arch/powerpc/kernel/epapr_hcalls.S

   1 /*
   2  * Copyright (C) 2012 Freescale Semiconductor, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version
   7  * 2 of the License, or (at your option) any later version.
   8  */
   9
  10 #include <linux/threads.h>
  11 #include <asm/epapr_hcalls.h>
  12 #include <asm/reg.h>
  13 #include <asm/page.h>
  14 #include <asm/cputable.h>
  15 #include <asm/thread_info.h>
  16 #include <asm/ppc_asm.h>
  17 #include <asm/asm-compat.h>
  18 #include <asm/asm-offsets.h>
  19
  20 #ifndef CONFIG_PPC64
  21 /* epapr_ev_idle() was derived from e500_idle() */
  22 _GLOBAL(epapr_ev_idle)
  23         CURRENT_THREAD_INFO(r3, r1)
  24         PPC_LL  r4, TI_LOCAL_FLAGS(r3)  /* set napping bit */
  25         ori     r4, r4,_TLF_NAPPING     /* so when we take an exception */
  26         PPC_STL r4, TI_LOCAL_FLAGS(r3)  /* it will return to our caller */
  27
  28         wrteei  1
  29
  30 idle_loop:
  31         LOAD_REG_IMMEDIATE(r11, EV_HCALL_TOKEN(EV_IDLE))
  32
  33 .global epapr_ev_idle_start
  34 epapr_ev_idle_start:
  35         li      r3, -1
  36         nop
  37         nop
  38         nop
  39
  40         /*
  41          * Guard against spurious wakeups from a hypervisor --
  42          * only interrupt will cause us to return to LR due to
  43          * _TLF_NAPPING.
  44          */
  45         b       idle_loop
  46 #endif
  47
  48 /* Hypercall entry point. Will be patched with device tree instructions. */
  49 .global epapr_hypercall_start
  50 epapr_hypercall_start:
  51         li      r3, -1
  52         nop
  53         nop
  54         nop
  55         blr