[PATCH v6 06/11] powerpc/powernv: abstraction for saving SPRs before entering deep idle states

Shreyas B. Prabhu
2016-06-08T16:55:13Z

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@linux.vnet.ibm.com>
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
---
- No changes since v3

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

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

diff --git a/arch/powerpc/kernel/idle_power_common.S b/arch/powerpc/kernel/idle_power_common.S
index a8397e3..2f909a1 100644
--- a/arch/powerpc/kernel/idle_power_common.S
+++ b/arch/powerpc/kernel/idle_power_common.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)
--
2.1.4