1 files changed, 71 insertions, 0 deletions
diff --git a/gcip-kernel-driver/include/gcip/gcip-mem-pool.h b/gcip-kernel-driver/include/gcip/gcip-mem-pool.h
new file mode 100644
index 0000000..c770300
--- /dev/null
+++ b/gcip-kernel-driver/include/gcip/gcip-mem-pool.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * A simple memory allocator to help allocating reserved memory pools.
+ *
+ * Copyright (C) 2022 Google LLC
+ */
+
+#ifndef __GCIP_MEM_POOL_H__
+#define __GCIP_MEM_POOL_H__
+
+#include <linux/device.h>
+#include <linux/genalloc.h>
+#include <linux/types.h>
+
+struct gcip_mem_pool {
+	struct device *dev;
+	struct gen_pool *gen_pool;
+	phys_addr_t base_paddr;
+	size_t granule;
+};
+
+/*
+ * Initializes the memory pool object.
+ *
+ * @pool: The memory pool object to be initialized.
+ * @dev: Used for logging only.
+ * @base_paddr: The base physical address of the pool. Must be greater than 0 and a multiple of
+ *              @granule.
+ * @size: The size of the pool. @size should be a multiple of @granule.
+ * @granule: The granule when invoking the allocator. Should be a power of 2.
+ *
+ * Returns 0 on success, a negative errno otherwise.
+ *
+ * Call gcip_mem_pool_exit() to release the resources of @pool.
+ */
+int gcip_mem_pool_init(struct gcip_mem_pool *pool, struct device *dev, phys_addr_t base_paddr,
+		       size_t size, size_t granule);
+/*
+ * Releases resources of @pool.
+ *
+ * Note: you must release (by calling gcip_mem_pool_free) all allocations before calling this
+ * function.
+ */
+void gcip_mem_pool_exit(struct gcip_mem_pool *pool);
+
+/*
+ * Allocates and returns the allocated physical address.
+ *
+ * @size: Size to be allocated.
+ *
+ * Returns the allocated address. Returns 0 on allocation failure.
+ */
+phys_addr_t gcip_mem_pool_alloc(struct gcip_mem_pool *pool, size_t size);
+/*
+ * Returns the address previously allocated by gcip_mem_pool_alloc().
+ *
+ * The size and address must match what previously passed to / returned by gcip_mem_pool_alloc().
+ */
+void gcip_mem_pool_free(struct gcip_mem_pool *pool, phys_addr_t paddr, size_t size);
+
+/*
+ * Returns the offset between @paddr and @base_paddr passed to gcip_mem_pool_init().
+ *
+ * @paddr must be a value returned by gcip_mem_pool_alloc().
+ */
+static inline size_t gcip_mem_pool_offset(struct gcip_mem_pool *pool, phys_addr_t paddr)
+{
+	return paddr - pool->base_paddr;
+}
+
+#endif /* __GCIP_MEM_POOL_H__ */