/*
 * Copyright 2018 Advanced Micro Devices, Inc.
 * All Rights Reserved.
 *
 * 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
 * on the rights to use, copy, modify, merge, publish, distribute, sub
 * license, 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 NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHOR(S) AND/OR THEIR SUPPLIERS 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 "si_pipe.h"
#include "util/format/u_format.h"
#include "util/format_srgb.h"

/* Note: Compute shaders always use SI_COMPUTE_DST_CACHE_POLICY for dst
 * and L2_STREAM for src.
 */
static enum si_cache_policy get_cache_policy(struct si_context *sctx,
					     enum si_coherency coher,
					     uint64_t size)
{
	if ((sctx->chip_class >= GFX9 && (coher == SI_COHERENCY_CB_META ||
					  coher == SI_COHERENCY_CP)) ||
	    (sctx->chip_class >= GFX7 && coher == SI_COHERENCY_SHADER))
		return size <= 256 * 1024 ? L2_LRU : L2_STREAM;

	return L2_BYPASS;
}

unsigned si_get_flush_flags(struct si_context *sctx, enum si_coherency coher,
			    enum si_cache_policy cache_policy)
{
	switch (coher) {
	default:
	case SI_COHERENCY_NONE:
	case SI_COHERENCY_CP:
		return 0;
	case SI_COHERENCY_SHADER:
		return SI_CONTEXT_INV_SCACHE |
		       SI_CONTEXT_INV_VCACHE |
		       (cache_policy == L2_BYPASS ? SI_CONTEXT_INV_L2 : 0);
	case SI_COHERENCY_CB_META:
		return SI_CONTEXT_FLUSH_AND_INV_CB;
	}
}

static void si_compute_internal_begin(struct si_context *sctx)
{
	sctx->flags &= ~SI_CONTEXT_START_PIPELINE_STATS;
	sctx->flags |= SI_CONTEXT_STOP_PIPELINE_STATS;
	sctx->render_cond_force_off = true;
}

static void si_compute_internal_end(struct si_context *sctx)
{
	sctx->flags &= ~SI_CONTEXT_STOP_PIPELINE_STATS;
	sctx->flags |= SI_CONTEXT_START_PIPELINE_STATS;
	sctx->render_cond_force_off = false;
}

static void si_compute_clear_12bytes_buffer(struct si_context *sctx,
					struct pipe_resource *dst,
					unsigned dst_offset,
					unsigned size,
					const uint32_t *clear_value,
					enum si_coherency coher)
{
	struct pipe_context *ctx = &sctx->b;

	assert(dst_offset % 4 == 0);
	assert(size % 4 == 0);
	unsigned size_12 = DIV_ROUND_UP(size, 12);

	unsigned data[4] = {0};
	memcpy(data, clear_value, 12);

	si_compute_internal_begin(sctx);

	sctx->flags |= SI_CONTEXT_PS_PARTIAL_FLUSH |
		       SI_CONTEXT_CS_PARTIAL_FLUSH |
		       si_get_flush_flags(sctx, coher, SI_COMPUTE_DST_CACHE_POLICY);

	struct pipe_shader_buffer saved_sb = {0};
	si_get_shader_buffers(sctx, PIPE_SHADER_COMPUTE, 0, 1, &saved_sb);

	unsigned saved_writable_mask = 0;
	if (sctx->const_and_shader_buffers[PIPE_SHADER_COMPUTE].writable_mask &
	    (1u << si_get_shaderbuf_slot(0)))
		saved_writable_mask = 1;

	struct pipe_constant_buffer saved_cb = {};
	si_get_pipe_constant_buffer(sctx, PIPE_SHADER_COMPUTE, 0, &saved_cb);

	void *saved_cs = sctx->cs_shader_state.program;

	struct pipe_constant_buffer cb = {};
	cb.buffer_size = sizeof(data);
	cb.user_buffer = data;
	ctx->set_constant_buffer(ctx, PIPE_SHADER_COMPUTE, 0, &cb);

	struct pipe_shader_buffer sb = {0};
	sb.buffer = dst;
	sb.buffer_offset = dst_offset;
	sb.buffer_size = size;

	ctx->set_shader_buffers(ctx, PIPE_SHADER_COMPUTE, 0, 1, &sb, 0x1);

	struct pipe_grid_info info = {0};

	if (!sctx->cs_clear_12bytes_buffer)
		sctx->cs_clear_12bytes_buffer =
			si_clear_12bytes_buffer_shader(ctx);
	ctx->bind_compute_state(ctx, sctx->cs_clear_12bytes_buffer);
	info.block[0] = 64;
	info.last_block[0] = size_12 % 64;
	info.block[1] = 1;
	info.block[2] = 1;
	info.grid[0] = DIV_ROUND_UP(size_12, 64);
	info.grid[1] = 1;
	info.grid[2] = 1;

	ctx->launch_grid(ctx, &info);

	ctx->bind_compute_state(ctx, saved_cs);
	ctx->set_shader_buffers(ctx, PIPE_SHADER_COMPUTE, 0, 1, &saved_sb, saved_writable_mask);
	ctx->set_constant_buffer(ctx, PIPE_SHADER_COMPUTE, 0, &saved_cb);

	si_compute_internal_end(sctx);
}

static void si_compute_do_clear_or_copy(struct si_context *sctx,
					struct pipe_resource *dst,
					unsigned dst_offset,
					struct pipe_resource *src,
					unsigned src_offset,
					unsigned size,
					const uint32_t *clear_value,
					unsigned clear_value_size,
					enum si_coherency coher)
{
	struct pipe_context *ctx = &sctx->b;

	assert(src_offset % 4 == 0);
	assert(dst_offset % 4 == 0);
	assert(size % 4 == 0);

	assert(dst->target != PIPE_BUFFER || dst_offset + size <= dst->width0);
	assert(!src || src_offset + size <= src->width0);

	si_compute_internal_begin(sctx);
	sctx->flags |= SI_CONTEXT_PS_PARTIAL_FLUSH |
		       SI_CONTEXT_CS_PARTIAL_FLUSH |
		       si_get_flush_flags(sctx, coher, SI_COMPUTE_DST_CACHE_POLICY);

	/* Save states. */
	void *saved_cs = sctx->cs_shader_state.program;
	struct pipe_shader_buffer saved_sb[2] = {};
	si_get_shader_buffers(sctx, PIPE_SHADER_COMPUTE, 0, src ? 2 : 1, saved_sb);

	unsigned saved_writable_mask = 0;
	for (unsigned i = 0; i < (src ? 2 : 1); i++) {
		if (sctx->const_and_shader_buffers[PIPE_SHADER_COMPUTE].writable_mask &
		    (1u << si_get_shaderbuf_slot(i)))
			saved_writable_mask |= 1 << i;
	}

	/* The memory accesses are coalesced, meaning that the 1st instruction writes
	 * the 1st contiguous block of data for the whole wave, the 2nd instruction
	 * writes the 2nd contiguous block of data, etc.
	 */
	unsigned dwords_per_thread = src ? SI_COMPUTE_COPY_DW_PER_THREAD :
					   SI_COMPUTE_CLEAR_DW_PER_THREAD;
	unsigned instructions_per_thread = MAX2(1, dwords_per_thread / 4);
	unsigned dwords_per_instruction = dwords_per_thread / instructions_per_thread;
	unsigned wave_size = sctx->screen->compute_wave_size;
	unsigned dwords_per_wave = dwords_per_thread * wave_size;

	unsigned num_dwords = size / 4;
	unsigned num_instructions = DIV_ROUND_UP(num_dwords, dwords_per_instruction);

	struct pipe_grid_info info = {};
	info.block[0] = MIN2(wave_size, num_instructions);
	info.block[1] = 1;
	info.block[2] = 1;
	info.grid[0] = DIV_ROUND_UP(num_dwords, dwords_per_wave);
	info.grid[1] = 1;
	info.grid[2] = 1;

	struct pipe_shader_buffer sb[2] = {};
	sb[0].buffer = dst;
	sb[0].buffer_offset = dst_offset;
	sb[0].buffer_size = size;

	bool shader_dst_stream_policy = SI_COMPUTE_DST_CACHE_POLICY != L2_LRU;

	if (src) {
		sb[1].buffer = src;
		sb[1].buffer_offset = src_offset;
		sb[1].buffer_size = size;

		ctx->set_shader_buffers(ctx, PIPE_SHADER_COMPUTE, 0, 2, sb, 0x1);

		if (!sctx->cs_copy_buffer) {
			sctx->cs_copy_buffer = si_create_dma_compute_shader(&sctx->b,
							     SI_COMPUTE_COPY_DW_PER_THREAD,
							     shader_dst_stream_policy, true);
		}
		ctx->bind_compute_state(ctx, sctx->cs_copy_buffer);
	} else {
		assert(clear_value_size >= 4 &&
		       clear_value_size <= 16 &&
		       util_is_power_of_two_or_zero(clear_value_size));

		for (unsigned i = 0; i < 4; i++)
			sctx->cs_user_data[i] = clear_value[i % (clear_value_size / 4)];

		ctx->set_shader_buffers(ctx, PIPE_SHADER_COMPUTE, 0, 1, sb, 0x1);

		if (!sctx->cs_clear_buffer) {
			sctx->cs_clear_buffer = si_create_dma_compute_shader(&sctx->b,
							     SI_COMPUTE_CLEAR_DW_PER_THREAD,
							     shader_dst_stream_policy, false);
		}
		ctx->bind_compute_state(ctx, sctx->cs_clear_buffer);
	}

	ctx->launch_grid(ctx, &info);

	enum si_cache_policy cache_policy = get_cache_policy(sctx, coher, size);
	sctx->flags |= SI_CONTEXT_CS_PARTIAL_FLUSH |
		       (cache_policy == L2_BYPASS ? SI_CONTEXT_WB_L2 : 0);

	if (cache_policy != L2_BYPASS)
		si_resource(dst)->TC_L2_dirty = true;

	/* Restore states. */
	ctx->bind_compute_state(ctx, saved_cs);
	ctx->set_shader_buffers(ctx, PIPE_SHADER_COMPUTE, 0, src ? 2 : 1, saved_sb,
				saved_writable_mask);
	si_compute_internal_end(sctx);
}

void si_clear_buffer(struct si_context *sctx, struct pipe_resource *dst,
		     uint64_t offset, uint64_t size, uint32_t *clear_value,
		     uint32_t clear_value_size, enum si_coherency coher,
		     bool force_cpdma)
{
	if (!size)
		return;

	ASSERTED unsigned clear_alignment = MIN2(clear_value_size, 4);

	assert(clear_value_size != 3 && clear_value_size != 6); /* 12 is allowed. */
	assert(offset % clear_alignment == 0);
	assert(size % clear_alignment == 0);
	assert(size < (UINT_MAX & ~0xf)); /* TODO: test 64-bit sizes in all codepaths */

	/* Reduce a large clear value size if possible. */
	if (clear_value_size > 4) {
		bool clear_dword_duplicated = true;

		/* See if we can lower large fills to dword fills. */
		for (unsigned i = 1; i < clear_value_size / 4; i++) {
			if (clear_value[0] != clear_value[i]) {
				clear_dword_duplicated = false;
				break;
			}
		}
		if (clear_dword_duplicated)
			clear_value_size = 4;
	}

	/* Expand a small clear value size. */
	uint32_t tmp_clear_value;
	if (clear_value_size <= 2) {
		if (clear_value_size == 1) {
			tmp_clear_value = *(uint8_t*)clear_value;
			tmp_clear_value |= (tmp_clear_value << 8) |
					   (tmp_clear_value << 16) |
					   (tmp_clear_value << 24);
		} else {
			tmp_clear_value = *(uint16_t*)clear_value;
			tmp_clear_value |= tmp_clear_value << 16;
		}
		clear_value = &tmp_clear_value;
		clear_value_size = 4;
	}

	if (clear_value_size == 12) {
		si_compute_clear_12bytes_buffer(sctx, dst, offset, size, clear_value, coher);
		return;
	}

	uint64_t aligned_size = size & ~3ull;
	if (aligned_size >= 4) {
		/* Before GFX9, CP DMA was very slow when clearing GTT, so never
		 * use CP DMA clears on those chips, because we can't be certain
		 * about buffer placements.
		 */
		if (clear_value_size > 4 ||
		    (!force_cpdma &&
		     clear_value_size == 4 &&
		     offset % 4 == 0 &&
		     (size > 32*1024 || sctx->chip_class <= GFX8))) {
			si_compute_do_clear_or_copy(sctx, dst, offset, NULL, 0,
						    aligned_size, clear_value,
						    clear_value_size, coher);
		} else {
			assert(clear_value_size == 4);
			si_cp_dma_clear_buffer(sctx, sctx->gfx_cs, dst, offset,
					       aligned_size, *clear_value, 0, coher,
					       get_cache_policy(sctx, coher, size));
		}

		offset += aligned_size;
		size -= aligned_size;
	}

	/* Handle non-dword alignment. */
	if (size) {
		assert(dst);
		assert(dst->target == PIPE_BUFFER);
		assert(size < 4);

		pipe_buffer_write(&sctx->b, dst, offset, size, clear_value);
	}
}

static void si_pipe_clear_buffer(struct pipe_context *ctx,
				 struct pipe_resource *dst,
				 unsigned offset, unsigned size,
				 const void *clear_value,
				 int clear_value_size)
{
	si_clear_buffer((struct si_context*)ctx, dst, offset, size, (uint32_t*)clear_value,
			clear_value_size, SI_COHERENCY_SHADER, false);
}

void si_copy_buffer(struct si_context *sctx,
		    struct pipe_resource *dst, struct pipe_resource *src,
		    uint64_t dst_offset, uint64_t src_offset, unsigned size)
{
	if (!size)
		return;

	enum si_coherency coher = SI_COHERENCY_SHADER;
	enum si_cache_policy cache_policy = get_cache_policy(sctx, coher, size);

	/* Only use compute for VRAM copies on dGPUs. */
	if (sctx->screen->info.has_dedicated_vram &&
	    si_resource(dst)->domains & RADEON_DOMAIN_VRAM &&
	    si_resource(src)->domains & RADEON_DOMAIN_VRAM &&
	    size > 32 * 1024 &&
	    dst_offset % 4 == 0 && src_offset % 4 == 0 && size % 4 == 0) {
		si_compute_do_clear_or_copy(sctx, dst, dst_offset, src, src_offset,
					    size, NULL, 0, coher);
	} else {
		si_cp_dma_copy_buffer(sctx, dst, src, dst_offset, src_offset, size,
				      0, coher, cache_policy);
	}
}

void si_compute_copy_image(struct si_context *sctx,
			   struct pipe_resource *dst,
			   unsigned dst_level,
			   struct pipe_resource *src,
			   unsigned src_level,
			   unsigned dstx, unsigned dsty, unsigned dstz,
			   const struct pipe_box *src_box)
{
	struct pipe_context *ctx = &sctx->b;
	unsigned width = src_box->width;
	unsigned height = src_box->height;
	unsigned depth = src_box->depth;

	unsigned data[] = {src_box->x, src_box->y, src_box->z, 0, dstx, dsty, dstz, 0};

	if (width == 0 || height == 0)
		return;

	si_compute_internal_begin(sctx);
	sctx->flags |= SI_CONTEXT_CS_PARTIAL_FLUSH |
		       si_get_flush_flags(sctx, SI_COHERENCY_SHADER, L2_STREAM);

	/* src and dst have the same number of samples. */
	si_make_CB_shader_coherent(sctx, src->nr_samples, true,
				   /* Only src can have DCC.*/
				   ((struct si_texture*)src)->surface.u.gfx9.dcc.pipe_aligned);

	struct pipe_constant_buffer saved_cb = {};
	si_get_pipe_constant_buffer(sctx, PIPE_SHADER_COMPUTE, 0, &saved_cb);

	struct si_images *images = &sctx->images[PIPE_SHADER_COMPUTE];
	struct pipe_image_view saved_image[2] = {0};
	util_copy_image_view(&saved_image[0], &images->views[0]);
	util_copy_image_view(&saved_image[1], &images->views[1]);

	void *saved_cs = sctx->cs_shader_state.program;

	struct pipe_constant_buffer cb = {};
	cb.buffer_size = sizeof(data);
	cb.user_buffer = data;
	ctx->set_constant_buffer(ctx, PIPE_SHADER_COMPUTE, 0, &cb);

	struct pipe_image_view image[2] = {0};
	image[0].resource = src;
	image[0].shader_access = image[0].access = PIPE_IMAGE_ACCESS_READ;
	image[0].format = util_format_linear(src->format);
	image[0].u.tex.level = src_level;
	image[0].u.tex.first_layer = 0;
	image[0].u.tex.last_layer =
		src->target == PIPE_TEXTURE_3D ? u_minify(src->depth0, src_level) - 1
						: (unsigned)(src->array_size - 1);
	image[1].resource = dst;
	image[1].shader_access = image[1].access = PIPE_IMAGE_ACCESS_WRITE;
	image[1].format = util_format_linear(dst->format);
	image[1].u.tex.level = dst_level;
	image[1].u.tex.first_layer = 0;
	image[1].u.tex.last_layer =
		dst->target == PIPE_TEXTURE_3D ? u_minify(dst->depth0, dst_level) - 1
						: (unsigned)(dst->array_size - 1);

	if (src->format == PIPE_FORMAT_R9G9B9E5_FLOAT)
		image[0].format = image[1].format = PIPE_FORMAT_R32_UINT;

	/* SNORM8 blitting has precision issues on some chips. Use the SINT
	 * equivalent instead, which doesn't force DCC decompression.
	 * Note that some chips avoid this issue by using SDMA.
	 */
	if (util_format_is_snorm8(dst->format)) {
		image[0].format = image[1].format =
			util_format_snorm8_to_sint8(dst->format);
	}

	ctx->set_shader_images(ctx, PIPE_SHADER_COMPUTE, 0, 2, image);

	struct pipe_grid_info info = {0};

	if (dst->target == PIPE_TEXTURE_1D_ARRAY && src->target == PIPE_TEXTURE_1D_ARRAY) {
		if (!sctx->cs_copy_image_1d_array)
			sctx->cs_copy_image_1d_array =
				si_create_copy_image_compute_shader_1d_array(ctx);
		ctx->bind_compute_state(ctx, sctx->cs_copy_image_1d_array);
		info.block[0] = 64;
		info.last_block[0] = width % 64;
		info.block[1] = 1;
		info.block[2] = 1;
		info.grid[0] = DIV_ROUND_UP(width, 64);
		info.grid[1] = depth;
		info.grid[2] = 1;
	} else {
		if (!sctx->cs_copy_image)
			sctx->cs_copy_image = si_create_copy_image_compute_shader(ctx);
		ctx->bind_compute_state(ctx, sctx->cs_copy_image);
		info.block[0] = 8;
		info.last_block[0] = width % 8;
		info.block[1] = 8;
		info.last_block[1] = height % 8;
		info.block[2] = 1;
		info.grid[0] = DIV_ROUND_UP(width, 8);
		info.grid[1] = DIV_ROUND_UP(height, 8);
		info.grid[2] = depth;
	}

	ctx->launch_grid(ctx, &info);

	sctx->flags |= SI_CONTEXT_CS_PARTIAL_FLUSH |
		       (sctx->chip_class <= GFX8 ? SI_CONTEXT_WB_L2 : 0) |
		       si_get_flush_flags(sctx, SI_COHERENCY_SHADER, L2_STREAM);
	ctx->bind_compute_state(ctx, saved_cs);
	ctx->set_shader_images(ctx, PIPE_SHADER_COMPUTE, 0, 2, saved_image);
	ctx->set_constant_buffer(ctx, PIPE_SHADER_COMPUTE, 0, &saved_cb);
	si_compute_internal_end(sctx);
}

void si_retile_dcc(struct si_context *sctx, struct si_texture *tex)
{
	struct pipe_context *ctx = &sctx->b;

	sctx->flags |= SI_CONTEXT_PS_PARTIAL_FLUSH |
		       SI_CONTEXT_CS_PARTIAL_FLUSH |
		       si_get_flush_flags(sctx, SI_COHERENCY_CB_META, L2_LRU) |
		       si_get_flush_flags(sctx, SI_COHERENCY_SHADER, L2_LRU);
	sctx->emit_cache_flush(sctx);

	/* Save states. */
	void *saved_cs = sctx->cs_shader_state.program;
	struct pipe_image_view saved_img[3] = {};

	for (unsigned i = 0; i < 3; i++) {
		util_copy_image_view(&saved_img[i],
				     &sctx->images[PIPE_SHADER_COMPUTE].views[i]);
	}

	/* Set images. */
	bool use_uint16 = tex->surface.u.gfx9.dcc_retile_use_uint16;
	unsigned num_elements = tex->surface.u.gfx9.dcc_retile_num_elements;
	struct pipe_image_view img[3];

	assert(tex->surface.dcc_retile_map_offset && tex->surface.dcc_retile_map_offset <= UINT_MAX);
	assert(tex->surface.dcc_offset && tex->surface.dcc_offset <= UINT_MAX);
	assert(tex->surface.display_dcc_offset && tex->surface.display_dcc_offset <= UINT_MAX);

	for (unsigned i = 0; i < 3; i++) {
		img[i].resource = &tex->buffer.b.b;
		img[i].access = i == 2 ? PIPE_IMAGE_ACCESS_WRITE : PIPE_IMAGE_ACCESS_READ;
		img[i].shader_access = SI_IMAGE_ACCESS_AS_BUFFER;
	}

	img[0].format = use_uint16 ? PIPE_FORMAT_R16G16B16A16_UINT :
				     PIPE_FORMAT_R32G32B32A32_UINT;
	img[0].u.buf.offset = tex->surface.dcc_retile_map_offset;
	img[0].u.buf.size = num_elements * (use_uint16 ? 2 : 4);

	img[1].format = PIPE_FORMAT_R8_UINT;
	img[1].u.buf.offset = tex->surface.dcc_offset;
	img[1].u.buf.size = tex->surface.dcc_size;

	img[2].format = PIPE_FORMAT_R8_UINT;
	img[2].u.buf.offset = tex->surface.display_dcc_offset;
	img[2].u.buf.size = tex->surface.u.gfx9.display_dcc_size;

	ctx->set_shader_images(ctx, PIPE_SHADER_COMPUTE, 0, 3, img);

	/* Bind the compute shader. */
	if (!sctx->cs_dcc_retile)
		sctx->cs_dcc_retile = si_create_dcc_retile_cs(ctx);
	ctx->bind_compute_state(ctx, sctx->cs_dcc_retile);

	/* Dispatch compute. */
	/* img[0] has 4 channels per element containing 2 pairs of DCC offsets. */
	unsigned num_threads = num_elements / 4;

	struct pipe_grid_info info = {};
	info.block[0] = 64;
	info.block[1] = 1;
	info.block[2] = 1;
	info.grid[0] = DIV_ROUND_UP(num_threads, 64); /* includes the partial block */
	info.grid[1] = 1;
	info.grid[2] = 1;
	info.last_block[0] = num_threads % 64;

	ctx->launch_grid(ctx, &info);

	/* Don't flush caches or wait. The driver will wait at the end of this IB,
	 * and L2 will be flushed by the kernel fence.
	 */

	/* Restore states. */
	ctx->bind_compute_state(ctx, saved_cs);
	ctx->set_shader_images(ctx, PIPE_SHADER_COMPUTE, 0, 3, saved_img);
}

/* Expand FMASK to make it identity, so that image stores can ignore it. */
void si_compute_expand_fmask(struct pipe_context *ctx, struct pipe_resource *tex)
{
	struct si_context *sctx = (struct si_context *)ctx;
	bool is_array = tex->target == PIPE_TEXTURE_2D_ARRAY;
	unsigned log_fragments = util_logbase2(tex->nr_storage_samples);
	unsigned log_samples = util_logbase2(tex->nr_samples);
	assert(tex->nr_samples >= 2);

	/* EQAA FMASK expansion is unimplemented. */
	if (tex->nr_samples != tex->nr_storage_samples)
		return;

	si_compute_internal_begin(sctx);

	/* Flush caches and sync engines. */
	sctx->flags |= SI_CONTEXT_CS_PARTIAL_FLUSH |
		       si_get_flush_flags(sctx, SI_COHERENCY_SHADER, L2_STREAM);
	si_make_CB_shader_coherent(sctx, tex->nr_samples, true,
				   true /* DCC is not possible with image stores */);

	/* Save states. */
	void *saved_cs = sctx->cs_shader_state.program;
	struct pipe_image_view saved_image = {0};
	util_copy_image_view(&saved_image, &sctx->images[PIPE_SHADER_COMPUTE].views[0]);

	/* Bind the image. */
	struct pipe_image_view image = {0};
	image.resource = tex;
	/* Don't set WRITE so as not to trigger FMASK expansion, causing
	 * an infinite loop. */
	image.shader_access = image.access = PIPE_IMAGE_ACCESS_READ;
	image.format = util_format_linear(tex->format);
	if (is_array)
		image.u.tex.last_layer = tex->array_size - 1;

	ctx->set_shader_images(ctx, PIPE_SHADER_COMPUTE, 0, 1, &image);

	/* Bind the shader. */
	void **shader = &sctx->cs_fmask_expand[log_samples - 1][is_array];
	if (!*shader)
		*shader = si_create_fmask_expand_cs(ctx, tex->nr_samples, is_array);
	ctx->bind_compute_state(ctx, *shader);

	/* Dispatch compute. */
	struct pipe_grid_info info = {0};
	info.block[0] = 8;
	info.last_block[0] = tex->width0 % 8;
	info.block[1] = 8;
	info.last_block[1] = tex->height0 % 8;
	info.block[2] = 1;
	info.grid[0] = DIV_ROUND_UP(tex->width0, 8);
	info.grid[1] = DIV_ROUND_UP(tex->height0, 8);
	info.grid[2] = is_array ? tex->array_size : 1;

	ctx->launch_grid(ctx, &info);

	/* Flush caches and sync engines. */
	sctx->flags |= SI_CONTEXT_CS_PARTIAL_FLUSH |
		       (sctx->chip_class <= GFX8 ? SI_CONTEXT_WB_L2 : 0) |
		       si_get_flush_flags(sctx, SI_COHERENCY_SHADER, L2_STREAM);

	/* Restore previous states. */
	ctx->bind_compute_state(ctx, saved_cs);
	ctx->set_shader_images(ctx, PIPE_SHADER_COMPUTE, 0, 1, &saved_image);
	si_compute_internal_end(sctx);

	/* Array of fully expanded FMASK values, arranged by [log2(fragments)][log2(samples)-1]. */
#define INVALID 0 /* never used */
	static const uint64_t fmask_expand_values[][4] = {
		/* samples */
		/* 2 (8 bpp) 4 (8 bpp)   8 (8-32bpp) 16 (16-64bpp)      fragments */
		{0x02020202, 0x0E0E0E0E, 0xFEFEFEFE, 0xFFFEFFFE},         /* 1 */
		{0x02020202, 0xA4A4A4A4, 0xAAA4AAA4, 0xAAAAAAA4},         /* 2 */
		{INVALID,    0xE4E4E4E4, 0x44443210, 0x4444444444443210}, /* 4 */
		{INVALID,    INVALID,    0x76543210, 0x8888888876543210}, /* 8 */
	};

	/* Clear FMASK to identity. */
	struct si_texture *stex = (struct si_texture*)tex;
	si_clear_buffer(sctx, tex, stex->surface.fmask_offset, stex->surface.fmask_size,
			(uint32_t*)&fmask_expand_values[log_fragments][log_samples - 1],
			4, SI_COHERENCY_SHADER, false);
}

void si_init_compute_blit_functions(struct si_context *sctx)
{
	sctx->b.clear_buffer = si_pipe_clear_buffer;
}

/* Clear a region of a color surface to a constant value. */
void si_compute_clear_render_target(struct pipe_context *ctx,
				    struct pipe_surface *dstsurf,
				    const union pipe_color_union *color,
				    unsigned dstx, unsigned dsty,
				    unsigned width, unsigned height,
				    bool render_condition_enabled)
{
	struct si_context *sctx = (struct si_context *)ctx;
	unsigned num_layers = dstsurf->u.tex.last_layer - dstsurf->u.tex.first_layer + 1;
	unsigned data[4 + sizeof(color->ui)] = {dstx, dsty, dstsurf->u.tex.first_layer, 0};

	if (width == 0 || height == 0)
		return;

	if (util_format_is_srgb(dstsurf->format)) {
		union pipe_color_union color_srgb;
		for (int i = 0; i < 3; i++)
			color_srgb.f[i] = util_format_linear_to_srgb_float(color->f[i]);
		color_srgb.f[3] = color->f[3];
		memcpy(data + 4, color_srgb.ui, sizeof(color->ui));
	} else {
		memcpy(data + 4, color->ui, sizeof(color->ui));
	}

	si_compute_internal_begin(sctx);
	sctx->render_cond_force_off = !render_condition_enabled;

	sctx->flags |= SI_CONTEXT_CS_PARTIAL_FLUSH |
		       si_get_flush_flags(sctx, SI_COHERENCY_SHADER, L2_STREAM);
	si_make_CB_shader_coherent(sctx, dstsurf->texture->nr_samples, true,
				   true /* DCC is not possible with image stores */);

	struct pipe_constant_buffer saved_cb = {};
	si_get_pipe_constant_buffer(sctx, PIPE_SHADER_COMPUTE, 0, &saved_cb);

	struct si_images *images = &sctx->images[PIPE_SHADER_COMPUTE];
	struct pipe_image_view saved_image = {0};
	util_copy_image_view(&saved_image, &images->views[0]);

	void *saved_cs = sctx->cs_shader_state.program;

	struct pipe_constant_buffer cb = {};
	cb.buffer_size = sizeof(data);
	cb.user_buffer = data;
	ctx->set_constant_buffer(ctx, PIPE_SHADER_COMPUTE, 0, &cb);

	struct pipe_image_view image = {0};
	image.resource = dstsurf->texture;
	image.shader_access = image.access = PIPE_IMAGE_ACCESS_WRITE;
	image.format = util_format_linear(dstsurf->format);
	image.u.tex.level = dstsurf->u.tex.level;
	image.u.tex.first_layer = 0; /* 3D images ignore first_layer (BASE_ARRAY) */
	image.u.tex.last_layer = dstsurf->u.tex.last_layer;

	ctx->set_shader_images(ctx, PIPE_SHADER_COMPUTE, 0, 1, &image);

	struct pipe_grid_info info = {0};

	if (dstsurf->texture->target != PIPE_TEXTURE_1D_ARRAY) {
		if (!sctx->cs_clear_render_target)
			sctx->cs_clear_render_target = si_clear_render_target_shader(ctx);
		ctx->bind_compute_state(ctx, sctx->cs_clear_render_target);
		info.block[0] = 8;
		info.last_block[0] = width % 8;
		info.block[1] = 8;
		info.last_block[1] = height % 8;
		info.block[2] = 1;
		info.grid[0] = DIV_ROUND_UP(width, 8);
		info.grid[1] = DIV_ROUND_UP(height, 8);
		info.grid[2] = num_layers;
	} else {
		if (!sctx->cs_clear_render_target_1d_array)
			sctx->cs_clear_render_target_1d_array =
				si_clear_render_target_shader_1d_array(ctx);
		ctx->bind_compute_state(ctx, sctx->cs_clear_render_target_1d_array);
		info.block[0] = 64;
		info.last_block[0] = width % 64;
		info.block[1] = 1;
		info.block[2] = 1;
		info.grid[0] = DIV_ROUND_UP(width, 64);
		info.grid[1] = num_layers;
		info.grid[2] = 1;
	}

	ctx->launch_grid(ctx, &info);

	sctx->flags |= SI_CONTEXT_CS_PARTIAL_FLUSH |
		       (sctx->chip_class <= GFX8 ? SI_CONTEXT_WB_L2 : 0) |
		       si_get_flush_flags(sctx, SI_COHERENCY_SHADER, L2_STREAM);
	ctx->bind_compute_state(ctx, saved_cs);
	ctx->set_shader_images(ctx, PIPE_SHADER_COMPUTE, 0, 1, &saved_image);
	ctx->set_constant_buffer(ctx, PIPE_SHADER_COMPUTE, 0, &saved_cb);
	si_compute_internal_end(sctx);
}