lib/magma/src/magma_util/address_space_allocator.h

// Copyright 2016 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef ADDRESS_SPACE_ALLOCATOR_H
#define ADDRESS_SPACE_ALLOCATOR_H

#include "magma_util/macros.h"

namespace magma {

class AddressSpaceAllocator {
public:
    // Constructs an address space ranging from address base to address base + size.
    AddressSpaceAllocator(uint64_t base, size_t size) : base_(base), size_(size)
    {
        DASSERT(size > 0);
        DASSERT(size <= UINT64_MAX - base);
    }

    virtual ~AddressSpaceAllocator() = default;

    uint64_t base() const { return base_; }
    size_t size() const { return size_; }

    // Allocates an address for a region of the given size and alignment, where alignment
    // is specified by 2 << align_pow2.
    // If alignment is less than a page than page alignment will be used.
    // On success returns true and addr_out is set; otherwise returns false.
    virtual bool Alloc(size_t size, uint8_t align_pow2, uint64_t* addr_out) = 0;

    // Frees an address that was previously allocated.
    virtual bool Free(uint64_t addr) = 0;

    // Returns true and the size of the region if mapped; otherwise returns false.
    virtual bool GetSize(uint64_t addr, size_t* size_out) = 0;

private:
    uint64_t base_;
    size_t size_;
};

} // namespace magma

#endif // ADDRESS_SPACE_ALLOCATOR_H