Re: [igt-dev] [PATCH i-g-t] lib/intel_batchbuffer: Use safe alignment in fast-copy raw

["Dixit, Ashutosh" <ashutosh.dixit@intel.com>]

On Mon, 21 Feb 2022 00:41:23 -0800, Zbigniew Kempczyński wrote:
>
> diff --git a/lib/intel_batchbuffer.c b/lib/intel_batchbuffer.c
> index e5666cd4f..23055855b 100644
> --- a/lib/intel_batchbuffer.c
> +++ b/lib/intel_batchbuffer.c
> @@ -990,13 +990,14 @@ void igt_blitter_fast_copy__raw(int fd,
>	uint32_t dword0, dword1;
>	uint32_t src_pitch, dst_pitch;
>	uint64_t batch_offset, src_offset, dst_offset;
> +	uint64_t align = gem_detect_safe_alignment(fd);
>	int i = 0;
>
>	batch_handle = gem_create(fd, 4096);
>	if (ahnd) {
> -		src_offset = get_offset(ahnd, src_handle, src_size, 0);
> -		dst_offset = get_offset(ahnd, dst_handle, dst_size, 0);
> -		batch_offset = get_offset(ahnd, batch_handle, 4096, 0);
> +		src_offset = get_offset(ahnd, src_handle, src_size, align);
> +		dst_offset = get_offset(ahnd, dst_handle, dst_size, align);
> +		batch_offset = get_offset(ahnd, batch_handle, 4096, align);

Is it possible to modify the allocator so that say '0' (or alternatively
-1ULL) denotes the "default" alignment? And the default alignment will the
safe_alignment which can be stored as part of the allocator itself?

This will avoid having to pass this safe_alignment in a large number of
IGT's. If some IGT's want to override the default alignment they can always
do so. Thoughts?