asahi: Add tiling routines

For the 64x64 Morton order pattern we know how to use for textures and
framebuffers. (AGX also supports a framebuffer compression scheme. This
is not that.)

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Acked-by: Jason Ekstrand <jason@jlekstrand.net>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10582>

src/asahi/lib/meson.build

@@ -19,6 +19,10 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 # SOFTWARE.
 
+libasahi_lib_files = files(
+  'tiling.c',
+)
+
 libasahi_decode_files = files(
   'decode.c',
 )
@@ -36,6 +40,16 @@ idep_agx_pack = declare_dependency(
   include_directories : include_directories('.'),
 )
 
+libasahi_lib = static_library(
+  'asahi_lib',
+  [libasahi_lib_files, agx_pack],
+  include_directories : [inc_include, inc_src, inc_mapi, inc_mesa, inc_gallium, inc_gallium_aux],
+  c_args : [no_override_init_args],
+  gnu_symbol_visibility : 'hidden',
+  dependencies: [dep_libdrm, idep_nir],
+  build_by_default : false,
+)
+
 libasahi_decode = static_library(
   'asahi_decode',
   [libasahi_decode_files, agx_pack],

src/asahi/lib/tiling.c

@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2021 Alyssa Rosenzweig <alyssa@rosenzweig.io>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include "tiling.h"
+
+/* Z-order with 64x64 tiles:
+ *
+ * 	[y5][x5][y4][x4][y3][x3][y2][x2][y1][x1][y0][x0]
+ *
+ * Efficient tiling algorithm described in
+ * https://fgiesen.wordpress.com/2011/01/17/texture-tiling-and-swizzling/ but
+ * for posterity, we split into X and Y parts, and are faced with the problem
+ * of incrementing:
+ *
+ * 	0 [x5] 0 [x4] 0 [x3] 0 [x2] 0 [x1] 0 [x0]
+ *
+ * To do so, we fill in the "holes" with 1's by adding the bitwise inverse of
+ * the mask of bits we care about
+ *
+ * 	0 [x5] 0 [x4] 0 [x3] 0 [x2] 0 [x1] 0 [x0]
+ *    + 1  0   1  0   1  0   1  0   1  0   1  0
+ *    ------------------------------------------
+ * 	1 [x5] 1 [x4] 1 [x3] 1 [x2] 1 [x1] 1 [x0]
+ *
+ * Then when we add one, the holes are passed over by forcing carry bits high.
+ * Finally, we need to zero out the holes, by ANDing with the mask of bits we
+ * care about. In total, we get the expression (X + ~mask + 1) & mask, and
+ * applying the two's complement identity, we are left with (X - mask) & mask
+ */
+
+#define TILE_WIDTH 64
+#define TILE_HEIGHT 64
+#define TILE_SHIFT 6
+#define TILE_MASK ((1 << TILE_SHIFT) - 1)
+
+/* mask of bits used for X coordinate in a tile */
+#define SPACE_MASK 0x555 // 0b010101010101
+
+#define MAX2(x, y) (((x) > (y)) ? (x) : (y))
+#define MIN2(x, y) (((x) < (y)) ? (x) : (y))
+
+static uint32_t
+agx_space_bits(unsigned x)
+{
+   assert(x < TILE_WIDTH);
+   return ((x & 1) << 0) | ((x & 2) << 1) | ((x & 4) << 2) |
+          ((x & 8) << 3) | ((x & 16) << 4) | ((x & 32) << 5);
+}
+
+#define TILED_UNALIGNED_TYPE(pixel_t, is_store) { \
+	unsigned tiles_per_row = (width + TILE_WIDTH - 1) >> TILE_SHIFT;\
+	unsigned y_offs = agx_space_bits(sy & TILE_MASK) << 1;\
+	unsigned x_offs_start = agx_space_bits(sx & TILE_MASK);\
+\
+	for (unsigned y = sy; y < smaxy; ++y) {\
+		unsigned tile_y = (y >> TILE_SHIFT);\
+		unsigned tile_row = tile_y * tiles_per_row;\
+		unsigned x_offs = x_offs_start;\
+\
+		pixel_t *linear_row = linear;\
+		\
+		for (unsigned x = sx; x < smaxx; ++x) {\
+			unsigned tile_x = (x >> TILE_SHIFT);\
+			unsigned tile_idx = (tile_row + tile_x);\
+			unsigned tile_base = tile_idx * (TILE_WIDTH * TILE_HEIGHT);\
+\
+			pixel_t *ptiled = &tiled[tile_base + y_offs + x_offs];\
+			pixel_t *plinear = (linear_row++);\
+			pixel_t *outp = (pixel_t *) (is_store ? ptiled : plinear); \
+			pixel_t *inp = (pixel_t *) (is_store ? plinear : ptiled); \
+			*outp = *inp;\
+			x_offs = (x_offs - SPACE_MASK) & SPACE_MASK;\
+		}\
+\
+		y_offs = (((y_offs >> 1) - SPACE_MASK) & SPACE_MASK) << 1;\
+		linear += linear_pitch;\
+	}\
+}
+
+void
+agx_detile(void *_tiled, void *_linear,
+           unsigned width, unsigned bpp, unsigned linear_pitch,
+           unsigned sx, unsigned sy, unsigned smaxx, unsigned smaxy)
+{
+   /* TODO: parametrize with macro magic */
+   assert(bpp == 32);
+
+   uint32_t *linear = _linear;
+   uint32_t *tiled = _tiled;
+   TILED_UNALIGNED_TYPE(uint32_t, false);
+}
+
+void
+agx_tile(void *_tiled, void *_linear,
+         unsigned width, unsigned bpp, unsigned linear_pitch,
+         unsigned sx, unsigned sy, unsigned smaxx, unsigned smaxy)
+{
+   /* TODO: parametrize with macro magic */
+   assert(bpp == 32);
+
+   uint32_t *linear = _linear;
+   uint32_t *tiled = _tiled;
+   TILED_UNALIGNED_TYPE(uint32_t, true);
+}

src/asahi/lib/tiling.h

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2021 Alyssa Rosenzweig <alyssa@rosenzweig.io>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef __AGX_TILING_H
+#define __AGX_TILING_H
+
+void agx_detile(void *tiled, void *linear,
+                unsigned width, unsigned bpp, unsigned linear_pitch,
+                unsigned sx, unsigned sy, unsigned smaxx, unsigned smaxy);
+
+void agx_tile(void *tiled, void *linear,
+         unsigned width, unsigned bpp, unsigned linear_pitch,
+         unsigned sx, unsigned sy, unsigned smaxx, unsigned smaxy);
+
+#endif