With the latest cache fix for non-access faults and the support for non-access faults (code 17) in handle_interruption, we can remove the fast path emulation for fdc, fic, pdc, lpa, probe and probei instructions. Signed-off-by: John David Anglin <dave.anglin@xxxxxxxx> --- diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S index 6e9cdb269862..ecf50159359e 100644 --- a/arch/parisc/kernel/entry.S +++ b/arch/parisc/kernel/entry.S @@ -1288,74 +1288,12 @@ nadtlb_check_alias_20: nadtlb_emulate: /* - * Non access misses can be caused by fdc,fic,pdc,lpa,probe and - * probei instructions. We don't want to fault for these - * instructions (not only does it not make sense, it can cause - * deadlocks, since some flushes are done with the mmap - * semaphore held). If the translation doesn't exist, we can't - * insert a translation, so have to emulate the side effects - * of the instruction. Since we don't insert a translation - * we can get a lot of faults during a flush loop, so it makes - * sense to try to do it here with minimum overhead. We only - * emulate fdc,fic,pdc,probew,prober instructions whose base - * and index registers are not shadowed. We defer everything - * else to the "slow" path. + * Non-access misses can be caused by fdc,fic,pdc,lpa,probe and + * probei instructions. The kernel no longer faults doing flushes. + * Use of lpa and probe instructions is rare. Given the issue + * with shadow registers, we defer everything to the "slow" path. */ - - mfctl %cr19,%r9 /* Get iir */ - - /* PA 2.0 Arch Ref. Book pg 382 has a good description of the insn bits. - Checks for fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw */ - - /* Checks for fdc,fdce,pdc,"fic,4f" only */ - ldi 0x280,%r16 - and %r9,%r16,%r17 - cmpb,<>,n %r16,%r17,nadtlb_probe_check - bb,>=,n %r9,26,nadtlb_nullify /* m bit not set, just nullify */ - BL get_register,%r25 - extrw,u %r9,15,5,%r8 /* Get index register # */ - cmpib,COND(=),n -1,%r1,nadtlb_fault /* have to use slow path */ - copy %r1,%r24 - BL get_register,%r25 - extrw,u %r9,10,5,%r8 /* Get base register # */ - cmpib,COND(=),n -1,%r1,nadtlb_fault /* have to use slow path */ - BL set_register,%r25 - add,l %r1,%r24,%r1 /* doesn't affect c/b bits */ - -nadtlb_nullify: - mfctl %ipsw,%r8 - ldil L%PSW_N,%r9 - or %r8,%r9,%r8 /* Set PSW_N */ - mtctl %r8,%ipsw - - rfir - nop - - /* - When there is no translation for the probe address then we - must nullify the insn and return zero in the target register. - This will indicate to the calling code that it does not have - write/read privileges to this address. - - This should technically work for prober and probew in PA 1.1, - and also probe,r and probe,w in PA 2.0 - - WARNING: USE ONLY NON-SHADOW REGISTERS WITH PROBE INSN! - THE SLOW-PATH EMULATION HAS NOT BEEN WRITTEN YET. - - */ -nadtlb_probe_check: - ldi 0x80,%r16 - and %r9,%r16,%r17 - cmpb,<>,n %r16,%r17,nadtlb_fault /* Must be probe,[rw]*/ - BL get_register,%r25 /* Find the target register */ - extrw,u %r9,31,5,%r8 /* Get target register */ - cmpib,COND(=),n -1,%r1,nadtlb_fault /* have to use slow path */ - BL set_register,%r25 - copy %r0,%r1 /* Write zero to target register */ - b nadtlb_nullify /* Nullify return insn */ - nop - + b,n nadtlb_fault #ifdef CONFIG_64BIT itlb_miss_20w:
Attachment:
signature.asc
Description: PGP signature
