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dcdbas: Make use of smp_call_on_cpu()

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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>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Douglas_Warzecha@dell.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akataria@vmware.com
Cc: boris.ostrovsky@oracle.com
Cc: chrisw@sous-sol.org
Cc: david.vrabel@citrix.com
Cc: hpa@zytor.com
Cc: jdelvare@suse.com
Cc: jeremy@goop.org
Cc: linux@roeck-us.net
Cc: pali.rohar@gmail.com
Cc: rusty@rustcorp.com.au
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1472453327-19050-6-git-send-email-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Juergen Gross 2016-08-29 08:48:46 +02:00 committed by Ingo Molnar
parent 99bc67536d
commit e23f22b5cb
1 changed files with 26 additions and 25 deletions
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51
drivers/firmware/dcdbas.c
View file

@ -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, &current->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;
}