#include <vfs.h>
#include <vfs_ext.h>
#include <vfs_int.h>
+#include <mm_virt.h> // MM_USER_MAX
#define MMAP_PAGES_PER_BLOCK 16
void *VFS_MMap_Anon(void *Destination, size_t Length, Uint FlagsSet, Uint FlagsMask);
int VFS_MMap_MapPage(tVFS_Node *Node, unsigned int PageNum, tVFS_MMapPageBlock *pb, void *mapping_dest, unsigned int Protection);
//int VFS_MUnmap(void *Addr, size_t Length);
+bool _range_free(const tPage *Base, Uint NumPages);
// === CODE ===
void *VFS_MMap(void *DestHint, size_t Length, int Protection, int Flags, int FD, Uint64 Offset)
{
- ENTER("pDestHint iLength xProtection xFlags xFD XOffset", DestHint, Length, Protection, Flags, FD, Offset);
+ ENTER("pDestHint xLength xProtection xFlags xFD XOffset", DestHint, Length, Protection, Flags, FD, Offset);
if( Flags & MMAP_MAP_ANONYMOUS )
Offset = (tVAddr)DestHint & 0xFFF;
unsigned int npages = ((Offset & (PAGE_SIZE-1)) + Length + (PAGE_SIZE - 1)) / PAGE_SIZE;
unsigned int pagenum = Offset / PAGE_SIZE;
+ LOG("npages=%u,pagenum=%u", npages, pagenum);
tVAddr mapping_base = (tVAddr)DestHint;
else
{
Log_Warning("VFS", "MMap: TODO Handle non-fixed mappings");
- if( DestHint == NULL )
+
+ // Locate a free location in the address space (between brk and MM_USER_MAX)
+ // TODO: Prefer first location after DestHint, but can go below
+
+ // Search downwards from the top of user memory
+ mapping_base = 0;
+ for( tPage *dst = (tPage*)MM_USER_MAX - npages; dst > (tPage*)PAGE_SIZE; dst -- )
+ {
+ if( _range_free(dst, npages) ) {
+ mapping_base = (tVAddr)dst;
+ break;
+ }
+ }
+ if( mapping_base == 0 )
{
- // TODO: Locate space for the allocation
- Log_Warning("VFS", "Mmap: Handle NULL destination hint");
+ Log_Warning("VFS", "MMap: Out of address space");
+ errno = ENOMEM;
LEAVE('n');
return NULL;
}
}
tPage *mapping_dest = (void*)(mapping_base & ~(PAGE_SIZE-1));
+ if( !_range_free(mapping_dest, npages) )
+ {
+ LOG("Specified range is not free");
+ //errno = EINVAL;
+ //LEAVE('n');
+ //return NULL;
+ Log_Warning("VFS", "MMap: Overwriting/replacing maps at %p+%x", mapping_base, Length);
+ }
+
// Handle anonymous mappings
if( Flags & MMAP_MAP_ANONYMOUS )
{
// - Sorted list of 16 page blocks
for( pb = h->Node->MMapInfo; pb; pb_pnp = &pb->Next, pb = pb->Next )
{
- if( pb->BaseOffset + MMAP_PAGES_PER_BLOCK <= pagenum )
+ if( pb->BaseOffset + MMAP_PAGES_PER_BLOCK > pagenum )
break;
}
int VFS_MUnmap(void *Addr, size_t Length)
{
+ UNIMPLEMENTED();
return 0;
}
+
+bool _range_free(const tPage *Base, Uint NumPages)
+{
+ for( int i = 0; i < NumPages; i ++ )
+ {
+ if( MM_GetPhysAddr(Base + i) )
+ {
+ // Oh.
+ return false;
+ }
+ }
+ return true;
+}