Re: [PATCH 10/19] drm/i915/perf: Use gt-specific ggtt for OA and noa-wait buffers

[Lionel Landwerlin <lionel.g.landwerlin@xxxxxxxxx>]

On 23/08/2022 23:41, Umesh Nerlige Ramappa wrote:
> User passes uabi engine class and instance to the perf OA interface. Use
> gt corresponding to the engine to pin the buffers to the right ggtt.
>
> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@xxxxxxxxx>

I didn't know there was a GGTT per engine.

Do I understand this correct?


Thanks,

-Lionel


> ---
>   drivers/gpu/drm/i915/i915_perf.c | 21 +++++++++++++++++++--
>   1 file changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
> index 87b92d2946f4..f7621b45966c 100644
> --- a/drivers/gpu/drm/i915/i915_perf.c
> +++ b/drivers/gpu/drm/i915/i915_perf.c
> @@ -1765,6 +1765,7 @@ static void gen12_init_oa_buffer(struct i915_perf_stream *stream)
>   static int alloc_oa_buffer(struct i915_perf_stream *stream)
>   {
>   	struct drm_i915_private *i915 = stream->perf->i915;
> +	struct intel_gt *gt = stream->engine->gt;
>   	struct drm_i915_gem_object *bo;
>   	struct i915_vma *vma;
>   	int ret;
> @@ -1784,11 +1785,22 @@ static int alloc_oa_buffer(struct i915_perf_stream *stream)
>   	i915_gem_object_set_cache_coherency(bo, I915_CACHE_LLC);
>   
>   	/* PreHSW required 512K alignment, HSW requires 16M */
> -	vma = i915_gem_object_ggtt_pin(bo, NULL, 0, SZ_16M, 0);
> +	vma = i915_vma_instance(bo, &gt->ggtt->vm, NULL);
>   	if (IS_ERR(vma)) {
>   		ret = PTR_ERR(vma);
>   		goto err_unref;
>   	}
> +
> +	/*
> +	 * PreHSW required 512K alignment.
> +	 * HSW and onwards, align to requested size of OA buffer.
> +	 */
> +	ret = i915_vma_pin(vma, 0, SZ_16M, PIN_GLOBAL | PIN_HIGH);
> +	if (ret) {
> +		drm_err(&gt->i915->drm, "Failed to pin OA buffer %d\n", ret);
> +		goto err_unref;
> +	}
> +
>   	stream->oa_buffer.vma = vma;
>   
>   	stream->oa_buffer.vaddr =
> @@ -1838,6 +1850,7 @@ static u32 *save_restore_register(struct i915_perf_stream *stream, u32 *cs,
>   static int alloc_noa_wait(struct i915_perf_stream *stream)
>   {
>   	struct drm_i915_private *i915 = stream->perf->i915;
> +	struct intel_gt *gt = stream->engine->gt;
>   	struct drm_i915_gem_object *bo;
>   	struct i915_vma *vma;
>   	const u64 delay_ticks = 0xffffffffffffffff -
> @@ -1878,12 +1891,16 @@ static int alloc_noa_wait(struct i915_perf_stream *stream)
>   	 * multiple OA config BOs will have a jump to this address and it
>   	 * needs to be fixed during the lifetime of the i915/perf stream.
>   	 */
> -	vma = i915_gem_object_ggtt_pin_ww(bo, &ww, NULL, 0, 0, PIN_HIGH);
> +	vma = i915_vma_instance(bo, &gt->ggtt->vm, NULL);
>   	if (IS_ERR(vma)) {
>   		ret = PTR_ERR(vma);
>   		goto out_ww;
>   	}
>   
> +	ret = i915_vma_pin_ww(vma, &ww, 0, 0, PIN_GLOBAL | PIN_HIGH);
> +	if (ret)
> +		goto out_ww;
> +
>   	batch = cs = i915_gem_object_pin_map(bo, I915_MAP_WB);
>   	if (IS_ERR(batch)) {
>   		ret = PTR_ERR(batch);