On Sat, 2007-10-27 at 14:19 +1000, Benjamin Herrenschmidt wrote:
> On Fri, 2007-10-26 at 15:46 -0500, Will Schmidt wrote:
> > [Powerpc] fix switch_slb handling of 1T ESID values
> >
> > Now that we have 1TB segment size support, we need to be using the
> > GET_ESID_1T macro when comparing ESID values for pc,stack, and
> > unmapped_base within switch_slb() when we're on a CPU that supports it.
> >
> > This also happens to fix a duplicate-slb-entry inspired machine-check
> > exception I was seeing when trying to run java on a power6 partition.
> >
> > Tested on power6 and power5.
> >
> > Signed-Off-By: Will Schmidt <[EMAIL PROTECTED]>
>
> Good catch !
>
> A minor comment is maybe you could factor out the code better doing
> something like a ESID_COMPARE() macro ?
Yeah, thats a good idea. I'll spin up a new patch in the next day or
so.
It occurred to me that I should continue to use GET_ESID when the user
address is < 1T too.
>
> > ---
> >
> > There is a similar bit of code in stab.c switch_stab(). Should this change
> > also be made there?
> > ---
>
> There is no machine that does stab and 1T segments.
Ok, thanks for the clarification.
-Will
>
> Ben.
>
> >
> > arch/powerpc/mm/slb.c | 19 ++++++++++++++-----
> > 1 files changed, 14 insertions(+), 5 deletions(-)
> >
> >
> > diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
> > index bbd2c51..0c527d7 100644
> > --- a/arch/powerpc/mm/slb.c
> > +++ b/arch/powerpc/mm/slb.c
> > @@ -193,16 +193,25 @@ void switch_slb(struct task_struct *tsk, struct
> > mm_struct *mm)
> > return;
> > slb_allocate(pc);
> >
> > - if (GET_ESID(pc) == GET_ESID(stack))
> > - return;
> > + if (cpu_has_feature(CPU_FTR_1T_SEGMENT)) {
> > + if (GET_ESID_1T(pc) == GET_ESID_1T(stack))
> > + return;
> > + } else
> > + if (GET_ESID(pc) == GET_ESID(stack))
> > + return;
> >
> > if (is_kernel_addr(stack))
> > return;
> > slb_allocate(stack);
> >
> > - if ((GET_ESID(pc) == GET_ESID(unmapped_base))
> > - || (GET_ESID(stack) == GET_ESID(unmapped_base)))
> > - return;
> > + if (cpu_has_feature(CPU_FTR_1T_SEGMENT)) {
> > + if ((GET_ESID_1T(pc) == GET_ESID_1T(unmapped_base))
> > + || (GET_ESID_1T(stack) == GET_ESID_1T(unmapped_base)))
> > + return;
> > + } else
> > + if ((GET_ESID(pc) == GET_ESID(unmapped_base))
> > + || (GET_ESID(stack) == GET_ESID(unmapped_base)))
> > + return;
> >
> > if (is_kernel_addr(unmapped_base))
> > return;
> >
> >
> > _______________________________________________
> > Linuxppc-dev mailing list
> > Linuxppc-dev@ozlabs.org
> > https://ozlabs.org/mailman/listinfo/linuxppc-dev
>
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