kapi: add basic support for MMIO mapping

1 files changed, 41 insertions, 0 deletions

diff --git a/kernel/include/kernel/memory/mmio_allocator.hpp b/kernel/include/kernel/memory/mmio_allocator.hpp
new file mode 100644
index 0000000..4ec6bec
--- /dev/null
+++ b/kernel/include/kernel/memory/mmio_allocator.hpp
@@ -0,0 +1,41 @@
+#ifndef TEACHOS_KERNEL_MEMORY_MMIO_ALLOCATOR_HPP
+#define TEACHOS_KERNEL_MEMORY_MMIO_ALLOCATOR_HPP
+
+#include "kapi/memory.hpp"
+
+#include <kstd/allocator>
+#include <kstd/memory>
+
+#include <cstddef>
+
+namespace kernel::memory
+{
+
+  struct mmio_allocator
+  {
+    mmio_allocator(kapi::memory::linear_address base, std::size_t pages);
+
+    [[nodiscard]] auto allocate(std::size_t page_count) -> kapi::memory::linear_address;
+    auto release(kapi::memory::linear_address base) -> void;
+
+  private:
+    struct node
+    {
+      kapi::memory::linear_address base{};
+      std::size_t page_count{};
+      node * next{};
+      node * previous{};
+      bool is_free{};
+    };
+
+    auto make_node(kapi::memory::linear_address base, std::size_t page_count, node * next, node * previous,
+                   bool is_free) -> node *;
+    auto destroy_node(node *) -> void;
+
+    [[no_unique_address]] kstd::allocator<node> m_allocator{};
+    node * m_head{};
+  };
+
+}  // namespace kernel::memory
+
+#endif