From: Dongsheng Wang <dongsheng.wang@freescale.com>
To: <scottwood@freescale.com>
Cc: linuxppc-dev@lists.ozlabs.org,
Wang Dongsheng <dongsheng.wang@freescale.com>
Subject: [PATCH v4 2/4] powerpc/85xx: add hardware automatically enter altivec idle state
Date: Tue, 24 Sep 2013 17:28:43 +0800 [thread overview]
Message-ID: <1380014925-23300-2-git-send-email-dongsheng.wang@freescale.com> (raw)
From: Wang Dongsheng <dongsheng.wang@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.wang@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
next reply other threads:[~2013-09-24 9:34 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-24 9:28 Dongsheng Wang [this message]
2013-09-24 9:28 ` [PATCH v4 3/4] powerpc/85xx: add hardware automatically enter pw20 state Dongsheng Wang
2013-09-24 9:28 ` [PATCH v4 4/4] powerpc/85xx: add sysfs for pw20 state and altivec idle Dongsheng Wang
2013-09-25 6:22 ` Bhushan Bharat-R65777
2013-09-25 8:10 ` Wang Dongsheng-B40534
2013-09-25 8:33 ` Bhushan Bharat-R65777
2013-09-25 17:56 ` Scott Wood
2013-09-26 2:32 ` Wang Dongsheng-B40534
2013-09-26 4:23 ` Bhushan Bharat-R65777
2013-09-26 6:18 ` Wang Dongsheng-B40534
2013-09-26 21:37 ` Scott Wood
2013-09-27 3:34 ` Wang Dongsheng-B40534
2013-09-27 21:33 ` Scott Wood
2013-09-29 6:57 ` Wang Dongsheng-B40534
2013-09-30 23:06 ` Scott Wood
2013-10-08 3:58 ` Wang Dongsheng-B40534
2013-10-08 14:50 ` Scott Wood
2013-10-11 7:43 ` Wang Dongsheng-B40534
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