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-rw-r--r--arch/powerpc/kernel/idle_power4.S78
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diff --git a/arch/powerpc/kernel/idle_power4.S b/arch/powerpc/kernel/idle_power4.S
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+/*
+ * 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