1 files changed, 78 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/idle_power4.S b/arch/powerpc/kernel/idle_power4.S
new file mode 100644
index 000000000000..5596fad6c87c
--- /dev/null
+++ b/arch/powerpc/kernel/idle_power4.S
@@ -0,0 +1,78 @@
+/*
+ *  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
+ *  as published by the Free Software Foundation; either version
+ *  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>
+#include <asm/cputable.h>
+#include <asm/thread_info.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+
+#undef DEBUG
+
+        .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
+         */
+        LOADBASE(r3,cur_cpu_spec)
+        ld      r4,cur_cpu_spec@l(r3)
+        ld      r4,CPU_SPEC_FEATURES(r4)
+        andi.   r0,r4,CPU_FTR_CAN_NAP
+        beqlr
+        /* Now check if user or arch enabled NAP mode */
+        LOADBASE(r3,powersave_nap)
+        lwz     r4,powersave_nap@l(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)
+        oris    r7,r7,MSR_POW@h
+        sync
+        isync
+        mtmsrd  r7
+        isync
+        sync
+        blr