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// SPDX-License-Identifier: GPL-2.0
#include <linux/export.h>
#include <linux/types.h>
#include <linux/bits.h>
#include "probe.h"
static umode_t
not_visible(struct kobject *kobj, struct attribute *attr, int i)
{
return 0;
}
/*
* Accepts msr[] array with non populated entries as long as either
* msr[i].msr is 0 or msr[i].grp is NULL. Note that the default sysfs
* visibility is visible when group->is_visible callback is set.
*/
unsigned long
perf_msr_probe(struct perf_msr *msr, int cnt, bool zero, void *data)
{
unsigned long avail = 0;
unsigned int bit;
u64 val;
if (cnt >= BITS_PER_LONG)
return 0;
for (bit = 0; bit < cnt; bit++) {
if (!msr[bit].no_check) {
struct attribute_group *grp = msr[bit].grp;
/* skip entry with no group */
if (!grp)
continue;
grp->is_visible = not_visible;
/* skip unpopulated entry */
if (!msr[bit].msr)
continue;
if (msr[bit].test && !msr[bit].test(bit, data))
continue;
/* Virt sucks; you cannot tell if a R/O MSR is present :/ */
if (rdmsrl_safe(msr[bit].msr, &val))
continue;
/* Disable zero counters if requested. */
if (!zero && !val)
continue;
grp->is_visible = NULL;
}
avail |= BIT(bit);
}
return avail;
}
EXPORT_SYMBOL_GPL(perf_msr_probe);
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