diff options
Diffstat (limited to 'arch/sparc/kernel/dtlb_prot.S')
| -rw-r--r-- | arch/sparc/kernel/dtlb_prot.S | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/arch/sparc/kernel/dtlb_prot.S b/arch/sparc/kernel/dtlb_prot.S new file mode 100644 index 00000000000..b2c2c5be281 --- /dev/null +++ b/arch/sparc/kernel/dtlb_prot.S @@ -0,0 +1,54 @@ +/* + * 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 |