cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

word-at-a-time.h (1376B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2#ifndef _ASM_WORD_AT_A_TIME_H
      3#define _ASM_WORD_AT_A_TIME_H
      4
      5#include <asm/compiler.h>
      6
      7/*
      8 * word-at-a-time interface for Alpha.
      9 */
     10
     11/*
     12 * We do not use the word_at_a_time struct on Alpha, but it needs to be
     13 * implemented to humour the generic code.
     14 */
     15struct word_at_a_time {
     16	const unsigned long unused;
     17};
     18
     19#define WORD_AT_A_TIME_CONSTANTS { 0 }
     20
     21/* Return nonzero if val has a zero */
     22static inline unsigned long has_zero(unsigned long val, unsigned long *bits, const struct word_at_a_time *c)
     23{
     24	unsigned long zero_locations = __kernel_cmpbge(0, val);
     25	*bits = zero_locations;
     26	return zero_locations;
     27}
     28
     29static inline unsigned long prep_zero_mask(unsigned long val, unsigned long bits, const struct word_at_a_time *c)
     30{
     31	return bits;
     32}
     33
     34#define create_zero_mask(bits) (bits)
     35
     36static inline unsigned long find_zero(unsigned long bits)
     37{
     38#if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
     39	/* Simple if have CIX instructions */
     40	return __kernel_cttz(bits);
     41#else
     42	unsigned long t1, t2, t3;
     43	/* Retain lowest set bit only */
     44	bits &= -bits;
     45	/* Binary search for lowest set bit */
     46	t1 = bits & 0xf0;
     47	t2 = bits & 0xcc;
     48	t3 = bits & 0xaa;
     49	if (t1) t1 = 4;
     50	if (t2) t2 = 2;
     51	if (t3) t3 = 1;
     52	return t1 + t2 + t3;
     53#endif
     54}
     55
     56#define zero_bytemask(mask) ((2ul << (find_zero(mask) * 8)) - 1)
     57
     58#endif /* _ASM_WORD_AT_A_TIME_H */