arch/powerpc/kernel/vdso64/getcpu.S

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  *
   4  * Copyright (C) IBM Corporation, 2012
   5  *
   6  * Author: Anton Blanchard <anton@au.ibm.com>
   7  */
   8 #include <asm/ppc_asm.h>
   9 #include <asm/vdso.h>
  10
  11         .text
  12 /*
  13  * Exact prototype of getcpu
  14  *
  15  * int __kernel_getcpu(unsigned *cpu, unsigned *node);
  16  *
  17  */
  18 V_FUNCTION_BEGIN(__kernel_getcpu)
  19   .cfi_startproc
  20         mfspr   r5,SPRN_SPRG_VDSO_READ
  21         cmpdi   cr0,r3,0
  22         cmpdi   cr1,r4,0
  23         clrlwi  r6,r5,16
  24         rlwinm  r7,r5,16,31-15,31-0
  25         beq     cr0,1f
  26         stw     r6,0(r3)
  27 1:      beq     cr1,2f
  28         stw     r7,0(r4)
  29 2:      crclr   cr0*4+so
  30         li      r3,0                    /* always success */
  31         blr
  32   .cfi_endproc
  33 V_FUNCTION_END(__kernel_getcpu)