drm/i915: don't frob mm.suspended when not using ums

In kernel modeset driver mode we're in full control of the chip,
always. So there's no need at all to set mm.suspended in
i915_gem_idle. Hence move that out into the leavevt ioctl. Since
i915_gem_idle doesn't suspend gem any more we can also drop the
re-enabling for KMS in the thaw function.

Also clean up the handling of mm.suspend at driver load by coalescing
all the assignments.

Stumbled over while reading through our resume code for unrelated
reasons.

v2: Shovel mm.suspended into the (newly created) ums dungeon as
suggested by Chris Wilson. The plan is that once we've completely
stopped relying on the register save/restore code we could shovel even
that in there.

v3: Improve the locking for the entervt/leavevt ioctls a bit by moving
the dev->struct_mutex locking outside of i915_gem_idle. Also don't
clear dev_priv->ums.mm_suspended for the kms case, we allocate it with
kzalloc. Both suggested by Chris Wilson.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 24 insertions, 16 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 339404937ab..20b10a0fa45 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2082,7 +2082,7 @@ int __i915_add_request(struct intel_ring_buffer *ring,
 	trace_i915_gem_request_add(ring, request->seqno);
 	ring->outstanding_lazy_request = 0;
 
-	if (!dev_priv->mm.suspended) {
+	if (!dev_priv->ums.mm_suspended) {
 		if (i915_enable_hangcheck) {
 			mod_timer(&dev_priv->gpu_error.hangcheck_timer,
 				  round_jiffies_up(jiffies + DRM_I915_HANGCHECK_JIFFIES));
@@ -2398,7 +2398,7 @@ i915_gem_retire_work_handler(struct work_struct *work)
 		idle &= list_empty(&ring->request_list);
 	}
 
-	if (!dev_priv->mm.suspended && !idle)
+	if (!dev_priv->ums.mm_suspended && !idle)
 		queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work,
 				   round_jiffies_up_relative(HZ));
 	if (idle)
@@ -3992,9 +3992,7 @@ i915_gem_idle(struct drm_device *dev)
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	int ret;
 
-	mutex_lock(&dev->struct_mutex);
-
-	if (dev_priv->mm.suspended) {
+	if (dev_priv->ums.mm_suspended) {
 		mutex_unlock(&dev->struct_mutex);
 		return 0;
 	}
@@ -4012,18 +4010,11 @@ i915_gem_idle(struct drm_device *dev)
 
 	i915_gem_reset_fences(dev);
 
-	/* Hack!  Don't let anybody do execbuf while we don't control the chip.
-	 * We need to replace this with a semaphore, or something.
-	 * And not confound mm.suspended!
-	 */
-	dev_priv->mm.suspended = 1;
 	del_timer_sync(&dev_priv->gpu_error.hangcheck_timer);
 
 	i915_kernel_lost_context(dev);
 	i915_gem_cleanup_ringbuffer(dev);
 
-	mutex_unlock(&dev->struct_mutex);
-
 	/* Cancel the retire work handler, which should be idle now. */
 	cancel_delayed_work_sync(&dev_priv->mm.retire_work);
 
@@ -4233,7 +4224,7 @@ int
 i915_gem_entervt_ioctl(struct drm_device *dev, void *data,
 		       struct drm_file *file_priv)
 {
-	drm_i915_private_t *dev_priv = dev->dev_private;
+	struct drm_i915_private *dev_priv = dev->dev_private;
 	int ret;
 
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
@@ -4245,7 +4236,7 @@ i915_gem_entervt_ioctl(struct drm_device *dev, void *data,
 	}
 
 	mutex_lock(&dev->struct_mutex);
-	dev_priv->mm.suspended = 0;
+	dev_priv->ums.mm_suspended = 0;
 
 	ret = i915_gem_init_hw(dev);
 	if (ret != 0) {
@@ -4265,7 +4256,7 @@ i915_gem_entervt_ioctl(struct drm_device *dev, void *data,
 cleanup_ringbuffer:
 	mutex_lock(&dev->struct_mutex);
 	i915_gem_cleanup_ringbuffer(dev);
-	dev_priv->mm.suspended = 1;
+	dev_priv->ums.mm_suspended = 1;
 	mutex_unlock(&dev->struct_mutex);
 
 	return ret;
@@ -4275,11 +4266,26 @@ int
 i915_gem_leavevt_ioctl(struct drm_device *dev, void *data,
 		       struct drm_file *file_priv)
 {
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int ret;
+
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		return 0;
 
 	drm_irq_uninstall(dev);
-	return i915_gem_idle(dev);
+
+	mutex_lock(&dev->struct_mutex);
+	ret =  i915_gem_idle(dev);
+
+	/* Hack!  Don't let anybody do execbuf while we don't control the chip.
+	 * We need to replace this with a semaphore, or something.
+	 * And not confound ums.mm_suspended!
+	 */
+	if (ret != 0)
+		dev_priv->ums.mm_suspended = 1;
+	mutex_unlock(&dev->struct_mutex);
+
+	return ret;
 }
 
 void
@@ -4290,9 +4296,11 @@ i915_gem_lastclose(struct drm_device *dev)
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		return;
 
+	mutex_lock(&dev->struct_mutex);
 	ret = i915_gem_idle(dev);
 	if (ret)
 		DRM_ERROR("failed to idle hardware: %d\n", ret);
+	mutex_unlock(&dev->struct_mutex);
 }
 
 static void