Re: [PATCH 19/53] drm/i915: Add explicit request management to i915_gem_init_hw()

Tomas Elf
2015-03-05T17:14:00Z

On 19/02/2015 17:17, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
>
> Now that a single per ring loop is being done for all the different
> intialisation steps in i915_gem_init_hw(), it is possible to add proper request
> management as well. The last remaining issue is that the context enable call
> eventually ends up within *_render_state_init() and this does it's own private
> _i915_add_request() call.
>
> This patch adds explicit request creation and submission to the top level loop
> and removes the add_request() from deep within the sub-functions. Note that the
> old add_request() call was being passed a batch object. This is now explicitly
> written to the request object instead. A warning has also been added to
> i915_add_request() to ensure that there is never an attempt to add two batch
> objects to a single request - e.g. because render_state_init() was called during
> execbuffer processing.
>
> For: VIZ-5115
> Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 3 ++-
> drivers/gpu/drm/i915/i915_gem.c | 18 ++++++++++++++++++
> drivers/gpu/drm/i915/i915_gem_render_state.c | 3 ++-
> drivers/gpu/drm/i915/intel_lrc.c | 8 +++-----
> 4 files changed, 25 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 653c82d..ea0da6b 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -2158,7 +2158,8 @@ struct drm_i915_gem_request {
> struct intel_context *ctx;
> struct intel_ringbuffer *ringbuf;
>
> - /** Batch buffer related to this request if any */
> + /** Batch buffer related to this request if any (used for
> + error state dump only) */
> struct drm_i915_gem_object *batch_obj;
>
> /** Time at which this request was emitted, in jiffies. */
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 5850991..efed49a 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2467,6 +2467,7 @@ int __i915_add_request(struct intel_engine_cs *ring,
> * inactive_list and lose its active reference. Hence we do not need
> * to explicitly hold another reference here.
> */
> + WARN_ON(request->batch_obj && obj);
> request->batch_obj = obj;
>
> if (!i915.enable_execlists) {
> @@ -4861,8 +4862,16 @@ i915_gem_init_hw(struct drm_device *dev)
>
> /* Now it is safe to go back round and do everything else: */
> for_each_ring(ring, dev_priv, i) {
> + struct drm_i915_gem_request *req;
> +
> WARN_ON(!ring->default_context);
>
> + ret = dev_priv->gt.alloc_request(ring, ring->default_context, &req);
> + if (ret) {
> + i915_gem_cleanup_ringbuffer(dev);
> + return ret;
> + }
> +
> if (ring->id == RCS) {
> for (i = 0; i < NUM_L3_SLICES(dev); i++)
> i915_gem_l3_remap(ring, i);
> @@ -4871,6 +4880,7 @@ i915_gem_init_hw(struct drm_device *dev)
> ret = i915_ppgtt_init_ring(ring);
> if (ret && ret != -EIO) {
> DRM_ERROR("PPGTT enable ring #%d failed %d\n", i, ret);
> + i915_gem_request_unreference(req);
> i915_gem_cleanup_ringbuffer(dev);
> return ret;
> }
> @@ -4878,8 +4888,16 @@ i915_gem_init_hw(struct drm_device *dev)
> ret = i915_gem_context_enable(ring);
> if (ret && ret != -EIO) {
> DRM_ERROR("Context enable ring #%d failed %d\n", i, ret);
> + i915_gem_request_unreference(req);
> i915_gem_cleanup_ringbuffer(dev);
> + return ret;
> + }
>
> + ret = i915_add_request_no_flush(ring);
> + if (ret) {
> + DRM_ERROR("Add request ring #%d failed: %d\n", i, ret);
> + i915_gem_request_unreference(req);
> + i915_gem_cleanup_ringbuffer(dev);
> return ret;
> }
> }
> diff --git a/drivers/gpu/drm/i915/i915_gem_render_state.c b/drivers/gpu/drm/i915/i915_gem_render_state.c
> index aba39c3..989476e 100644
> --- a/drivers/gpu/drm/i915/i915_gem_render_state.c
> +++ b/drivers/gpu/drm/i915/i915_gem_render_state.c
> @@ -173,7 +173,8 @@ int i915_gem_render_state_init(struct intel_engine_cs *ring)
>
> i915_vma_move_to_active(i915_gem_obj_to_ggtt(so.obj), ring);
>
> - ret = __i915_add_request(ring, NULL, so.obj, true);
> + WARN_ON(ring->outstanding_lazy_request->batch_obj);
> + ring->outstanding_lazy_request->batch_obj = so.obj;
> /* __i915_add_request moves object to inactive if it fails */
> out:
> i915_gem_render_state_fini(&so);
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index 0d88e9c..dff7829 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -1350,8 +1350,6 @@ static int intel_lr_context_render_state_init(struct intel_engine_cs *ring,
> {
> struct intel_ringbuffer *ringbuf = ctx->engine[ring->id].ringbuf;
> struct render_state so;
> - struct drm_i915_file_private *file_priv = ctx->file_priv;
> - struct drm_file *file = file_priv ? file_priv->file : NULL;
> int ret;
>
> ret = i915_gem_render_state_prepare(ring, &so);
> @@ -1370,9 +1368,9 @@ static int intel_lr_context_render_state_init(struct intel_engine_cs *ring,
>
> i915_vma_move_to_active(i915_gem_obj_to_ggtt(so.obj), ring);
>
> - ret = __i915_add_request(ring, file, so.obj, true);
> - /* intel_logical_ring_add_request moves object to inactive if it
> - * fails */
> + WARN_ON(ring->outstanding_lazy_request->batch_obj);
> + ring->outstanding_lazy_request->batch_obj = so.obj;
> + /* __i915_add_request moves object to inactive if it fails */
> out:
> i915_gem_render_state_fini(&so);
> return ret;
>

Reviewed-by: Tomas Elf <tomas.elf@intel.com>

Thanks,
Tomas