From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757895AbcFAKFA (ORCPT ); Wed, 1 Jun 2016 06:05:00 -0400 Received: from mail.skyhub.de ([78.46.96.112]:39555 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757713AbcFAKE6 (ORCPT ); Wed, 1 Jun 2016 06:04:58 -0400 From: Borislav Petkov To: linux-hwmon@vger.kernel.org Cc: X86 ML , LKML , Rui Huang , Sherry Hurwitz , Guenter Roeck Subject: [PATCH] hwmon: (fam15h_power) Disable preemption when reading registers Date: Wed, 1 Jun 2016 12:04:46 +0200 Message-Id: <1464775486-23446-1-git-send-email-bp@alien8.de> X-Mailer: git-send-email 2.7.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Borislav Petkov We need to read a bunch of registers on each compute unit and possibly on the current CPU too. Disable preemption around it. Signed-off-by: Borislav Petkov Cc: Rui Huang Cc: Sherry Hurwitz Cc: Guenter Roeck --- drivers/hwmon/fam15h_power.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/hwmon/fam15h_power.c b/drivers/hwmon/fam15h_power.c index eb97a9241d17..69bb810f528b 100644 --- a/drivers/hwmon/fam15h_power.c +++ b/drivers/hwmon/fam15h_power.c @@ -172,9 +172,9 @@ static void do_read_registers_on_cu(void *_data) */ static int read_registers(struct fam15h_power_data *data) { - int this_cpu, ret, cpu; int core, this_core; cpumask_var_t mask; + int ret, cpu; ret = zalloc_cpumask_var(&mask, GFP_KERNEL); if (!ret) @@ -183,7 +183,6 @@ static int read_registers(struct fam15h_power_data *data) memset(data->cu_on, 0, sizeof(int) * MAX_CUS); get_online_cpus(); - this_cpu = smp_processor_id(); /* * Choose the first online core of each compute unit, and then @@ -205,10 +204,13 @@ static int read_registers(struct fam15h_power_data *data) cpumask_set_cpu(cpumask_any(topology_sibling_cpumask(cpu)), mask); } - if (cpumask_test_cpu(this_cpu, mask)) + preempt_disable(); + smp_call_function_many(mask, do_read_registers_on_cu, data, true); + + if (cpumask_test_cpu(smp_processor_id(), mask)) do_read_registers_on_cu(data); - smp_call_function_many(mask, do_read_registers_on_cu, data, true); + preempt_enable(); put_online_cpus(); free_cpumask_var(mask); -- 2.7.3