From a70b487b07cf4201bc6702e7f646fa593b23009f Mon Sep 17 00:00:00 2001
From: Michael Ellerman <mpe@ellerman.id.au>
Date: Mon, 17 Jul 2017 21:19:01 +1000
Subject: [PATCH] powerpc/powernv: Fix boot on Power8 bare metal due to
opal_configure_cores()
References: bsc#1055117, fate#323286
Patch-mainline: v4.13-rc2
Git-commit: a70b487b07cf4201bc6702e7f646fa593b23009f
In commit 1c0eaf0f56d6 ("powerpc/powernv: Tell OPAL about our MMU mode
on POWER9"), we added additional flags to the OPAL call to configure
CPUs at boot.
These flags only work on Power9 firmwares, and worse can cause boot
failures on Power8 machines, so we check for CPU_FTR_ARCH_300 (aka POWER9)
before adding the extra flags.
Unfortunately we forgot that opal_configure_cores() is called before
the CPU feature checks are dynamically patched, meaning the check
always returns true.
We definitely need to do something to make the CPU feature checks less
prone to bugs like this, but for now the minimal fix is to use
early_cpu_has_feature().
Reported-and-tested-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Fixes: 1c0eaf0f56d6 ("powerpc/powernv: Tell OPAL about our MMU mode on POWER9")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/platforms/powernv/opal.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 9b87abb178f0..cad6b57ce494 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -78,7 +78,7 @@ void opal_configure_cores(void)
* ie. Host hash supports hash guests
* Host radix supports hash/radix guests
*/
- if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+ if (early_cpu_has_feature(CPU_FTR_ARCH_300)) {
reinit_flags |= OPAL_REINIT_CPUS_MMU_HASH;
if (early_radix_enabled())
reinit_flags |= OPAL_REINIT_CPUS_MMU_RADIX;
--
2.10.2