[PATCH 07/43] drm/i915/bdw: Allocate ringbuffers for Logical Ring Contexts

Thomas Daniel
2014-07-24T16:05:01Z

From: Oscar Mateo <oscar.mateo@intel.com>

As we have said a couple of times by now, logical ring contexts have
their own ringbuffers: not only the backing pages, but the whole
management struct.

In a previous version of the series, this was achieved with two separate
patches:
drm/i915/bdw: Allocate ringbuffer backing objects for default global LRC
drm/i915/bdw: Allocate ringbuffer for user-created LRCs

Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 1 +
drivers/gpu/drm/i915/intel_lrc.c | 38 +++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_ringbuffer.c | 6 ++---
drivers/gpu/drm/i915/intel_ringbuffer.h | 4 ++++
4 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index f2a6598..ff2c373 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -625,6 +625,7 @@ struct intel_context {
/* Execlists */
struct {
struct drm_i915_gem_object *state;
+ struct intel_ringbuffer *ringbuf;
} engine[I915_NUM_RINGS];

struct list_head link;
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index a3fc6fc..0a12b8c 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -63,7 +63,11 @@ void intel_lr_context_free(struct intel_context *ctx)

for (i = 0; i < I915_NUM_RINGS; i++) {
struct drm_i915_gem_object *ctx_obj = ctx->engine[i].state;
+ struct intel_ringbuffer *ringbuf = ctx->engine[i].ringbuf;
+
if (ctx_obj) {
+ intel_destroy_ringbuffer_obj(ringbuf);
+ kfree(ringbuf);
i915_gem_object_ggtt_unpin(ctx_obj);
drm_gem_object_unreference(&ctx_obj->base);
}
@@ -97,6 +101,7 @@ int intel_lr_context_deferred_create(struct intel_context *ctx,
struct drm_device *dev = ring->dev;
struct drm_i915_gem_object *ctx_obj;
uint32_t context_size;
+ struct intel_ringbuffer *ringbuf;
int ret;

BUG_ON(ctx->legacy_hw_ctx.rcs_state != NULL);
@@ -117,6 +122,39 @@ int intel_lr_context_deferred_create(struct intel_context *ctx,
return ret;
}

+ ringbuf = kzalloc(sizeof(*ringbuf), GFP_KERNEL);
+ if (!ringbuf) {
+ DRM_DEBUG_DRIVER("Failed to allocate ringbuffer %s\n",
+ ring->name);
+ i915_gem_object_ggtt_unpin(ctx_obj);
+ drm_gem_object_unreference(&ctx_obj->base);
+ ret = -ENOMEM;
+ return ret;
+ }
+
+ ringbuf->size = 32 * PAGE_SIZE;
+ ringbuf->effective_size = ringbuf->size;
+ ringbuf->head = 0;
+ ringbuf->tail = 0;
+ ringbuf->space = ringbuf->size;
+ ringbuf->last_retired_head = -1;
+
+ /* TODO: For now we put this in the mappable region so that we can reuse
+ * the existing ringbuffer code which ioremaps it. When we start
+ * creating many contexts, this will no longer work and we must switch
+ * to a kmapish interface.
+ */
+ ret = intel_alloc_ringbuffer_obj(dev, ringbuf);
+ if (ret) {
+ DRM_DEBUG_DRIVER("Failed to allocate ringbuffer obj %s: %d\n",
+ ring->name, ret);
+ kfree(ringbuf);
+ i915_gem_object_ggtt_unpin(ctx_obj);
+ drm_gem_object_unreference(&ctx_obj->base);
+ return ret;
+ }
+
+ ctx->engine[ring->id].ringbuf = ringbuf;
ctx->engine[ring->id].state = ctx_obj;

return 0;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 599709e..01e9840 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1495,7 +1495,7 @@ static int init_phys_status_page(struct intel_engine_cs *ring)
return 0;
}

-static void intel_destroy_ringbuffer_obj(struct intel_ringbuffer *ringbuf)
+void intel_destroy_ringbuffer_obj(struct intel_ringbuffer *ringbuf)
{
if (!ringbuf->obj)
return;
@@ -1506,8 +1506,8 @@ static void intel_destroy_ringbuffer_obj(struct intel_ringbuffer *ringbuf)
ringbuf->obj = NULL;
}

-static int intel_alloc_ringbuffer_obj(struct drm_device *dev,
- struct intel_ringbuffer *ringbuf)
+int intel_alloc_ringbuffer_obj(struct drm_device *dev,
+ struct intel_ringbuffer *ringbuf)
{
struct drm_i915_private *dev_priv = to_i915(dev);
struct drm_i915_gem_object *obj;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index ed59410..053d004 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -353,6 +353,10 @@ intel_write_status_page(struct intel_engine_cs *ring,
#define I915_GEM_HWS_SCRATCH_INDEX 0x30
#define I915_GEM_HWS_SCRATCH_ADDR (I915_GEM_HWS_SCRATCH_INDEX << MI_STORE_DWORD_INDEX_SHIFT)

+void intel_destroy_ringbuffer_obj(struct intel_ringbuffer *ringbuf);
+int intel_alloc_ringbuffer_obj(struct drm_device *dev,
+ struct intel_ringbuffer *ringbuf);
+
void intel_stop_ring_buffer(struct intel_engine_cs *ring);
void intel_cleanup_ring_buffer(struct intel_engine_cs *ring);

--
1.7.9.5