This is so that we have symmetry with intel_lrc.c and avoid a source of
if (i915.enable_execlists) layering violation within i915_gem_context.c -
that is we move the specific handling of the dev_priv->kernel_context
for legacy submission into the legacy submission code.
This depends upon the init/fini ordering between contexts and engines
already defined by intel_lrc.c, and also exporting the context alignment
required for pinning the legacy context.
v2: Separate out pin/unpin context funcs for greater symmetry with
intel_lrc. One more step towards unifying behaviour between the two
classes of engines and towards fixing another bug in i915_switch_context
vs requests.
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_drv.h | 2 ++
drivers/gpu/drm/i915/i915_gem_context.c | 27 ++--------------
drivers/gpu/drm/i915/intel_ringbuffer.c | 55 +++++++++++++++++++++++++++++++++
3 files changed, 60 insertions(+), 24 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index f1c6c65c6a5e..bb1148b4966c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -867,6 +867,8 @@ struct i915_gem_context {
u32 user_handle;
#define CONTEXT_NO_ZEROMAP (1<<0)
+ u32 ggtt_alignment;
+
struct intel_context {
struct drm_i915_gem_object *state;
struct intel_ringbuffer *ringbuf;
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index a3b11aac23a4..c620fe6c9d96 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -268,6 +268,8 @@ __create_hw_context(struct drm_device *dev,
list_add_tail(&ctx->link, &dev_priv->context_list);
ctx->i915 = dev_priv;
+ ctx->ggtt_alignment = get_context_alignment(dev_priv);
+
if (dev_priv->hw_context_size) {
struct drm_i915_gem_object *obj =
i915_gem_alloc_context_obj(dev, dev_priv->hw_context_size);
@@ -413,26 +415,6 @@ int i915_gem_context_init(struct drm_device *dev)
return PTR_ERR(ctx);
}
- if (!i915.enable_execlists && ctx->engine[RCS].state) {
- int ret;
-
- /* We may need to do things with the shrinker which
- * require us to immediately switch back to the default
- * context. This can cause a problem as pinning the
- * default context also requires GTT space which may not
- * be available. To avoid this we always pin the default
- * context.
- */
- ret = i915_gem_obj_ggtt_pin(ctx->engine[RCS].state,
- get_context_alignment(dev_priv), 0);
- if (ret) {
- DRM_ERROR("Failed to pinned default global context (error %d)\n",
- ret);
- i915_gem_context_unreference(ctx);
- return ret;
- }
- }
-
dev_priv->kernel_context = ctx;
DRM_DEBUG_DRIVER("%s context support initialized\n",
@@ -469,9 +451,6 @@ void i915_gem_context_fini(struct drm_device *dev)
lockdep_assert_held(&dev->struct_mutex);
- if (!i915.enable_execlists && dctx->engine[RCS].state)
- i915_gem_object_ggtt_unpin(dctx->engine[RCS].state);
-
i915_gem_context_unreference(dctx);
dev_priv->kernel_context = NULL;
@@ -721,7 +700,7 @@ static int do_rcs_switch(struct drm_i915_gem_request *req)
/* Trying to pin first makes error handling easier. */
ret = i915_gem_obj_ggtt_pin(to->engine[RCS].state,
- get_context_alignment(engine->i915),
+ to->ggtt_alignment,
0);
if (ret)
return ret;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 8d35a3978f9b..92bb376e5039 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2240,6 +2240,47 @@ intel_ringbuffer_free(struct intel_ringbuffer *ring)
kfree(ring);
}
+static int intel_ring_context_pin(struct i915_gem_context *ctx,
+ struct intel_engine_cs *engine)
+{
+ struct intel_context *ce = &ctx->engine[engine->id];
+ int ret;
+
+ lockdep_assert_held(&ctx->i915->dev->struct_mutex);
+
+ if (ce->pin_count++)
+ return 0;
+
+ if (ce->state) {
+ ret = i915_gem_obj_ggtt_pin(ce->state, ctx->ggtt_alignment, 0);
+ if (ret)
+ goto error;
+ }
+
+ i915_gem_context_reference(ctx);
+ return 0;
+
+error:
+ ce->pin_count = 0;
+ return ret;
+}
+
+static void intel_ring_context_unpin(struct i915_gem_context *ctx,
+ struct intel_engine_cs *engine)
+{
+ struct intel_context *ce = &ctx->engine[engine->id];
+
+ lockdep_assert_held(&ctx->i915->dev->struct_mutex);
+
+ if (--ce->pin_count)
+ return;
+
+ if (ce->state)
+ i915_gem_object_ggtt_unpin(ce->state);
+
+ i915_gem_context_unreference(ctx);
+}
+
static int intel_init_ring_buffer(struct drm_device *dev,
struct intel_engine_cs *engine)
{
@@ -2260,6 +2301,17 @@ static int intel_init_ring_buffer(struct drm_device *dev,
init_waitqueue_head(&engine->irq_queue);
+ /* We may need to do things with the shrinker which
+ * require us to immediately switch back to the default
+ * context. This can cause a problem as pinning the
+ * default context also requires GTT space which may not
+ * be available. To avoid this we always pin the default
+ * context.
+ */
+ ret = intel_ring_context_pin(dev_priv->kernel_context, engine);
+ if (ret)
+ goto error;
+
ringbuf = intel_engine_create_ringbuffer(engine, 32 * PAGE_SIZE);
if (IS_ERR(ringbuf)) {
ret = PTR_ERR(ringbuf);
@@ -2327,6 +2379,9 @@ void intel_cleanup_engine(struct intel_engine_cs *engine)
i915_cmd_parser_fini_ring(engine);
i915_gem_batch_pool_fini(&engine->batch_pool);
+
+ intel_ring_context_unpin(dev_priv->kernel_context, engine);
+
engine->i915 = NULL;
}
--
2.8.1
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