Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1240844

Re: Missing operand for tlbie instruction on Power7

Show all headers | View raw

On 10/05/2015 08:35 PM, Michael Ellerman wrote:
> On Fri, 2015-10-02 at 08:43 -0700, Laura Abbott wrote:
>> Hi,
>>
>> We received a report (https://bugzilla.redhat.com/show_bug.cgi?id=1267395) of bad assembly
>> when compiling on powerpc with little endian
>
> ...
>
>> After some discussion with the binutils folks, it turns out that the tlbie
>> instruction actually requires another operand and binutils was updated to
>> check for this https://sourceware.org/ml/binutils/2015-05/msg00133.html .
>>
>> The code sequence in arch/powerpc/include/asm/ppc_asm.h now needs to be updated:
>>
>> #if !defined(CONFIG_4xx) && !defined(CONFIG_8xx)
>> #define tlbia                                   \
>>           li      r4,1024;                        \
>>           mtctr   r4;                             \
>>           lis     r4,KERNELBASE@h;                \
>> 0:      tlbie   r4;                             \
>>           addi    r4,r4,0x1000;                   \
>>           bdnz    0b
>> #endif
>>
>> I don't know enough ppc assembly to properly fix this but I can test.
>
> How are you testing? This code is fairly old and I'm dubious if it still works.
>
> These days we have a ppc_md hook for flushing the TLB, ppc_md.flush_tlb().
> Ideally the swsusp code would use that.
>
> cheers
>
>

Testing would probably just be compile and maybe boot. I don't have regular
access to the hardware. This problem just showed up for me when someone
tried to compile Fedora rawhide with the latest binutils.

 From what I can tell, it looks like the .flush_tlb of the cpu_spec is only
defined for power7 and power8 and I don't see a ppc_md.flush_tlb on the
master branch. It's not clear what to do for the case where there is no
flush_tlb function. Would filling in a .flush_tlb for all the PPC_BOOK3S_64
with the existing tlbia sequence work? It's also worth noting that the
__flush_power7 uses tlbiel instead of tlbie.

Thanks,
Laura
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Re: Missing operand for tlbie instruction on Power7 Michael Ellerman <mpe@ellerman.id.au> - 2015-10-06 05:40 +0200
  Re: Missing operand for tlbie instruction on Power7 Laura Abbott <labbott@redhat.com> - 2015-10-06 20:30 +0200
    Re: Missing operand for tlbie instruction on Power7 Michael Ellerman <mpe@ellerman.id.au> - 2015-10-07 08:10 +0200
      Re: Missing operand for tlbie instruction on Power7 Segher Boessenkool <segher@kernel.crashing.org> - 2015-10-07 10:30 +0200
        Re: Missing operand for tlbie instruction on Power7 Michael Ellerman <mpe@ellerman.id.au> - 2015-10-07 11:20 +0200
          Re: Missing operand for tlbie instruction on Power7 Josh Boyer <jwboyer@fedoraproject.org> - 2015-10-07 16:40 +0200
            Re: Missing operand for tlbie instruction on Power7 Josh Boyer <jwboyer@fedoraproject.org> - 2015-10-08 02:20 +0200
              Re: Missing operand for tlbie instruction on Power7 Michael Ellerman <mpe@ellerman.id.au> - 2015-10-08 02:40 +0200
            Re: Missing operand for tlbie instruction on Power7 Michael Ellerman <mpe@ellerman.id.au> - 2015-10-08 02:20 +0200

csiph-web