asahi: Add synctvb debug flag

This requests synchronous TVB growth (instead of split renders). Mostly
for testing at this point.

Only works with newer kernels and the kernel will complain on dmesg for
now.

Signed-off-by: Asahi Lina <lina@asahilina.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24258>

src/asahi/lib/agx_device.h

@@ -26,6 +26,7 @@ enum agx_dbg {
    AGX_DBG_RESOURCE = BITFIELD_BIT(10),
    AGX_DBG_BATCH = BITFIELD_BIT(11),
    AGX_DBG_NOWC = BITFIELD_BIT(12),
+   AGX_DBG_SYNCTVB = BITFIELD_BIT(13),
 };
 
 /* Dummy partial declarations, pending real UAPI */

src/gallium/drivers/asahi/agx_pipe.c

@@ -64,6 +64,7 @@ static const struct debug_named_value agx_debug_options[] = {
    {"resource",  AGX_DBG_RESOURCE, "Log resource operations"},
    {"batch",     AGX_DBG_BATCH,    "Log batches"},
    {"nowc",      AGX_DBG_NOWC,     "Disable write-combining"},
+   {"synctvb",   AGX_DBG_SYNCTVB,  "Synchronous TVB growth"},
    DEBUG_NAMED_VALUE_END
 };
 /* clang-format on */