diff options
authorMatt Redfearn <matt.redfearn@imgtec.com>2016-09-22 11:59:47 +0100
committerRalf Baechle <ralf@linux-mips.org>2016-09-29 18:59:49 +0200
commit6ca8ac773e97e2dfa5734ae435c40e672dd19ac4 (patch)
parent08895a8b6b06ed2323cd97a36ee40a116b3db8ed (diff)
MIPS: smp-cps: Avoid BUG() when offlining pre-r6 CPUs
Commit 0d2808f338c7 ("MIPS: smp-cps: Add support for CPU hotplug of MIPSr6 processors") added a call to mips_cm_lock_other in order to lock the CPC in CPUs containing a version 3 or higher Coherence Manager, which use the general CM core other register, where previous CMs had a dedicated core other register for the CPC. A kernel BUG() is triggered, however, if mips_cm_lock_other is called with a VP other than 0 on a CPU with CM < 3, a condition introduced by 0d2808f338c7. Avoid the BUG() by always locking VP0 when locking the CPC, since the required register, cpc_stat_conf, is shared by all vps in a core. Fixes: 0d2808f338c7 ("MIPS: smp-cps: Add support for CPU hotplug...) Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Qais Yousef <qsyousef@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14297/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
index e9d9fc6c754c..6183ad84cc73 100644
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -513,7 +513,7 @@ static void cps_cpu_die(unsigned int cpu)
* in which case the CPC will refuse to power down the core.
do {
- mips_cm_lock_other(core, vpe_id);
+ mips_cm_lock_other(core, 0);
stat = read_cpc_co_stat_conf();