1 /* SPDX-License-Identifier: GPL-2.0 */
3 * dtlb_prot.S: DTLB protection trap strategy.
4 * This is included directly into the trap table.
6 * Copyright (C) 1996,1998 David S. Miller (davem@redhat.com)
7 * Copyright (C) 1997,1998 Jakub Jelinek (jj@ultra.linux.cz)
10 /* Ways we can get here:
12 * [TL == 0] 1) User stores to readonly pages.
13 * [TL == 0] 2) Nucleus stores to user readonly pages.
14 * [TL > 0] 3) Nucleus stores to user readonly stack frame.
17 /* PROT ** ICACHE line 1: User DTLB protection trap */
19 stxa %g0, [%g1] ASI_DMMU ! Clear FaultValid bit
20 membar #Sync ! Synchronize stores
21 rdpr %pstate, %g5 ! Move into alt-globals
22 wrpr %g5, PSTATE_AG|PSTATE_MG, %pstate
23 rdpr %tl, %g1 ! Need a winfixup?
24 cmp %g1, 1 ! Trap level >1?
25 mov TLB_TAG_ACCESS, %g4 ! For reload of vaddr
27 /* PROT ** ICACHE line 2: More real fault processing */
28 ldxa [%g4] ASI_DMMU, %g5 ! Put tagaccess in %g5
29 srlx %g5, PAGE_SHIFT, %g5
30 sllx %g5, PAGE_SHIFT, %g5 ! Clear context ID bits
31 bgu,pn %xcc, winfix_trampoline ! Yes, perform winfixup
32 mov FAULT_CODE_DTLB | FAULT_CODE_WRITE, %g4
33 ba,pt %xcc, sparc64_realfault_common ! Nope, normal fault
37 /* PROT ** ICACHE line 3: Unused... */
47 /* PROT ** ICACHE line 4: Unused... */