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| author | Ingo Molnar <mingo@kernel.org> | 2015-04-28 08:51:17 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-05-19 15:47:55 +0200 |
| commit | 5b07343034ec9ebb0d443743c7381b25875d0067 (patch) | |
| tree | fabe0f5a8c60c36a206fb3aa2135ed10bc4140a7 /arch/x86/include/asm/fpu/api.h | |
| parent | 62784854502895321d100b1004b486131b9dd286 (diff) | |
| download | linux-5b07343034ec9ebb0d443743c7381b25875d0067.tar.bz2 | |
x86/fpu: Introduce cpu_has_xfeatures(xfeatures_mask, feature_name)
A lot of FPU using driver code is querying complex CPU features to be
able to figure out whether a given set of xstate features is supported
by the CPU or not.
Introduce a simplified API function that can be used on any CPU type
to get this information. Also add an error string return pointer,
so that the driver can print a meaningful error message with a
standardized feature name.
Also mark xfeatures_mask as __read_only.
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/fpu/api.h')
| -rw-r--r-- | arch/x86/include/asm/fpu/api.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index 62035cc1d961..1429a7c736db 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -36,4 +36,13 @@ extern bool irq_fpu_usable(void); extern int irq_ts_save(void); extern void irq_ts_restore(int TS_state); +/* + * Query the presence of one or more xfeatures. Works on any legacy CPU as well. + * + * If 'feature_name' is set then put a human-readable description of + * the feature there as well - this can be used to print error (or success) + * messages. + */ +extern int cpu_has_xfeatures(u64 xfeatures_mask, const char **feature_name); + #endif /* _ASM_X86_FPU_API_H */ |