arch/powerpc/kernel/vdso/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 #if defined(CONFIG_PPC64)
  19 V_FUNCTION_BEGIN(__kernel_getcpu)
  20   .cfi_startproc
  21         mfspr   r5,SPRN_SPRG_VDSO_READ
  22         PPC_LCMPI       cr0,r3,0
  23         PPC_LCMPI       cr1,r4,0
  24         clrlwi  r6,r5,16
  25         rlwinm  r7,r5,16,31-15,31-0
  26         beq     cr0,1f
  27         stw     r6,0(r3)
  28 1:      crclr   cr0*4+so
  29         li      r3,0                    /* always success */
  30         beqlr   cr1
  31         stw     r7,0(r4)
  32         blr
  33   .cfi_endproc
  34 V_FUNCTION_END(__kernel_getcpu)
  35 #elif !defined(CONFIG_SMP)
  36 V_FUNCTION_BEGIN(__kernel_getcpu)
  37   .cfi_startproc
  38         cmpwi   cr0, r3, 0
  39         cmpwi   cr1, r4, 0
  40         li      r5, 0
  41         beq     cr0, 1f
  42         stw     r5, 0(r3)
  43 1:      li      r3, 0                   /* always success */
  44         crclr   cr0*4+so
  45         beqlr   cr1
  46         stw     r5, 0(r4)
  47         blr
  48   .cfi_endproc
  49 V_FUNCTION_END(__kernel_getcpu)
  50 #endif