1 files changed, 24 insertions, 14 deletions

diff --git a/drivers/gpu/nvgpu/include/nvgpu/nvgpu_mem.h b/drivers/gpu/nvgpu/include/nvgpu/nvgpu_mem.h
index 2b8b7015..04e947e0 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/nvgpu_mem.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/nvgpu_mem.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2017-2018, NVIDIA CORPORATION.  All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -54,12 +54,19 @@ enum nvgpu_aperture {
         APERTURE_VIDMEM
 };
 
+/*
+ * Forward declared opaque placeholder type that does not really exist, but
+ * helps the compiler help us about getting types right. In reality,
+ * implementors of nvgpu_sgt_ops will have some concrete type in place of this.
+ */
+struct nvgpu_sgl;
+
 struct nvgpu_sgt_ops {
-        void *(*sgl_next)(void *sgl);
-        u64   (*sgl_phys)(void *sgl);
-        u64   (*sgl_dma)(void *sgl);
-        u64   (*sgl_length)(void *sgl);
-        u64   (*sgl_gpu_addr)(struct gk20a *g, void *sgl,
+        struct nvgpu_sgl *(*sgl_next)(struct nvgpu_sgl *sgl);
+        u64   (*sgl_phys)(struct nvgpu_sgl *sgl);
+        u64   (*sgl_dma)(struct nvgpu_sgl *sgl);
+        u64   (*sgl_length)(struct nvgpu_sgl *sgl);
+        u64   (*sgl_gpu_addr)(struct gk20a *g, struct nvgpu_sgl *sgl,
                               struct nvgpu_gmmu_attrs *attrs);
         /*
          * If left NULL then iommuable is assumed to be false.
@@ -85,15 +92,16 @@ struct nvgpu_sgt {
         /*
          * The first node in the scatter gather list.
          */
-        void *sgl;
+        struct nvgpu_sgl *sgl;
 };
 
 /*
  * This struct holds the necessary information for describing a struct
  * nvgpu_mem's scatter gather list.
  *
- * Not all nvgpu_sgt's use this particular implementation. Nor is a given OS
- * required to use this at all.
+ * This is one underlying implementation for nvgpu_sgl. Not all nvgpu_sgt's use
+ * this particular implementation. Nor is a given OS required to use this at
+ * all.
  */
 struct nvgpu_mem_sgl {
         /*
@@ -233,11 +241,13 @@ struct nvgpu_sgt *nvgpu_sgt_create(struct gk20a *g);
 struct nvgpu_sgt *nvgpu_sgt_create_from_mem(struct gk20a *g,
                                             struct nvgpu_mem *mem);
 
-void *nvgpu_sgt_get_next(struct nvgpu_sgt *sgt, void *sgl);
-u64 nvgpu_sgt_get_phys(struct nvgpu_sgt *sgt, void *sgl);
-u64 nvgpu_sgt_get_dma(struct nvgpu_sgt *sgt, void *sgl);
-u64 nvgpu_sgt_get_length(struct nvgpu_sgt *sgt, void *sgl);
-u64 nvgpu_sgt_get_gpu_addr(struct gk20a *g, struct nvgpu_sgt *sgt, void *sgl,
+struct nvgpu_sgl *nvgpu_sgt_get_next(struct nvgpu_sgt *sgt,
+                                          struct nvgpu_sgl *sgl);
+u64 nvgpu_sgt_get_phys(struct nvgpu_sgt *sgt, struct nvgpu_sgl *sgl);
+u64 nvgpu_sgt_get_dma(struct nvgpu_sgt *sgt, struct nvgpu_sgl *sgl);
+u64 nvgpu_sgt_get_length(struct nvgpu_sgt *sgt, struct nvgpu_sgl *sgl);
+u64 nvgpu_sgt_get_gpu_addr(struct gk20a *g, struct nvgpu_sgt *sgt,
+                           struct nvgpu_sgl *sgl,
                            struct nvgpu_gmmu_attrs *attrs);
 void nvgpu_sgt_free(struct gk20a *g, struct nvgpu_sgt *sgt);