// 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);