extern void Error_Backtrace(Uint IP, Uint BP);
extern tPAddr gInitialPML4[512];
extern void Threads_SegFault(tVAddr Addr);
+extern char _UsertextBase[];
// === PROTOTYPES ===
void MM_InitVirt(void);
//void MM_FinishVirtualInit(void);
+void MM_int_ClonePageEnt( Uint64 *Ent, void *NextLevel, tVAddr Addr, int bTable );
int MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs);
void MM_DumpTables(tVAddr Start, tVAddr End);
int MM_GetPageEntryPtr(tVAddr Addr, BOOL bTemp, BOOL bAllocate, BOOL bLargePage, tPAddr **Pointer);
// === CODE ===
void MM_InitVirt(void)
{
+ Log_Debug("MMVirt", "&PAGEMAPLVL4(0) = %p", &PAGEMAPLVL4(0));
// MM_DumpTables(0, -1L);
}
}
/**
+ * \brief Clone a page from an entry
+ * \param Ent Pointer to the entry in the PML4/PDP/PD/PT
+ * \param NextLevel Pointer to contents of the entry
+ * \param Addr Dest address
+ * \note Used in COW
+ */
+void MM_int_ClonePageEnt( Uint64 *Ent, void *NextLevel, tVAddr Addr, int bTable )
+{
+ tPAddr curpage = *Ent & PADDR_MASK;
+ if( MM_GetRefCount( curpage ) <= 0 ) {
+ Log_KernelPanic("MMVirt", "Page %P still marked COW, but unreferenced", curpage);
+ }
+// Log_Debug("MM_Virt", "%P refcount %i", curpage, MM_GetRefCount( curpage ));
+ if( MM_GetRefCount( curpage ) == 1 )
+ {
+ *Ent &= ~PF_COW;
+ *Ent |= PF_PRESENT|PF_WRITE;
+// Log_Debug("MMVirt", "COW ent at %p (%p), last (%P)", Ent, NextLevel, curpage);
+ }
+ else
+ {
+ void *tmp;
+ tPAddr paddr;
+
+ if( !(paddr = MM_AllocPhys()) ) {
+ Threads_SegFault(Addr);
+ return ;
+ }
+
+ ASSERT(paddr != curpage);
+
+ tmp = (void*)MM_MapTemp(paddr);
+ memcpy( tmp, NextLevel, 0x1000 );
+ MM_FreeTemp( (tVAddr)tmp );
+
+// Log_Debug("MMVirt", "COW ent at %p (%p) from %P to %P", Ent, NextLevel, curpage, paddr);
+
+ MM_DerefPhys( curpage );
+ *Ent &= PF_USER;
+ *Ent |= paddr|PF_PRESENT|PF_WRITE;
+ }
+ INVLPG( (tVAddr)NextLevel );
+
+ // Mark COW on pages
+ if(bTable)
+ {
+ Uint64 *dp = NextLevel;
+ int i;
+ for( i = 0; i < 512; i ++ )
+ {
+ if( !(dp[i] & PF_PRESENT) ) continue;
+ MM_RefPhys( dp[i] & PADDR_MASK );
+ if( dp[i] & PF_WRITE ) {
+ dp[i] &= ~PF_WRITE;
+ dp[i] |= PF_COW;
+ }
+ }
+ }
+}
+
+/*
* \brief Called on a page fault
*/
int MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
if( PAGEMAPLVL4(Addr>>39) & PF_PRESENT
&& PAGEDIRPTR (Addr>>30) & PF_PRESENT
&& PAGEDIR (Addr>>21) & PF_PRESENT
- && PAGETABLE (Addr>>12) & PF_PRESENT
- && PAGETABLE (Addr>>12) & PF_COW )
+ && PAGETABLE (Addr>>12) & PF_PRESENT )
{
- tPAddr paddr;
- if(MM_GetRefCount( PAGETABLE(Addr>>12) & PADDR_MASK ) == 1)
+ // PML4 Entry
+ if( PAGEMAPLVL4(Addr>>39) & PF_COW )
{
- PAGETABLE(Addr>>12) &= ~PF_COW;
- PAGETABLE(Addr>>12) |= PF_PRESENT|PF_WRITE;
+ tPAddr *dp = &PAGEDIRPTR((Addr>>39)*512);
+ MM_int_ClonePageEnt( &PAGEMAPLVL4(Addr>>39), dp, Addr, 1 );
+// MM_DumpTables(Addr>>39 << 39, (((Addr>>39) + 1) << 39) - 1);
}
- else
+ // PDP Entry
+ if( PAGEDIRPTR(Addr>>30) & PF_COW )
{
- void *tmp;
- //Log("MM_PageFault: COW - MM_DuplicatePage(0x%x)", Addr);
- paddr = MM_AllocPhys();
- if( !paddr ) {
- Threads_SegFault(Addr);
- return 0;
- }
- tmp = (void*)MM_MapTemp(paddr);
- memcpy( tmp, (void*)(Addr & ~0xFFF), 0x1000 );
- MM_FreeTemp( (tVAddr)tmp );
- MM_DerefPhys( PAGETABLE(Addr>>12) & PADDR_MASK );
- PAGETABLE(Addr>>12) &= PF_USER;
- PAGETABLE(Addr>>12) |= paddr|PF_PRESENT|PF_WRITE;
+ tPAddr *dp = &PAGEDIR( (Addr>>30)*512 );
+ MM_int_ClonePageEnt( &PAGEDIRPTR(Addr>>30), dp, Addr, 1 );
+// MM_DumpTables(Addr>>30 << 30, (((Addr>>30) + 1) << 30) - 1);
+ }
+ // PD Entry
+ if( PAGEDIR(Addr>>21) & PF_COW )
+ {
+ tPAddr *dp = &PAGETABLE( (Addr>>21)*512 );
+ MM_int_ClonePageEnt( &PAGEDIR(Addr>>21), dp, Addr, 1 );
+// MM_DumpTables(Addr>>21 << 21, (((Addr>>21) + 1) << 21) - 1);
+ }
+ // PT Entry
+ if( PAGETABLE(Addr>>12) & PF_COW )
+ {
+ MM_int_ClonePageEnt( &PAGETABLE(Addr>>12), (void*)(Addr & ~0xFFF), Addr, 0 );
+ INVLPG( Addr & ~0xFFF );
+ return 0;
}
-
- INVLPG( Addr & ~0xFFF );
- return 0;
}
#endif
if( !(PAGEMAPLVL4(page>>27) & PF_PRESENT) ) {
page += (1 << 27) - 1;
curPos += (1L << 39) - 0x1000;
- //Debug("pml4 ent unset (page = 0x%x now)", page);
continue;
}
if( !(PAGEDIRPTR(page>>18) & PF_PRESENT) ) {
page += (1 << 18) - 1;
curPos += (1L << 30) - 0x1000;
- //Debug("pdp ent unset (page = 0x%x now)", page);
continue;
}
if( !(PAGEDIR(page>>9) & PF_PRESENT) ) {
page += (1 << 9) - 1;
curPos += (1L << 21) - 0x1000;
- //Debug("pd ent unset (page = 0x%x now)", page);
continue;
}
if( !(PAGETABLE(page) & PF_PRESENT) ) continue;
if( !(PAGEDIRPTR(VAddr >> 30) & 1) ) return ;
// Check Page Dir
if( !(PAGEDIR(VAddr >> 21) & 1) ) return ;
-
+
PAGETABLE(VAddr >> PTAB_SHIFT) = 0;
INVLPG( VAddr );
}
ret -= 0x1000;
PAddr -= 0x1000;
MM_Map(ret, PAddr);
+ MM_RefPhys(PAddr);
}
return ret;
// Log_KernelPanic("MM", "TODO: Implement MM_UnmapHWPages");
while( Number -- )
{
+ MM_DerefPhys( MM_GetPhysAddr(VAddr) );
MM_Unmap(VAddr);
VAddr += 0x1000;
}
phys = MM_AllocPhys();
*PhysAddr = phys;
ret = MM_MapHWPages(phys, 1);
- if(ret == 0) {
- MM_DerefPhys(phys);
- return 0;
- }
+ MM_DerefPhys(phys);
return ret;
}
// Allocated successfully, now map
ret = MM_MapHWPages(phys, Pages);
+ // MapHWPages references the pages, so deref them back down to 1
+ for(;Pages--;phys+=0x1000)
+ MM_DerefPhys(phys);
if( ret == 0 ) {
// If it didn't map, free then return 0
- for(;Pages--;phys+=0x1000)
- MM_DerefPhys(phys);
return 0;
}
continue ;
*ent = PAddr | 3;
+ MM_RefPhys(PAddr);
+ INVLPG(ret);
return ret;
}
return 0;
{
TMPMAPLVL4(i) = PAGEMAPLVL4(i);
// Log_Debug("MM", "TMPMAPLVL4(%i) = 0x%016llx", i, TMPMAPLVL4(i));
- if( TMPMAPLVL4(i) & 1 )
- {
- MM_RefPhys( TMPMAPLVL4(i) & PADDR_MASK );
+ if( !(TMPMAPLVL4(i) & PF_PRESENT) ) continue ;
+
+ MM_RefPhys( TMPMAPLVL4(i) & PADDR_MASK );
+
+ if( TMPMAPLVL4(i) & PF_WRITE ) {
TMPMAPLVL4(i) |= PF_COW;
TMPMAPLVL4(i) &= ~PF_WRITE;
}
// There is 1 guard page below the stack
kstackbase = Proc_GetCurThread()->KernelStack - KERNEL_STACK_SIZE;
-// Log("MM_Clone: kstackbase = %p", kstackbase);
+ Log("MM_Clone: kstackbase = %p", kstackbase);
TMPMAPLVL4(MM_KSTACK_BASE >> PML4_SHIFT) = 0;
for( i = 1; i < KERNEL_STACK_SIZE/0x1000; i ++ )
git.ucc.asn.au / tpg / acess2.git / blobdiff
UCC git Repository :: git.ucc.asn.au