From 218785c4a95319145b194db4ca9fe9fbc0713461 Mon Sep 17 00:00:00 2001
From: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Date: Tue, 10 Mar 2020 16:20:18 -0400
Subject: pan/bi: Implement sysvals

Now that it's all abstracted nicely with an implementation shared with
Midgard, this is pretty easy to get.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4150>
---
 src/panfrost/bifrost/bifrost_compile.c | 55 ++++++++++++++++++++++++++++++++++
 src/panfrost/bifrost/compiler.h        |  1 +
 2 files changed, 56 insertions(+)

diff --git a/src/panfrost/bifrost/bifrost_compile.c b/src/panfrost/bifrost/bifrost_compile.c
index 39ae2a62748..46f9aea5496 100644
--- a/src/panfrost/bifrost/bifrost_compile.c
+++ b/src/panfrost/bifrost/bifrost_compile.c
@@ -163,9 +163,45 @@ bi_emit_ld_uniform(bi_context *ctx, nir_intrinsic_instr *instr)
 {
         bi_instruction ld = bi_load(BI_LOAD_UNIFORM, instr);
         ld.src[1] = BIR_INDEX_ZERO; /* TODO: UBO index */
+
+        /* TODO: Indirect access, since we need to multiply by the element
+         * size. I believe we can get this lowering automatically via
+         * nir_lower_io (as mul instructions) with the proper options, but this
+         * is TODO */
+        assert(ld.src[0] & BIR_INDEX_CONSTANT);
+        ld.constant.u64 += ctx->sysvals.sysval_count;
+        ld.constant.u64 *= 16;
+
         bi_emit(ctx, ld);
 }
 
+static void
+bi_emit_sysval(bi_context *ctx, nir_instr *instr,
+                unsigned nr_components, unsigned offset)
+{
+        nir_dest nir_dest;
+
+        /* Figure out which uniform this is */
+        int sysval = panfrost_sysval_for_instr(instr, &nir_dest);
+        void *val = _mesa_hash_table_u64_search(ctx->sysvals.sysval_to_id, sysval);
+
+        /* Sysvals are prefix uniforms */
+        unsigned uniform = ((uintptr_t) val) - 1;
+
+        /* Emit the read itself -- this is never indirect */
+
+        bi_instruction load = {
+                .type = BI_LOAD_UNIFORM,
+                .writemask = (1 << (nr_components * 4)) - 1,
+                .src = { BIR_INDEX_CONSTANT},
+                .constant = { (uniform * 16) + offset },
+                .dest = bir_dest_index(&nir_dest),
+                .dest_type = nir_type_uint32, /* TODO */
+        };
+
+        bi_emit(ctx, load);
+}
+
 static void
 emit_intrinsic(bi_context *ctx, nir_intrinsic_instr *instr)
 {
@@ -198,6 +234,21 @@ emit_intrinsic(bi_context *ctx, nir_intrinsic_instr *instr)
                 bi_emit_ld_uniform(ctx, instr);
                 break;
 
+        case nir_intrinsic_load_ssbo_address:
+                bi_emit_sysval(ctx, &instr->instr, 1, 0);
+                break;
+
+        case nir_intrinsic_get_buffer_size:
+                bi_emit_sysval(ctx, &instr->instr, 1, 8);
+                break;
+
+        case nir_intrinsic_load_viewport_scale:
+        case nir_intrinsic_load_viewport_offset:
+        case nir_intrinsic_load_num_work_groups:
+        case nir_intrinsic_load_sampler_lod_parameters_pan:
+                bi_emit_sysval(ctx, &instr->instr, 3, 0);
+                break;
+
         default:
                 /* todo */
                 break;
@@ -800,6 +851,10 @@ bifrost_compile_shader_nir(nir_shader *nir, panfrost_program *program, unsigned
         bi_optimize_nir(nir);
         nir_print_shader(nir, stdout);
 
+        panfrost_nir_assign_sysvals(&ctx->sysvals, nir);
+        program->sysval_count = ctx->sysvals.sysval_count;
+        memcpy(program->sysvals, ctx->sysvals.sysvals, sizeof(ctx->sysvals.sysvals[0]) * ctx->sysvals.sysval_count);
+
         nir_foreach_function(func, nir) {
                 if (!func->impl)
                         continue;
diff --git a/src/panfrost/bifrost/compiler.h b/src/panfrost/bifrost/compiler.h
index cd0408b6119..49ecb19302b 100644
--- a/src/panfrost/bifrost/compiler.h
+++ b/src/panfrost/bifrost/compiler.h
@@ -325,6 +325,7 @@ typedef struct {
        nir_shader *nir;
        gl_shader_stage stage;
        struct list_head blocks; /* list of bi_block */
+       struct panfrost_sysvals sysvals;
        uint32_t quirks;
 
        /* During NIR->BIR */
-- 
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