gpu: nvgpu: SMMU bypass

Improve GMMU mapping code to cope with discontiguous buffers.

Add debugfs entry that allows bypassing SMMU and disabling big pages.

Bug 1605769

Change-Id: I14d32c62293a16ff8c7195377c75a85fa8061083
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/717503
Reviewed-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/737533
Reviewed-by: Alexander Van Brunt <avanbrunt@nvidia.com>
Tested-by: Alexander Van Brunt <avanbrunt@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User

1 files changed, 20 insertions, 3 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.c b/drivers/gpu/nvgpu/gk20a/gk20a.c
index f3a333f3..f6c9f901 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.c
@@ -1482,6 +1482,8 @@ static int gk20a_probe(struct platform_device *dev)
         spin_lock_init(&gk20a->debugfs_lock);
         gk20a->mm.ltc_enabled = true;
         gk20a->mm.ltc_enabled_debug = true;
+        gk20a->mm.bypass_smmu = platform->bypass_smmu;
+        gk20a->mm.disable_bigpage = platform->disable_bigpage;
         gk20a->debugfs_ltc_enabled =
                         debugfs_create_bool("ltc_enabled", S_IRUGO|S_IWUSR,
                                  platform->debugfs,
@@ -1496,6 +1498,16 @@ static int gk20a_probe(struct platform_device *dev)
                                         S_IRUGO|S_IWUSR,
                                         platform->debugfs,
                                         &gk20a->timeouts_enabled);
+        gk20a->debugfs_bypass_smmu =
+                        debugfs_create_bool("bypass_smmu",
+                                        S_IRUGO|S_IWUSR,
+                                        platform->debugfs,
+                                        &gk20a->mm.bypass_smmu);
+        gk20a->debugfs_disable_bigpage =
+                        debugfs_create_bool("disable_bigpage",
+                                        S_IRUGO|S_IWUSR,
+                                        platform->debugfs,
+                                        &gk20a->mm.disable_bigpage);
         gk20a_pmu_debugfs_init(dev);
         gk20a_cde_debugfs_init(dev);
 #endif
@@ -1929,9 +1941,14 @@ int gk20a_init_gpu_characteristics(struct gk20a *g)
         gpu->pde_coverage_bit_count =
                 gk20a_mm_pde_coverage_bit_count(&g->mm.pmu.vm);
 
-        gpu->available_big_page_sizes = gpu->big_page_size;
-        if (g->ops.mm.get_big_page_sizes)
-                gpu->available_big_page_sizes |= g->ops.mm.get_big_page_sizes();
+        if (g->mm.disable_bigpage) {
+                gpu->big_page_size = 0;
+                gpu->available_big_page_sizes = 0;
+        } else {
+                gpu->available_big_page_sizes = gpu->big_page_size;
+                if (g->ops.mm.get_big_page_sizes)
+                        gpu->available_big_page_sizes |= g->ops.mm.get_big_page_sizes();
+        }
 
         gpu->flags = NVGPU_GPU_FLAGS_SUPPORT_PARTIAL_MAPPINGS
                 | NVGPU_GPU_FLAGS_SUPPORT_SYNC_FENCE_FDS;