diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/x86/vdso/vgetcpu.c')
-rw-r--r-- | ANDROID_3.4.5/arch/x86/vdso/vgetcpu.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/arch/x86/vdso/vgetcpu.c b/ANDROID_3.4.5/arch/x86/vdso/vgetcpu.c new file mode 100644 index 00000000..5463ad55 --- /dev/null +++ b/ANDROID_3.4.5/arch/x86/vdso/vgetcpu.c @@ -0,0 +1,35 @@ +/* + * Copyright 2006 Andi Kleen, SUSE Labs. + * Subject to the GNU Public License, v.2 + * + * Fast user context implementation of getcpu() + */ + +#include <linux/kernel.h> +#include <linux/getcpu.h> +#include <linux/jiffies.h> +#include <linux/time.h> +#include <asm/vsyscall.h> +#include <asm/vgtod.h> + +notrace long +__vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused) +{ + unsigned int p; + + if (VVAR(vgetcpu_mode) == VGETCPU_RDTSCP) { + /* Load per CPU data from RDTSCP */ + native_read_tscp(&p); + } else { + /* Load per CPU data from GDT */ + asm("lsl %1,%0" : "=r" (p) : "r" (__PER_CPU_SEG)); + } + if (cpu) + *cpu = p & 0xfff; + if (node) + *node = p >> 12; + return 0; +} + +long getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache) + __attribute__((weak, alias("__vdso_getcpu"))); |