From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH 6/9] powerpc/64s: idle expand core idle state bits
Date: Wed, 19 Apr 2017 23:05:48 +1000 [thread overview]
Message-ID: <20170419130551.32378-7-npiggin@gmail.com> (raw)
In-Reply-To: <20170419130551.32378-1-npiggin@gmail.com>
In preparation for adding more bits to the core idle state word, move
the lock bit up, and unlock by flipping the lock bit rather than masking
off all but the thread bits.
Add branch hints for atomic operations while we're here.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/cpuidle.h | 4 ++--
arch/powerpc/kernel/idle_book3s.S | 33 +++++++++++++++++----------------
2 files changed, 19 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/include/asm/cpuidle.h b/arch/powerpc/include/asm/cpuidle.h
index 4649ca0d28e3..dd6a63f0a10f 100644
--- a/arch/powerpc/include/asm/cpuidle.h
+++ b/arch/powerpc/include/asm/cpuidle.h
@@ -7,8 +7,8 @@
#define PNV_THREAD_NAP 1
#define PNV_THREAD_SLEEP 2
#define PNV_THREAD_WINKLE 3
-#define PNV_CORE_IDLE_LOCK_BIT 0x100
-#define PNV_CORE_IDLE_THREAD_BITS 0x0FF
+#define PNV_CORE_IDLE_LOCK_BIT 0x10000000
+#define PNV_CORE_IDLE_THREAD_BITS 0x000000FF
/*
* ============================ NOTE =================================
diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index cc016757d743..13b7044c1541 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -95,12 +95,12 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
core_idle_lock_held:
HMT_LOW
3: lwz r15,0(r14)
- andi. r15,r15,PNV_CORE_IDLE_LOCK_BIT
+ andis. r15,r15,PNV_CORE_IDLE_LOCK_BIT@h
bne 3b
HMT_MEDIUM
lwarx r15,0,r14
- andi. r9,r15,PNV_CORE_IDLE_LOCK_BIT
- bne core_idle_lock_held
+ andis. r9,r15,PNV_CORE_IDLE_LOCK_BIT@h
+ bne- core_idle_lock_held
blr
/*
@@ -213,8 +213,8 @@ pnv_enter_arch207_idle_mode:
lwarx_loop1:
lwarx r15,0,r14
- andi. r9,r15,PNV_CORE_IDLE_LOCK_BIT
- bnel core_idle_lock_held
+ andis. r9,r15,PNV_CORE_IDLE_LOCK_BIT@h
+ bnel- core_idle_lock_held
andc r15,r15,r7 /* Clear thread bit */
@@ -241,7 +241,7 @@ common_enter: /* common code for all the threads entering sleep or winkle */
IDLE_STATE_ENTER_SEQ_NORET(PPC_SLEEP)
fastsleep_workaround_at_entry:
- ori r15,r15,PNV_CORE_IDLE_LOCK_BIT
+ oris r15,r15,PNV_CORE_IDLE_LOCK_BIT@h
stwcx. r15,0,r14
bne- lwarx_loop1
isync
@@ -251,10 +251,10 @@ fastsleep_workaround_at_entry:
li r4,1
bl opal_config_cpu_idle_state
- /* Clear Lock bit */
- li r0,0
+ /* Unlock */
+ xoris r15,r15,PNV_CORE_IDLE_LOCK_BIT@h
lwsync
- stw r0,0(r14)
+ stw r15,0(r14)
b common_enter
enter_winkle:
@@ -302,8 +302,8 @@ power_enter_stop:
lwarx_loop_stop:
lwarx r15,0,r14
- andi. r9,r15,PNV_CORE_IDLE_LOCK_BIT
- bnel core_idle_lock_held
+ andis. r9,r15,PNV_CORE_IDLE_LOCK_BIT@h
+ bnel- core_idle_lock_held
andc r15,r15,r7 /* Clear thread bit */
stwcx. r15,0,r14
@@ -573,7 +573,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
ld r14,PACA_CORE_IDLE_STATE_PTR(r13)
lwarx_loop2:
lwarx r15,0,r14
- andi. r9,r15,PNV_CORE_IDLE_LOCK_BIT
+ andis. r9,r15,PNV_CORE_IDLE_LOCK_BIT@h
/*
* Lock bit is set in one of the 2 cases-
* a. In the sleep/winkle enter path, the last thread is executing
@@ -582,9 +582,10 @@ lwarx_loop2:
* workaround undo code or resyncing timebase or restoring context
* In either case loop until the lock bit is cleared.
*/
- bnel core_idle_lock_held
+ bnel- core_idle_lock_held
- cmpwi cr2,r15,0
+ andi. r9,r15,PNV_CORE_IDLE_THREAD_BITS
+ cmpwi cr2,r9,0
/*
* At this stage
@@ -593,7 +594,7 @@ lwarx_loop2:
* cr4 - gt or eq if waking up from complete hypervisor state loss.
*/
- ori r15,r15,PNV_CORE_IDLE_LOCK_BIT
+ oris r15,r15,PNV_CORE_IDLE_LOCK_BIT@h
stwcx. r15,0,r14
bne- lwarx_loop2
isync
@@ -683,7 +684,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
mtspr SPRN_WORC,r4
clear_lock:
- andi. r15,r15,PNV_CORE_IDLE_THREAD_BITS
+ xoris r15,r15,PNV_CORE_IDLE_LOCK_BIT@h
lwsync
stw r15,0(r14)
--
2.11.0
next prev parent reply other threads:[~2017-04-19 13:06 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-19 13:05 [PATCH v2 0/9] idle fixes and changes for POWER8 and POWER9 Nicholas Piggin
2017-04-19 13:05 ` [PATCH 1/9] powerpc/64s: Remove unnecessary relocation branch from idle handler Nicholas Piggin
2017-04-23 11:53 ` [1/9] " Michael Ellerman
2017-04-19 13:05 ` [PATCH 2/9] powerpc/64s: move remaining system reset idle code into idle_book3s.S Nicholas Piggin
2017-04-19 13:05 ` [PATCH 3/9] powerpc/64s: stop using bit in HSPRG0 to test winkle Nicholas Piggin
2017-04-19 13:05 ` [PATCH 4/9] powerpc/64s: use alternative feature patching Nicholas Piggin
2017-04-19 13:05 ` [PATCH 5/9] powerpc/64s: fix POWER9 machine check handler from stop state Nicholas Piggin
2017-04-19 13:05 ` Nicholas Piggin [this message]
2017-04-19 13:05 ` [PATCH 7/9] powerpc/64s: idle do not hold reservation longer than required Nicholas Piggin
2017-04-19 13:05 ` [PATCH 8/9] powerpc/64s: idle POWER8 avoid full state loss recovery where possible Nicholas Piggin
2017-04-19 13:05 ` [PATCH 9/9] powerpc/64s: Simplify POWER9 DD1 idle workaround code Nicholas Piggin
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