linux-kernel - Re: Missing operand for tlbie instruction on Power7

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Message-ID: <1444102518.16909.3.camel@ellerman.id.au>
Date:	Tue, 06 Oct 2015 14:35:18 +1100
From:	Michael Ellerman <mpe@...erman.id.au>
To:	Laura Abbott <labbott@...hat.com>
Cc:	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Paul Mackerras <paulus@...ba.org>,
	"linuxppc-dev@...ts.ozlabs.org" <linuxppc-dev@...ts.ozlabs.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: Missing operand for tlbie instruction on Power7

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


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