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powerpc: Make sysfs code use smp_call_function_single

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Impact: performance improvement

This fixes 'powerpc: avoid cpumask games in arch/powerpc/kernel/sysfs.c'
which talked about using smp_call_function_single, but actually used
work_on_cpu (an older version of the patch).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Rusty Russell 2009-03-11 12:20:05 +00:00 committed by Benjamin Herrenschmidt
parent c5785f9e1c
commit 9a3719341a
1 changed files with 6 additions and 25 deletions
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31
arch/powerpc/kernel/sysfs.c
View file

@ -134,36 +134,16 @@ void ppc_enable_pmcs(void)
}
EXPORT_SYMBOL(ppc_enable_pmcs);
#if defined(CONFIG_6xx) || defined(CONFIG_PPC64)
/* XXX convert to rusty's on_one_cpu */
static unsigned long run_on_cpu(unsigned long cpu,
unsigned long (*func)(unsigned long),
unsigned long arg)
{
cpumask_t old_affinity = current->cpus_allowed;
unsigned long ret;
/* should return -EINVAL to userspace */
if (set_cpus_allowed(current, cpumask_of_cpu(cpu)))
return 0;
ret = func(arg);
set_cpus_allowed(current, old_affinity);
return ret;
}
#endif
#define SYSFS_PMCSETUP(NAME, ADDRESS) \
static unsigned long read_##NAME(unsigned long junk) \
static void read_##NAME(void *val) \
{ \
return mfspr(ADDRESS); \
mtspr(ADDRESS, *(unsigned long *)val); \
} \
static unsigned long write_##NAME(unsigned long val) \
{ \
ppc_enable_pmcs(); \
mtspr(ADDRESS, val); \
mtspr(ADDRESS, *(unsigned long *)val); \
return 0; \
} \
static ssize_t show_##NAME(struct sys_device *dev, \
@ -171,7 +151,8 @@ static ssize_t show_##NAME(struct sys_device *dev, \
char *buf) \
{ \
struct cpu *cpu = container_of(dev, struct cpu, sysdev); \
unsigned long val = run_on_cpu(cpu->sysdev.id, read_##NAME, 0); \
unsigned long val; \
smp_call_function_single(cpu->sysdev.id, read_##NAME, &val, 1); \
return sprintf(buf, "%lx\n", val); \
} \
static ssize_t __used \
@ -183,7 +164,7 @@ static ssize_t __used \
int ret = sscanf(buf, "%lx", &val); \
if (ret != 1) \
return -EINVAL; \
run_on_cpu(cpu->sysdev.id, write_##NAME, val); \
smp_call_function_single(cpu->sysdev.id, write_##NAME, &val, 1); \
return count; \
}