gpu: nvgpu: ioctl for flushing GPU L2

CUDA devtools need to be able to flush the GPU's cache
in a sideband fashion and so cannot use methods. This
change implements an nvgpu_gpu_ioctl to flush and
optionally invalidate the GPU's L2 cache and flush fb.

Change-Id: Ib06a0bc8d8880ffbfe4b056518cc3c3df0cc4988
Signed-off-by: sujeet baranwal <sbaranwal@nvidia.com>
Signed-off-by: Mayank Kaushik <mkaushik@nvidia.com>
Reviewed-on: http://git-master/r/671809
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/include/uapi/linux/nvgpu.h b/include/uapi/linux/nvgpu.h
index ebeacf9b..3c53ba94 100644
--- a/include/uapi/linux/nvgpu.h
+++ b/include/uapi/linux/nvgpu.h
@@ -242,6 +242,14 @@ struct nvgpu_gpu_open_channel_args {
         __s32 channel_fd;
 };
 
+/* L2 cache writeback, optionally invalidate clean lines and flush fb */
+struct nvgpu_gpu_l2_fb_args {
+        __u32 l2_flush:1;
+        __u32 l2_invalidate:1;
+        __u32 fb_flush:1;
+        __u32 reserved;
+} __packed;
+
 #define NVGPU_GPU_IOCTL_ZCULL_GET_CTX_SIZE \
         _IOR(NVGPU_GPU_IOCTL_MAGIC, 1, struct nvgpu_gpu_zcull_get_ctx_size_args)
 #define NVGPU_GPU_IOCTL_ZCULL_GET_INFO \
@@ -264,13 +272,14 @@ struct nvgpu_gpu_open_channel_args {
         _IOWR(NVGPU_GPU_IOCTL_MAGIC, 10, struct nvgpu_gpu_get_tpc_masks_args)
 #define NVGPU_GPU_IOCTL_OPEN_CHANNEL \
         _IOWR(NVGPU_GPU_IOCTL_MAGIC, 11, struct nvgpu_gpu_open_channel_args)
+#define NVGPU_GPU_IOCTL_FLUSH_L2 \
+        _IOWR(NVGPU_DBG_GPU_IOCTL_MAGIC, 12, struct nvgpu_gpu_l2_fb_args)
 
 #define NVGPU_GPU_IOCTL_LAST            \
-        _IOC_NR(NVGPU_GPU_IOCTL_OPEN_CHANNEL)
+        _IOC_NR(NVGPU_GPU_IOCTL_FLUSH_L2)
 #define NVGPU_GPU_IOCTL_MAX_ARG_SIZE    \
         sizeof(struct nvgpu_gpu_prepare_compressible_read_args)
 
-
 /*
  * /dev/nvhost-tsg-gpu device
  *