From: Juergen Gross <jgross@suse.com>
To: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org
Cc: Juergen Gross <jgross@suse.com>,
jeremy@goop.org, jdelvare@suse.com, peterz@infradead.org,
hpa@zytor.com, akataria@vmware.com, x86@kernel.org,
rusty@rustcorp.com.au, virtualization@lists.linux-foundation.org,
chrisw@sous-sol.org, mingo@redhat.com, david.vrabel@citrix.com,
Douglas_Warzecha@dell.com, pali.rohar@gmail.com,
boris.ostrovsky@oracle.com, tglx@linutronix.de,
linux@roeck-us.net
Subject: [PATCH v4 6/6] hwmon: use smp_call_on_cpu() for dell-smm i8k
Date: Tue, 5 Apr 2016 07:10:07 +0200 [thread overview]
Message-ID: <1459833007-11618-7-git-send-email-jgross__18782.1288397119$1459833116$gmane$org@suse.com> (raw)
In-Reply-To: <1459833007-11618-1-git-send-email-jgross@suse.com>
Use the smp_call_on_cpu() function to call system management
mode 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 <jgross@suse.com>
---
V4: add call to get_online_cpus()
---
drivers/hwmon/dell-smm-hwmon.c | 35 ++++++++++++++++++++---------------
1 file changed, 20 insertions(+), 15 deletions(-)
diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
index c43318d..643f3a1 100644
--- a/drivers/hwmon/dell-smm-hwmon.c
+++ b/drivers/hwmon/dell-smm-hwmon.c
@@ -21,6 +21,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/types.h>
@@ -35,6 +36,7 @@
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/sched.h>
+#include <linux/smp.h>
#include <linux/i8k.h>
@@ -130,23 +132,15 @@ static inline const char *i8k_get_dmi_data(int field)
/*
* Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
*/
-static int i8k_smm(struct smm_regs *regs)
+static int i8k_smm_func(void *par)
{
int rc;
+ struct smm_regs *regs = par;
int eax = regs->eax;
- cpumask_var_t old_mask;
/* SMM requires CPU 0 */
- if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
- return -ENOMEM;
- cpumask_copy(old_mask, ¤t->cpus_allowed);
- rc = set_cpus_allowed_ptr(current, cpumask_of(0));
- if (rc)
- goto out;
- if (smp_processor_id() != 0) {
- rc = -EBUSY;
- goto out;
- }
+ if (smp_processor_id() != 0)
+ return -EBUSY;
#if defined(CONFIG_X86_64)
asm volatile("pushq %%rax\n\t"
@@ -204,13 +198,24 @@ static int i8k_smm(struct smm_regs *regs)
if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
rc = -EINVAL;
-out:
- set_cpus_allowed_ptr(current, old_mask);
- free_cpumask_var(old_mask);
return rc;
}
/*
+ * Call the System Management Mode BIOS.
+ */
+static int i8k_smm(struct smm_regs *regs)
+{
+ int ret;
+
+ get_online_cpus();
+ ret = smp_call_on_cpu(0, true, i8k_smm_func, regs);
+ put_online_cpus();
+
+ return ret;
+}
+
+/*
* Read the fan status.
*/
static int i8k_get_fan_status(int fan)
--
2.6.2
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next prev parent reply other threads:[~2016-04-05 5:10 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1459833007-11618-1-git-send-email-jgross@suse.com>
2016-04-05 5:10 ` [PATCH v4 1/6] xen: sync xen header Juergen Gross
2016-04-05 5:10 ` [PATCH v4 2/6] virt, sched: add generic vcpu pinning support Juergen Gross
2016-04-05 5:10 ` [PATCH v4 3/6] smp: add function to execute a function synchronously on a cpu Juergen Gross
2016-04-05 5:10 ` [PATCH v4 4/6] xen: add xen_pin_vcpu() to support calling functions on a dedicated pcpu Juergen Gross
2016-04-05 5:10 ` [PATCH v4 5/6] dcdbas: make use of smp_call_on_cpu() Juergen Gross
2016-04-05 5:10 ` Juergen Gross [this message]
[not found] ` <1459833007-11618-4-git-send-email-jgross@suse.com>
2016-04-05 8:11 ` [PATCH v4 3/6] smp: add function to execute a function synchronously on a cpu Peter Zijlstra
[not found] ` <20160405081107.GH3448@twins.programming.kicks-ass.net>
2016-04-05 10:05 ` Juergen Gross
[not found] ` <1459833007-11618-2-git-send-email-jgross@suse.com>
2016-04-05 9:34 ` [PATCH v4 1/6] xen: sync xen header David Vrabel
[not found] ` <1459833007-11618-5-git-send-email-jgross@suse.com>
2016-04-05 9:45 ` [PATCH v4 4/6] xen: add xen_pin_vcpu() to support calling functions on a dedicated pcpu David Vrabel
[not found] ` <57038927.1030205@citrix.com>
2016-04-05 10:01 ` Juergen Gross
[not found] ` <57038D0E.1040708@suse.com>
2016-04-05 10:03 ` David Vrabel
[not found] ` <1459833007-11618-7-git-send-email-jgross@suse.com>
2016-04-05 14:54 ` [PATCH v4 6/6] hwmon: use smp_call_on_cpu() for dell-smm i8k Guenter Roeck
[not found] ` <20160405145414.GB27359@roeck-us.net>
2016-04-05 19:31 ` Pali Rohár
[not found] ` <201604052131.52765@pali>
2016-04-21 10:57 ` Pali Rohár
[not found] ` <20160421105724.GK29406@pali>
2016-04-21 13:12 ` Juergen Gross
[not found] ` <5718D1D4.3040309@suse.com>
2016-04-21 13:27 ` Pali Rohár
[not found] ` <20160421132735.GR29406@pali>
2016-05-09 14:37 ` Juergen Gross
[not found] ` <5730A08D.60100@suse.com>
2016-05-12 8:51 ` Pali Rohár
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