diff options
| author | Matt Redfearn <matt.redfearn@imgtec.com> | 2016-09-22 11:59:47 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@google.com> | 2018-02-05 08:58:35 -0800 |
| commit | b4af2637b68c69878febbff5a392af838b9b57ff (patch) | |
| tree | 3c15b1c7cdfdabe1593ac20a961311902338c666 /arch/mips/kernel | |
| parent | 63a30ac54ee77099ebeae3c524d664c602f5b730 (diff) | |
UPSTREAM: 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>
(cherry picked from commit 6ca8ac773e97e2dfa5734ae435c40e672dd19ac4)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Diffstat (limited to 'arch/mips/kernel')
| -rw-r--r-- | arch/mips/kernel/smp-cps.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c index a211bbe82d0d..0ed4bfdaa65d 100644 --- a/arch/mips/kernel/smp-cps.c +++ b/arch/mips/kernel/smp-cps.c @@ -504,7 +504,7 @@ 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); mips_cpc_lock_other(core); stat = read_cpc_co_stat_conf(); stat &= CPC_Cx_STAT_CONF_SEQSTATE_MSK; |