/* $Id: dtlb_prot.S,v 1.22 2001/04/11 23:40:32 davem Exp $ * dtlb_prot.S: DTLB protection trap strategy. * This is included directly into the trap table. * * Copyright (C) 1996,1998 David S. Miller (davem@redhat.com) * Copyright (C) 1997,1998 Jakub Jelinek (jj@ultra.linux.cz) */ /* Ways we can get here: * * [TL == 0] 1) User stores to readonly pages. * [TL == 0] 2) Nucleus stores to user readonly pages. * [TL > 0] 3) Nucleus stores to user readonly stack frame. */ /* PROT ** ICACHE line 1: User DTLB protection trap */ mov TLB_SFSR, %g1 stxa %g0, [%g1] ASI_DMMU ! Clear FaultValid bit membar #Sync ! Synchronize stores rdpr %pstate, %g5 ! Move into alt-globals wrpr %g5, PSTATE_AG|PSTATE_MG, %pstate rdpr %tl, %g1 ! Need a winfixup? cmp %g1, 1 ! Trap level >1? mov TLB_TAG_ACCESS, %g4 ! For reload of vaddr /* PROT ** ICACHE line 2: More real fault processing */ bgu,pn %xcc, winfix_trampoline ! Yes, perform winfixup ldxa [%g4] ASI_DMMU, %g5 ! Put tagaccess in %g5 ba,pt %xcc, sparc64_realfault_common ! Nope, normal fault mov FAULT_CODE_DTLB | FAULT_CODE_WRITE, %g4 nop nop nop nop /* PROT ** ICACHE line 3: Unused... */ nop nop nop nop nop nop nop nop /* PROT ** ICACHE line 4: Unused... */ nop nop nop nop nop nop nop nop