freedreno: Introduce a resource layout header.

This will be used for sharing resource layout code between freedreno and
tu.  Mostly copied from a commit by Rob, with a new location and the slice
struct renamed for consistency.

Acked-by: Rob Clark <robdclark@chromium.org>

src/freedreno/fdl/freedreno_layout.h

@@ -0,0 +1,164 @@
+/*
+ * Copyright © 2019 Google, Inc.
+ *
+ * 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 FREEDRENO_LAYOUT_H_
+#define FREEDRENO_LAYOUT_H_
+
+/* Shared freedreno mipmap layout helper
+ *
+ * It does *not* attempt to track surface transitions, in particular
+ * about UBWC state.  Possibly it should, but
+ *  (a) I'm not sure if in all cases we can transparently do in-
+ *      place transitions (ie. a5xx textures with interleaved
+ *      meta and pixel data
+ *  (b) Even if we can, we probably can't assume that we have
+ *      figured out yet how to do in-place transition for every
+ *      generation.
+ */
+
+/* Texture Layout on a3xx:
+ * -----------------------
+ *
+ * Each mipmap-level contains all of it's layers (ie. all cubmap
+ * faces, all 1d/2d array elements, etc).  The texture sampler is
+ * programmed with the start address of each mipmap level, and hw
+ * derives the layer offset within the level.
+ *
+ *
+ * Texture Layout on a4xx+:
+ * -----------------------
+ *
+ * For cubemap and 2d array, each layer contains all of it's mipmap
+ * levels (layer_first layout).
+ *
+ * 3d textures are laid out as on a3xx.
+ *
+ * In either case, the slice represents the per-miplevel information,
+ * but in layer_first layout it only includes the first layer, and
+ * an additional offset of (rsc->layer_size * layer) must be added.
+ *
+ *
+ * UBWC Color Compressions (a5xx+):
+ * -------------------------------
+ *
+ * Color compression is only supported for tiled layouts.  In general
+ * the meta "flag" buffer (ie. what holds the compression state for
+ * each block) can be separate from the color data, except for textures
+ * on a5xx where it needs to be interleaved with layers/levels of a
+ * texture.
+ */
+
+struct fdl_slice {
+	uint32_t offset;         /* offset of first layer in slice */
+	uint32_t pitch;
+	uint32_t size0;          /* size of first layer in slice */
+};
+
+/**
+ * Encapsulates the layout of a resource, including position of given 2d
+ * surface (layer, level) within.  Or rather all the information needed
+ * to derive this.
+ */
+struct fdl_layout {
+	struct fdl_slice slices[MAX_MIP_LEVELS];
+	uint32_t layer_size;
+	bool layer_first : 1;    /* see above description */
+
+	/* Note that for tiled textures, beyond a certain mipmap level (ie.
+	 * when width is less than block size) things switch to linear.  In
+	 * general you should not directly look at fdl_layout::tile_mode,
+	 * but instead use fdl_surface::tile_mode which will correctly take
+	 * this into account.
+	 */
+	uint32_t tile_mode : 2;
+	/* Bytes per pixel (where a "pixel" is a single row of a block in the case
+	 * of compression), including each sample in the case of multisample
+	 * layouts.
+	 */
+	uint8_t cpp;
+
+	uint32_t width0, height0, depth0;
+
+	/* UBWC specific fields: */
+	uint32_t offset;         /* offset to start of pixel data */
+	uint32_t ubwc_offset;    /* offset to UBWC meta data */
+	uint32_t ubwc_pitch;
+	uint32_t ubwc_size;
+};
+
+static inline uint32_t
+fdl_layer_stride(const struct fdl_layout *layout, unsigned level)
+{
+	if (layout->layer_first)
+		return layout->layer_size;
+	else
+		return layout->slices[level].size0;
+}
+
+static inline uint32_t
+fdl_surface_offset(const struct fdl_layout *layout, unsigned level, unsigned layer)
+{
+	const struct fdl_slice *slice = &layout->slices[level];
+	unsigned offset = slice->offset;
+	offset += fdl_layer_stride(layout, level) * layer;
+	return offset + layout->offset;
+}
+
+static inline uint32_t
+fdl_ubwc_offset(const struct fdl_layout *layout, unsigned level, unsigned layer)
+{
+	/* for now this doesn't do anything clever, but when UBWC is enabled
+	 * for multi layer/level images, it will.
+	 */
+	if (layout->ubwc_size) {
+		debug_assert(level == 0);
+		debug_assert(layer == 0);
+	}
+	return layout->ubwc_offset;
+}
+
+static inline bool
+fdl_level_linear(const struct fdl_layout *layout, int level)
+{
+	unsigned w = u_minify(layout->width0, level);
+	if (w < 16)
+		return true;
+	return false;
+}
+
+static inline uint32_t
+fdl_tile_mode(const struct fdl_layout *layout, int level)
+{
+	if (layout->tile_mode && fdl_level_linear(layout, level))
+		return 0; /* linear */
+	else
+		return layout->tile_mode;
+}
+
+static inline bool
+fdl_ubwc_enabled(const struct fdl_layout *layout, int level)
+{
+	return layout->ubwc_size && fdl_tile_mode(layout, level);
+}
+
+#endif /* FREEDRENO_LAYOUT_H_ */