On 07/10/2013 07:41 PM, Aneesh Kumar K.V wrote: > Mahesh J Salgaonkar <[email protected]> writes: > >> From: Mahesh Salgaonkar <[email protected]> >> >> During Machine Check interrupt on pseries platform, R3 generally points to >> memory region inside RTAS (FWNMI) area. We see r3 corruption because when >> RTAS >> delivers the machine check exception it passes the address inside FWNMI area >> with the top most bit set. This patch fixes this issue by masking top two bit >> in machine check exception handler. > > I always got that error and used to wonder why I find FWNMI > corrupt. IS this a rtas bug or is it documented in papr ?
Nope. There is no mention of it in PAPR. It looks like a bug in RTAS. > > >> >> Signed-off-by: Mahesh Salgaonkar <[email protected]> >> --- >> arch/powerpc/platforms/pseries/ras.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/arch/powerpc/platforms/pseries/ras.c >> b/arch/powerpc/platforms/pseries/ras.c >> index 7b3cbde..721c058 100644 >> --- a/arch/powerpc/platforms/pseries/ras.c >> +++ b/arch/powerpc/platforms/pseries/ras.c >> @@ -287,6 +287,9 @@ static struct rtas_error_log *fwnmi_get_errinfo(struct >> pt_regs *regs) >> unsigned long *savep; >> struct rtas_error_log *h, *errhdr = NULL; >> >> + /* Mask top two bits */ >> + regs->gpr[3] &= ~(0x3UL << 62); >> + >> if (!VALID_FWNMI_BUFFER(regs->gpr[3])) { >> printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]); >> return NULL; >> > > -aneesh > > _______________________________________________ > Linuxppc-dev mailing list > [email protected] > https://lists.ozlabs.org/listinfo/linuxppc-dev > _______________________________________________ Linuxppc-dev mailing list [email protected] https://lists.ozlabs.org/listinfo/linuxppc-dev
