From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753359AbcDFOSO (ORCPT ); Wed, 6 Apr 2016 10:18:14 -0400 Received: from mx2.suse.de ([195.135.220.15]:58306 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752953AbcDFOSK (ORCPT ); Wed, 6 Apr 2016 10:18:10 -0400 From: Juergen Gross To: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org Cc: boris.ostrovsky@oracle.com, david.vrabel@citrix.com, mingo@redhat.com, peterz@infradead.org, Douglas_Warzecha@dell.com, pali.rohar@gmail.com, jdelvare@suse.com, linux@roeck-us.net, tglx@linutronix.de, hpa@zytor.com, jeremy@goop.org, chrisw@sous-sol.org, akataria@vmware.com, rusty@rustcorp.com.au, virtualization@lists.linux-foundation.org, x86@kernel.org, Juergen Gross Subject: [PATCH v5 5/6] dcdbas: make use of smp_call_on_cpu() Date: Wed, 6 Apr 2016 16:17:45 +0200 Message-Id: <1459952266-3687-6-git-send-email-jgross@suse.com> X-Mailer: git-send-email 2.6.6 In-Reply-To: <1459952266-3687-1-git-send-email-jgross@suse.com> References: <1459952266-3687-1-git-send-email-jgross@suse.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use smp_call_on_cpu() to raise SMI on cpu 0. Make call secure by adding get_online_cpus() to avoid e.g. suspend resume cycles in between. Signed-off-by: Juergen Gross --- V4: add call to get_online_cpus() --- drivers/firmware/dcdbas.c | 51 ++++++++++++++++++++++++----------------------- 1 file changed, 26 insertions(+), 25 deletions(-) diff --git a/drivers/firmware/dcdbas.c b/drivers/firmware/dcdbas.c index 829eec8..2fe1a13 100644 --- a/drivers/firmware/dcdbas.c +++ b/drivers/firmware/dcdbas.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include #include @@ -238,33 +239,14 @@ static ssize_t host_control_on_shutdown_store(struct device *dev, return count; } -/** - * dcdbas_smi_request: generate SMI request - * - * Called with smi_data_lock. - */ -int dcdbas_smi_request(struct smi_cmd *smi_cmd) +static int raise_smi(void *par) { - cpumask_var_t old_mask; - int ret = 0; + struct smi_cmd *smi_cmd = par; - if (smi_cmd->magic != SMI_CMD_MAGIC) { - dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n", - __func__); - return -EBADR; - } - - /* SMI requires CPU 0 */ - if (!alloc_cpumask_var(&old_mask, GFP_KERNEL)) - return -ENOMEM; - - cpumask_copy(old_mask, ¤t->cpus_allowed); - set_cpus_allowed_ptr(current, cpumask_of(0)); if (smp_processor_id() != 0) { dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n", __func__); - ret = -EBUSY; - goto out; + return -EBUSY; } /* generate SMI */ @@ -280,9 +262,28 @@ int dcdbas_smi_request(struct smi_cmd *smi_cmd) : "memory" ); -out: - set_cpus_allowed_ptr(current, old_mask); - free_cpumask_var(old_mask); + return 0; +} +/** + * dcdbas_smi_request: generate SMI request + * + * Called with smi_data_lock. + */ +int dcdbas_smi_request(struct smi_cmd *smi_cmd) +{ + int ret; + + if (smi_cmd->magic != SMI_CMD_MAGIC) { + dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n", + __func__); + return -EBADR; + } + + /* SMI requires CPU 0 */ + get_online_cpus(); + ret = smp_call_on_cpu(0, raise_smi, smi_cmd, true); + put_online_cpus(); + return ret; } -- 2.6.6