drm/i915: Remove intel_ring.last_retired_head

Storing the position of the breadcrumb of the last retired request as
a separate last_retired_head is superfluous as we always copy that into
head prior to recalculation of the intel_ring.space.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170321102552.24357-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 47e707d83c4dad4d4855aca1143724007e81c141..29bf11d8b620749604151f24ac10e5185272b661 100644 (file)
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1938,9 +1938,8 @@ static int i915_gem_framebuffer_info(struct seq_file *m, void *data)
 
 static void describe_ctx_ring(struct seq_file *m, struct intel_ring *ring)
 {
-       seq_printf(m, " (ringbuffer, space: %d, head: %u, tail: %u, last head: %d)",
-                  ring->space, ring->head, ring->tail,
-                  ring->last_retired_head);
+       seq_printf(m, " (ringbuffer, space: %d, head: %u, tail: %u)",
+                  ring->space, ring->head, ring->tail);
 }
 
 static int i915_context_status(struct seq_file *m, void *unused)

diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index 0e8d1010cecb4c4dd7ab53ed3b0ff87cb3f0b837..dbfa9db2419d7b48a1315028bf9ad34ac809ce23 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -295,7 +295,7 @@ static void i915_gem_request_retire(struct drm_i915_gem_request *request)
         * completion order.
         */
        list_del(&request->ring_link);
-       request->ring->last_retired_head = request->postfix;
+       request->ring->head = request->postfix;
        if (!--request->i915->gt.active_requests) {
                GEM_BUG_ON(!request->i915->gt.awake);
                mod_delayed_work(request->i915->wq,

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index a88380876ce9f515aa9732cc884af7c2237d18cd..090238eefd49557d03a7f8e4a0d4fbba41d616d7 100644 (file)
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1260,7 +1260,6 @@ static void reset_common_ring(struct intel_engine_cs *engine,
        ce->lrc_reg_state[CTX_RING_HEAD+1] = request->postfix;
 
        request->ring->head = request->postfix;
-       request->ring->last_retired_head = -1;
        intel_ring_update_space(request->ring);
 
        /* Catch up with any missed context-switch interrupts */
@@ -2047,7 +2046,6 @@ void intel_lr_context_resume(struct drm_i915_private *dev_priv)
                        i915_gem_object_unpin_map(ce->state->obj);
 
                        ce->ring->head = ce->ring->tail = 0;
-                       ce->ring->last_retired_head = -1;
                        intel_ring_update_space(ce->ring);
                }
        }

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index d9b8d17c3fc679b54bfef38542d2f1e2723f9dbe..0ca5ea7a940799fb52f4ae7abfb7f59a8e94b06c 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -49,13 +49,7 @@ static int __intel_ring_space(int head, int tail, int size)
 
 void intel_ring_update_space(struct intel_ring *ring)
 {
-       if (ring->last_retired_head != -1) {
-               ring->head = ring->last_retired_head;
-               ring->last_retired_head = -1;
-       }
-
-       ring->space = __intel_ring_space(ring->head & HEAD_ADDR,
-                                        ring->tail, ring->size);
+       ring->space = __intel_ring_space(ring->head, ring->tail, ring->size);
 }
 
 static int
@@ -618,12 +612,8 @@ static void reset_ring_common(struct intel_engine_cs *engine,
                }
 
                /* If the rq hung, jump to its breadcrumb and skip the batch */
-               if (request->fence.error == -EIO) {
-                       struct intel_ring *ring = request->ring;
-
-                       ring->head = request->postfix;
-                       ring->last_retired_head = -1;
-               }
+               if (request->fence.error == -EIO)
+                       request->ring->head = request->postfix;
        } else {
                engine->legacy_active_context = NULL;
        }
@@ -1392,7 +1382,6 @@ intel_engine_create_ring(struct intel_engine_cs *engine, int size)
        if (IS_I830(engine->i915) || IS_I845G(engine->i915))
                ring->effective_size -= 2 * CACHELINE_BYTES;
 
-       ring->last_retired_head = -1;
        intel_ring_update_space(ring);
 
        vma = intel_ring_create_vma(engine->i915, size);
@@ -1571,10 +1560,8 @@ void intel_legacy_submission_resume(struct drm_i915_private *dev_priv)
        struct intel_engine_cs *engine;
        enum intel_engine_id id;
 
-       for_each_engine(engine, dev_priv, id) {
+       for_each_engine(engine, dev_priv, id)
                engine->buffer->head = engine->buffer->tail;
-               engine->buffer->last_retired_head = -1;
-       }
 }
 
 static int ring_request_alloc(struct drm_i915_gem_request *request)

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 847aea554464d99db458b809582e1b901d2b4310..2ecb41788fb6db150f5e40c31b781b720c387595 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -149,16 +149,6 @@ struct intel_ring {
        int space;
        int size;
        int effective_size;
-
-       /** We track the position of the requests in the ring buffer, and
-        * when each is retired we increment last_retired_head as the GPU
-        * must have finished processing the request and so we know we
-        * can advance the ringbuffer up to that position.
-        *
-        * last_retired_head is set to -1 after the value is consumed so
-        * we can detect new retirements.
-        */
-       u32 last_retired_head;
 };
 
 struct i915_gem_context;

diff --git a/drivers/gpu/drm/i915/selftests/mock_engine.c b/drivers/gpu/drm/i915/selftests/mock_engine.c
index 8d5ba037064c967fce08c2538ba5ef26989e42bd..0ad624a1db90a0315a19fc1a973d49f7ccfe68b9 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/mock_engine.c
+++ b/drivers/gpu/drm/i915/selftests/mock_engine.c
@@ -118,7 +118,6 @@ static struct intel_ring *mock_ring(struct intel_engine_cs *engine)
        ring->vaddr = (void *)(ring + 1);
 
        INIT_LIST_HEAD(&ring->request_list);
-       ring->last_retired_head = -1;
        intel_ring_update_space(ring);
 
        return ring;