etnaviv: flush used render buffers on context flush when neccessary

Some resources like backbuffers are explicitly flushed by the frontend
at the appropriate time, others however won't get flushed explicitly.
Remember those resources when they get emitted as a render buffer and
flush them on a context flush to make their content visible to other
entities sharing the buffer.

We still keep the optimized path for most resources where the frontend
promises to do the flushing for us and only enable implicit flushing
when a buffer handle is exported/imported without the
PIPE_HANDLE_USAGE_EXPLICIT_FLUSH flag set.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7603>

src/gallium/drivers/etnaviv/etnaviv_context.c

@@ -129,6 +129,9 @@ etna_context_destroy(struct pipe_context *pctx)
       _mesa_set_destroy(ctx->used_resources_write, NULL);
 
    }
+   if (ctx->flush_resources)
+      _mesa_set_destroy(ctx->flush_resources, NULL);
+
    mtx_unlock(&ctx->lock);
 
    if (ctx->dummy_desc_bo)
@@ -490,6 +493,14 @@ etna_flush(struct pipe_context *pctx, struct pipe_fence_handle **fence,
    list_for_each_entry(struct etna_acc_query, aq, &ctx->active_acc_queries, node)
       etna_acc_query_suspend(aq, ctx);
 
+   /* flush all resources that need an implicit flush */
+   set_foreach(ctx->flush_resources, entry) {
+      struct pipe_resource *prsc = (struct pipe_resource *)entry->key;
+
+      pctx->flush_resource(pctx, prsc);
+   }
+   _mesa_set_clear(ctx->flush_resources, NULL);
+
    etna_cmd_stream_flush(ctx->stream, ctx->in_fence_fd,
                           (flags & PIPE_FLUSH_FENCE_FD) ? &out_fence_fd : NULL);
 
@@ -596,6 +607,11 @@ etna_context_create(struct pipe_screen *pscreen, void *priv, unsigned flags)
    if (!ctx->used_resources_write)
       goto fail;
 
+   ctx->flush_resources = _mesa_set_create(NULL, _mesa_hash_pointer,
+                                           _mesa_key_pointer_equal);
+   if (!ctx->flush_resources)
+      goto fail;
+
    mtx_init(&ctx->lock, mtx_recursive);
 
    /* context ctxate setup */

src/gallium/drivers/etnaviv/etnaviv_context.h

@@ -206,6 +206,9 @@ struct etna_context {
    struct set *used_resources_read;
    struct set *used_resources_write;
 
+   /* resources that must be flushed implicitly at the context flush time */
+   struct set *flush_resources;
+
    mtx_t lock;
 };
 

src/gallium/drivers/etnaviv/etnaviv_resource.c

@@ -265,6 +265,7 @@ etna_resource_alloc(struct pipe_screen *pscreen, unsigned layout,
    rsc->base.nr_samples = nr_samples;
    rsc->layout = layout;
    rsc->halign = halign;
+   rsc->explicit_flush = true;
 
    pipe_reference_init(&rsc->base.reference, 1);
    util_range_init(&rsc->valid_buffer_range);
@@ -519,6 +520,9 @@ etna_resource_from_handle(struct pipe_screen *pscreen,
    rsc->layout = modifier_to_layout(handle->modifier);
    rsc->halign = TEXTURE_HALIGN_FOUR;
 
+   if (usage & PIPE_HANDLE_USAGE_EXPLICIT_FLUSH)
+      rsc->explicit_flush = true;
+
    level->width = tmpl->width0;
    level->height = tmpl->height0;
    level->depth = tmpl->depth0;
@@ -584,6 +588,9 @@ etna_resource_get_handle(struct pipe_screen *pscreen,
    handle->offset = rsc->levels[0].offset;
    handle->modifier = layout_to_modifier(rsc->layout);
 
+   if (!(usage & PIPE_HANDLE_USAGE_EXPLICIT_FLUSH))
+      rsc->explicit_flush = false;
+
    if (handle->type == WINSYS_HANDLE_TYPE_SHARED) {
       return etna_bo_get_name(rsc->bo, &handle->handle) == 0;
    } else if (handle->type == WINSYS_HANDLE_TYPE_KMS) {

src/gallium/drivers/etnaviv/etnaviv_resource.h

@@ -93,6 +93,8 @@ struct etna_resource {
    struct pipe_resource *texture;
    /* for when PE doesn't support the base layout */
    struct pipe_resource *render;
+   /* frontend flushes resource via an explicit call to flush_resource */
+   bool explicit_flush;
 
    enum etna_resource_status status;
 

src/gallium/drivers/etnaviv/etnaviv_state.c

@@ -753,6 +753,21 @@ etna_update_zsa(struct etna_context *ctx)
    return true;
 }
 
+static bool
+etna_record_flush_resources(struct etna_context *ctx)
+{
+   struct pipe_framebuffer_state *fb = &ctx->framebuffer_s;
+
+   if (fb->nr_cbufs > 0) {
+      struct etna_surface *surf = etna_surface(fb->cbufs[0]);
+
+      if (!etna_resource(surf->prsc)->explicit_flush)
+         _mesa_set_add(ctx->flush_resources, surf->prsc);
+   }
+
+   return true;
+}
+
 struct etna_state_updater {
    bool (*update)(struct etna_context *ctx);
    uint32_t dirty;
@@ -780,6 +795,9 @@ static const struct etna_state_updater etna_state_updates[] = {
    },
    {
       etna_update_zsa, ETNA_DIRTY_ZSA | ETNA_DIRTY_SHADER,
+   },
+   {
+      etna_record_flush_resources, ETNA_DIRTY_FRAMEBUFFER,
    }
 };