_DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock)
+		    != lock.context) {
+			long j = jiffies - dev->lock.lock_time;
+
+			if (j > 0 && j <= DRM_LOCK_SLICE) {
+				/* Can't take lock if we just had it and
+				   there is contention. */
+				current->state = TASK_INTERRUPTIBLE;
+				schedule_timeout(j);
+			}
+		}
+		add_wait_queue(&dev->lock.lock_queue, &entry);
+		for (;;) {
+			current->state = TASK_INTERRUPTIBLE;
+			if (!dev->lock.hw_lock) {
+				/* Device has been unregistered */
+				ret = -EINTR;
+				break;
+			}
+			if (drm_lock_take(&dev->lock.hw_lock->lock,
+					  lock.context)) {
+				dev->lock.pid	    = current->pid;
+				dev->lock.lock_time = jiffies;
+				atomic_inc(&dev->total_locks);
+				atomic_inc(&q->total_locks);
+				break;	/* Got lock */
+			}
+			
+				/* Contention */
+			atomic_inc(&dev->total_sleeps);
+			schedule();
+			if (signal_pending(current)) {
+				ret = -ERESTARTSYS;
+				break;
+			}
+		}
+		current->state = TASK_RUNNING;
+		remove_wait_queue(&dev->lock.lock_queue, &entry);
+	}
+
+	drm_flush_unblock(dev, lock.context, lock.flags); /* cleanup phase */
+	
+	if (!ret) {
+		if (lock.flags & _DRM_LOCK_READY)
+			gamma_dma_ready(dev);
+		if (lock.flags & _DRM_LOCK_QUIESCENT) {
+			if (gamma_found() == 1) {
+				gamma_dma_quiescent_single(dev);
+			} else {
+				gamma_dma_quiescent_dual(dev);
+			}
+		}
+	}
+	DRM_DEBUG("%d %s\n", lock.context, ret ? "interrupted" : "has lock");
+
+#if DRM_DMA_HISTOGRAM
+	atomic_inc(&dev->histo.lacq[drm_histogram_slot(get_cycles() - start)]);
+#endif
+	
+	return ret;
+}
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)