Merge pull request #32 from nekernel-org/dev

0.0.2e3

1 files changed, 88 insertions, 0 deletions

diff --git a/dev/kernel/DmaKit/DmaPool.h b/dev/kernel/DmaKit/DmaPool.h
new file mode 100644
index 00000000..ec98745d
--- /dev/null
+++ b/dev/kernel/DmaKit/DmaPool.h
@@ -0,0 +1,88 @@
+/* -------------------------------------------
+
+  Copyright (C) 2025, Amlal El Mahrouss , all rights reserved.
+
+  File: FileMgr.h
+  Purpose: Kernel file manager.
+
+------------------------------------------- */
+
+#pragma once
+
+#include <HALKit/AMD64/Processor.h>
+#include <KernelKit/DebugOutput.h>
+
+#ifdef __NE_AMD64__
+#define kNeDMAPoolStart (0x1000000)
+#define kNeDMAPoolSize (0x1000000)
+
+namespace Kernel {
+/// @brief DMA pool base pointer, here we're sure that AHCI or whatever tricky standard sees it.
+inline UInt8*       kDmaPoolPtr = (UInt8*) kNeDMAPoolStart;
+inline const UInt8* kDmaPoolEnd = (UInt8*) (kNeDMAPoolStart + kNeDMAPoolSize);
+
+/***********************************************************************************/
+/// @brief allocate from the rtl_dma_alloc system.
+/// @param size the size of the chunk to allocate.
+/// @param align alignement of pointer.
+/***********************************************************************************/
+inline VoidPtr rtl_dma_alloc(SizeT size, SizeT align) {
+  if (!size) {
+    return nullptr;
+  }
+
+  UIntPtr addr = (UIntPtr) kDmaPoolPtr;
+
+  /// here we just align the address according to a `align` variable, i'd rather be a power of two
+  /// really.
+  addr = (addr + (align - 1)) & ~(align - 1);
+
+  if ((addr + size) >= reinterpret_cast<UIntPtr>(kDmaPoolEnd)) {
+    err_global_get() = kErrorDmaExhausted;
+    return nullptr;
+  }
+
+  kDmaPoolPtr = (UInt8*) (addr + size);
+
+  HAL::mm_memory_fence((VoidPtr)addr);
+
+  return (VoidPtr) addr;
+}
+
+/***********************************************************************************/
+/// @brief Free DMA pointer.
+/***********************************************************************************/
+inline Void rtl_dma_free(SizeT size) {
+  if (!size) return;
+
+  auto ptr = (UInt8*) (kDmaPoolPtr - size);
+
+  if (!ptr || ptr < (UInt8*) kNeDMAPoolStart) {
+    err_global_get() = kErrorDmaExhausted;
+    return;
+  }
+
+  kDmaPoolPtr = ptr;
+
+  HAL::mm_memory_fence(ptr);
+}
+
+/***********************************************************************************/
+/// @brief Flush DMA pointer.
+/***********************************************************************************/
+inline Void rtl_dma_flush(VoidPtr ptr, SizeT size_buffer) {
+  if (ptr > kDmaPoolEnd) {
+    return;
+  }
+
+  if (!ptr || ptr < (UInt8*) kNeDMAPoolStart) {
+    err_global_get() = kErrorDmaExhausted;
+    return;
+  }
+
+  for (SizeT buf_idx = 0UL; buf_idx < size_buffer; ++buf_idx) {
+    HAL::mm_memory_fence((VoidPtr) ((UInt8*) ptr + buf_idx));
+  }
+}
+}  // namespace Kernel
+#endif
\ No newline at end of file