LXR linux/arch/powerpc/kernel/idle

   1/*
   2 *  This file contains the power_save function for 970-family CPUs.
   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/processor.h>
  12#include <asm/page.h>
  13#include <asm/cputable.h>
  14#include <asm/thread_info.h>
  15#include <asm/ppc_asm.h>
  16#include <asm/asm-offsets.h>
  17#include <asm/irqflags.h>
  18
  19#undef DEBUG
  20
  21        .text
  22
  23_GLOBAL(power4_idle)
  24BEGIN_FTR_SECTION
  25        blr
  26END_FTR_SECTION_IFCLR(CPU_FTR_CAN_NAP)
  27        /* Now check if user or arch enabled NAP mode */
  28        LOAD_REG_ADDRBASE(r3,powersave_nap)
  29        lwz     r4,ADDROFF(powersave_nap)(r3)
  30        cmpwi   0,r4,0
  31        beqlr
  32
  33        /* Hard disable interrupts */
  34        mfmsr   r7
  35        rldicl  r0,r7,48,1
  36        rotldi  r0,r0,16
  37        mtmsrd  r0,1
  38
  39        /* Check if something happened while soft-disabled */
  40        lbz     r0,PACAIRQHAPPENED(r13)
  41        cmpwi   cr0,r0,0
  42        bnelr
  43
  44        /* Soft-enable interrupts */
  45#ifdef CONFIG_TRACE_IRQFLAGS
  46        mflr    r0
  47        std     r0,16(r1)
  48        stdu    r1,-128(r1)
  49        bl      .trace_hardirqs_on
  50        addi    r1,r1,128
  51        ld      r0,16(r1)
  52        mtlr    r0
  53        mfmsr   r7
  54#endif /* CONFIG_TRACE_IRQFLAGS */
  55
  56        li      r0,1
  57        stb     r0,PACASOFTIRQEN(r13)   /* we'll hard-enable shortly */
  58BEGIN_FTR_SECTION
  59        DSSALL
  60        sync
  61END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
  62        CURRENT_THREAD_INFO(r9, r1)
  63        ld      r8,TI_LOCAL_FLAGS(r9)   /* set napping bit */
  64        ori     r8,r8,_TLF_NAPPING      /* so when we take an exception */
  65        std     r8,TI_LOCAL_FLAGS(r9)   /* it will return to our caller */
  66        ori     r7,r7,MSR_EE
  67        oris    r7,r7,MSR_POW@h
  681:      sync
  69        isync
  70        mtmsrd  r7
  71        isync
  72        b       1b
  73
  74