1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * dtlb_prot.S: DTLB protection trap strategy. 4 * This is included directly into the trap table. 5 * 6 * Copyright (C) 1996,1998 David S. Miller (davem@redhat.com) 7 * Copyright (C) 1997,1998 Jakub Jelinek (jj@ultra.linux.cz) 8 */ 9 10/* Ways we can get here: 11 * 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. 15 */ 16 17/* PROT ** ICACHE line 1: User DTLB protection trap */ 18 mov TLB_SFSR, %g1 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 26 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 34 nop 35 nop 36 37/* PROT ** ICACHE line 3: Unused... */ 38 nop 39 nop 40 nop 41 nop 42 nop 43 nop 44 nop 45 nop 46 47/* PROT ** ICACHE line 4: Unused... */ 48 nop 49 nop 50 nop 51 nop 52 nop 53 nop 54 nop 55 nop 56