[PATCH i-g-t 3/5] lib/intel_compute: Allow the user to provide a custom compute kernel

[Zbigniew Kempczyński]

On Wed, Feb 05, 2025 at 11:17:04AM +0100, Francois Dugast wrote:
> Allow the user to provide a custom compute kernel which will be used
> instead of the default compute square one. This will be helpful to
> try out corner cases which require a specific compute kernel.
> 
> Signed-off-by: Francois Dugast <francois.dugast at intel.com>
> ---
>  lib/intel_compute.c | 26 ++++++++++++++++++--------
>  lib/intel_compute.h |  2 ++
>  2 files changed, 20 insertions(+), 8 deletions(-)
> 
> diff --git a/lib/intel_compute.c b/lib/intel_compute.c
> index e0776fb6d..a826d58c0 100644
> --- a/lib/intel_compute.c
> +++ b/lib/intel_compute.c
> @@ -1770,6 +1770,8 @@ static bool __run_intel_compute_kernel(int fd,
>  	unsigned int batch;
>  	const struct intel_compute_kernels *kernels = intel_compute_square_kernels;
>  	enum intel_driver driver = get_intel_driver(fd);
> +	const unsigned char *kernel;
> +	unsigned int kernel_size;
>  
>  	for (batch = 0; batch < ARRAY_SIZE(intel_compute_batches); batch++) {
>  		if (ip_ver == intel_compute_batches[batch].ip_ver)
> @@ -1787,16 +1789,24 @@ static bool __run_intel_compute_kernel(int fd,
>  		return false;
>  	}
>  
> -	while (kernels->kernel) {
> -		if (ip_ver == kernels->ip_ver)
> -			break;
> -		kernels++;
> +	/* If the user provides a kernel, use it */
> +	if (user && user->kernel) {
> +		kernel = user->kernel;
> +		kernel_size = user->kernel_size;
> +	} else {
> +		while (kernels->kernel) {
> +			if (ip_ver == kernels->ip_ver)
> +				break;
> +			kernels++;
> +		}
> +		if (!kernels->kernel)
> +			return false;
> +		kernel = kernels->kernel;
> +		kernel_size = kernels->size;

According to how we build pipeline indirect data we're limited to
three arguments - *input, *output, count. Allowing the user to provide
a custom kernel won't work unless type constraint will be met.
I don't like this change, because someone who doesn't know how
this work will start providing its own kernels will be surprised
it doesn't work.

--
Zbigniew

>  	}
> -	if (!kernels->kernel)
> -		return false;
>  
> -	intel_compute_batches[batch].compute_exec(fd, kernels->kernel,
> -						  kernels->size, eci, user);
> +	intel_compute_batches[batch].compute_exec(fd, kernel,
> +						  kernel_size, eci, user);
>  
>  	return true;
>  }
> diff --git a/lib/intel_compute.h b/lib/intel_compute.h
> index c4b4ee5e1..6096bb83a 100644
> --- a/lib/intel_compute.h
> +++ b/lib/intel_compute.h
> @@ -35,6 +35,8 @@ struct intel_compute_kernels {
>  
>  struct user_execenv {
>  	uint32_t vm;
> +	const unsigned char *kernel;
> +	unsigned int kernel_size;
>  };
>  
>  extern const struct intel_compute_kernels intel_compute_square_kernels[];
> -- 
> 2.43.0
>