3 * - Open, Close and ChDir
11 #define MMAP_PAGES_PER_BLOCK 16
12 #define PAGE_SIZE 0x1000 // Should be in mm_virt.h
15 typedef struct sVFS_MMapPageBlock tVFS_MMapPageBlock;
16 struct sVFS_MMapPageBlock
18 tVFS_MMapPageBlock *Next;
19 Uint64 BaseOffset; // Must be a multiple of MMAP_PAGES_PER_BLOCK*PAGE_SIZE
20 tPAddr PhysAddrs[MMAP_PAGES_PER_BLOCK];
24 void *VFS_MMap(int *ErrNo, void *DestHint, size_t Length, int Protection, int Flags, int FD, Uint64 Offset)
29 tVFS_MMapPageBlock *pb, *prev;
31 npages = ((Offset & (PAGE_SIZE-1)) + Length) / PAGE_SIZE;
32 pagenum = Offset / PAGE_SIZE;
34 mapping_dest = DestHint;
36 // TODO: Locate space for the allocation
37 if( Flags & MAP_ANONYMOUS )
39 MM_Allocate(mapping_dest);
40 return (void*)mapping_dest;
43 h = VFS_GetHandle(FD);
44 if( !h || !h->Node ) return NULL;
46 // Search for existing mapping for each page
47 // - Sorted list of 16 page blocks
49 pb = h->Node->MMapInfo, prev = NULL;
50 pb && pb->BaseOffset + MMAP_PAGES_PER_BLOCK < pagenum;
51 prev = pb, pb = pb->Next
54 if( !pb || pb->BaseOffset > pagenum )
58 pb = malloc( sizeof(tVFS_MMapPageBlock) );
61 pb->BaseOffset = pagenum - pagenum % MMAP_PAGES_PER_BLOCK;
62 memset(pb->PhysAddrs, 0, sizeof(pb->PhysAddrs));
66 h->Node->MMapInfo = pb;
71 if( pb->PhysAddrs[pagenum - pb->BaseOffset] == 0 )
74 h->Node->MMap(h->Node, pagenum*PAGE_SIZE, PAGE_SIZE, (void*)mapping_dest);
77 // Allocate pages and read data
78 MM_Allocate(mapping_dest);
79 h->Node->Read(h->Node, pagenum*PAGE_SIZE, PAGE_SIZE, (void*)mapping_dest);
81 pb->PhysAddrs[pagenum - pb->BaseOffset] = MM_GetPhysAddr( mapping_dest );
85 MM_Map( mapping_dest, pb->PhysAddrs[pagenum - pb->BaseOffset] );
88 mapping_dest += PAGE_SIZE;
90 // Roll on to next block if needed
91 if(pagenum - pb->BaseOffset == MMAP_PAGES_PER_BLOCK)
93 if( pb->Next && pb->Next->BaseOffset == pagenum )
97 tVFS_MMapPageBlock *oldpb = pb;
98 pb = malloc( sizeof(tVFS_MMapPageBlock) );
99 pb->Next = oldpb->Next;
100 pb->BaseOffset = pagenum;
101 memset(pb->PhysAddrs, 0, sizeof(pb->PhysAddrs));
111 int VFS_MUnmap(int *ErrNo, void *Addr, size_t Length)