2 files changed, 74 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/include/nvgpu/dma.h b/drivers/gpu/nvgpu/include/nvgpu/dma.h
index 43cff215..1c6474e7 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/dma.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/dma.h
@@ -197,6 +197,11 @@ void nvgpu_dma_free(struct gk20a *g, struct nvgpu_mem *mem);
  * Note this is different than mapping it into the CPU. This memory can be
  * either placed in VIDMEM or SYSMEM, which ever is more convenient for the
  * driver.
+ *
+ * Note: currently a bug exists in the nvgpu_dma_alloc_map*() routines: you
+ * cannot use nvgpu_gmmu_map() on said buffer - it will overwrite the necessary
+ * information for the DMA unmap routines to actually unmap the buffer. You
+ * will either leak mappings or see GMMU faults.
  */
 int nvgpu_dma_alloc_map(struct vm_gk20a *vm, size_t size,
                 struct nvgpu_mem *mem);
diff --git a/drivers/gpu/nvgpu/include/nvgpu/gmmu.h b/drivers/gpu/nvgpu/include/nvgpu/gmmu.h
new file mode 100644
index 00000000..7fb0147e
--- /dev/null
+++ b/drivers/gpu/nvgpu/include/nvgpu/gmmu.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2017, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __NVGPU_GMMU_H__
+#define __NVGPU_GMMU_H__
+
+#include <nvgpu/types.h>
+
+/*
+ * This is the GMMU API visible to blocks outside of the GMMU. Basically this
+ * API supports all the different types of mappings that might be done in the
+ * GMMU.
+ */
+
+struct vm_gk20a;
+struct nvgpu_mem;
+
+enum nvgpu_aperture;
+
+/**
+ * nvgpu_gmmu_map - Map memory into the GMMU.
+ *
+ * Kernel space.
+ */
+u64 nvgpu_gmmu_map(struct vm_gk20a *vm,
+                   struct nvgpu_mem *mem,
+                   u64 size,
+                   u32 flags,
+                   int rw_flag,
+                   bool priv,
+                   enum nvgpu_aperture aperture);
+
+/**
+ * nvgpu_gmmu_map_fixed - Map memory into the GMMU.
+ *
+ * Kernel space.
+ */
+u64 nvgpu_gmmu_map_fixed(struct vm_gk20a *vm,
+                         struct nvgpu_mem *mem,
+                         u64 addr,
+                         u64 size,
+                         u32 flags,
+                         int rw_flag,
+                         bool priv,
+                         enum nvgpu_aperture aperture);
+
+/**
+ * nvgpu_gmmu_unmap - Unmap a buffer.
+ *
+ * Kernel space.
+ */
+void nvgpu_gmmu_unmap(struct vm_gk20a *vm,
+                      struct nvgpu_mem *mem,
+                      u64 gpu_va);
+
+#endif