arch/powerpc/kernel/idle_power4.S

   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 #include <asm/hw_irq.h>
  19 #include <asm/feature-fixups.h>
  20
  21 #undef DEBUG
  22
  23         .text
  24
  25 _GLOBAL(power4_idle)
  26 BEGIN_FTR_SECTION
  27         blr
  28 END_FTR_SECTION_IFCLR(CPU_FTR_CAN_NAP)
  29         /* Now check if user or arch enabled NAP mode */
  30         LOAD_REG_ADDRBASE(r3,powersave_nap)
  31         lwz     r4,ADDROFF(powersave_nap)(r3)
  32         cmpwi   0,r4,0
  33         beqlr
  34
  35         /* Hard disable interrupts */
  36         mfmsr   r7
  37         rldicl  r0,r7,48,1
  38         rotldi  r0,r0,16
  39         mtmsrd  r0,1
  40
  41         /* Check if something happened while soft-disabled */
  42         lbz     r0,PACAIRQHAPPENED(r13)
  43         cmpwi   cr0,r0,0
  44         bnelr
  45
  46         /* Soft-enable interrupts */
  47 #ifdef CONFIG_TRACE_IRQFLAGS
  48         mflr    r0
  49         std     r0,16(r1)
  50         stdu    r1,-128(r1)
  51         bl      trace_hardirqs_on
  52         addi    r1,r1,128
  53         ld      r0,16(r1)
  54         mtlr    r0
  55         mfmsr   r7
  56 #endif /* CONFIG_TRACE_IRQFLAGS */
  57
  58         li      r0,IRQS_ENABLED
  59         stb     r0,PACAIRQSOFTMASK(r13) /* we'll hard-enable shortly */
  60 BEGIN_FTR_SECTION
  61         DSSALL
  62         sync
  63 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
  64         CURRENT_THREAD_INFO(r9, r1)
  65         ld      r8,TI_LOCAL_FLAGS(r9)   /* set napping bit */
  66         ori     r8,r8,_TLF_NAPPING      /* so when we take an exception */
  67         std     r8,TI_LOCAL_FLAGS(r9)   /* it will return to our caller */
  68         ori     r7,r7,MSR_EE
  69         oris    r7,r7,MSR_POW@h
  70 1:      sync
  71         isync
  72         mtmsrd  r7
  73         isync
  74         b       1b
  75