73 lines
2.4 KiB
C++
73 lines
2.4 KiB
C++
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#include "ramdisk.hpp"
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#include "../../memory/memory.h"
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#include "../../memory/paging_internal.h"
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#include <cstring>
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namespace helos {
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constexpr uint16_t __Ramdisk_Alloc_None = 0,
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__Ramdisk_Alloc_Malloc = 1,
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__Ramdisk_Alloc_4KPages = 2,
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__Ramdisk_Alloc_2MPages = 3;
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BlockDeviceRamdisk::BlockDeviceRamdisk(uint64_t blockSize, uint64_t blockCount, ::helos::Permission perm)
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: blocksize(blockSize), blockcount(blockCount), perm(perm) {
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uint64_t bytes = blockSize * blockCount; // the number of bytes to allocate
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if (bytes < SYSTEM_PAGE_SIZE) {
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// less than a page: use malloc()
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alloctype = __Ramdisk_Alloc_Malloc;
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buffer = kMalloc(bytes);
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} else if (bytes < SYSTEM_PAGE_2M_SIZE * 64) {
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// less than 128M: 4K pages
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alloctype = __Ramdisk_Alloc_4KPages;
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buffer = (void *)memory_AllocateKernelMapping(bytes, SYSTEM_PAGE_SIZE);
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paging_map_PageAllocated((uint64_t)buffer, pages = roundUpToPageCount(bytes), (int)perm);
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} else {
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// more than 128M: 2M pages
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alloctype = __Ramdisk_Alloc_2MPages;
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buffer = (void *)memory_AllocateKernelMapping(bytes, SYSTEM_PAGE_2M_SIZE);
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paging_map_PageAllocated2M((uint64_t)buffer, pages = roundUpToPageCount2M(bytes), (int)perm);
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}
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}
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BlockDeviceRamdisk::BlockDeviceRamdisk(void *buffer, uint64_t blockSize, uint64_t blockCount, ::helos ::Permission perm)
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: buffer(buffer), blocksize(blockSize), blockcount(blockCount), perm(perm), alloctype(__Ramdisk_Alloc_None) {}
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BlockDeviceRamdisk::~BlockDeviceRamdisk() {
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switch (alloctype) {
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case __Ramdisk_Alloc_Malloc:
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kFree(buffer);
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break;
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case __Ramdisk_Alloc_4KPages:
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case __Ramdisk_Alloc_2MPages:
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paging_map_FreeAllocated(
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(uint64_t)buffer,
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(uint64_t)buffer + pages * ((alloctype == __Ramdisk_Alloc_4KPages) ? SYSTEM_PAGE_SIZE : SYSTEM_PAGE_2M_SIZE));
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break;
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}
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}
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uint64_t BlockDeviceRamdisk::ReadBlock(uint64_t offset, void *data, uint64_t count) const {
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if (!(perm & PermRead))
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return -1;
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if (count > blockcount - offset)
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count = blockcount - offset;
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memcpy(data, (uint8_t *)buffer + blocksize * offset, blocksize * count);
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return count;
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}
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uint64_t BlockDeviceRamdisk::WriteBlock(uint64_t offset, const void *data, uint64_t count) {
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if (!(perm & PermRead))
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return -1;
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if (count > blockcount - offset)
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count = blockcount - offset;
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memcpy((uint8_t *)buffer + blocksize * offset, data, blocksize * count);
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return count;
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}
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} // namespace helos
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