Before entering any idle state which can result in a state loss
we currently save the context in the stack before entering idle.
Encapsulate these steps in a macro IDLE_STATE_PREP. Move this
and other macros to commonly accessible location.
Signed-off-by: Shreyas B. Prabhu <shre...@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/cpuidle.h | 68 ++++++++++++++++++++++++++++++++++++++
arch/powerpc/kernel/idle_power7.S | 65 ++----------------------------------
2 files changed, 70 insertions(+), 63 deletions(-)
diff --git a/arch/powerpc/include/asm/cpuidle.h
b/arch/powerpc/include/asm/cpuidle.h
index d2f99ca1e3a6..6c678a779e8e 100644
--- a/arch/powerpc/include/asm/cpuidle.h
+++ b/arch/powerpc/include/asm/cpuidle.h
@@ -15,6 +15,74 @@ extern u32 pnv_fastsleep_workaround_at_entry[];
extern u32 pnv_fastsleep_workaround_at_exit[];
#endif
+/*
+ * IDLE_STATE_PREP - Will be called in preparation for entering
+ * any hardware idle state. Since idle states can result in a
+ * state loss, we create a regs frame on the stack, fill it up
+ * with the state we care about and stick a pointer to it in
+ * PACAR1. Use interrupt stack frame for this purpose.
+ * r3 - contains idle state to be entered
+ * r13 - PACA pointer
+ */
+#define IDLE_STATE_PREP \
+ mflr r0; \
+ std r0,16(r1); \
+ stdu r1,-INT_FRAME_SIZE(r1); \
+ std r0,_LINK(r1); \
+ std r0,_NIP(r1); \
+ \
+ /* Hard disable interrupts */ \
+ mfmsr r9; \
+ rldicl r9,r9,48,1; \
+ rotldi r9,r9,16; \
+ mtmsrd r9,1; /* hard-disable interrupts */ \
+ \
+ /* Check if something happened while soft-disabled */ \
+ lbz r0,PACAIRQHAPPENED(r13); \
+ andi. r0,r0,~PACA_IRQ_HARD_DIS@l; \
+ beq 1f; \
+ cmpwi cr0,r4,0; \
+ beq 1f; \
+ addi r1,r1,INT_FRAME_SIZE; \
+ ld r0,16(r1); \
+ li r3,0; /* Return 0 (no nap) */ \
+ mtlr r0; \
+ blr; \
+1: /* We mark irqs hard disabled as this is the state \
+ * we'll be in when returning and we need to tell \
+ * arch_local_irq_restore() about it */ \
+ li r0,PACA_IRQ_HARD_DIS; \
+ stb r0,PACAIRQHAPPENED(r13); \
+ \
+ /* We haven't lost state ... yet */ \
+ li r0,0; \
+ stb r0,PACA_NAPSTATELOST(r13); \
+ \
+ /* Continue saving state */ \
+ SAVE_GPR(2, r1); \
+ SAVE_NVGPRS(r1); \
+ mfcr r4; \
+ std r4,_CCR(r1); \
+ std r9,_MSR(r1); \
+ std r1,PACAR1(r13); \
+
+/*
+ * We use interrupt stack to save and restore few registers like
+ * PC, CR, LR and NVGPRs while enter/exiting idle states. Since
+ * volatile registers don't need to be saved/restored use that space
+ * instead to save/restore sprs which lose state during winkle.
+ */
+#define _SDR1 GPR3
+#define _RPR GPR4
+#define _SPURR GPR5
+#define _PURR GPR6
+#define _TSCR GPR7
+#define _DSCR GPR8
+#define _AMOR GPR9
+#define _WORT GPR10
+#define _WORC GPR11
+
+
#endif
#endif
diff --git a/arch/powerpc/kernel/idle_power7.S
b/arch/powerpc/kernel/idle_power7.S
index abc53e88a5b4..6af57e292848 100644
--- a/arch/powerpc/kernel/idle_power7.S
+++ b/arch/powerpc/kernel/idle_power7.S
@@ -24,20 +24,6 @@
#undef DEBUG
-/*
- * Use unused space in the interrupt stack to save and restore
- * registers for winkle support.
- */
-#define _SDR1 GPR3
-#define _RPR GPR4
-#define _SPURR GPR5
-#define _PURR GPR6
-#define _TSCR GPR7
-#define _DSCR GPR8
-#define _AMOR GPR9
-#define _WORT GPR10
-#define _WORC GPR11
-
/* Idle state entry routines */
#define IDLE_STATE_ENTER_SEQ(IDLE_INST) \
@@ -77,55 +63,8 @@ core_idle_lock_held:
* 1 - check
*/
_GLOBAL(power7_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
- * stick a pointer to it in PACAR1. We really only
- * need to save PC, some CR bits and the NV GPRs,
- * but for now an interrupt frame will do.
- */
- mflr r0
- std r0,16(r1)
- stdu r1,-INT_FRAME_SIZE(r1)
- std r0,_LINK(r1)
- std r0,_NIP(r1)
-
- /* Hard disable interrupts */
- mfmsr r9
- rldicl r9,r9,48,1
- rotldi r9,r9,16
- mtmsrd r9,1 /* hard-disable interrupts */
-
- /* Check if something happened while soft-disabled */
- lbz r0,PACAIRQHAPPENED(r13)
- andi. r0,r0,~PACA_IRQ_HARD_DIS@l
- beq 1f
- cmpwi cr0,r4,0
- beq 1f
- addi r1,r1,INT_FRAME_SIZE
- ld r0,16(r1)
- li r3,0 /* Return 0 (no nap) */
- mtlr r0
- blr
-
-1: /* We mark irqs hard disabled as this is the state we'll
- * be in when returning and we need to tell arch_local_irq_restore()
- * about it
- */
- li r0,PACA_IRQ_HARD_DIS
- stb r0,PACAIRQHAPPENED(r13)
-
- /* We haven't lost state ... yet */
- li r0,0
- stb r0,PACA_NAPSTATELOST(r13)
-
- /* Continue saving state */
- SAVE_GPR(2, r1)
- SAVE_NVGPRS(r1)
- mfcr r4
- std r4,_CCR(r1)
- std r9,_MSR(r1)
- std r1,PACAR1(r13)
+ /* Save PC, CR, LR and NVGPRs in stack */
+ IDLE_STATE_PREP;
/*
* Go to real mode to do the nap, as required by the architecture.
--
1.9.3
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
