[Freedreno] [PATCH 11/12] freedreno: shadow textures if possible to avoid stall/flush
Rob Clark
robdclark at gmail.com
Sat Jul 2 16:52:14 UTC 2016
To make batch re-ordering useful, we need to be able to create shadow
resources to avoid a flush/stall in transfer_map(). For example,
uploading new texture contents or updating a UBO mid-batch. In these
cases, we want to clone the buffer, and update the new buffer, leaving
the old buffer (whose reference is held by cmdstream) as a shadow.
This is done by blitting the remaining other levels (and whatever part
of current level that is not discarded) from the old/shadow buffer to
the new one.
Signed-off-by: Rob Clark <robdclark at gmail.com>
---
src/gallium/drivers/freedreno/freedreno_context.h | 5 +
src/gallium/drivers/freedreno/freedreno_resource.c | 208 ++++++++++++++++++++-
src/gallium/drivers/freedreno/freedreno_util.h | 6 +
3 files changed, 210 insertions(+), 9 deletions(-)
diff --git a/src/gallium/drivers/freedreno/freedreno_context.h b/src/gallium/drivers/freedreno/freedreno_context.h
index 012f452..ca3c01b 100644
--- a/src/gallium/drivers/freedreno/freedreno_context.h
+++ b/src/gallium/drivers/freedreno/freedreno_context.h
@@ -296,6 +296,11 @@ struct fd_context {
bool cond_cond; /* inverted rendering condition */
uint cond_mode;
+ /* Are we in process of shadowing a resource? Used to detect recursion
+ * in transfer_map, and skip unneeded synchronization.
+ */
+ bool in_shadow;
+
struct pipe_debug_callback debug;
/* GMEM/tile handling fxns: */
diff --git a/src/gallium/drivers/freedreno/freedreno_resource.c b/src/gallium/drivers/freedreno/freedreno_resource.c
index d7603b2..8ff0d4a 100644
--- a/src/gallium/drivers/freedreno/freedreno_resource.c
+++ b/src/gallium/drivers/freedreno/freedreno_resource.c
@@ -116,6 +116,171 @@ realloc_bo(struct fd_resource *rsc, uint32_t size)
util_range_set_empty(&rsc->valid_buffer_range);
}
+static void fd_blitter_pipe_begin(struct fd_context *ctx, bool render_cond);
+static void fd_blitter_pipe_end(struct fd_context *ctx);
+
+static void
+do_blit(struct fd_context *ctx, const struct pipe_blit_info *blit, bool fallback)
+{
+ /* TODO size threshold too?? */
+ if ((blit->src.resource->target != PIPE_BUFFER) && !fallback) {
+ /* do blit on gpu: */
+ fd_blitter_pipe_begin(ctx, false);
+ util_blitter_blit(ctx->blitter, blit);
+ fd_blitter_pipe_end(ctx);
+ } else {
+ /* do blit on cpu: */
+ util_resource_copy_region(&ctx->base,
+ blit->dst.resource, blit->dst.level, blit->dst.box.x,
+ blit->dst.box.y, blit->dst.box.z,
+ blit->src.resource, blit->src.level, &blit->src.box);
+ }
+}
+
+static bool
+fd_try_shadow_resource(struct fd_context *ctx, struct fd_resource *rsc,
+ unsigned level, unsigned usage, const struct pipe_box *box)
+{
+ struct pipe_context *pctx = &ctx->base;
+ struct pipe_resource *prsc = &rsc->base.b;
+ bool fallback = false;
+
+ /* TODO: somehow munge dimensions and format to copy unsupported
+ * render target format to something that is supported?
+ */
+ if (!pctx->screen->is_format_supported(pctx->screen,
+ prsc->format, prsc->target, prsc->nr_samples,
+ PIPE_BIND_RENDER_TARGET))
+ fallback = true;
+
+ /* these cases should be handled elsewhere.. just for future
+ * reference in case this gets split into a more generic(ish)
+ * helper.
+ */
+ debug_assert(!(usage & PIPE_TRANSFER_READ));
+ debug_assert(!(usage & PIPE_TRANSFER_DISCARD_WHOLE_RESOURCE));
+
+ /* if we do a gpu blit to clone the whole resource, we'll just
+ * end up stalling on that.. so only allow if we can discard
+ * current range (and blit, possibly cpu or gpu, the rest)
+ */
+ if (!(usage & PIPE_TRANSFER_DISCARD_RANGE))
+ return false;
+
+ bool whole_level = util_texrange_covers_whole_level(prsc, level,
+ box->x, box->y, box->z, box->width, box->height, box->depth);
+
+ /* TODO need to be more clever about current level */
+ if ((prsc->target > PIPE_TEXTURE_2D) && !whole_level)
+ return false;
+
+ struct pipe_resource *pshadow =
+ pctx->screen->resource_create(pctx->screen, prsc);
+
+ if (!pshadow)
+ return false;
+
+ assert(!ctx->in_shadow);
+ ctx->in_shadow = true;
+
+ /* get rid of any references that batch-cache might have to us (which
+ * should empty/destroy rsc->batches hashset)
+ */
+ fd_bc_invalidate_resource(rsc);
+
+ /* Swap the backing bo's, so shadow becomes the old buffer,
+ * blit from shadow to new buffer. From here on out, we
+ * cannot fail.
+ *
+ * Note that we need to do it in this order, otherwise if
+ * we go down cpu blit path, the recursive transfer_map()
+ * sees the wrong status..
+ */
+ struct fd_resource *shadow = fd_resource(pshadow);
+ DBG("shadow: %p (%d) -> %p (%d)\n", rsc, rsc->base.b.reference.count,
+ shadow, shadow->base.b.reference.count);
+
+ struct pipe_blit_info blit = {0};
+ blit.dst.resource = pshadow;
+ blit.dst.format = pshadow->format;
+ blit.src.resource = prsc;
+ blit.src.format = prsc->format;
+ blit.mask = util_format_get_mask(prsc->format);
+ blit.filter = PIPE_TEX_FILTER_NEAREST;
+
+#define set_box(field, val) do { \
+ blit.dst.field = (val); \
+ blit.src.field = (val); \
+ } while (0)
+
+ /* blit the other levels in their entirety: */
+ for (unsigned l = 0; l <= prsc->last_level; l++) {
+ if (l == level)
+ continue;
+
+ /* just blit whole level: */
+ set_box(level, l);
+ // TODO do these get minified?
+ set_box(box.width, u_minify(prsc->width0, l));
+ set_box(box.height, u_minify(prsc->height0, l));
+ set_box(box.depth, u_minify(prsc->depth0, l));
+
+ do_blit(ctx, &blit, fallback);
+ }
+
+ /* deal w/ current level specially, since we might need to split
+ * it up into a couple blits:
+ */
+ if (!whole_level) {
+ set_box(level, level);
+
+ switch (prsc->target) {
+ case PIPE_BUFFER:
+ case PIPE_TEXTURE_1D:
+ set_box(box.y, 0);
+ set_box(box.z, 0);
+ set_box(box.height, 1);
+ set_box(box.depth, 1);
+
+ if (box->x > 0) {
+ set_box(box.x, 0);
+ set_box(box.width, box->x);
+
+ do_blit(ctx, &blit, fallback);
+ }
+ if ((box->x + box->width) < u_minify(prsc->width0, level)) {
+ set_box(box.x, box->x + box->width);
+ set_box(box.width, u_minify(prsc->width0, level) - (box->x + box->width));
+
+ do_blit(ctx, &blit, fallback);
+ }
+ break;
+ case PIPE_TEXTURE_2D:
+ /* TODO */
+ default:
+ unreachable("TODO");
+ }
+ }
+
+ /* TODO valid_buffer_range?? */
+ swap(rsc->bo, shadow->bo);
+ swap(rsc->timestamp, shadow->timestamp);
+ swap(rsc->status, shadow->status);
+ swap(rsc->pending_batch, shadow->pending_batch);
+ swap(rsc->write_batch, shadow->write_batch);
+
+ struct list_head tmp;
+ list_replace(&rsc->list, &tmp);
+ list_replace(&shadow->list, &rsc->list);
+ list_replace(&tmp, &shadow->list);
+
+ ctx->in_shadow = false;
+
+ pipe_resource_reference(&pshadow, NULL);
+
+ return true;
+}
+
static unsigned
fd_resource_layer_offset(struct fd_resource *rsc,
struct fd_resource_slice *slice,
@@ -303,6 +468,9 @@ fd_resource_transfer_map(struct pipe_context *pctx,
ptrans->stride = util_format_get_nblocksx(format, slice->pitch) * rsc->cpp;
ptrans->layer_stride = rsc->layer_first ? rsc->layer_size : slice->size0;
+ if (ctx->in_shadow && !(usage & PIPE_TRANSFER_READ))
+ usage |= PIPE_TRANSFER_UNSYNCHRONIZED;
+
if (usage & PIPE_TRANSFER_READ)
op |= DRM_FREEDRENO_PREP_READ;
@@ -322,21 +490,46 @@ fd_resource_transfer_map(struct pipe_context *pctx,
* to wait.
*/
} else if (!(usage & PIPE_TRANSFER_UNSYNCHRONIZED)) {
+ bool needs_flush;
+
/* If the GPU is writing to the resource, or if it is reading from the
* resource and we're trying to write to it, flush the renders.
*/
- if (((ptrans->usage & PIPE_TRANSFER_WRITE) &&
- pending(rsc, FD_PENDING_READ | FD_PENDING_WRITE)) ||
- pending(rsc, FD_PENDING_WRITE))
+ if (usage & PIPE_TRANSFER_WRITE)
+ needs_flush = pending(rsc, FD_PENDING_READ | FD_PENDING_WRITE);
+ else
+ needs_flush = pending(rsc, FD_PENDING_WRITE);
+
+ bool busy = needs_flush | (0 == fd_bo_cpu_prep(rsc->bo,
+ ctx->screen->pipe, op | DRM_FREEDRENO_PREP_NOSYNC));
+
+ /* if we need to flush/stall, see if we can make a shadow buffer
+ * to avoid this:
+ *
+ * TODO we could go down this path !reorder && !busy_for_read
+ * ie. we only *don't* want to go down this path if the blit
+ * will trigger a flush!
+ */
+ if (ctx->screen->reorder && (needs_flush || busy) &&
+ !(usage & PIPE_TRANSFER_READ)) {
+ if (fd_try_shadow_resource(ctx, rsc, level, usage, box)) {
+ needs_flush = busy = false;
+ fd_invalidate_resource(ctx, prsc);
+ }
+ }
+
+ if (needs_flush)
fd_batch_flush(rsc->pending_batch);
/* The GPU keeps track of how the various bo's are being used, and
* will wait if necessary for the proper operation to have
* completed.
*/
- ret = fd_bo_cpu_prep(rsc->bo, ctx->screen->pipe, op);
- if (ret)
- goto fail;
+ if (busy) {
+ ret = fd_bo_cpu_prep(rsc->bo, ctx->screen->pipe, op);
+ if (ret)
+ goto fail;
+ }
}
buf = fd_bo_map(rsc->bo);
@@ -685,9 +878,6 @@ fail:
return NULL;
}
-static void fd_blitter_pipe_begin(struct fd_context *ctx, bool render_cond);
-static void fd_blitter_pipe_end(struct fd_context *ctx);
-
/**
* _copy_region using pipe (3d engine)
*/
diff --git a/src/gallium/drivers/freedreno/freedreno_util.h b/src/gallium/drivers/freedreno/freedreno_util.h
index 5cb958e..61b3c93 100644
--- a/src/gallium/drivers/freedreno/freedreno_util.h
+++ b/src/gallium/drivers/freedreno/freedreno_util.h
@@ -331,4 +331,10 @@ pack_rgba(enum pipe_format format, const float *rgba)
return uc.ui[0];
}
+/*
+ * swap - swap value of @a and @b
+ */
+#define swap(a, b) \
+ do { __typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
+
#endif /* FREEDRENO_UTIL_H_ */
--
2.7.4
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