/*
* 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 */
ldxa [%g4] ASI_DMMU, %g5 ! Put tagaccess in %g5
bgu,pn %xcc, winfix_trampoline ! Yes, perform winfixup
mov FAULT_CODE_DTLB | FAULT_CODE_WRITE, %g4
ba,pt %xcc, sparc64_realfault_common ! Nope, normal fault
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
