drm/vc4: Syncobj import support

Allow userland to specify a syncobj that is waited on before a render job
starts processing.

v2: Use 0 as invalid syncobj to drop flag (Eric)
    Drop extra newline (Eric)

Signed-off-by: Stefan Schake <stschake@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/1524607427-12876-2-git-send-email-stschake@gmail.com

1 files changed, 25 insertions, 5 deletions

diff --git a/drivers/gpu/drm/vc4/vc4_gem.c b/drivers/gpu/drm/vc4/vc4_gem.c
index 2107b0daf8ef..e305ccdedf47 100644
--- a/drivers/gpu/drm/vc4/vc4_gem.c
+++ b/drivers/gpu/drm/vc4/vc4_gem.c
@@ -27,6 +27,7 @@
 #include <linux/device.h>
 #include <linux/io.h>
 #include <linux/sched/signal.h>
+#include <linux/dma-fence-array.h>
 
 #include "uapi/drm/vc4_drm.h"
 #include "vc4_drv.h"
@@ -1115,6 +1116,7 @@ vc4_submit_cl_ioctl(struct drm_device *dev, void *data,
         struct drm_vc4_submit_cl *args = data;
         struct vc4_exec_info *exec;
         struct ww_acquire_ctx acquire_ctx;
+        struct dma_fence *in_fence;
         int ret = 0;
 
         if ((args->flags & ~(VC4_SUBMIT_CL_USE_CLEAR_COLOR |
@@ -1125,11 +1127,6 @@ vc4_submit_cl_ioctl(struct drm_device *dev, void *data,
                 return -EINVAL;
         }
 
-        if (args->pad2 != 0) {
-                DRM_DEBUG("->pad2 must be set to zero\n");
-                return -EINVAL;
-        }
-
         exec = kcalloc(1, sizeof(*exec), GFP_KERNEL);
         if (!exec) {
                 DRM_ERROR("malloc failure on exec struct\n");
@@ -1164,6 +1161,29 @@ vc4_submit_cl_ioctl(struct drm_device *dev, void *data,
                 }
         }
 
+        if (args->in_sync) {
+                ret = drm_syncobj_find_fence(file_priv, args->in_sync,
+                                             &in_fence);
+                if (ret)
+                        goto fail;
+
+                /* When the fence (or fence array) is exclusively from our
+                 * context we can skip the wait since jobs are executed in
+                 * order of their submission through this ioctl and this can
+                 * only have fences from a prior job.
+                 */
+                if (!dma_fence_match_context(in_fence,
+                                             vc4->dma_fence_context)) {
+                        ret = dma_fence_wait(in_fence, true);
+                        if (ret) {
+                                dma_fence_put(in_fence);
+                                goto fail;
+                        }
+                }
+
+                dma_fence_put(in_fence);
+        }
+
         if (exec->args->bin_cl_size != 0) {
                 ret = vc4_get_bcl(dev, exec);
                 if (ret)