From: Juergen Gross <jgross@suse.com>
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 <jgross@suse.com>
Subject: [PATCH v5 5/6] dcdbas: make use of smp_call_on_cpu()
Date: Wed, 6 Apr 2016 16:17:45 +0200 [thread overview]
Message-ID: <1459952266-3687-6-git-send-email-jgross@suse.com> (raw)
In-Reply-To: <1459952266-3687-1-git-send-email-jgross@suse.com>
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 <jgross@suse.com>
---
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 <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
+#include <linux/cpu.h>
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/kernel.h>
@@ -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
next prev parent reply other threads:[~2016-04-06 14:18 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-06 14:17 [PATCH v5 0/6] Support calling functions on dedicated physical cpu Juergen Gross
2016-04-06 14:17 ` [PATCH v5 1/6] xen: sync xen header Juergen Gross
2016-04-06 14:17 ` [PATCH v5 2/6] virt, sched: add generic vcpu pinning support Juergen Gross
2016-06-15 11:18 ` Juergen Gross
2016-04-06 14:17 ` [PATCH v5 3/6] smp: add function to execute a function synchronously on a cpu Juergen Gross
2016-04-06 18:04 ` Peter Zijlstra
2016-04-06 14:17 ` [PATCH v5 4/6] xen: add xen_pin_vcpu() to support calling functions on a dedicated pcpu Juergen Gross
2016-04-06 14:17 ` Juergen Gross [this message]
2016-06-15 11:19 ` [PATCH v5 5/6] dcdbas: make use of smp_call_on_cpu() Juergen Gross
2016-04-06 14:17 ` [PATCH v5 6/6] hwmon: use smp_call_on_cpu() for dell-smm i8k Juergen Gross
2016-06-13 19:05 ` Pali Rohár
2016-04-13 8:49 ` [PATCH v5 0/6] Support calling functions on dedicated physical cpu Juergen Gross
2016-05-17 11:21 ` Juergen Gross
2016-06-20 8:40 ` Juergen Gross
2016-06-27 10:34 ` Juergen Gross
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