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 v3 2/4] powerpc/85xx: add hardware automatically enter altivec idle state
Date: Wed, 11 Sep 2013 13:56:42 +0800 [thread overview]
Message-ID: <1378879004-2446-2-git-send-email-dongsheng.wang@freescale.com> (raw)
In-Reply-To: <1378879004-2446-1-git-send-email-dongsheng.wang@freescale.com>
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 | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/arch/powerpc/kernel/cpu_setup_fsl_booke.S b/arch/powerpc/kernel/cpu_setup_fsl_booke.S
index bfb18c7..3c03c109 100644
--- a/arch/powerpc/kernel/cpu_setup_fsl_booke.S
+++ b/arch/powerpc/kernel/cpu_setup_fsl_booke.S
@@ -53,11 +53,30 @@ _GLOBAL(__e500_dcache_setup)
isync
blr
+/*
+ * FIXME - We don't know the AltiVec application scenarios.
+ */
+#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 r4, AV_WAIT_IDLE_BIT
+
+ /* Set Automatic AltiVec Idle Count */
+ rlwimi r3, r4, 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 +138,7 @@ _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 prev parent reply other threads:[~2013-09-11 6:00 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-11 5:56 [PATCH v3 1/4] powerpc/fsl: add E6500 PVR and SPRN_PWRMGTCR0 define Dongsheng Wang
2013-09-11 5:56 ` Dongsheng Wang [this message]
2013-09-11 22:42 ` [PATCH v3 2/4] powerpc/85xx: add hardware automatically enter altivec idle state Scott Wood
2013-09-12 2:27 ` Wang Dongsheng-B40534
2013-09-11 5:56 ` [PATCH v3 3/4] powerpc/85xx: add hardware automatically enter pw20 state Dongsheng Wang
2013-09-11 5:56 ` [PATCH v3 4/4] powerpc/85xx: add sysfs for pw20 state and altivec idle Dongsheng Wang
2013-09-11 23:04 ` Scott Wood
2013-09-12 3:48 ` Wang Dongsheng-B40534
2013-09-12 18:06 ` Scott Wood
2013-09-13 2:53 ` Wang Dongsheng-B40534
2013-09-16 21:09 ` Scott Wood
2013-09-18 3:35 ` Wang Dongsheng-B40534
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