panfrost: Add backend targeting the DRM driver

This backend interacts with the new DRM driver for Midgard GPUs which is
currently in development.

When using this backend, Panfrost has roughly on-par functionality as
when using the non-DRM driver from Arm.

Alyssa Rosenzweig: To do so, we implement additional routines for
runtime GPU version detection and fencing. We cleanup some duplicate
code interfering with the new driver. We fix a long-standing memory leak
which is aggravated on the new driver. Finally, we implement BO
import/export in a way compatible with the new driver. These changes are
squashed to preserve bisectability given the hard-to-track ABI shifts in
the nondrm module

Signed-off-by: Tomeu Vizoso <[email protected]>
Reviewed-by: Alyssa Rosenzweig <[email protected]>

1 files changed, 6 insertions, 5 deletions

diff --git a/src/gallium/drivers/panfrost/pan_screen.c b/src/gallium/drivers/panfrost/pan_screen.c
index b8a119fd343..b7f2e4bb2e9 100644
--- a/src/gallium/drivers/panfrost/pan_screen.c
+++ b/src/gallium/drivers/panfrost/pan_screen.c
@@ -500,21 +500,22 @@ panfrost_get_timestamp(struct pipe_screen *_screen)
 }
 
 static void
-panfrost_fence_reference(struct pipe_screen *screen,
+panfrost_fence_reference(struct pipe_screen *pscreen,
                          struct pipe_fence_handle **ptr,
                          struct pipe_fence_handle *fence)
 {
-        *ptr = fence;
+        struct panfrost_screen *screen = pan_screen(pscreen);
+        screen->driver->fence_reference(pscreen, ptr, fence);
 }
 
 static boolean
-panfrost_fence_finish(struct pipe_screen *screen,
+panfrost_fence_finish(struct pipe_screen *pscreen,
                       struct pipe_context *ctx,
                       struct pipe_fence_handle *fence,
                       uint64_t timeout)
 {
-        assert(fence);
-        return TRUE;
+        struct panfrost_screen *screen = pan_screen(pscreen);
+        return screen->driver->fence_finish(pscreen, ctx, fence, timeout);
 }
 
 static const void *