137 lines
4.4 KiB
C
137 lines
4.4 KiB
C
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#include "memory.h"
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#include "paging_internal.h"
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#include "../runtime/stdio.h"
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#include <string.h>
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uint64_t paging_physical_Bitmap[MAX_SYSTEM_MEMORY_PAGES / BITMAP_BITS];
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static inline uint64_t fillBits(int begin, int last) {
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if (last == BITMAP_BITS - 1)
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return ~((1ull << begin) - 1ull);
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if (begin == 0)
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return (1ull << (last + 1ull)) - 1ull;
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return (~((1ull << begin) - 1ull)) & ((1ull << (last + 1ull)) - 1ull);
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}
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void paging_physical_BitmapWriteOne(int begin, int end) {
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int whereBegin = begin / BITMAP_BITS, whereLast = (end - 1) / BITMAP_BITS;
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if (whereBegin == whereLast)
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paging_physical_Bitmap[whereBegin] |= fillBits(begin % BITMAP_BITS, (end - 1) % BITMAP_BITS);
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else {
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paging_physical_Bitmap[whereBegin] |= fillBits(begin % BITMAP_BITS, BITMAP_BITS - 1);
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paging_physical_Bitmap[whereLast] |= fillBits(0, (end - 1) % BITMAP_BITS);
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for (int i = whereBegin + 1; i < whereLast; i++)
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paging_physical_Bitmap[i] = (~0ull);
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}
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}
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void paging_physical_BitmapWriteZero(int begin, int end) {
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int whereBegin = begin / BITMAP_BITS, whereLast = (end - 1) / BITMAP_BITS;
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if (whereBegin == whereLast)
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paging_physical_Bitmap[whereBegin] &= ~fillBits(begin % BITMAP_BITS, (end - 1) % BITMAP_BITS);
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else {
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paging_physical_Bitmap[whereBegin] &= ~fillBits(begin % BITMAP_BITS, BITMAP_BITS - 1);
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paging_physical_Bitmap[whereLast] &= ~fillBits(0, (end - 1) % BITMAP_BITS);
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for (int i = whereBegin + 1; i < whereLast; i++)
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paging_physical_Bitmap[i] = 0;
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}
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}
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static int phy_i = 1024 / 4 / BITMAP_BITS;
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uint64_t paging_physical_AllocateOneFrame() {
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// skip the first 1M
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/*for (; phy_i < paging_EndPhysicalPage / BITMAP_BITS; phy_i++)
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if (paging_physical_Bitmap[phy_i] != ~0ull)
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for (int j = 0; j < BITMAP_BITS; j++)
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if ((paging_physical_Bitmap[phy_i] & (1ull << j)) == 0) {
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paging_physical_Bitmap[phy_i] |= (1ull << j);
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uint64_t addr = (((uint64_t)phy_i) * BITMAP_BITS + j) * SYSTEM_PAGE_SIZE;
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memset((void *)addr, 0, SYSTEM_PAGE_SIZE);
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return addr;
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}*/
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uint64_t addr;
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paging_physical_AllocateFrames(1, &addr);
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return addr;
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}
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// skip the first 2M
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static int phy_i_2M = 2048 / 4 / BITMAP_BITS;
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uint64_t paging_physical_AllocateOneFrame2M() {
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// skip the first 2M
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/*for (; phy_i_2M < paging_EndPhysicalPage / BITMAP_BITS; phy_i_2M += 8) {
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for (int j = 0; j < 8; j++)
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if (paging_physical_Bitmap[phy_i_2M + j] != 0)
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goto for_end;
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// now here we have a whole chunk at [i, i+8)
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for (int j = 0; j < 8; j++)
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paging_physical_Bitmap[phy_i_2M + j] = ~0ull;
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uint64_t addr = (((uint64_t)phy_i_2M) * BITMAP_BITS) * SYSTEM_PAGE_SIZE;
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memset((void *)addr, 0, SYSTEM_PAGE_2M_SIZE);
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return addr;
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for_end:;
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}*/
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uint64_t addr;
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paging_physical_AllocateFrames2M(1, &addr);
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return addr;
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}
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int paging_physical_AllocateFrames(int pageCount, uint64_t frames[]) {
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// this code is in sync with paging_map.c, paging_map_PageAllocated, so you have to modify both
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int page = 0;
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for (; page < pageCount; page++) {
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frames[page] = 0;
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for (; phy_i < paging_EndPhysicalPage / BITMAP_BITS; phy_i++)
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if (paging_physical_Bitmap[phy_i] != ~0ull)
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for (int j = 0; j < BITMAP_BITS; j++)
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if ((paging_physical_Bitmap[phy_i] & (1ull << j)) == 0) {
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paging_physical_Bitmap[phy_i] |= (1ull << j);
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uint64_t addr = (((uint64_t)phy_i) * BITMAP_BITS + j) * SYSTEM_PAGE_SIZE;
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memset((void *)addr, 0, SYSTEM_PAGE_SIZE);
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frames[page] = addr;
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goto for_end; // break the phy_i loop
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}
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if (frames[page] == 0)
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break;
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for_end:;
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}
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return page;
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}
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int paging_physical_AllocateFrames2M(int pageCount, uint64_t frames[]) {
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int page = 0;
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for (; page < pageCount; page++) {
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frames[page] = 0;
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for (; phy_i_2M < paging_EndPhysicalPage / BITMAP_BITS; phy_i_2M += 8) {
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for (int j = 0; j < 8; j++)
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if (paging_physical_Bitmap[phy_i_2M + j] != 0)
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goto for_end; // continue the outer for loop
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// now here we have a whole chunk at [i, i+8)
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for (int j = 0; j < 8; j++)
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paging_physical_Bitmap[phy_i_2M + j] = ~0ull;
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uint64_t addr = (((uint64_t)phy_i_2M) * BITMAP_BITS) * SYSTEM_PAGE_SIZE;
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memset((void *)addr, 0, SYSTEM_PAGE_2M_SIZE);
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frames[page] = addr;
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break;
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for_end:;
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}
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if (frames[page] == 0)
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break;
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}
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return page;
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}
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void paging_physical_FreeFrame(uint64_t frame, int pageCount) {
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if (frame % SYSTEM_PAGE_SIZE != 0) {
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io_Printf("paging_physical_FreeFrame: frame %08llx is not aligned\n", frame);
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return;
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}
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paging_physical_BitmapWriteZero(frame / SYSTEM_PAGE_SIZE, frame / SYSTEM_PAGE_SIZE + pageCount);
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}
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