[PATCH v3 3/7] drm/i915: Cache ringbuffer GTT VMA

Tvrtko Ursulin
2016-01-12T11:42:43Z

From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

Purpose is to avoid calling i915_gem_obj_ggtt_offset from the
interrupt context without the big lock held.

v2: Renamed gtt_start to gtt_offset. (Daniel Vetter)
v3: Cache the VMA instead of address. (Chris Wilson)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/intel_lrc.c | 3 +--
drivers/gpu/drm/i915/intel_ringbuffer.c | 3 +++
drivers/gpu/drm/i915/intel_ringbuffer.h | 1 +
3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 504030ce7f93..94314b344f38 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -340,7 +340,6 @@ static int execlists_update_context(struct drm_i915_gem_request *rq)
struct intel_engine_cs *ring = rq->ring;
struct i915_hw_ppgtt *ppgtt = rq->ctx->ppgtt;
struct drm_i915_gem_object *ctx_obj = rq->ctx->engine[ring->id].state;
- struct drm_i915_gem_object *rb_obj = rq->ringbuf->obj;
struct page *page;
uint32_t *reg_state;

@@ -350,7 +349,7 @@ static int execlists_update_context(struct drm_i915_gem_request *rq)
reg_state = kmap_atomic(page);

reg_state[CTX_RING_TAIL+1] = rq->tail;
- reg_state[CTX_RING_BUFFER_START+1] = i915_gem_obj_ggtt_offset(rb_obj);
+ reg_state[CTX_RING_BUFFER_START+1] = rq->ringbuf->vma->node.start;

if (ppgtt && !USES_FULL_48BIT_PPGTT(ppgtt->base.dev)) {
/* True 32b PPGTT with dynamic page allocation: update PDP
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 339701d7a9a5..eccc5323d59b 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1988,6 +1988,7 @@ void intel_unpin_ringbuffer_obj(struct intel_ringbuffer *ringbuf)
else
iounmap(ringbuf->virtual_start);
ringbuf->virtual_start = NULL;
+ ringbuf->vma = NULL;
i915_gem_object_ggtt_unpin(ringbuf->obj);
}

@@ -2054,6 +2055,8 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev,
}
}

+ ringbuf->vma = i915_gem_obj_to_ggtt(obj);
+
return 0;
}

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 85ce2272f92c..ede57954080e 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -99,6 +99,7 @@ struct intel_ring_hangcheck {
struct intel_ringbuffer {
struct drm_i915_gem_object *obj;
void __iomem *virtual_start;
+ struct i915_vma *vma;

struct intel_engine_cs *ring;
struct list_head link;
--
1.9.1