freedreno: shadow textures if possible to avoid stall/flush

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 <[email protected]>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/gallium/drivers/freedreno/freedreno_util.h b/src/gallium/drivers/freedreno/freedreno_util.h
index ea08e31c465..6321cd7b4cd 100644
--- a/src/gallium/drivers/freedreno/freedreno_util.h
+++ b/src/gallium/drivers/freedreno/freedreno_util.h
@@ -332,4 +332,10 @@ 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_ */