drm/i915: Cleanup context switching through do_switch()

When bug hunting, I found the interface to do_switch() overly
complicated and I believe festered the earlier bug. This aims to make
the code a little clearer.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Chris Wilson 2012-07-15 12:34:24 +01:00 committed by Daniel Vetter
parent 54d63ca660
commit 9a3b530455
1 changed files with 26 additions and 31 deletions

View File

@ -97,8 +97,7 @@
static struct i915_hw_context *
i915_gem_context_get(struct drm_i915_file_private *file_priv, u32 id);
static int do_switch(struct drm_i915_gem_object *from_obj,
struct i915_hw_context *to, u32 seqno);
static int do_switch(struct i915_hw_context *to);
static int get_context_size(struct drm_device *dev)
{
@ -220,19 +219,20 @@ static int create_default_context(struct drm_i915_private *dev_priv)
*/
dev_priv->ring[RCS].default_context = ctx;
ret = i915_gem_object_pin(ctx->obj, CONTEXT_ALIGN, false);
if (ret) {
do_destroy(ctx);
return ret;
}
if (ret)
goto err_destroy;
ret = do_switch(ctx);
if (ret)
goto err_unpin;
ret = do_switch(NULL, ctx, 0);
if (ret) {
i915_gem_object_unpin(ctx->obj);
do_destroy(ctx);
} else {
DRM_DEBUG_DRIVER("Default HW context loaded\n");
}
return 0;
err_unpin:
i915_gem_object_unpin(ctx->obj);
err_destroy:
do_destroy(ctx);
return ret;
}
@ -359,17 +359,18 @@ mi_set_context(struct intel_ring_buffer *ring,
return ret;
}
static int do_switch(struct drm_i915_gem_object *from_obj,
struct i915_hw_context *to,
u32 seqno)
static int do_switch(struct i915_hw_context *to)
{
struct intel_ring_buffer *ring = NULL;
struct intel_ring_buffer *ring = to->ring;
struct drm_i915_gem_object *from_obj = ring->last_context_obj;
u32 hw_flags = 0;
int ret;
BUG_ON(to == NULL);
BUG_ON(from_obj != NULL && from_obj->pin_count == 0);
if (from_obj == to->obj)
return 0;
ret = i915_gem_object_pin(to->obj, CONTEXT_ALIGN, false);
if (ret)
return ret;
@ -393,7 +394,6 @@ static int do_switch(struct drm_i915_gem_object *from_obj,
else if (WARN_ON_ONCE(from_obj == to->obj)) /* not yet expected */
hw_flags |= MI_FORCE_RESTORE;
ring = to->ring;
ret = mi_set_context(ring, to, hw_flags);
if (ret) {
i915_gem_object_unpin(to->obj);
@ -407,6 +407,7 @@ static int do_switch(struct drm_i915_gem_object *from_obj,
* MI_SET_CONTEXT instead of when the next seqno has completed.
*/
if (from_obj != NULL) {
u32 seqno = i915_gem_next_request_seqno(ring);
from_obj->base.read_domains = I915_GEM_DOMAIN_INSTRUCTION;
i915_gem_object_move_to_active(from_obj, ring, seqno);
/* As long as MI_SET_CONTEXT is serializing, ie. it flushes the
@ -417,7 +418,7 @@ static int do_switch(struct drm_i915_gem_object *from_obj,
* swapped, but there is no way to do that yet.
*/
from_obj->dirty = 1;
BUG_ON(from_obj->ring != to->ring);
BUG_ON(from_obj->ring != ring);
i915_gem_object_unpin(from_obj);
drm_gem_object_unreference(&from_obj->base);
@ -448,10 +449,7 @@ int i915_switch_context(struct intel_ring_buffer *ring,
int to_id)
{
struct drm_i915_private *dev_priv = ring->dev->dev_private;
struct drm_i915_file_private *file_priv = NULL;
struct i915_hw_context *to;
struct drm_i915_gem_object *from_obj = ring->last_context_obj;
int ret;
if (dev_priv->hw_contexts_disabled)
return 0;
@ -459,21 +457,18 @@ int i915_switch_context(struct intel_ring_buffer *ring,
if (ring != &dev_priv->ring[RCS])
return 0;
if (file)
file_priv = file->driver_priv;
if (to_id == DEFAULT_CONTEXT_ID) {
to = ring->default_context;
} else {
to = i915_gem_context_get(file_priv, to_id);
if (file == NULL)
return -EINVAL;
to = i915_gem_context_get(file->driver_priv, to_id);
if (to == NULL)
return -ENOENT;
}
if (from_obj == to->obj)
return 0;
return do_switch(from_obj, to, i915_gem_next_request_seqno(to->ring));
return do_switch(to);
}
int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,