Add samsung specific changes

include/linux/mem-buf-altmap.h

@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ *  Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef _MEM_BUF_ALTMAP_H
+#define _MEM_BUF_ALTMAP_H
+
+
+#include <linux/dma-buf.h>
+#include <uapi/linux/mem-buf.h>
+#include <linux/gunyah/gh_rm_drv.h>
+#include "../../drivers/dma-buf/heaps/qcom_sg_ops.h"
+
+extern struct gen_pool *dmabuf_mem_pool;
+
+/*
+ * mem_buf_dmabuf_obj
+ * A dmabuf object representing memory shared/lent by another Virtual machine
+ * and obtained via mem_buf_retrieve().
+ * @buffer: data type expected by qcom_sg_buf_ops
+ * @pgmap: Arguments to memremap_pages
+ * @memmap: alternate memmap for the dmabuf if present
+ * @memmap_base: base ipa address of alternate memmap memory
+ * @memmap_size: ipa size of alternate memmap memory
+ */
+struct mem_buf_dmabuf_obj {
+	struct qcom_sg_buffer buffer;
+	struct dev_pagemap pgmap;
+	void *memmap;
+	unsigned long memmap_base;
+	size_t memmap_size;
+};
+
+int prepare_altmap(struct mem_buf_dmabuf_obj *obj,
+		struct gh_sgl_desc **__sgl_desc, size_t dmabuf_size);
+
+size_t determine_memmap_size(size_t dmabuf_size);
+
+#endif /* _MEM_BUF_ALTMAP_H */