summaryrefslogtreecommitdiff
path: root/arch/x86/events/probe.c
blob: c2ede2f3b27702ae4dab76217626447e7b05ec70 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
// 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;
}

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;

			grp->is_visible = not_visible;

			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);