linux-kernel - [PATCH v3 4/9] powerpc/powernv: Make power7_powersave

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Date:	Mon, 23 May 2016 20:48:37 +0530
From:	"Shreyas B. Prabhu" <shreyas@...ux.vnet.ibm.com>
To:	mpe@...erman.id.au
Cc:	linuxppc-dev@...ts.ozlabs.org, paulus@...abs.org,
	linux-kernel@...r.kernel.org, mikey@...ling.org,
	ego@...ux.vnet.ibm.com,
	"Shreyas B. Prabhu" <shreyas@...ux.vnet.ibm.com>
Subject: [PATCH v3 4/9] powerpc/powernv: Make power7_powersave_common more generic

power7_powersave_common does common steps needed before entering idle
state and eventually changes MSR to MSR_IDLE and does rfid to
power7_enter_nap_mode.

Move the updation of HSTATE_HWTHREAD_STATE to power7_powersave_common
from power7_enter_nap_mode and make it more generic by passing the rfid
address as a function parameter.

Also make function name more generic.

Reviewed-by: Gautham R. Shenoy <ego@...ux.vnet.ibm.com>
Signed-off-by: Shreyas B. Prabhu <shreyas@...ux.vnet.ibm.com>
---
Changes in v3:
==============
 - Moved HSTATE_HWTHREAD_STATE updation to power_powersave_common

 arch/powerpc/kernel/idle_power_common.S | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/kernel/idle_power_common.S b/arch/powerpc/kernel/idle_power_common.S
index 973c9a1..d100577 100644
--- a/arch/powerpc/kernel/idle_power_common.S
+++ b/arch/powerpc/kernel/idle_power_common.S
@@ -74,8 +74,10 @@ core_idle_lock_held:
  * To check IRQ_HAPPENED in r4
  * 	0 - don't check
  * 	1 - check
+ *
+ * Address to 'rfid' to in r5
  */
-_GLOBAL(power7_powersave_common)
+_GLOBAL(pnv_powersave_common)
 	/* Use r3 to pass state nap/sleep/winkle */
 	/* NAP is a state loss, we create a regs frame on the
 	 * stack, fill it up with the state we care about and
@@ -126,28 +128,27 @@ _GLOBAL(power7_powersave_common)
 	std	r9,_MSR(r1)
 	std	r1,PACAR1(r13)
 
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	/* Tell KVM we're napping */
+	li	r4,KVM_HWTHREAD_IN_NAP
+	stb	r4,HSTATE_HWTHREAD_STATE(r13)
+#endif
 	/*
 	 * Go to real mode to do the nap, as required by the architecture.
 	 * Also, we need to be in real mode before setting hwthread_state,
 	 * because as soon as we do that, another thread can switch
 	 * the MMU context to the guest.
 	 */
-	LOAD_REG_IMMEDIATE(r5, MSR_IDLE)
+	LOAD_REG_IMMEDIATE(r7, MSR_IDLE)
 	li	r6, MSR_RI
 	andc	r6, r9, r6
-	LOAD_REG_ADDR(r7, power7_enter_nap_mode)
 	mtmsrd	r6, 1		/* clear RI before setting SRR0/1 */
-	mtspr	SPRN_SRR0, r7
-	mtspr	SPRN_SRR1, r5
+	mtspr	SPRN_SRR0, r5
+	mtspr	SPRN_SRR1, r7
 	rfid
 
 	.globl	power7_enter_nap_mode
 power7_enter_nap_mode:
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-	/* Tell KVM we're napping */
-	li	r4,KVM_HWTHREAD_IN_NAP
-	stb	r4,HSTATE_HWTHREAD_STATE(r13)
-#endif
 	stb	r3,PACA_THREAD_IDLE_STATE(r13)
 	cmpwi	cr3,r3,PNV_THREAD_SLEEP
 	bge	cr3,2f
@@ -242,19 +243,22 @@ _GLOBAL(power7_idle)
 _GLOBAL(power7_nap)
 	mr	r4,r3
 	li	r3,PNV_THREAD_NAP
-	b	power7_powersave_common
+	LOAD_REG_ADDR(r5, power7_enter_nap_mode)
+	b	pnv_powersave_common
 	/* No return */
 
 _GLOBAL(power7_sleep)
 	li	r3,PNV_THREAD_SLEEP
 	li	r4,1
-	b	power7_powersave_common
+	LOAD_REG_ADDR(r5, power7_enter_nap_mode)
+	b	pnv_powersave_common
 	/* No return */
 
 _GLOBAL(power7_winkle)
 	li	r3,3
 	li	r4,1
-	b	power7_powersave_common
+	LOAD_REG_ADDR(r5, power7_enter_nap_mode)
+	b	pnv_powersave_common
 	/* No return */
 
 #define CHECK_HMI_INTERRUPT						\
-- 
2.4.11