[PATCH i-g-t v2 1/4] lib/intel_bufops: Add support for gen2 and i915 tiling layouts

[Zbigniew Kempczyński]

On Fri, Nov 22, 2024 at 10:48:01AM +0200, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Add support for tiling formats on gen2/3.
> 
> Our tile formats are as follows:
> X-tile:
>  gen2:  128B x 16, made of  8B QWords
>  gen3:  512B x  8, made of 32B SWords
>  gen4+: 512B x  8, made of 16B OWords
> Y-tile:
>  gen2:  128B x 16, made of  8B QWords
>  i915:  512B x  8, made of 32B SWords
>  i945+: 128B x 32, made of 16B OWords
> 
> We already had the i945+ Y-tile and i915+ X-tile
> (since the i945 OW vs. i915 SW makes no difference
> for X-tile). So just need to deal with gen2 X/Y-tile
> and i915 Y-tile.
> 
> Note that the gen2 check that was there was incorrect
> becasue it completely forgot about i915 Y-tile.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  lib/intel_bufops.c | 83 +++++++++++++++++++++++++++++++---------------
>  1 file changed, 56 insertions(+), 27 deletions(-)
> 
> diff --git a/lib/intel_bufops.c b/lib/intel_bufops.c
> index 600a485362b5..619222019fd8 100644
> --- a/lib/intel_bufops.c
> +++ b/lib/intel_bufops.c
> @@ -307,10 +307,9 @@ static void *linear_ptr(void *ptr,
>  
>  static void *x_ptr(void *ptr,
>  		   unsigned int x, unsigned int y,
> -		   unsigned int stride, unsigned int cpp)
> +		   unsigned int stride, unsigned int cpp,
> +		   const int tile_width, const int tile_height)
>  {
> -	const int tile_width = 512;
> -	const int tile_height = 8;
>  	const int tile_size = tile_width * tile_height;
>  	int offset_x, offset_y, pos;
>  	int tile_x, tile_y;
> @@ -327,13 +326,27 @@ static void *x_ptr(void *ptr,
>  	return ptr + pos;
>  }
>  
> +static void *gen2_x_ptr(void *ptr,
> +			unsigned int x, unsigned int y,
> +			unsigned int stride, unsigned int cpp)
> +{
> +	return x_ptr(ptr, x, y, stride, cpp, 128, 16);
> +}
> +
> +static void *gen3_x_ptr(void *ptr,
> +			unsigned int x, unsigned int y,
> +			unsigned int stride, unsigned int cpp)
> +{
> +	return x_ptr(ptr, x, y, stride, cpp, 512, 8);
> +}
> +
>  static void *y_ptr(void *ptr,
>  		   unsigned int x, unsigned int y,
> -		   unsigned int stride, unsigned int cpp)
> +		   unsigned int stride, unsigned int cpp,
> +		   const int tile_width,
> +		   const int tile_height,
> +		   const int owords)
>  {
> -	const int tile_width = 128;
> -	const int tile_height = 32;
> -	const int owords = 16;
>  	const int tile_size = tile_width * tile_height;
>  	int offset_x, offset_y, pos;
>  	int shift_x, shift_y;
> @@ -352,6 +365,27 @@ static void *y_ptr(void *ptr,
>  	return ptr + pos;
>  }
>  
> +static void *gen2_y_ptr(void *ptr,
> +			unsigned int x, unsigned int y,
> +			unsigned int stride, unsigned int cpp)
> +{
> +	return y_ptr(ptr, x, y, stride, cpp, 128, 16, 8);
> +}
> +
> +static void *i915_y_ptr(void *ptr,
> +			unsigned int x, unsigned int y,
> +			unsigned int stride, unsigned int cpp)
> +{
> +	return y_ptr(ptr, x, y, stride, cpp, 512, 8, 32);
> +}
> +
> +static void *i945_y_ptr(void *ptr,
> +			unsigned int x, unsigned int y,
> +			unsigned int stride, unsigned int cpp)
> +{
> +	return y_ptr(ptr, x, y, stride, cpp, 128, 32, 16);
> +}
> +
>  /*
>   * (x,y) to memory location in tiled-4 surface
>   *
> @@ -426,8 +460,10 @@ static void *yf_ptr(void *ptr,
>  
>  typedef void *(*tile_fn)(void *, unsigned int, unsigned int,
>  			unsigned int, unsigned int);
> -static tile_fn __get_tile_fn_ptr(int tiling)
> +static tile_fn __get_tile_fn_ptr(int fd, int tiling)
>  {
> +	const struct intel_device_info *info =
> +		intel_get_device_info(intel_get_drm_devid(fd));
>  	tile_fn fn = NULL;
>  
>  	switch (tiling) {
> @@ -435,10 +471,18 @@ static tile_fn __get_tile_fn_ptr(int tiling)
>  		fn = linear_ptr;
>  		break;
>  	case I915_TILING_X:
> -		fn = x_ptr;
> +		if (info->graphics_ver == 2)
> +			fn = gen2_x_ptr;
> +		else
> +			fn = gen3_x_ptr;
>  		break;
>  	case I915_TILING_Y:
> -		fn = y_ptr;
> +		if (info->graphics_ver == 2)
> +			fn = gen2_y_ptr;
> +		else if (info->is_grantsdale || info->is_alviso)
> +			fn = i915_y_ptr;
> +		else
> +			fn = i945_y_ptr;
>  		break;
>  	case I915_TILING_Yf:
>  		fn = yf_ptr;
> @@ -595,7 +639,7 @@ static void __copy_linear_to(int fd, struct intel_buf *buf,
>  			     const uint32_t *linear,
>  			     int tiling, uint32_t swizzle)
>  {
> -	const tile_fn fn = __get_tile_fn_ptr(tiling);
> +	const tile_fn fn = __get_tile_fn_ptr(fd, tiling);
>  	int height = intel_buf_height(buf);
>  	int width = intel_buf_width(buf);
>  	void *map = mmap_write(fd, buf);
> @@ -659,7 +703,7 @@ static void copy_linear_to_tile4(struct buf_ops *bops, struct intel_buf *buf,
>  static void __copy_to_linear(int fd, struct intel_buf *buf,
>  			     uint32_t *linear, int tiling, uint32_t swizzle)
>  {
> -	const tile_fn fn = __get_tile_fn_ptr(tiling);
> +	const tile_fn fn = __get_tile_fn_ptr(fd, tiling);
>  	int height = intel_buf_height(buf);
>  	int width = intel_buf_width(buf);
>  	void *map = mmap_write(fd, buf);
> @@ -1699,21 +1743,6 @@ static struct buf_ops *__buf_ops_create(int fd, bool check_idempotency)
>  		return bops;
>  	}
>  
> -	/*
> -	 * Warning!
> -	 *
> -	 * Gen2 software tiling/detiling is not supported! (yet).
> -	 *
> -	 * If you are brave hero with an access to Gen2 you can save the world.
> -	 * Until then we're doomed to use only hardware (de)tiling.

You're the brave one we were waiting for :)

I'm not able to test this as I have no access to such old platforms
but imo code looks good, so:

Acked-by: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>

Thanks!

--
Zbigniew


> -	 *
> -	 * Ok, you have been warned.
> -	 */
> -	if (bops->intel_gen == 2) {
> -		igt_warn("Gen2 detected. HW (de)tiling support only.");
> -		return bops;
> -	}
> -
>  	/* Let's probe X and Y hw tiling support */
>  	if (is_hw_tiling_supported(bops, I915_TILING_X)) {
>  		bool swizzling_supported;
> -- 
> 2.45.2
>