Re: [Intel-gfx] [PATCH 1/2] drm/i915/ttm: remove calc_ctrl_surf_instr_size

[Ramalingam C <ramalingam.c@intel.com>]

On 2022-08-05 at 14:22:39 +0100, Matthew Auld wrote:
> We only ever need to emit one ccs block copy command.
Since max size we handle at a time is CHUNK_SZ, we will need only one
cmd.

Reviewed-by: Ramalingam C<ramalingam.c@intel.com>
> 
> Signed-off-by: Matthew Auld <matthew.auld@intel.com>
> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> Cc: Ramalingam C <ramalingam.c@intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_migrate.c | 35 +++----------------------
>  1 file changed, 3 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_migrate.c b/drivers/gpu/drm/i915/gt/intel_migrate.c
> index 9a0814422ba4..1bbed7aa436a 100644
> --- a/drivers/gpu/drm/i915/gt/intel_migrate.c
> +++ b/drivers/gpu/drm/i915/gt/intel_migrate.c
> @@ -511,44 +511,16 @@ static inline u32 *i915_flush_dw(u32 *cmd, u32 flags)
>  	return cmd;
>  }
>  
> -static u32 calc_ctrl_surf_instr_size(struct drm_i915_private *i915, int size)
> -{
> -	u32 num_cmds, num_blks, total_size;
> -
> -	if (!GET_CCS_BYTES(i915, size))
> -		return 0;
> -
> -	/*
> -	 * XY_CTRL_SURF_COPY_BLT transfers CCS in 256 byte
> -	 * blocks. one XY_CTRL_SURF_COPY_BLT command can
> -	 * transfer upto 1024 blocks.
> -	 */
> -	num_blks = DIV_ROUND_UP(GET_CCS_BYTES(i915, size),
> -				NUM_CCS_BYTES_PER_BLOCK);
> -	num_cmds = DIV_ROUND_UP(num_blks, NUM_CCS_BLKS_PER_XFER);
> -	total_size = XY_CTRL_SURF_INSTR_SIZE * num_cmds;
> -
> -	/*
> -	 * Adding a flush before and after XY_CTRL_SURF_COPY_BLT
> -	 */
> -	total_size += 2 * MI_FLUSH_DW_SIZE;
> -
> -	return total_size;
> -}
> -
>  static int emit_copy_ccs(struct i915_request *rq,
>  			 u32 dst_offset, u8 dst_access,
>  			 u32 src_offset, u8 src_access, int size)
>  {
>  	struct drm_i915_private *i915 = rq->engine->i915;
>  	int mocs = rq->engine->gt->mocs.uc_index << 1;
> -	u32 num_ccs_blks, ccs_ring_size;
> +	u32 num_ccs_blks;
>  	u32 *cs;
>  
> -	ccs_ring_size = calc_ctrl_surf_instr_size(i915, size);
> -	WARN_ON(!ccs_ring_size);
> -
> -	cs = intel_ring_begin(rq, round_up(ccs_ring_size, 2));
> +	cs = intel_ring_begin(rq, 12);
>  	if (IS_ERR(cs))
>  		return PTR_ERR(cs);
>  
> @@ -583,8 +555,7 @@ static int emit_copy_ccs(struct i915_request *rq,
>  		FIELD_PREP(XY_CTRL_SURF_MOCS_MASK, mocs);
>  
>  	cs = i915_flush_dw(cs, MI_FLUSH_DW_LLC | MI_FLUSH_DW_CCS);
> -	if (ccs_ring_size & 1)
> -		*cs++ = MI_NOOP;
> +	*cs++ = MI_NOOP;
>  
>  	intel_ring_advance(rq, cs);
>  
> -- 
> 2.37.1
>