drm/i915/bdw: Allocate ringbuffers for Logical Ring Contexts

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>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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 cbae19bab4bf..eccb8e406e9c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -635,6 +635,7 @@ 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 9f30ee80e487..0c80bb1f5420 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -65,7 +65,11 @@ 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);
                 }
@@ -99,6 +103,7 @@ 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;
 
         WARN_ON(ctx->legacy_hw_ctx.rcs_state != NULL);
@@ -119,6 +124,39 @@ 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 a059b64a0fb2..064652034d7e 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1519,7 +1519,7 @@ 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;
@@ -1530,8 +1530,8 @@ 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 70525d0c2c74..669cc7527f9a 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -355,6 +355,10 @@ 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);