1 files changed, 100 insertions, 0 deletions
diff --git a/src/include/region.h b/src/include/region.h
new file mode 100644
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+++ b/src/include/region.h
@@ -0,0 +1,100 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2015 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that 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, write to the Free Software
+ * Foundation, Inc.
+ */
+
+#ifndef _REGION_H_
+#define _REGION_H_
+
+#include <stdint.h>
+#include <stddef.h>
+
+/*
+ * Region support.
+ *
+ * Regions are intended to abstract away the access mechanisms for blocks of
+ * data. This could be SPI, eMMC, or a memory region as the backing store.
+ * They are accessed through a region_device.  Subregions can be made by
+ * chaining together multiple region_devices.
+ */
+
+struct region_device;
+
+/*
+ * Returns NULL on error otherwise a buffer is returned with the conents of
+ * the requested data at offset of size.
+ */
+void *rdev_mmap(const struct region_device *rd, size_t offset, size_t size);
+
+/* Unmap a previously mapped area. Returns 0 on success, < 0 on error. */
+int rdev_munmap(const struct region_device *rd, void *mapping);
+
+/*
+ * Returns < 0 on error otherwise returns size of data read at provided
+ * offset filling in the buffer passed.
+ */
+ssize_t rdev_readat(const struct region_device *rd, void *b, size_t offset,
+			size_t size);
+
+
+/****************************************
+ *  Implementation of a region device   *
+ ****************************************/
+
+/*
+ * Create a child region of the parent provided the sub-region is within
+ * the parent's region. Returns < 0 on error otherwise 0 on success. Note
+ * that the child device only calls through the parent's operations.
+ */
+int rdev_chain(struct region_device *child, const struct region_device *parent,
+		size_t offset, size_t size);
+
+
+/* A region_device operations. */
+struct region_device_ops {
+	void *(*mmap)(const struct region_device *, size_t, size_t);
+	int (*munmap)(const struct region_device *, void *);
+	ssize_t (*readat)(const struct region_device *, void *, size_t, size_t);
+};
+
+struct region {
+	size_t offset;
+	size_t size;
+};
+
+struct region_device {
+	const struct region_device *root;
+	const struct region_device_ops *ops;
+	struct region region;
+};
+
+#define REGION_DEV_INIT(ops_, offset_, size_)		\
+	{						\
+		.root = NULL,				\
+		.ops = (ops_),				\
+		.region = {				\
+			.offset = (offset_),		\
+			.size = (size_),		\
+		},					\
+	}
+
+static inline size_t region_sz(const struct region *r)
+{
+	return r->size;
+}
+
+#endif /* _REGION_H_ */