src/gallium/drivers/panfrost/pan_context.c

/*
 * © Copyright 2018 Alyssa Rosenzweig
 * Copyright © 2014-2017 Broadcom
 * Copyright (C) 2017 Intel Corporation
 *
 * 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 <sys/poll.h>
#include <errno.h>

#include "pan_bo.h"
#include "pan_context.h"
#include "pan_minmax_cache.h"
#include "panfrost-quirks.h"

#include "util/macros.h"
#include "util/format/u_format.h"
#include "util/u_inlines.h"
#include "util/u_upload_mgr.h"
#include "util/u_memory.h"
#include "util/u_vbuf.h"
#include "util/half_float.h"
#include "util/u_helpers.h"
#include "util/format/u_format.h"
#include "util/u_prim.h"
#include "util/u_prim_restart.h"
#include "indices/u_primconvert.h"
#include "tgsi/tgsi_parse.h"
#include "tgsi/tgsi_from_mesa.h"
#include "util/u_math.h"

#include "pan_screen.h"
#include "pan_blending.h"
#include "pan_blend_shaders.h"
#include "pan_cmdstream.h"
#include "pan_util.h"
#include "pandecode/decode.h"

struct midgard_tiler_descriptor
panfrost_emit_midg_tiler(struct panfrost_batch *batch, unsigned vertex_count)
{
        struct panfrost_device *device = pan_device(batch->ctx->base.screen);
        bool hierarchy = !(device->quirks & MIDGARD_NO_HIER_TILING);
        struct midgard_tiler_descriptor t = {0};
        unsigned height = batch->key.height;
        unsigned width = batch->key.width;

        t.hierarchy_mask =
                panfrost_choose_hierarchy_mask(width, height, vertex_count, hierarchy);

        /* Compute the polygon header size and use that to offset the body */

        unsigned header_size = panfrost_tiler_header_size(
                                       width, height, t.hierarchy_mask, hierarchy);

        t.polygon_list_size = panfrost_tiler_full_size(
                                     width, height, t.hierarchy_mask, hierarchy);

        /* Sanity check */

        if (vertex_count) {
                struct panfrost_bo *tiler_heap;

                tiler_heap = panfrost_batch_get_tiler_heap(batch);
                t.polygon_list = panfrost_batch_get_polygon_list(batch,
                                                                 header_size +
                                                                 t.polygon_list_size);


                /* Allow the entire tiler heap */
                t.heap_start = tiler_heap->gpu;
                t.heap_end = tiler_heap->gpu + tiler_heap->size;
        } else {
                struct panfrost_bo *tiler_dummy;

                tiler_dummy = panfrost_batch_get_tiler_dummy(batch);
                header_size = MALI_TILER_MINIMUM_HEADER_SIZE;

                /* The tiler is disabled, so don't allow the tiler heap */
                t.heap_start = tiler_dummy->gpu;
                t.heap_end = t.heap_start;

                /* Use a dummy polygon list */
                t.polygon_list = tiler_dummy->gpu;

                /* Disable the tiler */
                if (hierarchy)
                        t.hierarchy_mask |= MALI_TILER_DISABLED;
                else {
                        t.hierarchy_mask = MALI_TILER_USER;
                        t.polygon_list_size = MALI_TILER_MINIMUM_HEADER_SIZE + 4;

                        /* We don't have a WRITE_VALUE job, so write the polygon list manually */
                        uint32_t *polygon_list_body = (uint32_t *) (tiler_dummy->cpu + header_size);
                        polygon_list_body[0] = 0xa0000000; /* TODO: Just that? */
                }
        }

        t.polygon_list_body =
                t.polygon_list + header_size;

        return t;
}

static void
panfrost_clear(
        struct pipe_context *pipe,
        unsigned buffers,
        const struct pipe_scissor_state *scissor_state,
        const union pipe_color_union *color,
        double depth, unsigned stencil)
{
        struct panfrost_context *ctx = pan_context(pipe);

        /* TODO: panfrost_get_fresh_batch_for_fbo() instantiates a new batch if
         * the existing batch targeting this FBO has draws. We could probably
         * avoid that by replacing plain clears by quad-draws with a specific
         * color/depth/stencil value, thus avoiding the generation of extra
         * fragment jobs.
         */
        struct panfrost_batch *batch = panfrost_get_fresh_batch_for_fbo(ctx);

        panfrost_batch_add_fbo_bos(batch);
        panfrost_batch_clear(batch, buffers, color, depth, stencil);
}

/* Reset per-frame context, called on context initialisation as well as after
 * flushing a frame */

void
panfrost_invalidate_frame(struct panfrost_context *ctx)
{
        /* TODO: When does this need to be handled? */
        ctx->active_queries = true;
}

bool
panfrost_writes_point_size(struct panfrost_context *ctx)
{
        assert(ctx->shader[PIPE_SHADER_VERTEX]);
        struct panfrost_shader_state *vs = panfrost_get_shader_state(ctx, PIPE_SHADER_VERTEX);

        return vs->writes_point_size && ctx->active_prim == PIPE_PRIM_POINTS;
}

void
panfrost_vertex_state_upd_attr_offs(struct panfrost_context *ctx,
                                    struct mali_vertex_tiler_postfix *vertex_postfix)
{
        if (!ctx->vertex)
                return;

        struct panfrost_vertex_state *so = ctx->vertex;

        /* Fixup offsets for the second pass. Recall that the hardware
         * calculates attribute addresses as:
         *
         *      addr = base + (stride * vtx) + src_offset;
         *
         * However, on Mali, base must be aligned to 64-bytes, so we
         * instead let:
         *
         *      base' = base & ~63 = base - (base & 63)
         *
         * To compensate when using base' (see emit_vertex_data), we have
         * to adjust src_offset by the masked off piece:
         *
         *      addr' = base' + (stride * vtx) + (src_offset + (base & 63))
         *            = base - (base & 63) + (stride * vtx) + src_offset + (base & 63)
         *            = base + (stride * vtx) + src_offset
         *            = addr;
         *
         * QED.
         */

        unsigned start = vertex_postfix->offset_start;

        for (unsigned i = 0; i < so->num_elements; ++i) {
                unsigned vbi = so->pipe[i].vertex_buffer_index;
                struct pipe_vertex_buffer *buf = &ctx->vertex_buffers[vbi];

                /* Adjust by the masked off bits of the offset. Make sure we
                 * read src_offset from so->hw (which is not GPU visible)
                 * rather than target (which is) due to caching effects */

                unsigned src_offset = so->pipe[i].src_offset;

                /* BOs aligned to 4k so guaranteed aligned to 64 */
                src_offset += (buf->buffer_offset & 63);

                /* Also, somewhat obscurely per-instance data needs to be
                 * offset in response to a delayed start in an indexed draw */

                if (so->pipe[i].instance_divisor && ctx->instance_count > 1 && start)
                        src_offset -= buf->stride * start;

                so->hw[i].src_offset = src_offset;
        }
}

/* Compute number of UBOs active (more specifically, compute the highest UBO
 * number addressable -- if there are gaps, include them in the count anyway).
 * We always include UBO #0 in the count, since we *need* uniforms enabled for
 * sysvals. */

unsigned
panfrost_ubo_count(struct panfrost_context *ctx, enum pipe_shader_type stage)
{
        unsigned mask = ctx->constant_buffer[stage].enabled_mask | 1;
        return 32 - __builtin_clz(mask);
}

/* The entire frame is in memory -- send it off to the kernel! */

void
panfrost_flush(
        struct pipe_context *pipe,
        struct pipe_fence_handle **fence,
        unsigned flags)
{
        struct panfrost_context *ctx = pan_context(pipe);
        struct util_dynarray fences;

        /* We must collect the fences before the flush is done, otherwise we'll
         * lose track of them.
         */
        if (fence) {
                util_dynarray_init(&fences, NULL);
                hash_table_foreach(ctx->batches, hentry) {
                        struct panfrost_batch *batch = hentry->data;

                        panfrost_batch_fence_reference(batch->out_sync);
                        util_dynarray_append(&fences,
                                             struct panfrost_batch_fence *,
                                             batch->out_sync);
                }
        }

        /* Submit all pending jobs */
        panfrost_flush_all_batches(ctx, false);

        if (fence) {
                struct panfrost_fence *f = panfrost_fence_create(ctx, &fences);
                pipe->screen->fence_reference(pipe->screen, fence, NULL);
                *fence = (struct pipe_fence_handle *)f;

                util_dynarray_foreach(&fences, struct panfrost_batch_fence *, fence)
                        panfrost_batch_fence_unreference(*fence);

                util_dynarray_fini(&fences);
        }

        if (pan_debug & PAN_DBG_TRACE)
                pandecode_next_frame();
}

#define DEFINE_CASE(c) case PIPE_PRIM_##c: return MALI_##c;

static int
g2m_draw_mode(enum pipe_prim_type mode)
{
        switch (mode) {
                DEFINE_CASE(POINTS);
                DEFINE_CASE(LINES);
                DEFINE_CASE(LINE_LOOP);
                DEFINE_CASE(LINE_STRIP);
                DEFINE_CASE(TRIANGLES);
                DEFINE_CASE(TRIANGLE_STRIP);
                DEFINE_CASE(TRIANGLE_FAN);
                DEFINE_CASE(QUADS);
                DEFINE_CASE(QUAD_STRIP);
                DEFINE_CASE(POLYGON);

        default:
                unreachable("Invalid draw mode");
        }
}

#undef DEFINE_CASE

static bool
panfrost_scissor_culls_everything(struct panfrost_context *ctx)
{
        const struct pipe_scissor_state *ss = &ctx->scissor;

        /* Check if we're scissoring at all */

        if (!(ctx->rasterizer && ctx->rasterizer->base.scissor))
                return false;

        return (ss->minx == ss->maxx) || (ss->miny == ss->maxy);
}

/* Count generated primitives (when there is no geom/tess shaders) for
 * transform feedback */

static void
panfrost_statistics_record(
                struct panfrost_context *ctx,
                const struct pipe_draw_info *info)
{
        if (!ctx->active_queries)
                return;

        uint32_t prims = u_prims_for_vertices(info->mode, info->count);
        ctx->prims_generated += prims;

        if (!ctx->streamout.num_targets)
                return;

        ctx->tf_prims_generated += prims;
}

static void
panfrost_update_streamout_offsets(struct panfrost_context *ctx)
{
        for (unsigned i = 0; i < ctx->streamout.num_targets; ++i) {
                unsigned count;

                count = u_stream_outputs_for_vertices(ctx->active_prim,
                                                      ctx->vertex_count);
                ctx->streamout.offsets[i] += count;
        }
}

static void
panfrost_draw_vbo(
        struct pipe_context *pipe,
        const struct pipe_draw_info *info)
{
        struct panfrost_context *ctx = pan_context(pipe);

        /* First of all, check the scissor to see if anything is drawn at all.
         * If it's not, we drop the draw (mostly a conformance issue;
         * well-behaved apps shouldn't hit this) */

        if (panfrost_scissor_culls_everything(ctx))
                return;

        int mode = info->mode;

        /* Fallback unsupported restart index */
        unsigned primitive_index = (1 << (info->index_size * 8)) - 1;

        if (info->primitive_restart && info->index_size
            && info->restart_index != primitive_index) {
                util_draw_vbo_without_prim_restart(pipe, info);
                return;
        }

        /* Fallback for unsupported modes */

        assert(ctx->rasterizer != NULL);

        if (!(ctx->draw_modes & (1 << mode))) {
                if (mode == PIPE_PRIM_QUADS && info->count == 4 && !ctx->rasterizer->base.flatshade) {
                        mode = PIPE_PRIM_TRIANGLE_FAN;
                } else {
                        if (info->count < 4) {
                                /* Degenerate case? */
                                return;
                        }

                        util_primconvert_save_rasterizer_state(ctx->primconvert, &ctx->rasterizer->base);
                        util_primconvert_draw_vbo(ctx->primconvert, info);
                        return;
                }
        }

        /* Now that we have a guaranteed terminating path, find the job.
         * Assignment commented out to prevent unused warning */

        struct panfrost_batch *batch = panfrost_get_batch_for_fbo(ctx);

        panfrost_batch_add_fbo_bos(batch);
        panfrost_batch_set_requirements(batch);

        /* Take into account a negative bias */
        ctx->vertex_count = info->count + abs(info->index_bias);
        ctx->instance_count = info->instance_count;
        ctx->active_prim = info->mode;

        struct mali_vertex_tiler_prefix vertex_prefix, tiler_prefix;
        struct mali_vertex_tiler_postfix vertex_postfix, tiler_postfix;
        union midgard_primitive_size primitive_size;
        unsigned vertex_count;

        panfrost_vt_init(ctx, PIPE_SHADER_VERTEX, &vertex_prefix, &vertex_postfix);
        panfrost_vt_init(ctx, PIPE_SHADER_FRAGMENT, &tiler_prefix, &tiler_postfix);

        panfrost_vt_set_draw_info(ctx, info, g2m_draw_mode(mode),
                                  &vertex_postfix, &tiler_prefix,
                                  &tiler_postfix, &vertex_count,
                                  &ctx->padded_count);

        panfrost_statistics_record(ctx, info);

        /* Dispatch "compute jobs" for the vertex/tiler pair as (1,
         * vertex_count, 1) */

        panfrost_pack_work_groups_fused(&vertex_prefix, &tiler_prefix,
                                        1, vertex_count, info->instance_count,
                                        1, 1, 1);

        /* Emit all sort of descriptors. */
        panfrost_emit_vertex_data(batch, &vertex_postfix);
        panfrost_emit_varying_descriptor(batch,
                                         ctx->padded_count *
                                         ctx->instance_count,
                                         &vertex_postfix, &tiler_postfix,
                                         &primitive_size);
        panfrost_emit_shader_meta(batch, PIPE_SHADER_VERTEX, &vertex_postfix);
        panfrost_emit_shader_meta(batch, PIPE_SHADER_FRAGMENT, &tiler_postfix);
        panfrost_emit_vertex_attr_meta(batch, &vertex_postfix);
        panfrost_emit_sampler_descriptors(batch, PIPE_SHADER_VERTEX, &vertex_postfix);
        panfrost_emit_sampler_descriptors(batch, PIPE_SHADER_FRAGMENT, &tiler_postfix);
        panfrost_emit_texture_descriptors(batch, PIPE_SHADER_VERTEX, &vertex_postfix);
        panfrost_emit_texture_descriptors(batch, PIPE_SHADER_FRAGMENT, &tiler_postfix);
        panfrost_emit_const_buf(batch, PIPE_SHADER_VERTEX, &vertex_postfix);
        panfrost_emit_const_buf(batch, PIPE_SHADER_FRAGMENT, &tiler_postfix);
        panfrost_emit_viewport(batch, &tiler_postfix);

        panfrost_vt_update_primitive_size(ctx, &tiler_prefix, &primitive_size);

        /* Fire off the draw itself */
        panfrost_emit_vertex_tiler_jobs(batch, &vertex_prefix, &vertex_postfix,
                                               &tiler_prefix, &tiler_postfix,
                                               &primitive_size);

        /* Adjust the batch stack size based on the new shader stack sizes. */
        panfrost_batch_adjust_stack_size(batch);

        /* Increment transform feedback offsets */
        panfrost_update_streamout_offsets(ctx);
}

/* CSO state */

static void
panfrost_generic_cso_delete(struct pipe_context *pctx, void *hwcso)
{
        free(hwcso);
}

static void *
panfrost_create_rasterizer_state(
        struct pipe_context *pctx,
        const struct pipe_rasterizer_state *cso)
{
        struct panfrost_rasterizer *so = CALLOC_STRUCT(panfrost_rasterizer);

        so->base = *cso;

        return so;
}

static void
panfrost_bind_rasterizer_state(
        struct pipe_context *pctx,
        void *hwcso)
{
        struct panfrost_context *ctx = pan_context(pctx);

        ctx->rasterizer = hwcso;

        if (!hwcso)
                return;

        /* Gauranteed with the core GL call, so don't expose ARB_polygon_offset */
        assert(ctx->rasterizer->base.offset_clamp == 0.0);

        /* Point sprites are emulated */

        struct panfrost_shader_state *variant = panfrost_get_shader_state(ctx, PIPE_SHADER_FRAGMENT);

        if (ctx->rasterizer->base.sprite_coord_enable || (variant && variant->point_sprite_mask))
                ctx->base.bind_fs_state(&ctx->base, ctx->shader[PIPE_SHADER_FRAGMENT]);
}

static void *
panfrost_create_vertex_elements_state(
        struct pipe_context *pctx,
        unsigned num_elements,
        const struct pipe_vertex_element *elements)
{
        struct panfrost_vertex_state *so = CALLOC_STRUCT(panfrost_vertex_state);

        so->num_elements = num_elements;
        memcpy(so->pipe, elements, sizeof(*elements) * num_elements);

        for (int i = 0; i < num_elements; ++i) {
                so->hw[i].index = i;

                enum pipe_format fmt = elements[i].src_format;
                const struct util_format_description *desc = util_format_description(fmt);
                so->hw[i].unknown1 = 0x2;
                so->hw[i].swizzle = panfrost_translate_swizzle_4(desc->swizzle);

                so->hw[i].format = panfrost_find_format(desc);
        }

        /* Let's also prepare vertex builtins */
        so->hw[PAN_VERTEX_ID].format = MALI_R32UI;
        so->hw[PAN_VERTEX_ID].swizzle = panfrost_get_default_swizzle(1);
        so->hw[PAN_INSTANCE_ID].format = MALI_R32UI;
        so->hw[PAN_INSTANCE_ID].swizzle = panfrost_get_default_swizzle(1);

        return so;
}

static void
panfrost_bind_vertex_elements_state(
        struct pipe_context *pctx,
        void *hwcso)
{
        struct panfrost_context *ctx = pan_context(pctx);
        ctx->vertex = hwcso;
}

static void *
panfrost_create_shader_state(
        struct pipe_context *pctx,
        const struct pipe_shader_state *cso,
        enum pipe_shader_type stage)
{
        struct panfrost_shader_variants *so = CALLOC_STRUCT(panfrost_shader_variants);
        so->base = *cso;

        /* Token deep copy to prevent memory corruption */

        if (cso->type == PIPE_SHADER_IR_TGSI)
                so->base.tokens = tgsi_dup_tokens(so->base.tokens);

        /* Precompile for shader-db if we need to */
        if (unlikely((pan_debug & PAN_DBG_PRECOMPILE) && cso->type == PIPE_SHADER_IR_NIR)) {
                struct panfrost_context *ctx = pan_context(pctx);

                struct panfrost_shader_state state;
                uint64_t outputs_written;

                panfrost_shader_compile(ctx, PIPE_SHADER_IR_NIR,
                                        so->base.ir.nir,
                                        tgsi_processor_to_shader_stage(stage),
                                        &state, &outputs_written);
        }

        return so;
}

static void
panfrost_delete_shader_state(
        struct pipe_context *pctx,
        void *so)
{
        struct panfrost_shader_variants *cso = (struct panfrost_shader_variants *) so;

        if (cso->base.type == PIPE_SHADER_IR_TGSI) {
                DBG("Deleting TGSI shader leaks duplicated tokens\n");
        }

        for (unsigned i = 0; i < cso->variant_count; ++i) {
                struct panfrost_shader_state *shader_state = &cso->variants[i];
                panfrost_bo_unreference(shader_state->bo);
                shader_state->bo = NULL;
        }
        free(cso->variants);

        free(so);
}

static void *
panfrost_create_sampler_state(
        struct pipe_context *pctx,
        const struct pipe_sampler_state *cso)
{
        struct panfrost_sampler_state *so = CALLOC_STRUCT(panfrost_sampler_state);
        struct panfrost_device *device = pan_device(pctx->screen);

        so->base = *cso;

        if (device->quirks & IS_BIFROST)
                panfrost_sampler_desc_init_bifrost(cso, &so->bifrost_hw);
        else
                panfrost_sampler_desc_init(cso, &so->midgard_hw);

        return so;
}

static void
panfrost_bind_sampler_states(
        struct pipe_context *pctx,
        enum pipe_shader_type shader,
        unsigned start_slot, unsigned num_sampler,
        void **sampler)
{
        assert(start_slot == 0);

        struct panfrost_context *ctx = pan_context(pctx);

        /* XXX: Should upload, not just copy? */
        ctx->sampler_count[shader] = num_sampler;
        memcpy(ctx->samplers[shader], sampler, num_sampler * sizeof (void *));
}

static bool
panfrost_variant_matches(
        struct panfrost_context *ctx,
        struct panfrost_shader_state *variant,
        enum pipe_shader_type type)
{
        struct pipe_rasterizer_state *rasterizer = &ctx->rasterizer->base;
        struct pipe_alpha_state *alpha = &ctx->depth_stencil->alpha;

        bool is_fragment = (type == PIPE_SHADER_FRAGMENT);

        if (is_fragment && (alpha->enabled || variant->alpha_state.enabled)) {
                /* Make sure enable state is at least the same */
                if (alpha->enabled != variant->alpha_state.enabled) {
                        return false;
                }

                /* Check that the contents of the test are the same */
                bool same_func = alpha->func == variant->alpha_state.func;
                bool same_ref = alpha->ref_value == variant->alpha_state.ref_value;

                if (!(same_func && same_ref)) {
                        return false;
                }
        }

        if (is_fragment && rasterizer && (rasterizer->sprite_coord_enable |
                                          variant->point_sprite_mask)) {
                /* Ensure the same varyings are turned to point sprites */
                if (rasterizer->sprite_coord_enable != variant->point_sprite_mask)
                        return false;

                /* Ensure the orientation is correct */
                bool upper_left =
                        rasterizer->sprite_coord_mode ==
                        PIPE_SPRITE_COORD_UPPER_LEFT;

                if (variant->point_sprite_upper_left != upper_left)
                        return false;
        }

        /* Otherwise, we're good to go */
        return true;
}

/**
 * Fix an uncompiled shader's stream output info, and produce a bitmask
 * of which VARYING_SLOT_* are captured for stream output.
 *
 * Core Gallium stores output->register_index as a "slot" number, where
 * slots are assigned consecutively to all outputs in info->outputs_written.
 * This naive packing of outputs doesn't work for us - we too have slots,
 * but the layout is defined by the VUE map, which we won't have until we
 * compile a specific shader variant.  So, we remap these and simply store
 * VARYING_SLOT_* in our copy's output->register_index fields.
 *
 * We then produce a bitmask of outputs which are used for SO.
 *
 * Implementation from iris.
 */

static uint64_t
update_so_info(struct pipe_stream_output_info *so_info,
               uint64_t outputs_written)
{
	uint64_t so_outputs = 0;
	uint8_t reverse_map[64] = {0};
	unsigned slot = 0;

	while (outputs_written)
		reverse_map[slot++] = u_bit_scan64(&outputs_written);

	for (unsigned i = 0; i < so_info->num_outputs; i++) {
		struct pipe_stream_output *output = &so_info->output[i];

		/* Map Gallium's condensed "slots" back to real VARYING_SLOT_* enums */
		output->register_index = reverse_map[output->register_index];

		so_outputs |= 1ull << output->register_index;
	}

	return so_outputs;
}

static void
panfrost_bind_shader_state(
        struct pipe_context *pctx,
        void *hwcso,
        enum pipe_shader_type type)
{
        struct panfrost_context *ctx = pan_context(pctx);
        ctx->shader[type] = hwcso;

        if (!hwcso) return;

        /* Match the appropriate variant */

        signed variant = -1;
        struct panfrost_shader_variants *variants = (struct panfrost_shader_variants *) hwcso;

        for (unsigned i = 0; i < variants->variant_count; ++i) {
                if (panfrost_variant_matches(ctx, &variants->variants[i], type)) {
                        variant = i;
                        break;
                }
        }

        if (variant == -1) {
                /* No variant matched, so create a new one */
                variant = variants->variant_count++;

                if (variants->variant_count > variants->variant_space) {
                        unsigned old_space = variants->variant_space;

                        variants->variant_space *= 2;
                        if (variants->variant_space == 0)
                                variants->variant_space = 1;

                        /* Arbitrary limit to stop runaway programs from
                         * creating an unbounded number of shader variants. */
                        assert(variants->variant_space < 1024);

                        unsigned msize = sizeof(struct panfrost_shader_state);
                        variants->variants = realloc(variants->variants,
                                                     variants->variant_space * msize);

                        memset(&variants->variants[old_space], 0,
                               (variants->variant_space - old_space) * msize);
                }

                struct panfrost_shader_state *v =
                                &variants->variants[variant];

                if (type == PIPE_SHADER_FRAGMENT) {
                        v->alpha_state = ctx->depth_stencil->alpha;

                        if (ctx->rasterizer) {
                                v->point_sprite_mask = ctx->rasterizer->base.sprite_coord_enable;
                                v->point_sprite_upper_left =
                                        ctx->rasterizer->base.sprite_coord_mode ==
                                        PIPE_SPRITE_COORD_UPPER_LEFT;
                        }
                }
        }

        /* Select this variant */
        variants->active_variant = variant;

        struct panfrost_shader_state *shader_state = &variants->variants[variant];
        assert(panfrost_variant_matches(ctx, shader_state, type));

        /* We finally have a variant, so compile it */

        if (!shader_state->compiled) {
                uint64_t outputs_written = 0;

                panfrost_shader_compile(ctx, variants->base.type,
                                        variants->base.type == PIPE_SHADER_IR_NIR ?
                                        variants->base.ir.nir :
                                        variants->base.tokens,
                                        tgsi_processor_to_shader_stage(type),
                                        shader_state,
                                        &outputs_written);

                shader_state->compiled = true;

                /* Fixup the stream out information, since what Gallium returns
                 * normally is mildly insane */

                shader_state->stream_output = variants->base.stream_output;
                shader_state->so_mask =
                        update_so_info(&shader_state->stream_output, outputs_written);
        }
}

static void *
panfrost_create_vs_state(struct pipe_context *pctx, const struct pipe_shader_state *hwcso)
{
        return panfrost_create_shader_state(pctx, hwcso, PIPE_SHADER_VERTEX);
}

static void *
panfrost_create_fs_state(struct pipe_context *pctx, const struct pipe_shader_state *hwcso)
{
        return panfrost_create_shader_state(pctx, hwcso, PIPE_SHADER_FRAGMENT);
}

static void
panfrost_bind_vs_state(struct pipe_context *pctx, void *hwcso)
{
        panfrost_bind_shader_state(pctx, hwcso, PIPE_SHADER_VERTEX);
}

static void
panfrost_bind_fs_state(struct pipe_context *pctx, void *hwcso)
{
        panfrost_bind_shader_state(pctx, hwcso, PIPE_SHADER_FRAGMENT);
}

static void
panfrost_set_vertex_buffers(
        struct pipe_context *pctx,
        unsigned start_slot,
        unsigned num_buffers,
        const struct pipe_vertex_buffer *buffers)
{
        struct panfrost_context *ctx = pan_context(pctx);

        util_set_vertex_buffers_mask(ctx->vertex_buffers, &ctx->vb_mask, buffers, start_slot, num_buffers);
}

static void
panfrost_set_constant_buffer(
        struct pipe_context *pctx,
        enum pipe_shader_type shader, uint index,
        const struct pipe_constant_buffer *buf)
{
        struct panfrost_context *ctx = pan_context(pctx);
        struct panfrost_constant_buffer *pbuf = &ctx->constant_buffer[shader];

        util_copy_constant_buffer(&pbuf->cb[index], buf);

        unsigned mask = (1 << index);

        if (unlikely(!buf)) {
                pbuf->enabled_mask &= ~mask;
                pbuf->dirty_mask &= ~mask;
                return;
        }

        pbuf->enabled_mask |= mask;
        pbuf->dirty_mask |= mask;
}

static void
panfrost_set_stencil_ref(
        struct pipe_context *pctx,
        const struct pipe_stencil_ref *ref)
{
        struct panfrost_context *ctx = pan_context(pctx);
        ctx->stencil_ref = *ref;
}

static enum mali_texture_type
panfrost_translate_texture_type(enum pipe_texture_target t) {
        switch (t)
        {
        case PIPE_BUFFER:
        case PIPE_TEXTURE_1D:
        case PIPE_TEXTURE_1D_ARRAY:
                return MALI_TEX_1D;

        case PIPE_TEXTURE_2D:
        case PIPE_TEXTURE_2D_ARRAY:
        case PIPE_TEXTURE_RECT:
                return MALI_TEX_2D;

        case PIPE_TEXTURE_3D:
                return MALI_TEX_3D;

        case PIPE_TEXTURE_CUBE:
        case PIPE_TEXTURE_CUBE_ARRAY:
                return MALI_TEX_CUBE;

        default:
                unreachable("Unknown target");
        }
}

static struct pipe_sampler_view *
panfrost_create_sampler_view(
        struct pipe_context *pctx,
        struct pipe_resource *texture,
        const struct pipe_sampler_view *template)
{
        struct panfrost_device *device = pan_device(pctx->screen);
        struct panfrost_sampler_view *so = rzalloc(pctx, struct panfrost_sampler_view);

        pipe_reference(NULL, &texture->reference);

        struct panfrost_resource *prsrc = (struct panfrost_resource *) texture;
        assert(prsrc->bo);

        so->base = *template;
        so->base.texture = texture;
        so->base.reference.count = 1;
        so->base.context = pctx;

        unsigned char user_swizzle[4] = {
                template->swizzle_r,
                template->swizzle_g,
                template->swizzle_b,
                template->swizzle_a
        };

        /* In the hardware, array_size refers specifically to array textures,
         * whereas in Gallium, it also covers cubemaps */

        unsigned array_size = texture->array_size;

        if (template->target == PIPE_TEXTURE_CUBE) {
                /* TODO: Cubemap arrays */
                assert(array_size == 6);
                array_size /= 6;
        }

        enum mali_texture_type type =
                panfrost_translate_texture_type(template->target);

        if (device->quirks & IS_BIFROST) {
                const struct util_format_description *desc =
                        util_format_description(template->format);
                unsigned char composed_swizzle[4];
                util_format_compose_swizzles(desc->swizzle, user_swizzle, composed_swizzle);

                unsigned size = panfrost_estimate_texture_payload_size(
                                template->u.tex.first_level,
                                template->u.tex.last_level,
                                template->u.tex.first_layer,
                                template->u.tex.last_layer,
                                type, prsrc->layout);

                so->bifrost_bo = pan_bo_create(device, size, 0);

                so->bifrost_descriptor = rzalloc(pctx, struct bifrost_texture_descriptor);
                panfrost_new_texture_bifrost(
                                so->bifrost_descriptor,
                                texture->width0, texture->height0,
                                texture->depth0, array_size,
                                template->format,
                                type, prsrc->layout,
                                template->u.tex.first_level,
                                template->u.tex.last_level,
                                template->u.tex.first_layer,
                                template->u.tex.last_layer,
                                prsrc->cubemap_stride,
                                panfrost_translate_swizzle_4(composed_swizzle),
                                prsrc->bo->gpu,
                                prsrc->slices,
                                so->bifrost_bo);
        } else {
                unsigned size = panfrost_estimate_texture_payload_size(
                                template->u.tex.first_level,
                                template->u.tex.last_level,
                                template->u.tex.first_layer,
                                template->u.tex.last_layer,
                                type, prsrc->layout);
                size += sizeof(struct mali_texture_descriptor);

                so->midgard_bo = pan_bo_create(device, size, 0);

                panfrost_new_texture(
                                so->midgard_bo->cpu,
                                texture->width0, texture->height0,
                                texture->depth0, array_size,
                                template->format,
                                type, prsrc->layout,
                                template->u.tex.first_level,
                                template->u.tex.last_level,
                                template->u.tex.first_layer,
                                template->u.tex.last_layer,
                                prsrc->cubemap_stride,
                                panfrost_translate_swizzle_4(user_swizzle),
                                prsrc->bo->gpu,
                                prsrc->slices);
        }

        return (struct pipe_sampler_view *) so;
}

static void
panfrost_set_sampler_views(
        struct pipe_context *pctx,
        enum pipe_shader_type shader,
        unsigned start_slot, unsigned num_views,
        struct pipe_sampler_view **views)
{
        struct panfrost_context *ctx = pan_context(pctx);
        unsigned new_nr = 0;
        unsigned i;

        assert(start_slot == 0);

        for (i = 0; i < num_views; ++i) {
                if (views[i])
                        new_nr = i + 1;
		pipe_sampler_view_reference((struct pipe_sampler_view **)&ctx->sampler_views[shader][i],
		                            views[i]);
        }

        for (; i < ctx->sampler_view_count[shader]; i++) {
		pipe_sampler_view_reference((struct pipe_sampler_view **)&ctx->sampler_views[shader][i],
		                            NULL);
        }
        ctx->sampler_view_count[shader] = new_nr;
}

static void
panfrost_sampler_view_destroy(
        struct pipe_context *pctx,
        struct pipe_sampler_view *pview)
{
        struct panfrost_sampler_view *view = (struct panfrost_sampler_view *) pview;

        pipe_resource_reference(&pview->texture, NULL);
        panfrost_bo_unreference(view->midgard_bo);
        panfrost_bo_unreference(view->bifrost_bo);
        if (view->bifrost_descriptor)
                ralloc_free(view->bifrost_descriptor);
        ralloc_free(view);
}

static void
panfrost_set_shader_buffers(
        struct pipe_context *pctx,
        enum pipe_shader_type shader,
        unsigned start, unsigned count,
        const struct pipe_shader_buffer *buffers,
        unsigned writable_bitmask)
{
        struct panfrost_context *ctx = pan_context(pctx);

        util_set_shader_buffers_mask(ctx->ssbo[shader], &ctx->ssbo_mask[shader],
                        buffers, start, count);
}

/* Hints that a framebuffer should use AFBC where possible */

static void
panfrost_hint_afbc(
                struct panfrost_device *device,
                const struct pipe_framebuffer_state *fb)
{
        /* AFBC implemenation incomplete; hide it */
        if (!(pan_debug & PAN_DBG_AFBC)) return;

        /* Hint AFBC to the resources bound to each color buffer */

        for (unsigned i = 0; i < fb->nr_cbufs; ++i) {
                struct pipe_surface *surf = fb->cbufs[i];
                struct panfrost_resource *rsrc = pan_resource(surf->texture);
                panfrost_resource_hint_layout(device, rsrc, MALI_TEXTURE_AFBC, 1);
        }

        /* Also hint it to the depth buffer */

        if (fb->zsbuf) {
                struct panfrost_resource *rsrc = pan_resource(fb->zsbuf->texture);
                panfrost_resource_hint_layout(device, rsrc, MALI_TEXTURE_AFBC, 1);
        }
}

static void
panfrost_set_framebuffer_state(struct pipe_context *pctx,
                               const struct pipe_framebuffer_state *fb)
{
        struct panfrost_context *ctx = pan_context(pctx);

        panfrost_hint_afbc(pan_device(pctx->screen), fb);
        util_copy_framebuffer_state(&ctx->pipe_framebuffer, fb);
        ctx->batch = NULL;
        panfrost_invalidate_frame(ctx);
}

static void *
panfrost_create_depth_stencil_state(struct pipe_context *pipe,
                                    const struct pipe_depth_stencil_alpha_state *depth_stencil)
{
        return mem_dup(depth_stencil, sizeof(*depth_stencil));
}

static void
panfrost_bind_depth_stencil_state(struct pipe_context *pipe,
                                  void *cso)
{
        struct panfrost_context *ctx = pan_context(pipe);
        struct pipe_depth_stencil_alpha_state *depth_stencil = cso;
        ctx->depth_stencil = depth_stencil;

        if (!depth_stencil)
                return;

        /* Alpha does not exist in the hardware (it's not in ES3), so it's
         * emulated in the fragment shader */

        if (depth_stencil->alpha.enabled) {
                /* We need to trigger a new shader (maybe) */
                ctx->base.bind_fs_state(&ctx->base, ctx->shader[PIPE_SHADER_FRAGMENT]);
        }

        /* Bounds test not implemented */
        assert(!depth_stencil->depth.bounds_test);
}

static void
panfrost_delete_depth_stencil_state(struct pipe_context *pipe, void *depth)
{
        free( depth );
}

static void
panfrost_set_sample_mask(struct pipe_context *pipe,
                         unsigned sample_mask)
{
}

static void
panfrost_set_clip_state(struct pipe_context *pipe,
                        const struct pipe_clip_state *clip)
{
        //struct panfrost_context *panfrost = pan_context(pipe);
}

static void
panfrost_set_viewport_states(struct pipe_context *pipe,
                             unsigned start_slot,
                             unsigned num_viewports,
                             const struct pipe_viewport_state *viewports)
{
        struct panfrost_context *ctx = pan_context(pipe);

        assert(start_slot == 0);
        assert(num_viewports == 1);

        ctx->pipe_viewport = *viewports;
}

static void
panfrost_set_scissor_states(struct pipe_context *pipe,
                            unsigned start_slot,
                            unsigned num_scissors,
                            const struct pipe_scissor_state *scissors)
{
        struct panfrost_context *ctx = pan_context(pipe);

        assert(start_slot == 0);
        assert(num_scissors == 1);

        ctx->scissor = *scissors;
}

static void
panfrost_set_polygon_stipple(struct pipe_context *pipe,
                             const struct pipe_poly_stipple *stipple)
{
        //struct panfrost_context *panfrost = pan_context(pipe);
}

static void
panfrost_set_active_query_state(struct pipe_context *pipe,
                                bool enable)
{
        struct panfrost_context *ctx = pan_context(pipe);
        ctx->active_queries = enable;
}

static void
panfrost_destroy(struct pipe_context *pipe)
{
        struct panfrost_context *panfrost = pan_context(pipe);

        if (panfrost->blitter)
                util_blitter_destroy(panfrost->blitter);

        if (panfrost->blitter_wallpaper)
                util_blitter_destroy(panfrost->blitter_wallpaper);

        util_unreference_framebuffer_state(&panfrost->pipe_framebuffer);
        u_upload_destroy(pipe->stream_uploader);

        ralloc_free(pipe);
}

static struct pipe_query *
panfrost_create_query(struct pipe_context *pipe,
                      unsigned type,
                      unsigned index)
{
        struct panfrost_query *q = rzalloc(pipe, struct panfrost_query);

        q->type = type;
        q->index = index;

        return (struct pipe_query *) q;
}

static void
panfrost_destroy_query(struct pipe_context *pipe, struct pipe_query *q)
{
        struct panfrost_query *query = (struct panfrost_query *) q;

        if (query->bo) {
                panfrost_bo_unreference(query->bo);
                query->bo = NULL;
        }

        ralloc_free(q);
}

static bool
panfrost_begin_query(struct pipe_context *pipe, struct pipe_query *q)
{
        struct panfrost_context *ctx = pan_context(pipe);
        struct panfrost_query *query = (struct panfrost_query *) q;

        switch (query->type) {
        case PIPE_QUERY_OCCLUSION_COUNTER:
        case PIPE_QUERY_OCCLUSION_PREDICATE:
        case PIPE_QUERY_OCCLUSION_PREDICATE_CONSERVATIVE:
                /* Allocate a bo for the query results to be stored */
                if (!query->bo) {
                        query->bo = pan_bo_create(
                                        pan_device(ctx->base.screen),
                                        sizeof(unsigned), 0);
                }

                unsigned *result = (unsigned *)query->bo->cpu;
                *result = 0; /* Default to 0 if nothing at all drawn. */
                ctx->occlusion_query = query;
                break;

        /* Geometry statistics are computed in the driver. XXX: geom/tess
         * shaders.. */

        case PIPE_QUERY_PRIMITIVES_GENERATED:
                query->start = ctx->prims_generated;
                break;
        case PIPE_QUERY_PRIMITIVES_EMITTED:
                query->start = ctx->tf_prims_generated;
                break;

        default:
                DBG("Skipping query %u\n", query->type);
                break;
        }

        return true;
}

static bool
panfrost_end_query(struct pipe_context *pipe, struct pipe_query *q)
{
        struct panfrost_context *ctx = pan_context(pipe);
        struct panfrost_query *query = (struct panfrost_query *) q;

        switch (query->type) {
        case PIPE_QUERY_OCCLUSION_COUNTER:
        case PIPE_QUERY_OCCLUSION_PREDICATE:
        case PIPE_QUERY_OCCLUSION_PREDICATE_CONSERVATIVE:
                ctx->occlusion_query = NULL;
                break;
        case PIPE_QUERY_PRIMITIVES_GENERATED:
                query->end = ctx->prims_generated;
                break;
        case PIPE_QUERY_PRIMITIVES_EMITTED:
                query->end = ctx->tf_prims_generated;
                break;
        }

        return true;
}

static bool
panfrost_get_query_result(struct pipe_context *pipe,
                          struct pipe_query *q,
                          bool wait,
                          union pipe_query_result *vresult)
{
        struct panfrost_query *query = (struct panfrost_query *) q;
        struct panfrost_context *ctx = pan_context(pipe);


        switch (query->type) {
        case PIPE_QUERY_OCCLUSION_COUNTER:
        case PIPE_QUERY_OCCLUSION_PREDICATE:
        case PIPE_QUERY_OCCLUSION_PREDICATE_CONSERVATIVE:
                /* Flush first */
                panfrost_flush_all_batches(ctx, true);

                /* Read back the query results */
                unsigned *result = (unsigned *) query->bo->cpu;
                unsigned passed = *result;

                if (query->type == PIPE_QUERY_OCCLUSION_COUNTER) {
                        vresult->u64 = passed;
                } else {
                        vresult->b = !!passed;
                }

                break;

        case PIPE_QUERY_PRIMITIVES_GENERATED:
        case PIPE_QUERY_PRIMITIVES_EMITTED:
                panfrost_flush_all_batches(ctx, true);
                vresult->u64 = query->end - query->start;
                break;

        default:
                DBG("Skipped query get %u\n", query->type);
                break;
        }

        return true;
}

static struct pipe_stream_output_target *
panfrost_create_stream_output_target(struct pipe_context *pctx,
                                     struct pipe_resource *prsc,
                                     unsigned buffer_offset,
                                     unsigned buffer_size)
{
        struct pipe_stream_output_target *target;

        target = rzalloc(pctx, struct pipe_stream_output_target);

        if (!target)
                return NULL;

        pipe_reference_init(&target->reference, 1);
        pipe_resource_reference(&target->buffer, prsc);

        target->context = pctx;
        target->buffer_offset = buffer_offset;
        target->buffer_size = buffer_size;

        return target;
}

static void
panfrost_stream_output_target_destroy(struct pipe_context *pctx,
                                      struct pipe_stream_output_target *target)
{
        pipe_resource_reference(&target->buffer, NULL);
        ralloc_free(target);
}

static void
panfrost_set_stream_output_targets(struct pipe_context *pctx,
                                   unsigned num_targets,
                                   struct pipe_stream_output_target **targets,
                                   const unsigned *offsets)
{
        struct panfrost_context *ctx = pan_context(pctx);
        struct panfrost_streamout *so = &ctx->streamout;

        assert(num_targets <= ARRAY_SIZE(so->targets));

        for (unsigned i = 0; i < num_targets; i++) {
                if (offsets[i] != -1)
                        so->offsets[i] = offsets[i];

                pipe_so_target_reference(&so->targets[i], targets[i]);
        }

        for (unsigned i = 0; i < so->num_targets; i++)
                pipe_so_target_reference(&so->targets[i], NULL);

        so->num_targets = num_targets;
}

struct pipe_context *
panfrost_create_context(struct pipe_screen *screen, void *priv, unsigned flags)
{
        struct panfrost_context *ctx = rzalloc(screen, struct panfrost_context);
        struct pipe_context *gallium = (struct pipe_context *) ctx;

        gallium->screen = screen;

        gallium->destroy = panfrost_destroy;

        gallium->set_framebuffer_state = panfrost_set_framebuffer_state;

        gallium->flush = panfrost_flush;
        gallium->clear = panfrost_clear;
        gallium->draw_vbo = panfrost_draw_vbo;

        gallium->set_vertex_buffers = panfrost_set_vertex_buffers;
        gallium->set_constant_buffer = panfrost_set_constant_buffer;
        gallium->set_shader_buffers = panfrost_set_shader_buffers;

        gallium->set_stencil_ref = panfrost_set_stencil_ref;

        gallium->create_sampler_view = panfrost_create_sampler_view;
        gallium->set_sampler_views = panfrost_set_sampler_views;
        gallium->sampler_view_destroy = panfrost_sampler_view_destroy;

        gallium->create_rasterizer_state = panfrost_create_rasterizer_state;
        gallium->bind_rasterizer_state = panfrost_bind_rasterizer_state;
        gallium->delete_rasterizer_state = panfrost_generic_cso_delete;

        gallium->create_vertex_elements_state = panfrost_create_vertex_elements_state;
        gallium->bind_vertex_elements_state = panfrost_bind_vertex_elements_state;
        gallium->delete_vertex_elements_state = panfrost_generic_cso_delete;

        gallium->create_fs_state = panfrost_create_fs_state;
        gallium->delete_fs_state = panfrost_delete_shader_state;
        gallium->bind_fs_state = panfrost_bind_fs_state;

        gallium->create_vs_state = panfrost_create_vs_state;
        gallium->delete_vs_state = panfrost_delete_shader_state;
        gallium->bind_vs_state = panfrost_bind_vs_state;

        gallium->create_sampler_state = panfrost_create_sampler_state;
        gallium->delete_sampler_state = panfrost_generic_cso_delete;
        gallium->bind_sampler_states = panfrost_bind_sampler_states;

        gallium->create_depth_stencil_alpha_state = panfrost_create_depth_stencil_state;
        gallium->bind_depth_stencil_alpha_state   = panfrost_bind_depth_stencil_state;
        gallium->delete_depth_stencil_alpha_state = panfrost_delete_depth_stencil_state;

        gallium->set_sample_mask = panfrost_set_sample_mask;

        gallium->set_clip_state = panfrost_set_clip_state;
        gallium->set_viewport_states = panfrost_set_viewport_states;
        gallium->set_scissor_states = panfrost_set_scissor_states;
        gallium->set_polygon_stipple = panfrost_set_polygon_stipple;
        gallium->set_active_query_state = panfrost_set_active_query_state;

        gallium->create_query = panfrost_create_query;
        gallium->destroy_query = panfrost_destroy_query;
        gallium->begin_query = panfrost_begin_query;
        gallium->end_query = panfrost_end_query;
        gallium->get_query_result = panfrost_get_query_result;

        gallium->create_stream_output_target = panfrost_create_stream_output_target;
        gallium->stream_output_target_destroy = panfrost_stream_output_target_destroy;
        gallium->set_stream_output_targets = panfrost_set_stream_output_targets;

        panfrost_resource_context_init(gallium);
        panfrost_blend_context_init(gallium);
        panfrost_compute_context_init(gallium);

        /* XXX: leaks */
        gallium->stream_uploader = u_upload_create_default(gallium);
        gallium->const_uploader = gallium->stream_uploader;
        assert(gallium->stream_uploader);

        /* Midgard supports ES modes, plus QUADS/QUAD_STRIPS/POLYGON */
        ctx->draw_modes = (1 << (PIPE_PRIM_POLYGON + 1)) - 1;

        ctx->primconvert = util_primconvert_create(gallium, ctx->draw_modes);

        ctx->blitter = util_blitter_create(gallium);
        ctx->blitter_wallpaper = util_blitter_create(gallium);

        assert(ctx->blitter);
        assert(ctx->blitter_wallpaper);

        /* Prepare for render! */

        panfrost_batch_init(ctx);
        panfrost_invalidate_frame(ctx);

        return gallium;
}