From: "Gautham R. Shenoy" <e...@linux.vnet.ibm.com>
Currently all the low-power idle states are expected to wake up
at reset vector 0x100. Which is why the macro IDLE_STATE_ENTER_SEQ
that puts the CPU to an idle state and never returns.
On ISA_300, when the ESL and EC bits in the PSSCR are zero, the
CPU is expected to wake up at the next instruction of the idle
instruction.
This patch adds a new macro named IDLE_STATE_ENTER_SEQ_NORET for the
no-return variant and reuses the name IDLE_STATE_ENTER_SEQ
for a variant that allows resuming operation at the instruction next
to the idle-instruction.
Signed-off-by: Gautham R. Shenoy <e...@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/cpuidle.h | 5 ++++-
arch/powerpc/kernel/exceptions-64s.S | 6 +++---
arch/powerpc/kernel/idle_book3s.S | 10 +++++-----
3 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/include/asm/cpuidle.h
b/arch/powerpc/include/asm/cpuidle.h
index 01b8a13..9fd23f6 100644
--- a/arch/powerpc/include/asm/cpuidle.h
+++ b/arch/powerpc/include/asm/cpuidle.h
@@ -21,7 +21,7 @@ extern u64 pnv_first_deep_stop_state;
/* Idle state entry routines */
#ifdef CONFIG_PPC_P7_NAP
-#define IDLE_STATE_ENTER_SEQ(IDLE_INST) \
+#define IDLE_STATE_ENTER_SEQ(IDLE_INST) \
/* Magic NAP/SLEEP/WINKLE mode enter sequence */ \
std r0,0(r1); \
ptesync; \
@@ -29,6 +29,9 @@ extern u64 pnv_first_deep_stop_state;
1: cmp cr0,r0,r0; \
bne 1b; \
IDLE_INST; \
+
+#define IDLE_STATE_ENTER_SEQ_NORET(IDLE_INST) \
+ IDLE_STATE_ENTER_SEQ(IDLE_INST) \
b .
#endif /* CONFIG_PPC_P7_NAP */
diff --git a/arch/powerpc/kernel/exceptions-64s.S
b/arch/powerpc/kernel/exceptions-64s.S
index bffec73..238307d 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1301,12 +1301,12 @@ machine_check_handle_early:
lbz r3,PACA_THREAD_IDLE_STATE(r13)
cmpwi r3,PNV_THREAD_NAP
bgt 10f
- IDLE_STATE_ENTER_SEQ(PPC_NAP)
+ IDLE_STATE_ENTER_SEQ_NORET(PPC_NAP)
/* No return */
10:
cmpwi r3,PNV_THREAD_SLEEP
bgt 2f
- IDLE_STATE_ENTER_SEQ(PPC_SLEEP)
+ IDLE_STATE_ENTER_SEQ_NORET(PPC_SLEEP)
/* No return */
2:
@@ -1320,7 +1320,7 @@ machine_check_handle_early:
*/
ori r13,r13,1
SET_PACA(r13)
- IDLE_STATE_ENTER_SEQ(PPC_WINKLE)
+ IDLE_STATE_ENTER_SEQ_NORET(PPC_WINKLE)
/* No return */
4:
#endif
diff --git a/arch/powerpc/kernel/idle_book3s.S
b/arch/powerpc/kernel/idle_book3s.S
index bd739fe..32d666b 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -188,7 +188,7 @@ pnv_enter_arch207_idle_mode:
stb r3,PACA_THREAD_IDLE_STATE(r13)
cmpwi cr3,r3,PNV_THREAD_SLEEP
bge cr3,2f
- IDLE_STATE_ENTER_SEQ(PPC_NAP)
+ IDLE_STATE_ENTER_SEQ_NORET(PPC_NAP)
/* No return */
2:
/* Sleep or winkle */
@@ -222,7 +222,7 @@ pnv_fastsleep_workaround_at_entry:
common_enter: /* common code for all the threads entering sleep or winkle */
bgt cr3,enter_winkle
- IDLE_STATE_ENTER_SEQ(PPC_SLEEP)
+ IDLE_STATE_ENTER_SEQ_NORET(PPC_SLEEP)
fastsleep_workaround_at_entry:
ori r15,r15,PNV_CORE_IDLE_LOCK_BIT
@@ -244,7 +244,7 @@ fastsleep_workaround_at_entry:
enter_winkle:
bl save_sprs_to_stack
- IDLE_STATE_ENTER_SEQ(PPC_WINKLE)
+ IDLE_STATE_ENTER_SEQ_NORET(PPC_WINKLE)
/*
* r3 - requested stop state
@@ -257,7 +257,7 @@ power_enter_stop:
ld r4,ADDROFF(pnv_first_deep_stop_state)(r5)
cmpd r3,r4
bge 2f
- IDLE_STATE_ENTER_SEQ(PPC_STOP)
+ IDLE_STATE_ENTER_SEQ_NORET(PPC_STOP)
2:
/*
* Entering deep idle state.
@@ -279,7 +279,7 @@ lwarx_loop_stop:
bl save_sprs_to_stack
- IDLE_STATE_ENTER_SEQ(PPC_STOP)
+ IDLE_STATE_ENTER_SEQ_NORET(PPC_STOP)
_GLOBAL(power7_idle)
/* Now check if user or arch enabled NAP mode */
--
1.9.4
