linux-kernel - [PATCH v8 06/11] powerpc/powernv: abstraction for saving SPRs before entering deep idle states

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Message-Id: <1467958853-35841-7-git-send-email-shreyas@linux.vnet.ibm.com>
Date:	Fri,  8 Jul 2016 11:50:48 +0530
From:	"Shreyas B. Prabhu" <shreyas@...ux.vnet.ibm.com>
To:	mpe@...erman.id.au
Cc:	benh@....ibm.com, paulus@...abs.org, mikey@...ling.org,
	ego@...ux.vnet.ibm.com, linuxppc-dev@...ts.ozlabs.org,
	linux-kernel@...r.kernel.org, maddy@...ux.vnet.ibm.com,
	"Shreyas B. Prabhu" <shreyas@...ux.vnet.ibm.com>
Subject: [PATCH v8 06/11] powerpc/powernv: abstraction for saving SPRs before entering deep idle states

Create a function for saving SPRs before entering deep idle states.
This function can be reused for POWER9 deep idle states.

Reviewed-by: Gautham R. Shenoy <ego@...ux.vnet.ibm.com>
Signed-off-by: Shreyas B. Prabhu <shreyas@...ux.vnet.ibm.com>
---
 - No changes since v3

Changes in v3:
=============
 - Newly added in v3

 arch/powerpc/kernel/idle_book3s.S | 54 +++++++++++++++++++++++----------------
 1 file changed, 32 insertions(+), 22 deletions(-)

diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index a8397e3..2f909a1 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -53,6 +53,36 @@
 	.text
 
 /*
+ * Used by threads before entering deep idle states. Saves SPRs
+ * in interrupt stack frame
+ */
+save_sprs_to_stack:
+	/*
+	 * Note all register i.e per-core, per-subcore or per-thread is saved
+	 * here since any thread in the core might wake up first
+	 */
+	mfspr	r3,SPRN_SDR1
+	std	r3,_SDR1(r1)
+	mfspr	r3,SPRN_RPR
+	std	r3,_RPR(r1)
+	mfspr	r3,SPRN_SPURR
+	std	r3,_SPURR(r1)
+	mfspr	r3,SPRN_PURR
+	std	r3,_PURR(r1)
+	mfspr	r3,SPRN_TSCR
+	std	r3,_TSCR(r1)
+	mfspr	r3,SPRN_DSCR
+	std	r3,_DSCR(r1)
+	mfspr	r3,SPRN_AMOR
+	std	r3,_AMOR(r1)
+	mfspr	r3,SPRN_WORT
+	std	r3,_WORT(r1)
+	mfspr	r3,SPRN_WORC
+	std	r3,_WORC(r1)
+
+	blr
+
+/*
  * Used by threads when the lock bit of core_idle_state is set.
  * Threads will spin in HMT_LOW until the lock bit is cleared.
  * r14 - pointer to core_idle_state
@@ -209,28 +239,8 @@ fastsleep_workaround_at_entry:
 	b	common_enter
 
 enter_winkle:
-	/*
-	 * Note all register i.e per-core, per-subcore or per-thread is saved
-	 * here since any thread in the core might wake up first
-	 */
-	mfspr	r3,SPRN_SDR1
-	std	r3,_SDR1(r1)
-	mfspr	r3,SPRN_RPR
-	std	r3,_RPR(r1)
-	mfspr	r3,SPRN_SPURR
-	std	r3,_SPURR(r1)
-	mfspr	r3,SPRN_PURR
-	std	r3,_PURR(r1)
-	mfspr	r3,SPRN_TSCR
-	std	r3,_TSCR(r1)
-	mfspr	r3,SPRN_DSCR
-	std	r3,_DSCR(r1)
-	mfspr	r3,SPRN_AMOR
-	std	r3,_AMOR(r1)
-	mfspr	r3,SPRN_WORT
-	std	r3,_WORT(r1)
-	mfspr	r3,SPRN_WORC
-	std	r3,_WORC(r1)
+	bl	save_sprs_to_stack
+
 	IDLE_STATE_ENTER_SEQ(PPC_WINKLE)
 
 _GLOBAL(power7_idle)
-- 
2.4.11