gpu: nvgpu: API to access fb memory

Add IOCTL API NVGPU_DBG_GPU_IOCTL_ACCESS_FB_MEMORY
to read/write fb/vidmem memory

Interface will accept dmabuf_fd of the buffer in vidmem,
offset into the buffer to access, temporary buffer
to copy data across API, size of read/write and
command indicating either read or write operation

API will first parse all the inputs, and then call
gk20a_vidbuf_access_memory() to complete fb access

gk20a_vidbuf_access_memory() will then just use
gk20a_mem_rd_n() or gk20a_mem_wr_n() depending
on the command issued

Bug 1804714
Jira DNVGPU-192

Change-Id: Iba3c42410abe12c2884d3b603fa33d27782e4c56
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/1255556
(cherry picked from commit 2c49a8a79d93fc526adbf6f808484fa9a3fa2498)
Reviewed-on: http://git-master/r/1260471
GVS: Gerrit_Virtual_Submit
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>

1 files changed, 19 insertions, 2 deletions

diff --git a/include/uapi/linux/nvgpu.h b/include/uapi/linux/nvgpu.h
index b1c602db..b4c7e829 100644
--- a/include/uapi/linux/nvgpu.h
+++ b/include/uapi/linux/nvgpu.h
@@ -917,11 +917,28 @@ struct nvgpu_dbg_gpu_suspend_resume_contexts_args {
         _IOWR(NVGPU_DBG_GPU_IOCTL_MAGIC, 18, struct nvgpu_dbg_gpu_suspend_resume_contexts_args)
 
 
+#define NVGPU_DBG_GPU_IOCTL_ACCESS_FB_MEMORY_CMD_READ   1
+#define NVGPU_DBG_GPU_IOCTL_ACCESS_FB_MEMORY_CMD_WRITE  2
+
+struct nvgpu_dbg_gpu_access_fb_memory_args {
+        __u32 cmd;       /* in: either read or write */
+
+        __s32 dmabuf_fd; /* in: dmabuf fd of the buffer in FB */
+        __u64 offset;    /* in: offset within buffer in FB, should be 4B aligned */
+
+        __u64 buffer;    /* in/out: temp buffer to read/write from */
+        __u64 size;      /* in: size of the buffer i.e. size of read/write in bytes, should be 4B aligned */
+};
+
+#define NVGPU_DBG_GPU_IOCTL_ACCESS_FB_MEMORY    \
+        _IOWR(NVGPU_DBG_GPU_IOCTL_MAGIC, 19, struct nvgpu_dbg_gpu_access_fb_memory_args)
+
+
 #define NVGPU_DBG_GPU_IOCTL_LAST                \
-        _IOC_NR(NVGPU_DBG_GPU_IOCTL_SUSPEND_RESUME_CONTEXTS)
+        _IOC_NR(NVGPU_DBG_GPU_IOCTL_ACCESS_FB_MEMORY)
 
 #define NVGPU_DBG_GPU_IOCTL_MAX_ARG_SIZE                \
-        sizeof(struct nvgpu_dbg_gpu_perfbuf_map_args)
+        sizeof(struct nvgpu_dbg_gpu_access_fb_memory_args)
 
 /*
  * /dev/nvhost-gpu device