linux 2.6.16.38 w/ vs2.0.3-rc1

[linux-2.6.git] / arch / powerpc / kernel / idle_power4.S

diff --git a/arch/powerpc/kernel/idle_power4.S b/arch/powerpc/kernel/idle_power4.S
index 30de81d..c16b4af 100644 (file)
--- a/arch/powerpc/kernel/idle_power4.S
+++ b/arch/powerpc/kernel/idle_power4.S
@@ -1,5 +1,11 @@
 /*
- *  This file contains the power_save function for 970-family CPUs.
+ *  This file contains the power_save function for 6xx & 7xxx CPUs
+ *  rewritten in assembler
+ *
+ *  Warning ! This code assumes that if your machine has a 750fx
+ *  it will have PLL 1 set to low speed mode (used during NAP/DOZE).
+ *  if this is not the case some additional changes will have to
+ *  be done to check a runtime var (a bit like powersave-nap)
  *
  *  This program is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU General Public License
@@ -7,6 +13,7 @@
  *  2 of the License, or (at your option) any later version.
  */
 
+#include <linux/config.h>
 #include <linux/threads.h>
 #include <asm/processor.h>
 #include <asm/page.h>
@@ -19,31 +26,53 @@
 
        .text
 
+/*
+ * Here is the power_save_6xx function. This could eventually be
+ * split into several functions & changing the function pointer
+ * depending on the various features.
+ */
 _GLOBAL(power4_idle)
 BEGIN_FTR_SECTION
        blr
 END_FTR_SECTION_IFCLR(CPU_FTR_CAN_NAP)
+       /* We must dynamically check for the NAP feature as it
+        * can be cleared by CPU init after the fixups are done
+        */
+       LOAD_REG_ADDRBASE(r3,cur_cpu_spec)
+       ld      r4,ADDROFF(cur_cpu_spec)(r3)
+       ld      r4,CPU_SPEC_FEATURES(r4)
+       andi.   r0,r4,CPU_FTR_CAN_NAP
+       beqlr
        /* Now check if user or arch enabled NAP mode */
        LOAD_REG_ADDRBASE(r3,powersave_nap)
        lwz     r4,ADDROFF(powersave_nap)(r3)
        cmpwi   0,r4,0
        beqlr
 
+       /* Clear MSR:EE */
+       mfmsr   r7
+       li      r4,0
+       ori     r4,r4,MSR_EE
+       andc    r0,r7,r4
+       mtmsrd  r0
+
+       /* Check current_thread_info()->flags */
+       clrrdi  r4,r1,THREAD_SHIFT
+       ld      r4,TI_FLAGS(r4)
+       andi.   r0,r4,_TIF_NEED_RESCHED
+       beq     1f
+       mtmsrd  r7      /* out of line this ? */
+       blr
+1:
        /* Go to NAP now */
 BEGIN_FTR_SECTION
        DSSALL
        sync
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
-       clrrdi  r9,r1,THREAD_SHIFT      /* current thread_info */
-       ld      r8,TI_LOCAL_FLAGS(r9)   /* set napping bit */
-       ori     r8,r8,_TLF_NAPPING      /* so when we take an exception */
-       std     r8,TI_LOCAL_FLAGS(r9)   /* it will return to our caller */
-       mfmsr   r7
-       ori     r7,r7,MSR_EE
        oris    r7,r7,MSR_POW@h
-1:     sync
+       sync
        isync
        mtmsrd  r7
        isync
-       b       1b
-
+       sync
+       blr