drm: implement video fence ioctl [1/3]

PD#SWPL-124599

Problem:
Unable to obtain video fence.

Solution:
implement video fence ioctl.

Verify:
t3x

Test:
DRM-OSD-65

Change-Id: Idf779bbccc05b08786ffbeebe27cd10aa80be682
Signed-off-by: chen.wang1 <chen.wang1@amlogic.com>

android/common14-5.15_abi_gki_aarch64_amlogic

@@ -1,3 +1,4 @@
   spi_finalize_current_message
   strim
   bpf_trace_run8
+  dma_fence_get_stub

drivers/drm/meson_drv.c

@@ -40,7 +40,7 @@
 #include "meson_sysfs.h"
 #include "meson_writeback.h"
 #include "meson_logo.h"
-
+#include "meson_plane.h"
 #include <linux/amlogic/media/osd/osd_logo.h>
 #include <linux/amlogic/media/vout/vout_notify.h>
 #include <linux/amlogic/cpu_version.h>
@@ -90,6 +90,10 @@ static const struct drm_ioctl_desc meson_ioctls[] = {
 	#endif
 	DRM_IOCTL_DEF_DRV(MESON_ASYNC_ATOMIC, meson_async_atomic_ioctl,
 			  DRM_UNLOCKED | DRM_AUTH | DRM_RENDER_ALLOW),
+	#if IS_ENABLED(CONFIG_SYNC_FILE)
+	DRM_IOCTL_DEF_DRV(MESON_DMABUF_EXPORT_SYNC_FILE, am_meson_dmabuf_export_sync_file_ioctl,
+			  DRM_MASTER),
+	#endif
 };
 
 DEFINE_DRM_GEM_FOPS(meson_drm_fops);

drivers/drm/meson_plane.c

@@ -4,9 +4,15 @@
  */
 
 #include <linux/types.h>
+#include <linux/sync_file.h>
+#include <linux/dma-fence.h>
+#include <linux/dma-buf.h>
+#include <uapi/linux/dma-buf.h>
+#include <uapi/linux/magic.h>
 #ifdef CONFIG_AMLOGIC_MEDIA_FB
 #include <linux/amlogic/media/osd/osd_logo.h>
 #endif
+
 #include "meson_plane.h"
 #include "meson_crtc.h"
 #include "meson_vpu.h"
@@ -125,6 +131,67 @@ static const u32 video_supported_drm_formats[] = {
 	DRM_FORMAT_VUY888,
 };
 
+#if IS_ENABLED(CONFIG_SYNC_FILE)
+int am_meson_dmabuf_export_sync_file_ioctl(struct drm_device *dev,
+	void *data, struct drm_file *file_priv)
+{
+	struct drm_meson_dma_buf_export_sync_file *arg = data;
+	struct dma_fence *fence = NULL;
+	struct dma_buf *dmabuf = NULL;
+	struct sync_file *sync_file;
+	int fd, ret;
+
+	DRM_DEBUG("dmabuf-%px fence-%px", dmabuf, fence);
+	if (arg->flags & ~DMA_BUF_SYNC_RW)
+		return -EINVAL;
+
+	if ((arg->flags & DMA_BUF_SYNC_RW) == 0)
+		return -EINVAL;
+
+	fd = get_unused_fd_flags(O_CLOEXEC);
+	if (fd < 0)
+		return fd;
+	if (arg->dmabuf_fd <= 0)
+		return -EINVAL;
+
+	dmabuf = dma_buf_get(arg->dmabuf_fd);
+	if (IS_ERR_OR_NULL(dmabuf))
+		return -EINVAL;
+
+	if (arg->flags & DMA_BUF_SYNC_WRITE) {
+		//fence = dma_resv_get_singleton_unlocked(dmabuf->resv);
+		//if (IS_ERR(fence)) {
+		//	ret = PTR_ERR(fence);
+		//	goto err_put_fd;
+		//}
+	} else if (arg->flags & DMA_BUF_SYNC_READ) {
+		fence = dma_resv_get_excl_unlocked(dmabuf->resv);
+	}
+	if (!fence)
+		fence = dma_fence_get_stub();
+
+	sync_file = sync_file_create(fence);
+
+	dma_fence_put(fence);
+	dma_buf_put(dmabuf);
+
+	if (!sync_file) {
+		ret = -ENOMEM;
+		goto err_put_fd;
+	}
+
+	fd_install(fd, sync_file->file);
+
+	arg->fd = fd;
+	DRM_DEBUG("dmabuf-%px fence-%px fd-%d", dmabuf, fence, fd);
+	return 0;
+
+err_put_fd:
+	put_unused_fd(fd);
+	return ret;
+}
+#endif
+
 static void
 meson_plane_position_calc(struct meson_vpu_osd_layer_info *plane_info,
 			  struct drm_plane_state *state,

drivers/drm/meson_plane.h

@@ -11,6 +11,7 @@
 #include <drm/drm_plane.h>
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
+#include <uapi/amlogic/drm/meson_drm.h>
 #include <linux/amlogic/media/vout/vout_notify.h>
 #include <linux/amlogic/meson_uvm_core.h>
 #include <drm/amlogic/meson_drm_plane.h>
@@ -109,4 +110,8 @@ meson_create_scaling_filter_prop(struct drm_device *dev,
 void meson_video_set_vfmmode(struct device_node *of_node,
 	struct meson_drm *priv);
 
+#if IS_ENABLED(CONFIG_SYNC_FILE)
+int am_meson_dmabuf_export_sync_file_ioctl(struct drm_device *dev,
+	void *data, struct drm_file *file_priv);
+#endif
 #endif

include/uapi/amlogic/drm/meson_drm.h

@@ -36,9 +36,46 @@ struct drm_meson_gem_create {
 	__u32 handle;
 };
 
+/**
+ * struct drm_meson_dma_buf_export_sync_file - Get a sync_file from a dma-buf
+ *
+ * Userspace can perform a DMA_BUF_IOCTL_EXPORT_SYNC_FILE to retrieve the
+ * current set of fences on a dma-buf file descriptor as a sync_file.  CPU
+ * waits via poll() or other driver-specific mechanisms typically wait on
+ * whatever fences are on the dma-buf at the time the wait begins.  This
+ * is similar except that it takes a snapshot of the current fences on the
+ * dma-buf for waiting later instead of waiting immediately.  This is
+ * useful for modern graphics APIs such as Vulkan which assume an explicit
+ * synchronization model but still need to inter-operate with dma-buf.
+ */
+struct drm_meson_dma_buf_export_sync_file {
+	/**
+	 * @flags: Read/write flags
+	 *
+	 * Must be DMA_BUF_SYNC_READ, DMA_BUF_SYNC_WRITE, or both.
+	 *
+	 * If DMA_BUF_SYNC_READ is set and DMA_BUF_SYNC_WRITE is not set,
+	 * the returned sync file waits on any writers of the dma-buf to
+	 * complete.  Waiting on the returned sync file is equivalent to
+	 * poll() with POLLIN.
+	 *
+	 * If DMA_BUF_SYNC_WRITE is set, the returned sync file waits on
+	 * any users of the dma-buf (read or write) to complete.  Waiting
+	 * on the returned sync file is equivalent to poll() with POLLOUT.
+	 * If both DMA_BUF_SYNC_WRITE and DMA_BUF_SYNC_READ are set, this
+	 * is equivalent to just DMA_BUF_SYNC_WRITE.
+	 */
+	__u32 flags;
+	__u32 dmabuf_fd;
+	/** @fd: Returned sync file descriptor */
+	__s32 fd;
+};
+
 /*Memory related.*/
 #define DRM_IOCTL_MESON_GEM_CREATE	DRM_IOWR(DRM_COMMAND_BASE + \
 		0x00, struct drm_meson_gem_create)
+#define DRM_IOCTL_MESON_DMABUF_EXPORT_SYNC_FILE	DRM_IOWR(DRM_COMMAND_BASE + \
+		0x02, struct drm_meson_dma_buf_export_sync_file)
 
 /*KMS related.*/
 #define DRM_IOCTL_MESON_ASYNC_ATOMIC    DRM_IOWR(DRM_COMMAND_BASE + \