diff options
| author |   Juergen Gross <jgross@suse.com> | 2016-08-29 08:48:47 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2016-09-05 13:52:41 +0200 |
| commit | 27046a3ffbb01ba715e6236c170701c84759b61d (patch) | |
| tree | a14915541849c1dc9355a176ef204d1cbd7580d6 /drivers | |
| parent | dcdbas: Make use of smp_call_on_cpu() (diff) | |
| download | linux-dev-27046a3ffbb01ba715e6236c170701c84759b61d.tar.xz linux-dev-27046a3ffbb01ba715e6236c170701c84759b61d.zip | |
hwmon: Use smp_call_on_cpu() for dell-smm i8k
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>
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/1472453327-19050-7-git-send-email-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/hwmon/dell-smm-hwmon.c | 36 |
1 files changed, 20 insertions, 16 deletions
diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c index acf9c0361d9f..34704b0451b4 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> @@ -36,6 +37,7 @@ #include <linux/io.h> #include <linux/sched.h> #include <linux/ctype.h> +#include <linux/smp.h> #include <linux/i8k.h> @@ -134,11 +136,11 @@ 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; #ifdef DEBUG int ebx = regs->ebx; @@ -149,16 +151,8 @@ static int i8k_smm(struct smm_regs *regs) #endif /* 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" @@ -216,10 +210,6 @@ 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); - #ifdef DEBUG rettime = ktime_get(); delta = ktime_sub(rettime, calltime); @@ -232,6 +222,20 @@ out: } /* + * 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, i8k_smm_func, regs, true); + put_online_cpus(); + + return ret; +} + +/* * Read the fan status. */ static int i8k_get_fan_status(int fan) |