Kernel: Allow contiguous allocations in physical memory

For that, we have a new type of VMObject, called
ContiguousVMObject, that is responsible for allocating contiguous
physical pages.

1 files changed, 66 insertions, 0 deletions

diff --git a/Kernel/VM/ContiguousVMObject.cpp b/Kernel/VM/ContiguousVMObject.cpp
new file mode 100644
index 0000000000..41a188f553
--- /dev/null
+++ b/Kernel/VM/ContiguousVMObject.cpp
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <Kernel/VM/ContiguousVMObject.h>
+#include <Kernel/VM/MemoryManager.h>
+#include <Kernel/VM/PhysicalPage.h>
+
+namespace Kernel {
+
+//#define CONTIGUOUS_VMOBJECT_DEBUG
+
+NonnullRefPtr<ContiguousVMObject> ContiguousVMObject::create_with_size(size_t size)
+{
+    return adopt(*new ContiguousVMObject(size));
+}
+
+ContiguousVMObject::ContiguousVMObject(size_t size)
+    : VMObject(size)
+{
+    auto contiguous_physical_pages = MM.allocate_contiguous_supervisor_physical_pages(size);
+    for (size_t i = 0; i < page_count(); i++) {
+        physical_pages()[i] = contiguous_physical_pages[i];
+#ifdef CONTIGUOUS_VMOBJECT_DEBUG
+        dbg() << "Contiguous page[" << i << "]: " << physical_pages()[i]->paddr();
+#endif
+    }
+}
+
+ContiguousVMObject::ContiguousVMObject(const ContiguousVMObject& other)
+    : VMObject(other)
+{
+}
+
+ContiguousVMObject::~ContiguousVMObject()
+{
+}
+
+NonnullRefPtr<VMObject> ContiguousVMObject::clone()
+{
+    ASSERT_NOT_REACHED();
+}
+
+}