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-rw-r--r--linux/i810_dma.c762
1 files changed, 762 insertions, 0 deletions
diff --git a/linux/i810_dma.c b/linux/i810_dma.c
new file mode 100644
index 00000000..09959b65
--- /dev/null
+++ b/linux/i810_dma.c
@@ -0,0 +1,762 @@
+/* i810_dma.c -- DMA support for the i810 -*- linux-c -*-
+ * Created: Mon Dec 13 01:50:01 1999 by jhartmann@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.
+ *
+ * Authors: Rickard E. (Rik) Faith <faith@precisioninsight.com>
+ * Jeff Hartmann <jhartmann@precisioninsight.com>
+ *
+ * $XFree86: xc/programs/Xserver/hw/xfree86/os-support/linux/drm/kernel/i810_dma.c,v 1.1 2000/02/11 17:26:04 dawes Exp $
+ *
+ */
+
+#define __NO_VERSION__
+#include "drmP.h"
+#include "i810_drv.h"
+
+#include <linux/interrupt.h> /* For task queue support */
+
+#define I810_REG(reg) 2
+#define I810_BASE(reg) ((unsigned long) \
+ dev->maplist[I810_REG(reg)]->handle)
+#define I810_ADDR(reg) (I810_BASE(reg) + reg)
+#define I810_DEREF(reg) *(__volatile__ int *)I810_ADDR(reg)
+#define I810_READ(reg) I810_DEREF(reg)
+#define I810_WRITE(reg,val) do { I810_DEREF(reg) = val; } while (0)
+
+void i810_dma_init(drm_device_t *dev)
+{
+ printk(KERN_INFO "i810_dma_init\n");
+}
+
+void i810_dma_cleanup(drm_device_t *dev)
+{
+ printk(KERN_INFO "i810_dma_cleanup\n");
+}
+
+static inline void i810_dma_dispatch(drm_device_t *dev, unsigned long address,
+ unsigned long length)
+{
+ printk(KERN_INFO "i810_dma_dispatch\n");
+}
+
+static inline void i810_dma_quiescent(drm_device_t *dev)
+{
+}
+
+static inline void i810_dma_ready(drm_device_t *dev)
+{
+ i810_dma_quiescent(dev);
+ printk(KERN_INFO "i810_dma_ready\n");
+}
+
+static inline int i810_dma_is_ready(drm_device_t *dev)
+{
+
+ i810_dma_quiescent(dev);
+
+ printk(KERN_INFO "i810_dma_is_ready\n");
+ return 1;
+}
+
+
+static void i810_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);
+ if (i810_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 i810_dma_schedule. */
+static int i810_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->bus_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 (!i810_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
+
+ i810_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 i810_dma_schedule_timer_wrapper(unsigned long dev)
+{
+ i810_dma_schedule((drm_device_t *)dev, 0);
+}
+
+static void i810_dma_schedule_tq_wrapper(void *dev)
+{
+ i810_dma_schedule(dev, 0);
+}
+
+int i810_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 = i810_do_dma(dev, locked))) {
+ atomic_inc(&dma->total_hit);
+ ++processed;
+ }
+ } else {
+ do {
+ next = drm_select_queue(dev,
+ i810_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 = i810_do_dma(dev, locked))) {
+ ++processed;
+ }
+ }
+ }
+
+ if (--expire) {
+ if (missed != atomic_read(&dma->total_missed_sched)) {
+ atomic_inc(&dma->total_lost);
+ if (i810_dma_is_ready(dev)) goto again;
+ }
+ if (processed && i810_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 i810_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
+ i810_dma_dispatch(dev, address, length);
+ if (drm_lock_free(dev, &dev->lock.hw_lock->lock,
+ DRM_KERNEL_CONTEXT)) {
+ DRM_ERROR("\n");
+ }
+
+ 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) {
+ i810_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 i810_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;
+ }
+
+ i810_dma_schedule(dev, 0);
+
+ if (d->flags & _DRM_DMA_BLOCK) {
+ DRM_DEBUG("%d waiting\n", current->pid);
+ current->state = TASK_INTERRUPTIBLE;
+ for (;;) {
+ 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 i810_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;
+
+ printk("i810_dma start\n");
+ 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 0
+ if (d.flags & _DRM_DMA_PRIORITY)
+ retcode = i810_dma_priority(dev, &d);
+ else
+ retcode = i810_dma_send_buffers(dev, &d);
+#endif
+ printk("i810_dma priority\n");
+
+ retcode = i810_dma_priority(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);
+
+ printk("i810_dma end (granted)\n");
+ return retcode;
+}
+
+int i810_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 = i810_dma_schedule_tq_wrapper;
+ dev->tq.data = dev;
+
+
+ /* Before installing handler */
+ /* TODO */
+ /* Install handler */
+ if ((retcode = request_irq(dev->irq,
+ i810_dma_service,
+ 0,
+ dev->devname,
+ dev))) {
+ down(&dev->struct_sem);
+ dev->irq = 0;
+ up(&dev->struct_sem);
+ return retcode;
+ }
+
+ /* After installing handler */
+ /* TODO */
+ return 0;
+}
+
+int i810_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);
+
+ /* TODO : Disable interrupts */
+ free_irq(irq, dev);
+
+ return 0;
+}
+
+
+int i810_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;
+
+ printk(KERN_INFO "i810_control\n");
+ i810_dma_init(dev);
+
+ copy_from_user_ret(&ctl, (drm_control_t *)arg, sizeof(ctl), -EFAULT);
+
+ switch (ctl.func) {
+ case DRM_INST_HANDLER:
+ if ((retcode = i810_irq_install(dev, ctl.irq)))
+ return retcode;
+ break;
+ case DRM_UNINST_HANDLER:
+ if ((retcode = i810_irq_uninstall(dev)))
+ return retcode;
+ break;
+ default:
+ return -EINVAL;
+ }
+ return 0;
+}
+
+int i810_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;
+ }
+
+ 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 (;;) {
+ 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);
+ current->state = TASK_INTERRUPTIBLE;
+ 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)
+ i810_dma_ready(dev);
+ if (lock.flags & _DRM_LOCK_QUIESCENT)
+ i810_dma_quiescent(dev);
+ }
+
+#if DRM_DMA_HISTOGRAM
+ atomic_inc(&dev->histo.lacq[drm_histogram_slot(get_cycles() - start)]);
+#endif
+
+ return ret;
+}