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Diffstat (limited to '')
-rw-r--r-- | arch/powerpc/include/asm/cpu_has_feature.h | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/cpu_has_feature.h b/arch/powerpc/include/asm/cpu_has_feature.h new file mode 100644 index 000000000..727d4b321 --- /dev/null +++ b/arch/powerpc/include/asm/cpu_has_feature.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_POWERPC_CPU_HAS_FEATURE_H +#define __ASM_POWERPC_CPU_HAS_FEATURE_H + +#ifndef __ASSEMBLY__ + +#include <linux/bug.h> +#include <asm/cputable.h> + +static __always_inline bool early_cpu_has_feature(unsigned long feature) +{ + return !!((CPU_FTRS_ALWAYS & feature) || + (CPU_FTRS_POSSIBLE & cur_cpu_spec->cpu_features & feature)); +} + +#ifdef CONFIG_JUMP_LABEL_FEATURE_CHECKS +#include <linux/jump_label.h> + +#define NUM_CPU_FTR_KEYS BITS_PER_LONG + +extern struct static_key_true cpu_feature_keys[NUM_CPU_FTR_KEYS]; + +static __always_inline bool cpu_has_feature(unsigned long feature) +{ + int i; + +#ifndef __clang__ /* clang can't cope with this */ + BUILD_BUG_ON(!__builtin_constant_p(feature)); +#endif + +#ifdef CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG + if (!static_key_initialized) { + printk("Warning! cpu_has_feature() used prior to jump label init!\n"); + dump_stack(); + return early_cpu_has_feature(feature); + } +#endif + + if (CPU_FTRS_ALWAYS & feature) + return true; + + if (!(CPU_FTRS_POSSIBLE & feature)) + return false; + + i = __builtin_ctzl(feature); + return static_branch_likely(&cpu_feature_keys[i]); +} +#else +static __always_inline bool cpu_has_feature(unsigned long feature) +{ + return early_cpu_has_feature(feature); +} +#endif + +#endif /* __ASSEMBLY__ */ +#endif /* __ASM_POWERPC_CPU_HAS_FEATURE_H */ |