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Diffstat (limited to 'dev/kernel/DmaKit')
| -rw-r--r-- | dev/kernel/DmaKit/DmaPool.h | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/dev/kernel/DmaKit/DmaPool.h b/dev/kernel/DmaKit/DmaPool.h new file mode 100644 index 00000000..5acff623 --- /dev/null +++ b/dev/kernel/DmaKit/DmaPool.h @@ -0,0 +1,91 @@ +/* + * Copyright (c) 2025 Amlal El Mahrouss. All rights reserved. + * + * 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. + */ + +#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)) { + kout << "DMA Pool is exhausted!\r"; + + err_global_get() = kErrorDmaExhausted; + + return nullptr; + } + + kDmaPoolPtr = (UInt8*) (addr + size); + return (VoidPtr) addr; +} + +/***********************************************************************************/ +/// @brief Free DMA pointer. +/***********************************************************************************/ +inline Void rtl_dma_free(SizeT size) { + if (!size) return; + + kDmaPoolPtr = (UInt8*) (kDmaPoolPtr - size); +} + +/***********************************************************************************/ +/// @brief Flush DMA pointer. +/***********************************************************************************/ +inline Void rtl_dma_flush(VoidPtr ptr, SizeT size_buffer) { + if (ptr > kDmaPoolEnd) { + return; + } + + if (!ptr || ptr < (UInt8*) kNeDMAPoolStart) { + return; + } + + for (SizeT buf_idx = 0UL; buf_idx < size_buffer; ++buf_idx) { + HAL::mm_memory_fence((VoidPtr) ((UInt8*) ptr + buf_idx)); + } +} +} // namespace Kernel +#endif
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