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, 3 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.h b/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
index 7bbaf283..7be4383b 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
@@ -688,4 +688,7 @@ static inline void nvgpu_free(void *p)
                 vfree(p);
 }
 
+int gk20a_mm_get_buffer_info(struct device *dev, int dmabuf_fd,
+                             u64 *buffer_id, u64 *buffer_len);
+
 #endif /* MM_GK20A_H */