From: Wang Dongsheng <dongsheng.w...@freescale.com>
Each core's AltiVec unit may be placed into a power savings mode
by turning off power to the unit. Core hardware will automatically
power down the AltiVec unit after no AltiVec instructions have
executed in N cycles. The AltiVec power-control is triggered by hardware.
Signed-off-by: Wang Dongsheng <dongsheng.w...@freescale.com>
---
*v3:
Assembly code instead of C code.
*v2:
Remove:
delete setup_idle_hw_governor function.
delete "Fix erratum" for rev1.
Move:
move setup_* into __setup/restore_cpu_e6500.
arch/powerpc/kernel/cpu_setup_fsl_booke.S | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/arch/powerpc/kernel/cpu_setup_fsl_booke.S
b/arch/powerpc/kernel/cpu_setup_fsl_booke.S
index bfb18c7..4789056 100644
--- a/arch/powerpc/kernel/cpu_setup_fsl_booke.S
+++ b/arch/powerpc/kernel/cpu_setup_fsl_booke.S
@@ -53,11 +53,31 @@ _GLOBAL(__e500_dcache_setup)
isync
blr
+/*
+ * FIXME - we haven't yet done testing to determine a reasonable default
+ * value for AV_WAIT_IDLE_BIT.
+ */
+#define AV_WAIT_IDLE_BIT 50 /* 1ms, TB frequency is 41.66MHZ */
+_GLOBAL(setup_altivec_idle)
+ mfspr r3, SPRN_PWRMGTCR0
+
+ /* Enable Altivec Idle */
+ oris r3, r3, PWRMGTCR0_AV_IDLE_PD_EN@h
+ li r11, AV_WAIT_IDLE_BIT
+
+ /* Set Automatic AltiVec Idle Count */
+ rlwimi r3, r11, PWRMGTCR0_AV_IDLE_CNT_SHIFT, PWRMGTCR0_AV_IDLE_CNT
+
+ mtspr SPRN_PWRMGTCR0, r3
+
+ blr
+
_GLOBAL(__setup_cpu_e6500)
mflr r6
#ifdef CONFIG_PPC64
bl .setup_altivec_ivors
#endif
+ bl setup_altivec_idle
bl __setup_cpu_e5500
mtlr r6
blr
@@ -119,6 +139,7 @@ _GLOBAL(__setup_cpu_e5500)
_GLOBAL(__restore_cpu_e6500)
mflr r5
bl .setup_altivec_ivors
+ bl .setup_altivec_idle
bl __restore_cpu_e5500
mtlr r5
blr
--
1.8.0
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