gpu: nvgpu: Enable IO coherency on GV100

This reverts commit 848af2ce6de6140323a6ffe3075bf8021e119434.

This is a revert of a revert, etc, etc. It re-enables IO coherence again.

JIRA EVLR-2333

Change-Id: Ibf97dce2f892e48a1200a06cd38a1c5d9603be04
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1669722
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/common/mm/nvgpu_mem.c b/drivers/gpu/nvgpu/common/mm/nvgpu_mem.c
index f7c51f42..2b32d869 100644
--- a/drivers/gpu/nvgpu/common/mm/nvgpu_mem.c
+++ b/drivers/gpu/nvgpu/common/mm/nvgpu_mem.c
@@ -28,6 +28,53 @@
 
 #include "gk20a/gk20a.h"
 
+/*
+ * Make sure to use the right coherency aperture if you use this function! This
+ * will not add any checks. If you want to simply use the default coherency then
+ * use nvgpu_aperture_mask().
+ */
+u32 __nvgpu_aperture_mask(struct gk20a *g, enum nvgpu_aperture aperture,
+                          u32 sysmem_mask, u32 sysmem_coh_mask, u32 vidmem_mask)
+{
+        /*
+         * Some iGPUs treat sysmem (i.e SoC DRAM) as vidmem. In these cases the
+         * "sysmem" aperture should really be translated to VIDMEM.
+         */
+        if (!nvgpu_is_enabled(g, NVGPU_MM_HONORS_APERTURE))
+                aperture = APERTURE_VIDMEM;
+
+        switch (aperture) {
+        case __APERTURE_SYSMEM_COH:
+                return sysmem_coh_mask;
+        case APERTURE_SYSMEM:
+                return sysmem_mask;
+        case APERTURE_VIDMEM:
+                return vidmem_mask;
+        case APERTURE_INVALID:
+                WARN_ON("Bad aperture");
+        }
+        return 0;
+}
+
+u32 nvgpu_aperture_mask(struct gk20a *g, struct nvgpu_mem *mem,
+                        u32 sysmem_mask, u32 sysmem_coh_mask, u32 vidmem_mask)
+{
+        enum nvgpu_aperture ap = mem->aperture;
+
+        /*
+         * Handle the coherent aperture: ideally most of the driver is not
+         * aware of the difference between coherent and non-coherent sysmem so
+         * we add this translation step here.
+         */
+        if (nvgpu_is_enabled(g, NVGPU_USE_COHERENT_SYSMEM) &&
+            ap == APERTURE_SYSMEM)
+                ap = __APERTURE_SYSMEM_COH;
+
+        return __nvgpu_aperture_mask(g, ap,
+                                     sysmem_mask, sysmem_coh_mask, vidmem_mask);
+}
+
+
 struct nvgpu_sgl *nvgpu_sgt_get_next(struct nvgpu_sgt *sgt,
                                      struct nvgpu_sgl *sgl)
 {