broadcom/vc4: Mark BOs as purgeable when they enter the BO cache

This patch makes use of the DRM_IOCTL_VC4_GEM_MADVISE ioctl to mark all
BOs placed in the mesa BO cache as purgeable so that the system can
reclaim this memory under memory pressure.

v2:
- Removed BOs from the cache when they've been purged by the kernel
- Check whether the madvise ioctl is supported or not before using it

v3: Don't walk the whole list when we find a busy BO (by anholt, acked by
    Boris)

Signed-off-by: Boris Brezillon <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/gallium/drivers/vc4/vc4_screen.h b/src/gallium/drivers/vc4/vc4_screen.h
index 85108219ee3..09d1c342ed1 100644
--- a/src/gallium/drivers/vc4/vc4_screen.h
+++ b/src/gallium/drivers/vc4/vc4_screen.h
@@ -95,6 +95,7 @@ struct vc4_screen {
         bool has_control_flow;
         bool has_etc1;
         bool has_threaded_fs;
+        bool has_madvise;
         bool has_tiling_ioctl;
 
         struct vc4_simulator_file *sim_file;