[Mesa-dev] [Intel-gfx] [PATCH 2/3] iris: Create a composite context for both compute and render pipelines

[Jordan Justen]

On 2019-03-25 03:58:59, Chris Wilson wrote:
> iris currently uses two distinct GEM contexts to have distinct logical
> HW contexts for the compute and render pipelines. However, using two
> distinct GEM contexts implies that they are distinct timelines, yet as
> they are a single GL context that implies they belong to a single
> timeline from the client perspective. Currently, fences are occasionally
> inserted to order the two timelines. Using 2 GEM contexts, also implies
> that we keep 2 ppGTT for identical buffer state. If we can create a
> single GEM context, with the right capabilities, we can have a single
> VM, a single timeline, but 2 logical HW contexts for the 2 pipelines.
> 
> This is allowed through the new context interface that allows VM to be
> shared, timelines to be specified, and for the logical contexts to be
> constructed as the user desires.
> 
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Kenneth Graunke <kenneth at whitecape.org>
> ---
>  src/gallium/drivers/iris/iris_batch.c   | 16 ++-----
>  src/gallium/drivers/iris/iris_batch.h   |  5 +--
>  src/gallium/drivers/iris/iris_context.c | 56 ++++++++++++++++++++++++-
>  3 files changed, 60 insertions(+), 17 deletions(-)
> 
> diff --git a/src/gallium/drivers/iris/iris_batch.c b/src/gallium/drivers/iris/iris_batch.c
> index 556422c38bc..40bcd939795 100644
> --- a/src/gallium/drivers/iris/iris_batch.c
> +++ b/src/gallium/drivers/iris/iris_batch.c
> @@ -164,24 +164,16 @@ iris_init_batch(struct iris_batch *batch,
>                  struct iris_vtable *vtbl,
>                  struct pipe_debug_callback *dbg,
>                  struct iris_batch *all_batches,
> -                enum iris_batch_name name,
> -                uint8_t engine,
> -                int priority)
> +                uint32_t hw_id,
> +                enum iris_batch_name name)
>  {
>     batch->screen = screen;
>     batch->vtbl = vtbl;
>     batch->dbg = dbg;
>     batch->name = name;
>  
> -   /* engine should be one of I915_EXEC_RENDER, I915_EXEC_BLT, etc. */
> -   assert((engine & ~I915_EXEC_RING_MASK) == 0);
> -   assert(util_bitcount(engine) == 1);
> -   batch->engine = engine;
> -
> -   batch->hw_ctx_id = iris_create_hw_context(screen->bufmgr);
> -   assert(batch->hw_ctx_id);
> -
> -   iris_hw_context_set_priority(screen->bufmgr, batch->hw_ctx_id, priority);
> +   batch->hw_ctx_id = hw_id;
> +   batch->engine = name;

I think this should fall-back to I915_EXEC_RENDER if the old style
contexts are created.

-Jordan