[Intel-gfx] [PATCH v2] drm/i915/guc: Keep the ctx_pool_vaddr mapped, for easy access

[Chris Wilson]

On Thu, Feb 16, 2017 at 06:15:05AM -0800, Oscar Mateo wrote:
>  static void guc_ctx_desc_init(struct intel_guc *guc,
>  			      struct i915_guc_client *client)
>  {
>  	struct drm_i915_private *dev_priv = guc_to_i915(guc);
>  	struct intel_engine_cs *engine;
>  	struct i915_gem_context *ctx = client->owner;
> -	struct guc_context_desc desc;
> -	struct sg_table *sg;
> +	struct guc_context_desc *desc;
>  	unsigned int tmp;
>  	u32 gfx_addr;
>  
> -	memset(&desc, 0, sizeof(desc));
> +	desc = __get_context_desc(client);

Do you want to make the assumption that these are zeroed-on-create
objects? We could switch to using non-swappable (internal) objects that
are not cleared on create. i.e.

diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index 4a752f2b6e24..4128e8937b45 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -650,7 +650,7 @@ struct i915_vma *intel_guc_allocate_vma(struct intel_guc *guc, u32 size)
        struct i915_vma *vma;
        int ret;
 
-       obj = i915_gem_object_create(dev_priv, size);
+       obj = i915_gem_object_create_internal(dev_priv, size);
        if (IS_ERR(obj))
                return ERR_CAST(obj);
 
Or do we write the entire desc? It doesn't look like we do, but do we do
enough?

Other than that potential booby trap for later,
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre