From: Michael Neuling mikey@neuling.org
[ Upstream commit 64ebb9a208c6e66316329a6d9101815d1ee06fa9 ]
The P9 PVR bits 12-15 don't indicate a revision but instead different chip configurations. From BookIV we have: Bits Configuration 0 : Scale out 12 cores 1 : Scale out 24 cores 2 : Scale up 12 cores 3 : Scale up 24 cores
DD1 doesn't use this but DD2 does. Linux will mostly use the "Scale out 24 core" configuration (ie. SMT4 not SMT8) which results in a PVR of 0x004e1200. The reported revision in /proc/cpuinfo is hence reported incorrectly as "18.0".
This patch fixes this to mask off only the relevant bits for the major revision (ie. bits 8-11) for POWER9.
Signed-off-by: Michael Neuling mikey@neuling.org Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- arch/powerpc/kernel/setup-common.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index 44c8d03558ac..aa25af44a971 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -310,6 +310,10 @@ static int show_cpuinfo(struct seq_file *m, void *v) maj = ((pvr >> 8) & 0xFF) - 1; min = pvr & 0xFF; break; + case 0x004e: /* POWER9 bits 12-15 give chip type */ + maj = (pvr >> 8) & 0x0F; + min = pvr & 0xFF; + break; default: maj = (pvr >> 8) & 0xFF; min = pvr & 0xFF;