Re: [PATCH 10/18] drm/i915: Unify legacy/execlists emission of MI_BATCHBUFFER_START

Joonas Lahtinen
2016-07-21T13:40:01Z

On ke, 2016-07-20 at 14:12 +0100, Chris Wilson wrote:
> Both the ->dispatch_execbuffer and ->emit_bb_start callbacks do exactly
> the same thing, add MI_BATCHBUFFER_START to the request's ringbuffer -
> we need only one vfunc.
>

Some ranting below,

Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/i915_gem_execbuffer.c   |  6 ++--
>  drivers/gpu/drm/i915/i915_gem_render_state.c | 16 +++++-----
>  drivers/gpu/drm/i915/intel_lrc.c             | 15 ++++++---
>  drivers/gpu/drm/i915/intel_ringbuffer.c      | 48 ++++++++++++++--------------
>  drivers/gpu/drm/i915/intel_ringbuffer.h      | 12 +++----
>  5 files changed, 50 insertions(+), 47 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> index 5cea95c6f98b..2d9f1f4bc058 100644
> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> @@ -1326,9 +1326,9 @@ i915_gem_ringbuffer_submission(struct i915_execbuffer_params *params,
>   if (exec_len == 0)
>   exec_len = params->batch_obj->base.size;
>
> - ret = params->engine->dispatch_execbuffer(params->request,
> -   exec_start, exec_len,
> -   params->dispatch_flags);
> + ret = params->engine->emit_bb_start(params->request,
> +     exec_start, exec_len,
> +     params->dispatch_flags);
>   if (ret)
>   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 b2be4676a5cf..2ba759f3ab6f 100644
> --- a/drivers/gpu/drm/i915/i915_gem_render_state.c
> +++ b/drivers/gpu/drm/i915/i915_gem_render_state.c
> @@ -234,18 +234,18 @@ int i915_gem_render_state_init(struct drm_i915_gem_request *req)
>   if (so.rodata == NULL)
>   return 0;
>
> - ret = req->engine->dispatch_execbuffer(req, so.ggtt_offset,
> -      so.rodata->batch_items * 4,
> -      I915_DISPATCH_SECURE);
> + ret = req->engine->emit_bb_start(req, so.ggtt_offset,
> +  so.rodata->batch_items * 4,
> +  I915_DISPATCH_SECURE);
>   if (ret)
>   goto out;
>
>   if (so.aux_batch_size > 8) {
> - ret = req->engine->dispatch_execbuffer(req,
> -      (so.ggtt_offset +
> -       so.aux_batch_offset),
> -      so.aux_batch_size,
> -      I915_DISPATCH_SECURE);
> + ret = req->engine->emit_bb_start(req,
> +  (so.ggtt_offset +
> +   so.aux_batch_offset),
> +  so.aux_batch_size,
> +  I915_DISPATCH_SECURE);
>   if (ret)
>   goto out;
>   }

The code above this line is exact reason why I don't like the a->b->c
(especially when there is repetition). But it's not new to this patch
so guess it'll do. Some future work to shorten down a little bit might
not hurt.

> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index 6cd0e24ed50c..d17a193e8eaf 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -859,7 +859,9 @@ int intel_execlists_submission(struct i915_execbuffer_params *params,
>   exec_start = params->batch_obj_vm_offset +
>        args->batch_start_offset;
>
> - ret = engine->emit_bb_start(params->request, exec_start, params->dispatch_flags);
> + ret = engine->emit_bb_start(params->request,
> +     exec_start, args->batch_len,
> +     params->dispatch_flags);
>   if (ret)
>   return ret;
>
> @@ -1535,7 +1537,8 @@ static int intel_logical_ring_emit_pdps(struct drm_i915_gem_request *req)
>  }
>
>  static int gen8_emit_bb_start(struct drm_i915_gem_request *req,
> -       u64 offset, unsigned dispatch_flags)
> +       u64 offset, u32 len,
> +       unsigned int dispatch_flags)
>  {
>   struct intel_ring *ring = req->ring;
>   bool ppgtt = !(dispatch_flags & I915_DISPATCH_SECURE);
> @@ -1811,13 +1814,15 @@ static int intel_lr_context_render_state_init(struct drm_i915_gem_request *req)
>   return 0;
>
>   ret = req->engine->emit_bb_start(req, so.ggtt_offset,
> -        I915_DISPATCH_SECURE);
> +  so.rodata->batch_items * 4,
> +  I915_DISPATCH_SECURE);
>   if (ret)
>   goto out;
>
>   ret = req->engine->emit_bb_start(req,
> -        (so.ggtt_offset + so.aux_batch_offset),
> -        I915_DISPATCH_SECURE);
> +  (so.ggtt_offset + so.aux_batch_offset),
> +  so.aux_batch_size,
> +  I915_DISPATCH_SECURE);
>   if (ret)
>   goto out;
>
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 6aa1657bbc9d..4488db485fa4 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -1779,9 +1779,9 @@ gen8_irq_disable(struct intel_engine_cs *engine)
>  }
>
>  static int
> -i965_dispatch_execbuffer(struct drm_i915_gem_request *req,
> -  u64 offset, u32 length,
> -  unsigned dispatch_flags)
> +i965_emit_bb_start(struct drm_i915_gem_request *req,
> +    u64 offset, u32 length,
> +    unsigned int dispatch_flags)
>  {
>   struct intel_ring *ring = req->ring;
>   int ret;
> @@ -1806,9 +1806,9 @@ i965_dispatch_execbuffer(struct drm_i915_gem_request *req,
>  #define I830_TLB_ENTRIES (2)
>  #define I830_WA_SIZE max(I830_TLB_ENTRIES*4096, I830_BATCH_LIMIT)
>  static int
> -i830_dispatch_execbuffer(struct drm_i915_gem_request *req,
> -  u64 offset, u32 len,
> -  unsigned dispatch_flags)
> +i830_emit_bb_start(struct drm_i915_gem_request *req,
> +    u64 offset, u32 len,
> +    unsigned int dispatch_flags)
>  {
>   struct intel_ring *ring = req->ring;
>   u32 cs_offset = req->engine->scratch.gtt_offset;
> @@ -1868,9 +1868,9 @@ i830_dispatch_execbuffer(struct drm_i915_gem_request *req,
>  }
>
>  static int
> -i915_dispatch_execbuffer(struct drm_i915_gem_request *req,
> -  u64 offset, u32 len,
> -  unsigned dispatch_flags)
> +i915_emit_bb_start(struct drm_i915_gem_request *req,
> +    u64 offset, u32 len,
> +    unsigned int dispatch_flags)
>  {
>   struct intel_ring *ring = req->ring;
>   int ret;
> @@ -2563,9 +2563,9 @@ static int gen6_bsd_ring_flush(struct drm_i915_gem_request *req,
>  }
>
>  static int
> -gen8_ring_dispatch_execbuffer(struct drm_i915_gem_request *req,
> -       u64 offset, u32 len,
> -       unsigned dispatch_flags)
> +gen8_emit_bb_start(struct drm_i915_gem_request *req,
> +    u64 offset, u32 len,
> +    unsigned int dispatch_flags)
>  {
>   struct intel_ring *ring = req->ring;
>   bool ppgtt = USES_PPGTT(req->i915) &&
> @@ -2589,9 +2589,9 @@ gen8_ring_dispatch_execbuffer(struct drm_i915_gem_request *req,
>  }
>
>  static int
> -hsw_ring_dispatch_execbuffer(struct drm_i915_gem_request *req,
> -      u64 offset, u32 len,
> -      unsigned dispatch_flags)
> +hsw_emit_bb_start(struct drm_i915_gem_request *req,
> +   u64 offset, u32 len,
> +   unsigned int dispatch_flags)
>  {
>   struct intel_ring *ring = req->ring;
>   int ret;
> @@ -2614,9 +2614,9 @@ hsw_ring_dispatch_execbuffer(struct drm_i915_gem_request *req,
>  }
>
>  static int
> -gen6_ring_dispatch_execbuffer(struct drm_i915_gem_request *req,
> -       u64 offset, u32 len,
> -       unsigned dispatch_flags)
> +gen6_emit_bb_start(struct drm_i915_gem_request *req,
> +    u64 offset, u32 len,
> +    unsigned int dispatch_flags)
>  {
>   struct intel_ring *ring = req->ring;
>   int ret;
> @@ -2820,15 +2820,15 @@ static void intel_ring_default_vfuncs(struct drm_i915_private *dev_priv,
>   engine->add_request = gen6_add_request;
>
>   if (INTEL_GEN(dev_priv) >= 8)
> - engine->dispatch_execbuffer = gen8_ring_dispatch_execbuffer;
> + engine->emit_bb_start = gen8_emit_bb_start;
>   else if (INTEL_GEN(dev_priv) >= 6)
> - engine->dispatch_execbuffer = gen6_ring_dispatch_execbuffer;
> + engine->emit_bb_start = gen6_emit_bb_start;
>   else if (INTEL_GEN(dev_priv) >= 4)
> - engine->dispatch_execbuffer = i965_dispatch_execbuffer;
> + engine->emit_bb_start = i965_emit_bb_start;
>   else if (IS_I830(dev_priv) || IS_845G(dev_priv))
> - engine->dispatch_execbuffer = i830_dispatch_execbuffer;
> + engine->emit_bb_start = i830_emit_bb_start;
>   else
> - engine->dispatch_execbuffer = i915_dispatch_execbuffer;
> + engine->emit_bb_start = i915_emit_bb_start;
>
>   intel_ring_init_irq(dev_priv, engine);
>   intel_ring_init_semaphores(dev_priv, engine);
> @@ -2866,7 +2866,7 @@ int intel_init_render_ring_buffer(struct intel_engine_cs *engine)
>   }
>
>   if (IS_HASWELL(dev_priv))
> - engine->dispatch_execbuffer = hsw_ring_dispatch_execbuffer;
> + engine->emit_bb_start = hsw_emit_bb_start;
>
>   engine->init_hw = init_render_ring;
>   engine->cleanup = render_ring_cleanup;
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
> index 49500cead7a5..85d6a70554b9 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
> @@ -214,12 +214,6 @@ struct intel_engine_cs {
>    * monotonic, even if not coherent.
>    */
>   void (*irq_seqno_barrier)(struct intel_engine_cs *ring);
> - int (*dispatch_execbuffer)(struct drm_i915_gem_request *req,
> -        u64 offset, u32 length,
> -        unsigned dispatch_flags);
> -#define I915_DISPATCH_SECURE 0x1
> -#define I915_DISPATCH_PINNED 0x2
> -#define I915_DISPATCH_RS     0x4
>   void (*cleanup)(struct intel_engine_cs *ring);
>
>   /* GEN8 signal/wait table - never trust comments!
> @@ -295,7 +289,11 @@ struct intel_engine_cs {
>         u32 invalidate_domains,
>         u32 flush_domains);
>   int (*emit_bb_start)(struct drm_i915_gem_request *req,
> -  u64 offset, unsigned dispatch_flags);
> +  u64 offset, u32 length,
> +  unsigned int dispatch_flags);
> +#define I915_DISPATCH_SECURE 0x1
> +#define I915_DISPATCH_PINNED 0x2
> +#define I915_DISPATCH_RS     0x4

BIT(0) BIT(1) etc. while touching it?

Regards, Joonas

>
>   /**
>    * List of objects currently involved in rendering from the
--
Joonas Lahtinen
Open Source Technology Center
Intel Corporation