gpu: nvgpu: Split vm_area management into vm code

The vm_reserve_va_node struct is essentially a special VM area that
can be used for sparse mappings and fixed mappings. The name of this
struct is somewhat confusing (as node is typically used for list
items). Though this struct is a part of a list it doesn't really
make sense to call this a list item since it's much more. Based on
that the struct has been renamed to nvgpu_vm_area to capture the
actual use of the struct more accurately.

This also moves all of the management code of vm areas to a new file
devoted solely to vm_area management.

Also add a brief overview of the VM architecture. This should help
other people follow along the hierachy of ownership and lifetimes in
the rather complex MM code.

JIRA NVGPU-12
JIRA NVGPU-30

Change-Id: If85e1cf868031d0dc265e7bed50b58a2aed2602e
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: http://git-master/r/1477744
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 63 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/include/nvgpu/vm_area.h b/drivers/gpu/nvgpu/include/nvgpu/vm_area.h
new file mode 100644
index 00000000..ffe4b99b
--- /dev/null
+++ b/drivers/gpu/nvgpu/include/nvgpu/vm_area.h
@@ -0,0 +1,63 @@
+/*
+ * 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_VM_AREA_H__
+#define __NVGPU_VM_AREA_H__
+
+#include <nvgpu/list.h>
+#include <nvgpu/types.h>
+
+struct vm_gk20a;
+struct gk20a_as_share;
+struct nvgpu_as_alloc_space_args;
+struct nvgpu_as_free_space_args;
+
+struct nvgpu_vm_area {
+        /*
+         * Entry into the list of VM areas owned by a VM.
+         */
+        struct nvgpu_list_node vm_area_list;
+
+        /*
+         * List of buffers mapped into this vm_area.
+         */
+        struct nvgpu_list_node buffer_list_head;
+
+        u32 flags;
+        u32 pgsz_idx;
+        u64 addr;
+        u64 size;
+        bool sparse;
+};
+
+static inline struct nvgpu_vm_area *
+nvgpu_vm_area_from_vm_area_list(struct nvgpu_list_node *node)
+{
+        return (struct nvgpu_vm_area *)
+                ((uintptr_t)node - offsetof(struct nvgpu_vm_area,
+                                            vm_area_list));
+};
+
+int nvgpu_vm_area_alloc(struct vm_gk20a *vm, u32 pages, u32 page_size,
+                        u64 *addr, u32 flags);
+int nvgpu_vm_area_free(struct vm_gk20a *vm, u64 addr);
+
+struct nvgpu_vm_area *nvgpu_vm_area_find(struct vm_gk20a *vm, u64 addr);
+int nvgpu_vm_area_validate_buffer(struct vm_gk20a *vm,
+                                  u64 map_offset, u64 map_size, int pgsz_idx,
+                                  struct nvgpu_vm_area **pvm_area);
+
+#endif