gpu: nvgpu: Cleanup usage of bypass_smmu

The GPU has multiple different operating modes in respect to IOMMU'ability.
As such there needs to be a clean way to tell the driver whether it is
IOMMU'able or not. This state also does not always reflect what is possible:
all becasue the GPU can generate IOMMU'ed memory requests doesn't mean it
wants to.

The nvgpu_iommuable() API has now existed for a little while which is a
useful way to convey whether nvgpu should consider the GPU as IOMMU'able.
However, there is also the g->mm.bypass_smmu flag which used to be able to
override what the GPU decided it should do. Typically it was assigned
the same value as nvgpu_iommuable() but that was not necessarily a
requirment.

This patch removes all the usages of g->mm.bypass_smmu and instead uses the
nvgpu_iommuable() function. All places where the check against
g->mm.bypass_smmu have been replaced with nvgpu_iommuable(). The code
should now be much cleaner.

Subsequently other checks can also be placed in the nvgpu_iommuable()
function. For example, when NVLINK comes online and the GPU should no
longer consider DMA addresses and instead use scatter-gather lists
directly the ngpu_iommuable() function will be able to check the state of
NVLINK and then act accordingly.

Change-Id: I0da6262386de15709decac89d63d3eecfec20cd7
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1648332
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/vgpu/gp10b/vgpu_mm_gp10b.c b/drivers/gpu/nvgpu/common/linux/vgpu/gp10b/vgpu_mm_gp10b.c
index 72214d3c..161a69e9 100644
--- a/drivers/gpu/nvgpu/common/linux/vgpu/gp10b/vgpu_mm_gp10b.c
+++ b/drivers/gpu/nvgpu/common/linux/vgpu/gp10b/vgpu_mm_gp10b.c
@@ -23,10 +23,10 @@
 #include "gk20a/mm_gk20a.h"
 
 #include <nvgpu/bug.h>
+#include <nvgpu/dma.h>
 
 int vgpu_gp10b_init_mm_setup_hw(struct gk20a *g)
 {
-        g->mm.bypass_smmu = true;
         g->mm.disable_bigpage = true;
         return 0;
 }
@@ -77,7 +77,7 @@ u64 vgpu_gp10b_locked_gmmu_map(struct vm_gk20a *vm,
 
         /* FIXME: add support for sparse mappings */
 
-        if (WARN_ON(!sgt) || WARN_ON(!g->mm.bypass_smmu))
+        if (WARN_ON(!sgt) || WARN_ON(nvgpu_iommuable(g)))
                 return 0;
 
         if (space_to_skip & (page_size - 1))