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Violators will be prosecuted for from ; Thu, 16 Mar 2017 08:10:56 -0400 Date: Thu, 16 Mar 2017 17:40:51 +0530 From: Gautham R Shenoy To: Nicholas Piggin Cc: linuxppc-dev@lists.ozlabs.org, Gautham R Shenoy , Vaidyanathan Srinivasan Subject: Re: [PATCH 6/8] powerpc/64s: idle expand usable core idle state bits Reply-To: ego@linux.vnet.ibm.com References: <20170314092349.10981-1-npiggin@gmail.com> <20170314092349.10981-7-npiggin@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20170314092349.10981-7-npiggin@gmail.com> Message-Id: <20170316121051.GD16462@in.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 > > Signed-off-by: Nicholas Piggin > --- > 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 >