COMPMID-485: Offset-based memory manager support.

Adds support for offset-based memory mappings used from CPU system
memory and SVM based allocations.

Change-Id: Ibee6a3c02a61df9b11fe8878cfe40dc6fd9a4be0
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/88307
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
diff --git a/src/runtime/OffsetMemoryPool.cpp b/src/runtime/OffsetMemoryPool.cpp
new file mode 100644
index 0000000..96f54f8
--- /dev/null
+++ b/src/runtime/OffsetMemoryPool.cpp
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2017 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include <algorithm>
+
+#include "arm_compute/runtime/OffsetMemoryPool.h"
+
+#include "arm_compute/core/Error.h"
+#include "arm_compute/runtime/IAllocator.h"
+#include "arm_compute/runtime/IMemoryPool.h"
+#include "arm_compute/runtime/Types.h"
+#include "support/ToolchainSupport.h"
+
+using namespace arm_compute;
+
+OffsetMemoryPool::OffsetMemoryPool(IAllocator *allocator, size_t blob_size)
+    : _allocator(allocator), _blob(), _blob_size(blob_size)
+{
+    ARM_COMPUTE_ERROR_ON(!allocator);
+    _blob = _allocator->allocate(_blob_size, 0);
+}
+
+OffsetMemoryPool::~OffsetMemoryPool()
+{
+    ARM_COMPUTE_ERROR_ON(!_allocator);
+    _allocator->free(_blob);
+    _blob = nullptr;
+}
+
+void OffsetMemoryPool::acquire(MemoryMappings &handles)
+{
+    ARM_COMPUTE_ERROR_ON(_blob == nullptr);
+
+    // Set memory to handlers
+    for(auto &handle : handles)
+    {
+        ARM_COMPUTE_ERROR_ON(handle.first == nullptr);
+        *handle.first = reinterpret_cast<uint8_t *>(_blob) + handle.second;
+    }
+}
+
+void OffsetMemoryPool::release(MemoryMappings &handles)
+{
+    for(auto &handle : handles)
+    {
+        ARM_COMPUTE_ERROR_ON(handle.first == nullptr);
+        *handle.first = nullptr;
+    }
+}
+
+MappingType OffsetMemoryPool::mapping_type() const
+{
+    return MappingType::OFFSETS;
+}
+
+std::unique_ptr<IMemoryPool> OffsetMemoryPool::duplicate()
+{
+    ARM_COMPUTE_ERROR_ON(!_allocator);
+    return support::cpp14::make_unique<OffsetMemoryPool>(_allocator, _blob_size);
+}
\ No newline at end of file