diff options
Diffstat (limited to 'arch/x86/include')
-rw-r--r-- | arch/x86/include/asm/segment.h | 41 | ||||
-rw-r--r-- | arch/x86/include/asm/vgtod.h | 26 |
2 files changed, 41 insertions, 26 deletions
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h index e3e788ea52e5..4d1f6cc62e13 100644 --- a/arch/x86/include/asm/segment.h +++ b/arch/x86/include/asm/segment.h @@ -224,6 +224,47 @@ #define GDT_ENTRY_TLS_ENTRIES 3 #define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES* 8) +#ifdef CONFIG_X86_64 + +/* Bit size and mask of CPU number stored in the per CPU data (and TSC_AUX) */ +#define VDSO_CPU_SIZE 12 +#define VDSO_CPU_MASK 0xfff + +#ifndef __ASSEMBLY__ + +/* Helper functions to store/load CPU and node numbers */ + +static inline unsigned long vdso_encode_cpu_node(int cpu, unsigned long node) +{ + return ((node << VDSO_CPU_SIZE) | cpu); +} + +static inline void vdso_read_cpu_node(unsigned *cpu, unsigned *node) +{ + unsigned int p; + + /* + * Load CPU and node number from GDT. LSL is faster than RDTSCP + * and works on all CPUs. This is volatile so that it orders + * correctly with respect to barrier() and to keep GCC from cleverly + * hoisting it out of the calling function. + * + * If RDPID is available, use it. + */ + alternative_io ("lsl %[seg],%[p]", + ".byte 0xf3,0x0f,0xc7,0xf8", /* RDPID %eax/rax */ + X86_FEATURE_RDPID, + [p] "=a" (p), [seg] "r" (__CPU_NUMBER_SEG)); + + if (cpu) + *cpu = (p & VDSO_CPU_MASK); + if (node) + *node = (p >> VDSO_CPU_SIZE); +} + +#endif /* !__ASSEMBLY__ */ +#endif /* CONFIG_X86_64 */ + #ifdef __KERNEL__ /* diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h index 4e81ea920722..056a61c8c5c7 100644 --- a/arch/x86/include/asm/vgtod.h +++ b/arch/x86/include/asm/vgtod.h @@ -77,30 +77,4 @@ static inline void gtod_write_end(struct vsyscall_gtod_data *s) ++s->seq; } -#ifdef CONFIG_X86_64 - -#define VGETCPU_CPU_MASK 0xfff - -static inline unsigned int __getcpu(void) -{ - unsigned int p; - - /* - * Load CPU (and node) number from GDT. LSL is faster than RDTSCP - * and works on all CPUs. This is volatile so that it orders - * correctly with respect to barrier() and to keep GCC from cleverly - * hoisting it out of the calling function. - * - * If RDPID is available, use it. - */ - alternative_io ("lsl %[seg],%[p]", - ".byte 0xf3,0x0f,0xc7,0xf8", /* RDPID %eax/rax */ - X86_FEATURE_RDPID, - [p] "=a" (p), [seg] "r" (__CPU_NUMBER_SEG)); - - return p; -} - -#endif /* CONFIG_X86_64 */ - #endif /* _ASM_X86_VGTOD_H */ |