path: root/src/panfrost/encoder/pan_texture.c

/*
 * Copyright (C) 2008 VMware, Inc.
 * Copyright (C) 2014 Broadcom
 * Copyright (C) 2018-2019 Alyssa Rosenzweig
 * Copyright (C) 2019-2020 Collabora, Ltd.
 *
 * 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 "util/macros.h"
#include "util/u_math.h"
#include "pan_texture.h"

/* Generates a texture descriptor. Ideally, descriptors are immutable after the
 * texture is created, so we can keep these hanging around in GPU memory in a
 * dedicated BO and not have to worry. In practice there are some minor gotchas
 * with this (the driver sometimes will change the format of a texture on the
 * fly for compression) but it's fast enough to just regenerate the descriptor
 * in those cases, rather than monkeypatching at drawtime.
 *
 * A texture descriptor consists of a 32-byte mali_texture_descriptor structure
 * followed by a variable number of pointers. Due to this variance and
 * potentially large size, we actually upload directly rather than returning
 * the descriptor. Whether the user does a copy themselves or not is irrelevant
 * to us here.
 */

/* Check if we need to set a custom stride by computing the "expected"
 * stride and comparing it to what the user actually wants. Only applies
 * to linear textures, since tiled/compressed textures have strict
 * alignment requirements for their strides as it is */

static bool
panfrost_needs_explicit_stride(
                struct panfrost_slice *slices,
                uint16_t width,
                unsigned first_level, unsigned last_level,
                unsigned bytes_per_pixel)
{
        for (unsigned l = first_level; l <= last_level; ++l) {
                unsigned actual = slices[l].stride;
                unsigned expected = u_minify(width, l) * bytes_per_pixel;

                if (actual != expected)
                        return true;
        }

        return false;
}

/* A Scalable Texture Compression (ASTC) corresponds to just a few texture type
 * in the hardware, but in fact can be parametrized to have various widths and
 * heights for the so-called "stretch factor". It turns out these parameters
 * are stuffed in the bottom bits of the payload pointers. This functions
 * computes these magic stuffing constants based on the ASTC format in use. The
 * constant in a given dimension is 3-bits, and two are stored side-by-side for
 * each active dimension.
 */

static unsigned
panfrost_astc_stretch(unsigned dim)
{
        assert(dim >= 4 && dim <= 12);
        return MIN2(dim, 11) - 4;
}

/* Texture addresses are tagged with information about AFBC (colour AFBC?) xor
 * ASTC (stretch factor) if in use. */

static unsigned
panfrost_compression_tag(
                const struct util_format_description *desc,
                enum mali_format format, enum mali_texture_layout layout)
{
        if (layout == MALI_TEXTURE_AFBC)
                return util_format_has_depth(desc) ? 0x0 : 0x1;
        else if (format == MALI_ASTC_HDR_SUPP || format == MALI_ASTC_SRGB_SUPP)
                return (panfrost_astc_stretch(desc->block.height) << 3) |
                        panfrost_astc_stretch(desc->block.width);
        else
                return 0;
}


/* Cubemaps have 6 faces as "layers" in between each actual layer. We
 * need to fix this up. TODO: logic wrong in the asserted out cases ...
 * can they happen, perhaps from cubemap arrays? */

static void
panfrost_adjust_cube_dimensions(
                unsigned *first_face, unsigned *last_face,
                unsigned *first_layer, unsigned *last_layer)
{
        *first_face = *first_layer % 6;
        *last_face = *last_layer % 6;
        *first_layer /= 6;
        *last_layer /= 6;

        assert((*first_layer == *last_layer) || (*first_face == 0 && *last_face == 5));
}

/* Following the texture descriptor is a number of pointers. How many? */

static unsigned
panfrost_texture_num_elements(
                unsigned first_level, unsigned last_level,
                unsigned first_layer, unsigned last_layer,
                bool is_cube, bool manual_stride)
{
        unsigned first_face  = 0, last_face = 0;

        if (is_cube) {
                panfrost_adjust_cube_dimensions(&first_face, &last_face,
                                &first_layer, &last_layer);
        }

        unsigned levels = 1 + last_level - first_level;
        unsigned layers = 1 + last_layer - first_layer;
        unsigned faces  = 1 + last_face  - first_face;
        unsigned num_elements = levels * layers * faces;

        if (manual_stride)
                num_elements *= 2;

        return num_elements;
}

/* Conservative estimate of the size of the texture descriptor a priori.
 * Average case, size equal to the actual size. Worst case, off by 2x (if
 * a manual stride is not needed on a linear texture). Returned value
 * must be greater than or equal to the actual size, so it's safe to use
 * as an allocation amount */

unsigned
panfrost_estimate_texture_size(
                unsigned first_level, unsigned last_level,
                unsigned first_layer, unsigned last_layer,
                enum mali_texture_type type, enum mali_texture_layout layout)
{
        /* Assume worst case */
        unsigned manual_stride = (layout == MALI_TEXTURE_LINEAR);

        unsigned elements = panfrost_texture_num_elements(
                        first_level, last_level,
                        first_layer, last_layer,
                        type == MALI_TEX_CUBE, manual_stride);

        return sizeof(struct mali_texture_descriptor) +
                sizeof(mali_ptr) * elements;
}

void
panfrost_new_texture(
        void *out,
        uint16_t width, uint16_t height,
        uint16_t depth, uint16_t array_size,
        enum pipe_format format,
        enum mali_texture_type type,
        enum mali_texture_layout layout,
        unsigned first_level, unsigned last_level,
        unsigned first_layer, unsigned last_layer,
        unsigned cube_stride,
        unsigned swizzle,
        mali_ptr base,
        struct panfrost_slice *slices)
{
        const struct util_format_description *desc =
                util_format_description(format);

        unsigned bytes_per_pixel = util_format_get_blocksize(format);

        enum mali_format mali_format = panfrost_find_format(desc);

        bool manual_stride = (layout == MALI_TEXTURE_LINEAR)
                && panfrost_needs_explicit_stride(slices, width,
                                first_level, last_level, bytes_per_pixel);

        struct mali_texture_descriptor descriptor = {
                .width = MALI_POSITIVE(u_minify(width, first_level)),
                .height = MALI_POSITIVE(u_minify(height, first_level)),
                .depth = MALI_POSITIVE(u_minify(depth, first_level)),
                .array_size = MALI_POSITIVE(array_size),
                .format = {
                        .swizzle = panfrost_translate_swizzle_4(desc->swizzle),
                        .format = mali_format,
                        .srgb = (desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB),
                        .type = type,
                        .layout = layout,
                        .manual_stride = manual_stride,
                        .unknown2 = 1,
                },
                .levels = last_level - first_level,
                .swizzle = swizzle
        };

        memcpy(out, &descriptor, sizeof(descriptor));

        base |= panfrost_compression_tag(desc, mali_format, layout);

        /* Inject the addresses in, interleaving array indices, mip levels,
         * cube faces, and strides in that order */

        unsigned first_face  = 0, last_face = 0, face_mult = 1;

        if (type == MALI_TEX_CUBE) {
                face_mult = 6;
                panfrost_adjust_cube_dimensions(&first_face, &last_face, &first_layer, &last_layer);
        }

        mali_ptr *payload = (mali_ptr *) (out + sizeof(struct mali_texture_descriptor));
        unsigned idx = 0;

        for (unsigned w = first_layer; w <= last_layer; ++w) {
                for (unsigned l = first_level; l <= last_level; ++l) {
                        for (unsigned f = first_face; f <= last_face; ++f) {
                                payload[idx++] = base + panfrost_texture_offset(
                                                slices, type == MALI_TEX_3D,
                                                cube_stride, l, w * face_mult + f);

                                if (manual_stride)
                                        payload[idx++] = slices[l].stride;
                        }
                }
        }
}

/* Computes sizes for checksumming, which is 8 bytes per 16x16 tile.
 * Checksumming is believed to be a CRC variant (CRC64 based on the size?).
 * This feature is also known as "transaction elimination". */

#define CHECKSUM_TILE_WIDTH 16
#define CHECKSUM_TILE_HEIGHT 16
#define CHECKSUM_BYTES_PER_TILE 8

unsigned
panfrost_compute_checksum_size(
        struct panfrost_slice *slice,
        unsigned width,
        unsigned height)
{
        unsigned aligned_width = ALIGN_POT(width, CHECKSUM_TILE_WIDTH);
        unsigned aligned_height = ALIGN_POT(height, CHECKSUM_TILE_HEIGHT);

        unsigned tile_count_x = aligned_width / CHECKSUM_TILE_WIDTH;
        unsigned tile_count_y = aligned_height / CHECKSUM_TILE_HEIGHT;

        slice->checksum_stride = tile_count_x * CHECKSUM_BYTES_PER_TILE;

        return slice->checksum_stride * tile_count_y;
}

unsigned
panfrost_get_layer_stride(struct panfrost_slice *slices, bool is_3d, unsigned cube_stride, unsigned level)
{
        return is_3d ? slices[level].size0 : cube_stride;
}

/* Computes the offset into a texture at a particular level/face. Add to
 * the base address of a texture to get the address to that level/face */

unsigned
panfrost_texture_offset(struct panfrost_slice *slices, bool is_3d, unsigned cube_stride, unsigned level, unsigned face)
{
        unsigned layer_stride = panfrost_get_layer_stride(slices, is_3d, cube_stride, level);
        return slices[level].offset + (face * layer_stride);
}