Re: [PATCH 6/8] powerpc/64s: idle expand usable core idle state bits
From: Gautham R Shenoy <hidden>
Date: 2017-03-16 12:11:04
Hi Nick, On Tue, Mar 14, 2017 at 07:23:47PM +1000, Nicholas Piggin wrote:
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.
Looks good. Reviewed-by: Gautham R. Shenoy <redacted>
quoted hunk ↗ jump to hunk
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 155731557c9b..b9d9f960dffd 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 9bdfba75a5e7..1c91dc35c559 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@@ -492,7 +492,7 @@ 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@@ -501,9 +501,10 @@ 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@@ -512,7 +513,7 @@ 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@@ -602,7 +603,7 @@ 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