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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cpu_has_feature.h (1339B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2#ifndef __ASM_POWERPC_CPU_HAS_FEATURE_H
      3#define __ASM_POWERPC_CPU_HAS_FEATURE_H
      4
      5#ifndef __ASSEMBLY__
      6
      7#include <linux/bug.h>
      8#include <asm/cputable.h>
      9
     10static __always_inline bool early_cpu_has_feature(unsigned long feature)
     11{
     12	return !!((CPU_FTRS_ALWAYS & feature) ||
     13		  (CPU_FTRS_POSSIBLE & cur_cpu_spec->cpu_features & feature));
     14}
     15
     16#ifdef CONFIG_JUMP_LABEL_FEATURE_CHECKS
     17#include <linux/jump_label.h>
     18
     19#define NUM_CPU_FTR_KEYS	BITS_PER_LONG
     20
     21extern struct static_key_true cpu_feature_keys[NUM_CPU_FTR_KEYS];
     22
     23static __always_inline bool cpu_has_feature(unsigned long feature)
     24{
     25	int i;
     26
     27#ifndef __clang__ /* clang can't cope with this */
     28	BUILD_BUG_ON(!__builtin_constant_p(feature));
     29#endif
     30
     31#ifdef CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG
     32	if (!static_key_initialized) {
     33		printk("Warning! cpu_has_feature() used prior to jump label init!\n");
     34		dump_stack();
     35		return early_cpu_has_feature(feature);
     36	}
     37#endif
     38
     39	if (CPU_FTRS_ALWAYS & feature)
     40		return true;
     41
     42	if (!(CPU_FTRS_POSSIBLE & feature))
     43		return false;
     44
     45	i = __builtin_ctzl(feature);
     46	return static_branch_likely(&cpu_feature_keys[i]);
     47}
     48#else
     49static __always_inline bool cpu_has_feature(unsigned long feature)
     50{
     51	return early_cpu_has_feature(feature);
     52}
     53#endif
     54
     55#endif /* __ASSEMBLY__ */
     56#endif /* __ASM_POWERPC_CPU_HAS_FEATURE_H */