5 files changed, 18 insertions, 3 deletions

diff --git a/drivers/gpu/nvgpu/common/mm/mm.c b/drivers/gpu/nvgpu/common/mm/mm.c
index 0608d66a..2e46e211 100644
--- a/drivers/gpu/nvgpu/common/mm/mm.c
+++ b/drivers/gpu/nvgpu/common/mm/mm.c
@@ -202,13 +202,21 @@ static int nvgpu_init_system_vm(struct mm_gk20a *mm)
         struct gk20a *g = gk20a_from_mm(mm);
         struct nvgpu_mem *inst_block = &mm->pmu.inst_block;
         u32 big_page_size = g->ops.mm.get_default_big_page_size();
-        u32 low_hole, aperture_size;
+        u64 low_hole, aperture_size;
+
+        /*
+         * For some reason the maxwell PMU code is dependent on the large page
+         * size. No reason AFAICT for this. Probably a bug somewhere.
+         */
+        if (nvgpu_is_enabled(g, NVGPU_MM_FORCE_128K_PMU_VM)) {
+                big_page_size = SZ_128K;
+        }
 
         /*
          * No user region - so we will pass that as zero sized.
          */
-        low_hole = SZ_4K * 16;
-        aperture_size = GK20A_PMU_VA_SIZE * 2;
+        low_hole = SZ_4K * 16UL;
+        aperture_size = GK20A_PMU_VA_SIZE;
 
         mm->pmu.aperture_size = GK20A_PMU_VA_SIZE;
         nvgpu_log_info(g, "pmu vm size = 0x%x", mm->pmu.aperture_size);
diff --git a/drivers/gpu/nvgpu/include/nvgpu/enabled.h b/drivers/gpu/nvgpu/include/nvgpu/enabled.h
index c0fb9218..a0b738e0 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/enabled.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/enabled.h
@@ -81,6 +81,8 @@ struct gk20a;
 #define NVGPU_USE_COHERENT_SYSMEM               26
 /* Use physical scatter tables instead of IOMMU */
 #define NVGPU_MM_USE_PHYSICAL_SG                27
+/* WAR for gm20b chips. */
+#define NVGPU_MM_FORCE_128K_PMU_VM              28
 
 /*
  * Host flags
diff --git a/drivers/gpu/nvgpu/os/linux/driver_common.c b/drivers/gpu/nvgpu/os/linux/driver_common.c
index c651e394..f1eccd06 100644
--- a/drivers/gpu/nvgpu/os/linux/driver_common.c
+++ b/drivers/gpu/nvgpu/os/linux/driver_common.c
@@ -215,6 +215,8 @@ static void nvgpu_init_mm_vars(struct gk20a *g)
                             platform->unified_memory);
         __nvgpu_set_enabled(g, NVGPU_MM_UNIFY_ADDRESS_SPACES,
                             platform->unify_address_spaces);
+        __nvgpu_set_enabled(g, NVGPU_MM_FORCE_128K_PMU_VM,
+                            platform->force_128K_pmu_vm);
 
         nvgpu_mutex_init(&g->mm.tlb_lock);
         nvgpu_mutex_init(&g->mm.priv_lock);
diff --git a/drivers/gpu/nvgpu/os/linux/platform_gk20a.h b/drivers/gpu/nvgpu/os/linux/platform_gk20a.h
index a4c3eca3..f3e80b8c 100644
--- a/drivers/gpu/nvgpu/os/linux/platform_gk20a.h
+++ b/drivers/gpu/nvgpu/os/linux/platform_gk20a.h
@@ -244,6 +244,8 @@ struct gk20a_platform {
         bool honors_aperture;
         /* unified or split memory with separate vidmem? */
         bool unified_memory;
+        /* WAR for gm20b chips. */
+        bool force_128K_pmu_vm;
 
         /*
          * DMA mask for Linux (both coh and non-coh). If not set defaults to
diff --git a/drivers/gpu/nvgpu/os/linux/platform_gk20a_tegra.c b/drivers/gpu/nvgpu/os/linux/platform_gk20a_tegra.c
index 432af108..033563dc 100644
--- a/drivers/gpu/nvgpu/os/linux/platform_gk20a_tegra.c
+++ b/drivers/gpu/nvgpu/os/linux/platform_gk20a_tegra.c
@@ -952,6 +952,7 @@ struct gk20a_platform gm20b_tegra_platform = {
 
         .unified_memory = true,
         .dma_mask = DMA_BIT_MASK(34),
+        .force_128K_pmu_vm = true,
 
         .secure_buffer_size = 335872,
 };