diff --git a/drivers/gpu/nvgpu/common/mm/mm.c b/drivers/gpu/nvgpu/common/mm/mm.c
index 0608d66ab..2e46e211c 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 c0fb9218d..a0b738e0b 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 c651e3949..f1eccd06a 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 a4c3eca3a..f3e80b8c4 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 432af1084..033563dc5 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,
 };