From: Gautham R Shenoy <ego@linux.vnet.ibm.com>
To: Nicholas Piggin <npiggin@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org,
"Gautham R . Shenoy" <ego@linux.vnet.ibm.com>,
"Shreyas B . Prabhu" <shreyas@linux.vnet.ibm.com>
Subject: Re: [PATCH 05/14] powerpc/64s: msgclr when handling doorbell exceptions
Date: Mon, 12 Jun 2017 20:08:15 +0530 [thread overview]
Message-ID: <20170612143815.GD10921@in.ibm.com> (raw)
In-Reply-To: <20170611235835.7400-6-npiggin@gmail.com>
On Mon, Jun 12, 2017 at 09:58:26AM +1000, Nicholas Piggin wrote:
> msgsnd doorbell exceptions are cleared when the doorbell interrupt is
> taken. However if a doorbell exception causes a system reset interrupt
> wake from power saving state, the message is not cleared. Processing
> the doorbell from the system reset interrupt requires msgclr to avoid
> taking the exception again.
>
So you are clearing the doorbell message in this patch.
> Testing this plus the previous wakup direct patch gives:
>
> original wakeup direct msgclr
> Different threads, same core: 315k/s 264k/s 345k/s
> Different cores: 235k/s 242k/s 242k/s
>
> Net speedup is +10% for same core, and +3% for different core.
This is good speedup.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
> arch/powerpc/include/asm/dbell.h | 13 +++++++++++++
> arch/powerpc/include/asm/ppc-opcode.h | 3 +++
> arch/powerpc/kernel/asm-offsets.c | 1 +
> arch/powerpc/kernel/exceptions-64s.S | 23 +++++++++++++++++++++--
> 4 files changed, 38 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/dbell.h b/arch/powerpc/include/asm/dbell.h
> index f70cbfe0ec04..9f2ae0d25e15 100644
> --- a/arch/powerpc/include/asm/dbell.h
> +++ b/arch/powerpc/include/asm/dbell.h
> @@ -56,6 +56,19 @@ static inline void ppc_msgsync(void)
> : : "i" (CPU_FTR_HVMODE|CPU_FTR_ARCH_300));
> }
>
> +static inline void _ppc_msgclr(u32 msg)
> +{
> + __asm__ __volatile__ (ASM_FTR_IFSET(PPC_MSGCLR(%1), PPC_MSGCLRP(%1), %0)
> + : : "i" (CPU_FTR_HVMODE), "r" (msg));
> +}
> +
> +static inline void ppc_msgclr(enum ppc_dbell type)
> +{
> + u32 msg = PPC_DBELL_TYPE(type);
> +
> + _ppc_msgclr(msg);
> +}
> +
> #else /* CONFIG_PPC_BOOK3S */
>
> #define PPC_DBELL_MSGTYPE PPC_DBELL
> diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
> index 3a8d278e7421..3b29c54e51fa 100644
> --- a/arch/powerpc/include/asm/ppc-opcode.h
> +++ b/arch/powerpc/include/asm/ppc-opcode.h
> @@ -221,6 +221,7 @@
> #define PPC_INST_MSGCLR 0x7c0001dc
> #define PPC_INST_MSGSYNC 0x7c0006ec
> #define PPC_INST_MSGSNDP 0x7c00011c
> +#define PPC_INST_MSGCLRP 0x7c00015c
> #define PPC_INST_MTTMR 0x7c0003dc
> #define PPC_INST_NOP 0x60000000
> #define PPC_INST_PASTE 0x7c00070c
> @@ -409,6 +410,8 @@
> ___PPC_RB(b))
> #define PPC_MSGSNDP(b) stringify_in_c(.long PPC_INST_MSGSNDP | \
> ___PPC_RB(b))
> +#define PPC_MSGCLRP(b) stringify_in_c(.long PPC_INST_MSGCLRP | \
> + ___PPC_RB(b))
> #define PPC_POPCNTB(a, s) stringify_in_c(.long PPC_INST_POPCNTB | \
> __PPC_RA(a) | __PPC_RS(s))
> #define PPC_POPCNTD(a, s) stringify_in_c(.long PPC_INST_POPCNTD | \
> diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
> index e15c178ba079..9624851ca276 100644
> --- a/arch/powerpc/kernel/asm-offsets.c
> +++ b/arch/powerpc/kernel/asm-offsets.c
> @@ -746,6 +746,7 @@ int main(void)
> #endif
>
> DEFINE(PPC_DBELL_SERVER, PPC_DBELL_SERVER);
> + DEFINE(PPC_DBELL_MSGTYPE, PPC_DBELL_MSGTYPE);
>
> #ifdef CONFIG_PPC_8xx
> DEFINE(VIRT_IMMR_BASE, (u64)__fix_to_virt(FIX_IMMR_BASE));
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index ae418b85c17c..a04ee0d7f88e 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -1552,6 +1552,25 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
> b 1b
>
> /*
> + * When doorbell is triggered from system reset wakeup, the message is
> + * not cleared, so it would fire again when EE is enabled.
> + *
> + * When coming from local_irq_enable, there may be the same problem if
> + * we were hard disabled.
> + *
> + * Execute msgclr to clear pending exceptions before handling it.
> + */
> +h_doorbell_common_msgclr:
> + LOAD_REG_IMMEDIATE(r3, PPC_DBELL_MSGTYPE << (63-36))
> + PPC_MSGCLR(3)
> + b h_doorbell_common
> +
> +doorbell_super_common_msgclr:
> + LOAD_REG_IMMEDIATE(r3, PPC_DBELL_MSGTYPE << (63-36))
> + PPC_MSGCLRP(3)
> + b doorbell_super_common
> +
> +/*
> * Called from arch_local_irq_enable when an interrupt needs
> * to be resent. r3 contains 0x500, 0x900, 0xa00 or 0xe80 to indicate
> * which kind of interrupt. MSR:EE is already off. We generate a
> @@ -1576,13 +1595,13 @@ _GLOBAL(__replay_interrupt)
> beq hardware_interrupt_common
> BEGIN_FTR_SECTION
> cmpwi r3,0xe80
> - beq h_doorbell_common
> + beq h_doorbell_common_msgclr
> cmpwi r3,0xea0
> beq h_virt_irq_common
> cmpwi r3,0xe60
> beq hmi_exception_common
> FTR_SECTION_ELSE
> cmpwi r3,0xa00
> - beq doorbell_super_common
> + beq doorbell_super_common_msgclr
> ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE)
> blr
> --
> 2.11.0
>
next prev parent reply other threads:[~2017-06-12 14:38 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-11 23:58 [PATCH 00/14 v2] idle performance improvements Nicholas Piggin
2017-06-11 23:58 ` [PATCH 01/14] powerpc/64s: idle move soft interrupt mask logic into C code Nicholas Piggin
2017-06-12 8:37 ` Gautham R Shenoy
2017-06-12 14:46 ` Nicholas Piggin
2017-06-13 4:28 ` Gautham R Shenoy
2017-06-11 23:58 ` [PATCH 02/14] powerpc/64s: idle hotplug lazy-irq simplification Nicholas Piggin
2017-06-11 23:58 ` [PATCH 03/14] powerpc/64s: idle provide a default idle for POWER9 Nicholas Piggin
2017-06-12 8:53 ` Gautham R Shenoy
2017-06-12 14:46 ` Nicholas Piggin
2017-06-11 23:58 ` [PATCH 04/14] powerpc/64s: idle process interrupts from system reset wakeup Nicholas Piggin
2017-06-12 9:41 ` Gautham R Shenoy
2017-06-12 14:51 ` Nicholas Piggin
2017-06-11 23:58 ` [PATCH 05/14] powerpc/64s: msgclr when handling doorbell exceptions Nicholas Piggin
2017-06-12 14:38 ` Gautham R Shenoy [this message]
2017-06-11 23:58 ` [PATCH 06/14] powerpc/64s: interrupt replay balance the return branch predictor Nicholas Piggin
2017-06-12 14:41 ` Gautham R Shenoy
2017-06-13 9:51 ` Michael Ellerman
2017-06-13 11:09 ` Nicholas Piggin
2017-06-11 23:58 ` [PATCH 07/14] powerpc/64s: idle branch to handler with virtual mode offset Nicholas Piggin
2017-06-11 23:58 ` [PATCH 08/14] powerpc/64s: idle avoid SRR usage in idle sleep/wake paths Nicholas Piggin
2017-06-13 10:25 ` Gautham R Shenoy
2017-06-13 10:45 ` Nicholas Piggin
2017-06-11 23:58 ` [PATCH 09/14] powerpc/64s: idle hmi wakeup is unlikely Nicholas Piggin
2017-06-12 15:03 ` Gautham R Shenoy
2017-06-11 23:58 ` [PATCH 10/14] powerpc/64s: cpuidle set polling before enabling irqs Nicholas Piggin
2017-06-12 15:10 ` Gautham R Shenoy
2017-06-12 15:20 ` Nicholas Piggin
2017-06-11 23:58 ` [PATCH 11/14] powerpc/64s: cpuidle read mostly for common globals Nicholas Piggin
2017-06-12 15:30 ` Gautham R Shenoy
2017-06-12 17:50 ` Vaidyanathan Srinivasan
2017-06-11 23:58 ` [PATCH 12/14] powerpc/64s: cpuidle no memory barrier after break from idle Nicholas Piggin
2017-06-12 17:48 ` Vaidyanathan Srinivasan
2017-06-13 12:47 ` Nicholas Piggin
2017-06-11 23:58 ` [PATCH 13/14] powerpc/64: runlatch CTRL[RUN] set optimisation Nicholas Piggin
2017-06-12 17:11 ` Vaidyanathan Srinivasan
2017-06-13 10:04 ` Michael Ellerman
2017-06-13 11:56 ` Nicholas Piggin
2017-06-13 13:45 ` Benjamin Herrenschmidt
2017-06-14 3:34 ` Michael Ellerman
2017-06-11 23:58 ` [PATCH 14/14] powerpc/64s: idle runlatch switch is done with MSR[EE]=0 Nicholas Piggin
2017-06-12 17:00 ` Vaidyanathan Srinivasan
-- strict thread matches above, loose matches on Subject: below --
2017-06-08 15:50 [PATCH 00/14] idle performance improvements Nicholas Piggin
2017-06-08 15:51 ` [PATCH 05/14] powerpc/64s: msgclr when handling doorbell exceptions Nicholas Piggin
2017-06-02 7:39 [RFC][PATCH 00/14] syscall, context switch, idle performance stuff Nicholas Piggin
2017-06-02 7:39 ` [PATCH 05/14] powerpc/64s: msgclr when handling doorbell exceptions Nicholas Piggin
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