gpu: nvgpu: Implement NVGPU_GPU_IOCTL_GET_BUFFER_INFO

Implement NVGPU_GPU_IOCTL_GET_BUFFER_INFO. The new IOCTL can be used
to identify buffers and retrieve their sizes. This allows the
userspace to be agnostic to the dmabuf implementation, as the generic
dmabuf fd interface does not have a reliable way for buffer
identification.

Bug 1614735
Bug 1623949
Bug 1660392

Change-Id: Ic3dd0a9385c9852778110ccb80636dd6f4f36208
Signed-off-by: Sami Kiminki <skiminki@nvidia.com>
Reviewed-on: http://git-master/r/822845
Reviewed-on: http://git-master/r/833252
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c b/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c
index 3b5ca298..0b6b5913 100644
--- a/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c
@@ -514,6 +514,13 @@ static int gk20a_ctrl_vsm_mapping(struct gk20a *g,
         return err;
 }
 
+static int gk20a_ctrl_get_buffer_info(
+        struct gk20a *g, struct nvgpu_gpu_get_buffer_info_args *args)
+{
+        return gk20a_mm_get_buffer_info(dev_from_gk20a(g), args->in.dmabuf_fd,
+                                        &args->out.id, &args->out.length);
+}
+
 long gk20a_ctrl_dev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
         struct platform_device *dev = filp->private_data;
@@ -729,6 +736,10 @@ long gk20a_ctrl_dev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg
                         (struct nvgpu_gpu_vsms_mapping *)buf);
                 break;
 
+        case NVGPU_GPU_IOCTL_GET_BUFFER_INFO:
+                err = gk20a_ctrl_get_buffer_info(g,
+                        (struct nvgpu_gpu_get_buffer_info_args *)buf);
+                break;
 
         default:
                 dev_dbg(dev_from_gk20a(g), "unrecognized gpu ioctl cmd: 0x%x", cmd);