drm/amdgpu: Add input fence to sync bo map/unmap

This patch adds input fences to VM_IOCTL for buffer object.
The kernel will map/unmap the BO only when the fence is signaled.
The UAPI for the same has been approved here:
https://gitlab.freedesktop.org/mesa/drm/-/merge_requests/392

V2: Bug fix (Arvind)
V3: Bug fix (Arvind)
V4: Rename UAPI objects as per UAPI review (Marek)
V5: Addressed review comemnts from Christian
     - function should return error.
     - Add 'TODO' comment
     - The input fence should be independent of the operation.
V6: Addressed review comemnts from Christian
    - Release the memory allocated by memdup_user().
V7: Addressed review comemnts from Christian
    - Drop the debug print and add "return r;" for the error handling.

V11: Rebase
v12: Fix 32-bit holes issue in sturct drm_amdgpu_gem_va.
v13: Fix deadlock issue.
v14: Fix merge conflict.
v15: Fix review comment by renaming syncobj handles.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian Koenig <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Arvind Yadav <arvind.yadav@amd.com>
Signed-off-by: Shashank Sharma <shashank.sharma@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index 542a1b70f2ee..bdf46cb4327f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -46,6 +46,45 @@
 #include "amdgpu_vm.h"
 
 static int
+amdgpu_gem_add_input_fence(struct drm_file *filp,
+			   uint64_t syncobj_handles_array,
+			   uint32_t num_syncobj_handles)
+{
+	struct dma_fence *fence;
+	uint32_t *syncobj_handles;
+	int ret, i;
+
+	if (!num_syncobj_handles)
+		return 0;
+
+	syncobj_handles = memdup_user(u64_to_user_ptr(syncobj_handles_array),
+				      sizeof(uint32_t) * num_syncobj_handles);
+	if (IS_ERR(syncobj_handles))
+		return PTR_ERR(syncobj_handles);
+
+	for (i = 0; i < num_syncobj_handles; i++) {
+
+		if (!syncobj_handles[i]) {
+			ret = -EINVAL;
+			goto free_memdup;
+		}
+
+		ret = drm_syncobj_find_fence(filp, syncobj_handles[i], 0, 0, &fence);
+		if (ret)
+			goto free_memdup;
+
+		dma_fence_wait(fence, false);
+
+		/* TODO: optimize async handling */
+		dma_fence_put(fence);
+	}
+
+free_memdup:
+	kfree(syncobj_handles);
+	return ret;
+}
+
+static int
 amdgpu_gem_update_timeline_node(struct drm_file *filp,
 				uint32_t syncobj_handle,
 				uint64_t point,
@@ -854,6 +893,12 @@ int amdgpu_gem_va_ioctl(struct drm_device *dev, void *data,
 		abo = NULL;
 	}
 
+	r = amdgpu_gem_add_input_fence(filp,
+				       args->input_fence_syncobj_handles,
+				       args->num_syncobj_handles);
+	if (r)
+		goto error_put_gobj;
+
 	drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT |
 		      DRM_EXEC_IGNORE_DUPLICATES, 0);
 	drm_exec_until_all_locked(&exec) {
@@ -928,6 +973,7 @@ int amdgpu_gem_va_ioctl(struct drm_device *dev, void *data,
 
 error:
 	drm_exec_fini(&exec);
+error_put_gobj:
 	drm_gem_object_put(gobj);
 	return r;
 }