gpu: nvgpu: SGL passthrough implementation

The basic nvgpu_mem_sgl implementation provides support
for OS specific scatter-gather list implementations by
simply copying them node by node. This is inefficient,
taking extra time and memory.

This patch implements an nvgpu_mem_sgt struct to act as
a header which is inserted at the front of any scatter-
gather list implementation. This labels every struct
with a set of ops which can be used to interact with
the attached scatter gather list.

Since nvgpu common code only has to interact with these
function pointers, any sgl implementation can be used.
Initialization only requires the allocation of a single
struct, removing the need to copy or iterate through the
sgl being converted.

Jira NVGPU-186

Change-Id: I2994f804a4a4cc141b702e987e9081d8560ba2e8
Signed-off-by: Sunny He <suhe@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1541426
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

2 files changed, 12 insertions, 11 deletions

diff --git a/drivers/gpu/nvgpu/vgpu/gp10b/vgpu_mm_gp10b.c b/drivers/gpu/nvgpu/vgpu/gp10b/vgpu_mm_gp10b.c
index ee9b791a..d9324363 100644
--- a/drivers/gpu/nvgpu/vgpu/gp10b/vgpu_mm_gp10b.c
+++ b/drivers/gpu/nvgpu/vgpu/gp10b/vgpu_mm_gp10b.c
@@ -40,7 +40,7 @@ static inline int add_mem_desc(struct tegra_vgpu_mem_desc *mem_desc,
 
 static u64 vgpu_gp10b_locked_gmmu_map(struct vm_gk20a *vm,
                                 u64 map_offset,
-                                struct nvgpu_mem_sgl *sgl,
+                                struct nvgpu_sgt *sgt,
                                 u64 buffer_offset,
                                 u64 size,
                                 int pgsz_idx,
@@ -66,12 +66,13 @@ static u64 vgpu_gp10b_locked_gmmu_map(struct vm_gk20a *vm,
         void *handle = NULL;
         size_t oob_size;
         u8 prot;
+        void *sgl;
 
         gk20a_dbg_fn("");
 
         /* FIXME: add support for sparse mappings */
 
-        if (WARN_ON(!sgl) || WARN_ON(!g->mm.bypass_smmu))
+        if (WARN_ON(!sgt) || WARN_ON(!g->mm.bypass_smmu))
                 return 0;
 
         if (space_to_skip & (page_size - 1))
@@ -97,7 +98,7 @@ static u64 vgpu_gp10b_locked_gmmu_map(struct vm_gk20a *vm,
                 err = -EINVAL;
                 goto fail;
         }
-
+        sgl = sgt->sgl;
         while (sgl) {
                 u64 phys_addr;
                 u64 chunk_length;
@@ -106,15 +107,15 @@ static u64 vgpu_gp10b_locked_gmmu_map(struct vm_gk20a *vm,
                  * Cut out sgl ents for space_to_skip.
                  */
                 if (space_to_skip &&
-                    space_to_skip >= nvgpu_mem_sgl_length(sgl)) {
-                        space_to_skip -= nvgpu_mem_sgl_length(sgl);
-                        sgl = nvgpu_mem_sgl_next(sgl);
+                    space_to_skip >= nvgpu_sgt_get_length(sgt, sgl)) {
+                        space_to_skip -= nvgpu_sgt_get_length(sgt, sgl);
+                        sgl = nvgpu_sgt_get_next(sgt, sgl);
                         continue;
                 }
 
-                phys_addr = nvgpu_mem_sgl_phys(sgl) + space_to_skip;
+                phys_addr = nvgpu_sgt_get_phys(sgt, sgl) + space_to_skip;
                 chunk_length = min(size,
-                                   nvgpu_mem_sgl_length(sgl) - space_to_skip);
+                           nvgpu_sgt_get_length(sgt, sgl) - space_to_skip);
 
                 if (add_mem_desc(&mem_desc[mem_desc_count++], phys_addr,
                                  chunk_length, &oob_size)) {
@@ -124,7 +125,7 @@ static u64 vgpu_gp10b_locked_gmmu_map(struct vm_gk20a *vm,
 
                 space_to_skip = 0;
                 size -= chunk_length;
-                sgl   = nvgpu_mem_sgl_next(sgl);
+                sgl   = nvgpu_sgt_get_next(sgt, sgl);
 
                 if (size == 0)
                         break;
diff --git a/drivers/gpu/nvgpu/vgpu/mm_vgpu.c b/drivers/gpu/nvgpu/vgpu/mm_vgpu.c
index 5da6f158..adb01ae5 100644
--- a/drivers/gpu/nvgpu/vgpu/mm_vgpu.c
+++ b/drivers/gpu/nvgpu/vgpu/mm_vgpu.c
@@ -78,7 +78,7 @@ int vgpu_init_mm_support(struct gk20a *g)
 
 static u64 vgpu_locked_gmmu_map(struct vm_gk20a *vm,
                                 u64 map_offset,
-                                struct nvgpu_mem_sgl *sgl,
+                                struct nvgpu_sgt *sgt,
                                 u64 buffer_offset,
                                 u64 size,
                                 int pgsz_idx,
@@ -98,7 +98,7 @@ static u64 vgpu_locked_gmmu_map(struct vm_gk20a *vm,
         struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(d);
         struct tegra_vgpu_cmd_msg msg;
         struct tegra_vgpu_as_map_params *p = &msg.params.as_map;
-        u64 addr = nvgpu_mem_sgl_gpu_addr(g, sgl, NULL);
+        u64 addr = nvgpu_sgt_get_gpu_addr(sgt, g, sgt->sgl, NULL);
         u8 prot;
 
         gk20a_dbg_fn("");