[parisc-linux] [PATCH] flush our cache through tmpalias space

[Joel Soete]

Joel Soete wrote:
> 
> 
> James Bottomley wrote:
> 
>> On Wed, 2006-06-21 at 16:25 -0500, James Bottomley wrote:
>>
>>> One of the current disadvantages parisc has is that we have to walk the
>>> inode mapping list to do a flush_dcache_page(), which means we get
>>> entangled in locking.  The reason we do this is because a VIPT cache
>>> can't be flushed without a mapping, so we have to find one to use
>>>
>>> The intent of this patch is to instead flush through the tmpalias space
>>> on the correct congruence boundary which would dispense with the need
>>> for finding a mapping at all.  However, in the current incarnation we
>>> still walk the mappings to check that all the usermappings are, indeed,
>>> on the correct congruence boundary.  Unfortunately, as you'll see if you
>>> try it out, not all are ... which is a bit of a problem.
>>
>>
>>
>> This patch is current and tested against 2.6.17-pa4.  It might eat your
>> data but I'm reasonably assured it won't kill kittens.
>>
>> James
>>
> Thanks a lot.
> 
> Just met a small compile pb:
> 
> gcc -Wp,-MD,arch/parisc/kernel/.entry.o.d  -nostdinc -isystem 
> /usr/lib/gcc/hppa-linux-gnu/4.0.4/include -D__KERNEL__ -Iinclude 
> -Iinclude2 -I/usr/src/linux-2.6.17-pa4/include -include 
> include/linux/autoconf.h -D__ASSEMBLY__ -traditional  -c -o 
> arch/parisc/kernel/entry.o 
> /usr/src/linux-2.6.17-pa4/arch/parisc/kernel/entry.S
> /usr/src/linux-2.6.17-pa4/arch/parisc/kernel/entry.S: Assembler messages:
> /usr/src/linux-2.6.17-pa4/arch/parisc/kernel/entry.S:1369: Error: 
> Unknown opcode: `mstp'
> /usr/src/linux-2.6.17-pa4/arch/parisc/kernel/entry.S:1630: Error: 
> Unknown opcode: `mstp'
> /usr/src/linux-2.6.17-pa4/arch/parisc/kernel/entry.S:1653: Error: symbol 
> `dtlb_check_alias_20' is already defined
> make[2]: *** [arch/parisc/kernel/entry.o] Error 1
> 
> effectively mstp doesn't exist but well mtsp?
> 
> For the second error it cames from this hunck:
> @@ -1617,6 +1645,14 @@
> 
>      f_extend    pte,t0   
> 
> +    iitlbt          pte,prot
> +
> +    rfir
> +    nop
> +   
> +dtlb_check_alias_20:
> +    do_alias    spc,t0,t1,va,pte,prot,itlb_fault
> +   
>      iitlbt          pte,prot
> 
>      rfir
> 
> Shouldn't it be here 'itlb_check_alias_20:'?
> 
> My 2pence diff looks like:
> --- arch/parisc/kernel/entry.S.Orig     2006-06-24 22:35:19.000000000 +0200
> +++ arch/parisc/kernel/entry.S  2006-06-24 22:55:49.000000000 +0200
> @@ -1366,7 +1366,7 @@
>         idtlba          pte,(%sr1,va)
>         idtlbp          prot,(%sr1,va)
> 
> -       mstp            t0,%sr1         /* Restore sr1 */
> +       mtsp            t0,%sr1         /* Restore sr1 */
> 
>         rfir
>         nop
> @@ -1627,7 +1627,7 @@
>         iitlba          pte,(%sr1,va)
>         iitlbp          prot,(%sr1,va)
> 
> -       mstp            t0,%sr1         /* Restore sr1 */
> +       mtsp            t0,%sr1         /* Restore sr1 */
> 
>         rfir
>         nop
> @@ -1650,7 +1650,7 @@
>         rfir
>         nop
> 
> -dtlb_check_alias_20:
> +itlb_check_alias_20:
>         do_alias        spc,t0,t1,va,pte,prot,itlb_fault
> 
>         iitlbt          pte,prot
> 
Just more in short:

No more pb to build but failed to boot (d380 up 32bit kernel 2.6.17-pa5 + patch)?

EXT3-fs: mounted filesystem with ordered data mode.
VFS: Mounted root (ext3 filesystem) readonly.
Freeing unused kernel memory: 340k freed
Backtrace:
  [<10157788>] __handle_mm_fault+0x488/0x95c
  [<1010502c>] do_page_fault+0x258/0x2fc
  [<10107154>] handle_interruption+0x25c/0x608
  [<1010a080>] intr_check_sig+0x0/0xc


Kernel Fault: Code=26 regs=106e4340 (Addr=0f23c000)

      YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00000000000001001111111100001111 Not tainted
r00-03  0004ff0f 00000040 10157788 10000000
r04-07  1049e000 104a21e0 10447810 4023c06c
r08-11  1046c804 000001e0 104b3de0 104a73e4
r12-15  104cc3c0 fb1fb054 1014075c 1013e308
r16-19  106e1b58 103fa810 00000002 0000000f
r20-23  00000000 00000000 00000001 00000020
r24-27  00000280 4023c06c 000093c0 103d8010
r28-31  0f23c000 106e1b58 106e4340 4023b180
sr00-03  00000001 00000000 00000000 00000001
sr04-07  00000000 00000000 00000000 00000000

IASQ: 00000000 00000000 IAOQ: 10105eec 10105ef0
  IIR: 0f801280    ISR: 00000000  IOR: 0f23c000
  CPU:        0   CR30: 106e4000 CR31: 10464000
  ORIG_R28: fffffffe
  IAOQ[0]: __clear_user_page_asm+0x20/0x70
  IAOQ[1]: __clear_user_page_asm+0x24/0x70
  RP(r2): __handle_mm_fault+0x488/0x95c
Kernel panic - not syncing: Kernel Fault
  <0>Rebooting in 30 seconds..

Sorry no time enough to analyse it in more details ;<(

Joel