cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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flex_proportions.h (2899B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2/*
      3 * Floating proportions with flexible aging period
      4 *
      5 *  Copyright (C) 2011, SUSE, Jan Kara <jack@suse.cz>
      6 */
      7
      8#ifndef _LINUX_FLEX_PROPORTIONS_H
      9#define _LINUX_FLEX_PROPORTIONS_H
     10
     11#include <linux/percpu_counter.h>
     12#include <linux/spinlock.h>
     13#include <linux/seqlock.h>
     14#include <linux/gfp.h>
     15
     16/*
     17 * When maximum proportion of some event type is specified, this is the
     18 * precision with which we allow limitting. Note that this creates an upper
     19 * bound on the number of events per period like
     20 *   ULLONG_MAX >> FPROP_FRAC_SHIFT.
     21 */
     22#define FPROP_FRAC_SHIFT 10
     23#define FPROP_FRAC_BASE (1UL << FPROP_FRAC_SHIFT)
     24
     25/*
     26 * ---- Global proportion definitions ----
     27 */
     28struct fprop_global {
     29	/* Number of events in the current period */
     30	struct percpu_counter events;
     31	/* Current period */
     32	unsigned int period;
     33	/* Synchronization with period transitions */
     34	seqcount_t sequence;
     35};
     36
     37int fprop_global_init(struct fprop_global *p, gfp_t gfp);
     38void fprop_global_destroy(struct fprop_global *p);
     39bool fprop_new_period(struct fprop_global *p, int periods);
     40
     41/*
     42 *  ---- SINGLE ----
     43 */
     44struct fprop_local_single {
     45	/* the local events counter */
     46	unsigned long events;
     47	/* Period in which we last updated events */
     48	unsigned int period;
     49	raw_spinlock_t lock;	/* Protect period and numerator */
     50};
     51
     52#define INIT_FPROP_LOCAL_SINGLE(name)			\
     53{	.lock = __RAW_SPIN_LOCK_UNLOCKED(name.lock),	\
     54}
     55
     56int fprop_local_init_single(struct fprop_local_single *pl);
     57void fprop_local_destroy_single(struct fprop_local_single *pl);
     58void __fprop_inc_single(struct fprop_global *p, struct fprop_local_single *pl);
     59void fprop_fraction_single(struct fprop_global *p,
     60	struct fprop_local_single *pl, unsigned long *numerator,
     61	unsigned long *denominator);
     62
     63static inline
     64void fprop_inc_single(struct fprop_global *p, struct fprop_local_single *pl)
     65{
     66	unsigned long flags;
     67
     68	local_irq_save(flags);
     69	__fprop_inc_single(p, pl);
     70	local_irq_restore(flags);
     71}
     72
     73/*
     74 * ---- PERCPU ----
     75 */
     76struct fprop_local_percpu {
     77	/* the local events counter */
     78	struct percpu_counter events;
     79	/* Period in which we last updated events */
     80	unsigned int period;
     81	raw_spinlock_t lock;	/* Protect period and numerator */
     82};
     83
     84int fprop_local_init_percpu(struct fprop_local_percpu *pl, gfp_t gfp);
     85void fprop_local_destroy_percpu(struct fprop_local_percpu *pl);
     86void __fprop_add_percpu(struct fprop_global *p, struct fprop_local_percpu *pl,
     87		long nr);
     88void __fprop_add_percpu_max(struct fprop_global *p,
     89		struct fprop_local_percpu *pl, int max_frac, long nr);
     90void fprop_fraction_percpu(struct fprop_global *p,
     91	struct fprop_local_percpu *pl, unsigned long *numerator,
     92	unsigned long *denominator);
     93
     94static inline
     95void fprop_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl)
     96{
     97	unsigned long flags;
     98
     99	local_irq_save(flags);
    100	__fprop_add_percpu(p, pl, 1);
    101	local_irq_restore(flags);
    102}
    103
    104#endif