From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id B59B710E4F2 for ; Fri, 25 Feb 2022 08:39:32 +0000 (UTC) Date: Fri, 25 Feb 2022 10:39:54 +0200 From: "Lisovskiy, Stanislav" To: Jeevan B Message-ID: <20220225083954.GB29898@intel.com> References: <20220225050853.8349-1-jeevan.b@intel.com> <20220225050853.8349-5-jeevan.b@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220225050853.8349-5-jeevan.b@intel.com> Subject: Re: [igt-dev] [PATCH i-g-t 04/10] lib/igt_draw: Add pixel math for tile-4 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: igt-dev@lists.freedesktop.org, juha-pekka.heikkila@intel.com, petri.latvala@intel.com Errors-To: igt-dev-bounces@lists.freedesktop.org Sender: "igt-dev" List-ID: On Fri, Feb 25, 2022 at 10:38:47AM +0530, Jeevan B wrote: > From: Matt Roper > > We need to implement the tile-4 math to convert x,y coordinates to > buffer offsets and vice versa for cases where we're using the CPU to > tile/detile rather than a GPU engine (e.g., the mmap_cpu and pwrite > subtests for kms_draw_crc). > > The bspec description of tiling-4 is very confusing/misleading, but the > implementation here does match the tile-4 content generated by GPU > engines and recognized properly by the display controller. > > Cc: Stanislav Lisovskiy > Signed-off-by: Matt Roper > Signed-off-by: Jeevan B Reviewed-by: Stanislav Lisovskiy > --- > lib/igt_draw.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 111 insertions(+), 2 deletions(-) > > diff --git a/lib/igt_draw.c b/lib/igt_draw.c > index 0ca43deb..d78ecdf0 100644 > --- a/lib/igt_draw.c > +++ b/lib/igt_draw.c > @@ -226,6 +226,71 @@ static int linear_x_y_to_ytiled_pos(int x, int y, uint32_t stride, int swizzle, > return pos / pixel_size; > } > > +#define OW_SIZE 16 /* in bytes */ > +#define TILE_4_SUBTILE_SIZE 64 /* in bytes */ > +#define TILE_4_WIDTH 128 /* in bytes */ > +#define TILE_4_HEIGHT 32 /* in pixels */ > +#define TILE_4_SUBTILE_WIDTH OW_SIZE /* in bytes */ > +#define TILE_4_SUBTILE_HEIGHT 4 /* in pixels */ > + > +/* > + * Subtile remapping for tile 4. Note that map[a]==b implies map[b]==a > + * so we can use the same table to tile and until. > + */ > +static const int tile4_subtile_map[] = { > + 0, 1, 2, 3, 8, 9, 10, 11, > + 4, 5, 6, 7, 12, 13, 14, 15, > + 16, 17, 18, 19, 24, 25, 26, 27, > + 20, 21, 22, 23, 28, 29, 30, 31, > + 32, 33, 34, 35, 40, 41, 42, 43, > + 36, 37, 38, 39, 44, 45, 46, 47, > + 48, 49, 50, 51, 56, 57, 58, 59, > + 52, 53, 54, 55, 60, 61, 62, 63 > +}; > + > +static int linear_x_y_to_4tiled_pos(int x, int y, uint32_t stride, int swizzle, > + int bpp) > +{ > + int tile_base_pos; > + int tile_x, tile_y; > + int subtile_col, subtile_row, subtile_num, new_subtile_num; > + int pixel_size = bpp / 8; > + int byte_x = x * pixel_size; > + int pos; > + > + /* Modern platforms that have 4-tiling don't use old bit 6 swizzling */ > + igt_assert_eq(swizzle, I915_BIT_6_SWIZZLE_NONE); > + > + /* > + * Where does the 4k tile start (in bytes)? This is the same for Y and > + * F so we can use the Y-tile algorithm to get to that point. > + */ > + tile_base_pos = (y / TILE_4_HEIGHT) * stride * TILE_4_HEIGHT + > + 4096 * (byte_x / TILE_4_WIDTH); > + > + /* Find pixel within tile */ > + tile_x = (byte_x % TILE_4_WIDTH); > + tile_y = y % TILE_4_HEIGHT; > + > + /* And figure out the subtile within the 4k tile */ > + subtile_col = tile_x / TILE_4_SUBTILE_WIDTH; > + subtile_row = tile_y / TILE_4_SUBTILE_HEIGHT; > + subtile_num = subtile_row * 8 + subtile_col; > + > + /* Swizzle the subtile number according to the bspec diagram */ > + new_subtile_num = tile4_subtile_map[subtile_num]; > + > + /* Calculate new position */ > + pos = tile_base_pos + > + new_subtile_num * TILE_4_SUBTILE_SIZE + > + (tile_y % TILE_4_SUBTILE_HEIGHT) * OW_SIZE + > + tile_x % TILE_4_SUBTILE_WIDTH; > + igt_assert(pos % pixel_size == 0); > + pos /= pixel_size; > + > + return pos; > +} > + > static void xtiled_pos_to_x_y_linear(int tiled_pos, uint32_t stride, > int swizzle, int bpp, int *x, int *y) > { > @@ -253,6 +318,44 @@ static void ytiled_pos_to_x_y_linear(int tiled_pos, uint32_t stride, > *x /= pixel_size; > } > > +static void tile4_pos_to_x_y_linear(int tiled_pos, uint32_t stride, > + int swizzle, int bpp, int *x, int *y) > +{ > + int pixel_size = bpp / 8; > + int tiles_per_line = stride / TILE_4_WIDTH; > + int tile_num, tile_offset, tile_row, tile_col; > + int tile_origin_x, tile_origin_y; > + int subtile_num, subtile_offset, subtile_row, subtile_col; > + int subtile_origin_x, subtile_origin_y; > + int oword_num, byte_num; > + > + /* Modern platforms that have 4-tiling don't use old bit 6 swizzling */ > + igt_assert_eq(swizzle, I915_BIT_6_SWIZZLE_NONE); > + > + /* Calculate the x,y of the start of the 4k tile */ > + tile_num = tiled_pos / 4096; > + tile_row = tile_num / tiles_per_line; > + tile_col = tile_num % tiles_per_line; > + tile_origin_x = tile_col * TILE_4_WIDTH; > + tile_origin_y = tile_row * TILE_4_HEIGHT; > + > + /* Now calculate the x,y offset of the start of the subtile */ > + tile_offset = tiled_pos % 4096; > + subtile_num = tile4_subtile_map[tile_offset / TILE_4_SUBTILE_SIZE]; > + subtile_row = subtile_num / 8; > + subtile_col = subtile_num % 8; > + subtile_origin_x = subtile_col * TILE_4_SUBTILE_WIDTH; > + subtile_origin_y = subtile_row * TILE_4_SUBTILE_HEIGHT; > + > + /* Next the oword and byte within the subtile */ > + subtile_offset = tiled_pos % TILE_4_SUBTILE_SIZE; > + oword_num = subtile_offset / OW_SIZE; > + byte_num = subtile_offset % OW_SIZE; > + > + *x = (tile_origin_x + subtile_origin_x + byte_num) / pixel_size; > + *y = tile_origin_y + subtile_origin_y + oword_num; > +} > + > static void set_pixel(void *_ptr, int index, uint32_t color, int bpp) > { > if (bpp == 16) { > @@ -318,10 +421,13 @@ static void draw_rect_ptr_tiled(void *ptr, uint32_t stride, uint32_t tiling, > swizzle, bpp); > break; > case I915_TILING_Y: > - case I915_TILING_4: > pos = linear_x_y_to_ytiled_pos(x, y, stride, > swizzle, bpp); > break; > + case I915_TILING_4: > + pos = linear_x_y_to_4tiled_pos(x, y, stride, > + swizzle, bpp); > + break; > default: > igt_assert(false); > } > @@ -470,10 +576,13 @@ static void draw_rect_pwrite_tiled(int fd, struct buf_data *buf, > swizzle, buf->bpp, &x, &y); > break; > case I915_TILING_Y: > - case I915_TILING_4: > ytiled_pos_to_x_y_linear(tiled_pos, buf->stride, > swizzle, buf->bpp, &x, &y); > break; > + case I915_TILING_4: > + tile4_pos_to_x_y_linear(tiled_pos, buf->stride, > + swizzle, buf->bpp, &x, &y); > + break; > default: > igt_assert(false); > } > -- > 2.17.1 >