| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Fast user context implementation of getcpu() |
| */ |
| |
| #include <asm/vdso.h> |
| #include <linux/getcpu.h> |
| |
| static __always_inline int read_cpu_id(void) |
| { |
| int cpu_id; |
| |
| __asm__ __volatile__( |
| " rdtime.d $zero, %0\n" |
| : "=r" (cpu_id) |
| : |
| : "memory"); |
| |
| return cpu_id; |
| } |
| |
| extern |
| int __vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused); |
| int __vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused) |
| { |
| int cpu_id; |
| |
| cpu_id = read_cpu_id(); |
| |
| if (cpu) |
| *cpu = cpu_id; |
| |
| if (node) |
| *node = vdso_u_arch_data.pdata[cpu_id].node; |
| |
| return 0; |
| } |
