/*
- * Acess2 VFS
- * - Open, Close and ChDir
+ * Acess2 Kernel VFS
+ * - By John Hodge (thePowersGang)
+ *
+ * mmap.c
+ * - VFS_MMap support
*/
#define DEBUG 0
#include <acess.h>
#include <vfs_int.h>
#define MMAP_PAGES_PER_BLOCK 16
-#define PAGE_SIZE 0x1000 // Should be in mm_virt.h
// === STRUCTURES ===
typedef struct sVFS_MMapPageBlock tVFS_MMapPageBlock;
void *VFS_MMap(void *DestHint, size_t Length, int Protection, int Flags, int FD, Uint64 Offset)
{
tVFS_Handle *h;
- tVAddr mapping_dest;
+ tVAddr mapping_dest, mapping_base;
int npages, pagenum;
tVFS_MMapPageBlock *pb, *prev;
+
+ ENTER("pDestHint iLength xProtection xFlags xFD XOffset", DestHint, Length, Protection, Flags, FD, Offset);
+
+ if( Flags & MMAP_MAP_ANONYMOUS )
+ Offset = (tVAddr)DestHint & 0xFFF;
- npages = ((Offset & (PAGE_SIZE-1)) + Length) / PAGE_SIZE;
+ npages = ((Offset & (PAGE_SIZE-1)) + Length + (PAGE_SIZE - 1)) / PAGE_SIZE;
pagenum = Offset / PAGE_SIZE;
- mapping_dest = (tVAddr)DestHint;
+ mapping_base = (tVAddr)DestHint;
+ mapping_dest = mapping_base & ~(PAGE_SIZE-1);
-#if 0
// TODO: Locate space for the allocation
- if( Flags & MAP_ANONYMOUS )
+
+ // Handle anonymous mappings
+ if( Flags & MMAP_MAP_ANONYMOUS )
{
- MM_Allocate(mapping_dest);
- return (void*)mapping_dest;
+ size_t ofs = 0;
+ LOG("%i pages anonymous to %p", npages, mapping_dest);
+ for( ; npages --; mapping_dest += PAGE_SIZE, ofs += PAGE_SIZE )
+ {
+ if( MM_GetPhysAddr(mapping_dest) ) {
+ // TODO: Set flags to COW if needed (well, if shared)
+ MM_SetFlags(mapping_dest, MM_PFLAG_COW, MM_PFLAG_COW);
+ LOG("clear from %p, %i bytes", (void*)(mapping_base + ofs),
+ PAGE_SIZE - (mapping_base & (PAGE_SIZE-1))
+ );
+ memset( (void*)(mapping_base + ofs), 0, PAGE_SIZE - (mapping_base & (PAGE_SIZE-1)));
+ }
+ else {
+ LOG("New empty page");
+ // TODO: Map a COW zero page instead
+ if( !MM_Allocate(mapping_dest) ) {
+ // TODO: Error
+ Log_Warning("VFS", "VFS_MMap: Anon alloc to %p failed", mapping_dest);
+ }
+ memset((void*)mapping_dest, 0, PAGE_SIZE);
+ LOG("Anon map to %p", mapping_dest);
+ }
+ }
+ LEAVE_RET('p', (void*)mapping_base);
}
-#endif
h = VFS_GetHandle(FD);
- if( !h || !h->Node ) return NULL;
+ if( !h || !h->Node ) LEAVE_RET('n', NULL);
+
+ LOG("h = %p", h);
+
+ Mutex_Acquire( &h->Node->Lock );
// Search for existing mapping for each page
// - Sorted list of 16 page blocks
prev = pb, pb = pb->Next
);
+ LOG("pb = %p, pb->BaseOffset = %X", pb, pb ? pb->BaseOffset : 0);
+
// - Allocate a block if needed
if( !pb || pb->BaseOffset > pagenum )
{
void *old_pb = pb;
pb = malloc( sizeof(tVFS_MMapPageBlock) );
- if(!pb) return NULL;
+ if(!pb) {
+ Mutex_Release( &h->Node->Lock );
+ LEAVE_RET('n', NULL);
+ }
pb->Next = old_pb;
pb->BaseOffset = pagenum - pagenum % MMAP_PAGES_PER_BLOCK;
memset(pb->PhysAddrs, 0, sizeof(pb->PhysAddrs));
// - Map (and allocate) pages
while( npages -- )
{
- if( pb->PhysAddrs[pagenum - pb->BaseOffset] == 0 )
+ if( MM_GetPhysAddr(mapping_dest) == 0 )
{
- if( h->Node->MMap )
- h->Node->MMap(h->Node, pagenum*PAGE_SIZE, PAGE_SIZE, (void*)mapping_dest);
- else
+ if( pb->PhysAddrs[pagenum - pb->BaseOffset] == 0 )
{
- // Allocate pages and read data
- if( MM_Allocate(mapping_dest) == 0 ) {
- // TODO: Unwrap
- return NULL;
+ tVFS_NodeType *nt = h->Node->Type;
+ if( !nt )
+ {
+ // TODO: error
+ }
+ else if( nt->MMap )
+ nt->MMap(h->Node, pagenum*PAGE_SIZE, PAGE_SIZE, (void*)mapping_dest);
+ else
+ {
+ int read_len;
+ // Allocate pages and read data
+ if( MM_Allocate(mapping_dest) == 0 ) {
+ // TODO: Unwrap
+ Mutex_Release( &h->Node->Lock );
+ LEAVE('n');
+ return NULL;
+ }
+ // TODO: Clip read length
+ read_len = nt->Read(h->Node, pagenum*PAGE_SIZE, PAGE_SIZE, (void*)mapping_dest);
+// if( read_len != PAGE_SIZE ) {
+// memset( (void*)(mapping_dest+read_len), 0, PAGE_SIZE-read_len );
+// }
}
- h->Node->Read(h->Node, pagenum*PAGE_SIZE, PAGE_SIZE, (void*)mapping_dest);
+ pb->PhysAddrs[pagenum - pb->BaseOffset] = MM_GetPhysAddr( mapping_dest );
+ MM_SetPageNode( pb->PhysAddrs[pagenum - pb->BaseOffset], h->Node );
+ MM_RefPhys( pb->PhysAddrs[pagenum - pb->BaseOffset] );
+ LOG("Read and map %X to %p (%P)", pagenum*PAGE_SIZE, mapping_dest,
+ pb->PhysAddrs[pagenum - pb->BaseOffset]);
+ }
+ else
+ {
+ MM_Map( mapping_dest, pb->PhysAddrs[pagenum - pb->BaseOffset] );
+ MM_RefPhys( pb->PhysAddrs[pagenum - pb->BaseOffset] );
+ LOG("Cached map %X to %p (%P)", pagenum*PAGE_SIZE, mapping_dest,
+ pb->PhysAddrs[pagenum - pb->BaseOffset]);
+ }
+ h->Node->ReferenceCount ++;
+
+ // Set flags
+ if( !(Protection & MMAP_PROT_WRITE) ) {
+ MM_SetFlags(mapping_dest, MM_PFLAG_RO, MM_PFLAG_RO);
+ }
+ else {
+ MM_SetFlags(mapping_dest, 0, MM_PFLAG_RO);
+ }
+
+ if( Protection & MMAP_PROT_EXEC ) {
+ MM_SetFlags(mapping_dest, MM_PFLAG_EXEC, MM_PFLAG_EXEC);
+ }
+ else {
+ MM_SetFlags(mapping_dest, 0, MM_PFLAG_EXEC);
}
- pb->PhysAddrs[pagenum - pb->BaseOffset] = MM_GetPhysAddr( mapping_dest );
-// MM_SetPageInfo( pb->PhysAddrs[pagenum - pb->BaseOffset], h->Node, pagenum*PAGE_SIZE );
}
else
{
- MM_Map( mapping_dest, pb->PhysAddrs[pagenum - pb->BaseOffset] );
+ LOG("Flag update on %p", mapping_dest);
+ if( (MM_GetFlags(mapping_dest) & MM_PFLAG_RO) && (Protection & MMAP_PROT_WRITE) )
+ {
+ MM_SetFlags(mapping_dest, 0, MM_PFLAG_RO);
+ }
}
+ if( Flags & MMAP_MAP_PRIVATE )
+ MM_SetFlags(mapping_dest, MM_PFLAG_COW, MM_PFLAG_COW);
pagenum ++;
mapping_dest += PAGE_SIZE;
-
+
// Roll on to next block if needed
if(pagenum - pb->BaseOffset == MMAP_PAGES_PER_BLOCK)
{
}
}
- return NULL;
+ Mutex_Release( &h->Node->Lock );
+
+ LEAVE('p', mapping_base);
+ return (void*)mapping_base;
}
int VFS_MUnmap(void *Addr, size_t Length)
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