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 ? > > 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
