/* * Copyright (C) 2019 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. * * Authors: * Alyssa Rosenzweig */ #include "pan_texture.h" /* Arm FrameBuffer Compression (AFBC) is a lossless compression scheme natively * implemented in Mali GPUs (as well as many display controllers paired with * Mali GPUs, etc). Where possible, Panfrost prefers to use AFBC for both * rendering and texturing. In most cases, this is a performance-win due to a * dramatic reduction in memory bandwidth and cache locality compared to a * linear resources. * * AFBC divides the framebuffer into 16x16 tiles (other sizes possible, TODO: * do we need to support this?). So, the width and height each must be aligned * up to 16 pixels. This is inherently good for performance; note that for a 4 * byte-per-pixel format like RGBA8888, that means that rows are 16*4=64 byte * aligned, which is the cache-line size. * * For each AFBC-compressed resource, there is a single contiguous * (CPU/GPU-shared) buffer. This buffer itself is divided into two parts: * header and body, placed immediately after each other. * * The AFBC header contains 16 bytes of metadata per tile. * * The AFBC body is the same size as the original linear resource (padded to * the nearest tile). Although the body comes immediately after the header, it * must also be cache-line aligned, so there can sometimes be a bit of padding * between the header and body. * * As an example, a 64x64 RGBA framebuffer contains 64/16 = 4 tiles horizontally and * 4 tiles vertically. There are 4*4=16 tiles in total, each containing 16 * bytes of metadata, so there is a 16*16=256 byte header. 64x64 is already * tile aligned, so the body is 64*64 * 4 bytes per pixel = 16384 bytes of * body. * * From userspace, Panfrost needs to be able to calculate these sizes. It * explicitly does not and can not know the format of the data contained within * this header and body. The GPU has native support for AFBC encode/decode. For * an internal FBO or a framebuffer used for scanout with an AFBC-compatible * winsys/display-controller, the buffer is maintained AFBC throughout flight, * and the driver never needs to know the internal data. For edge cases where * the driver really does need to read/write from the AFBC resource, we * generate a linear staging buffer and use the GPU to blit AFBC<--->linear. * TODO: Implement me. */ #define AFBC_TILE_WIDTH 16 #define AFBC_TILE_HEIGHT 16 #define AFBC_CACHE_ALIGN 64 /* AFBC supports compressing a few canonical formats. Additional formats are * available by using a canonical internal format. Given a PIPE format, find * the canonical AFBC internal format if it exists, or NONE if the format * cannot be compressed. */ enum pipe_format panfrost_afbc_format(const struct panfrost_device *dev, enum pipe_format format) { /* Don't allow swizzled formats on v7 */ switch (format) { case PIPE_FORMAT_B8G8R8A8_UNORM: case PIPE_FORMAT_B8G8R8X8_UNORM: case PIPE_FORMAT_A8R8G8B8_UNORM: case PIPE_FORMAT_X8R8G8B8_UNORM: case PIPE_FORMAT_X8B8G8R8_UNORM: case PIPE_FORMAT_A8B8G8R8_UNORM: case PIPE_FORMAT_B8G8R8_UNORM: case PIPE_FORMAT_B5G6R5_UNORM: if (dev->arch >= 7) return PIPE_FORMAT_NONE; break; default: break; } switch (format) { case PIPE_FORMAT_Z16_UNORM: return PIPE_FORMAT_R8G8_UNORM; case PIPE_FORMAT_R8G8B8_UNORM: case PIPE_FORMAT_B8G8R8_UNORM: return PIPE_FORMAT_R8G8B8_UNORM; case PIPE_FORMAT_R8G8B8A8_UNORM: case PIPE_FORMAT_R8G8B8X8_UNORM: case PIPE_FORMAT_Z24_UNORM_S8_UINT: case PIPE_FORMAT_Z24X8_UNORM: case PIPE_FORMAT_X24S8_UINT: case PIPE_FORMAT_B8G8R8A8_UNORM: case PIPE_FORMAT_B8G8R8X8_UNORM: case PIPE_FORMAT_A8R8G8B8_UNORM: case PIPE_FORMAT_X8R8G8B8_UNORM: case PIPE_FORMAT_X8B8G8R8_UNORM: case PIPE_FORMAT_A8B8G8R8_UNORM: return PIPE_FORMAT_R8G8B8A8_UNORM; case PIPE_FORMAT_R5G6B5_UNORM: case PIPE_FORMAT_B5G6R5_UNORM: return PIPE_FORMAT_R5G6B5_UNORM; /* TODO: More AFBC formats */ default: return PIPE_FORMAT_NONE; } } /* A format may be compressed as AFBC if it has an AFBC internal format */ bool panfrost_format_supports_afbc(const struct panfrost_device *dev, enum pipe_format format) { return panfrost_afbc_format(dev, format) != PIPE_FORMAT_NONE; } unsigned panfrost_afbc_header_size(unsigned width, unsigned height) { /* Align to tile */ unsigned aligned_width = ALIGN_POT(width, AFBC_TILE_WIDTH); unsigned aligned_height = ALIGN_POT(height, AFBC_TILE_HEIGHT); /* Compute size in tiles, rather than pixels */ unsigned tile_count_x = aligned_width / AFBC_TILE_WIDTH; unsigned tile_count_y = aligned_height / AFBC_TILE_HEIGHT; unsigned tile_count = tile_count_x * tile_count_y; /* Multiply to find the header size */ unsigned header_bytes = tile_count * AFBC_HEADER_BYTES_PER_TILE; /* Align and go */ return ALIGN_POT(header_bytes, AFBC_CACHE_ALIGN); } /* The lossless colour transform (AFBC_FORMAT_MOD_YTR) requires RGB. */ bool panfrost_afbc_can_ytr(enum pipe_format format) { const struct util_format_description *desc = util_format_description(format); /* YTR is only defined for RGB(A) */ if (desc->nr_channels != 3 && desc->nr_channels != 4) return false; /* The fourth channel if it exists doesn't matter */ return desc->colorspace == UTIL_FORMAT_COLORSPACE_RGB; }