From patchwork Wed Jan 22 07:08:19 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: preeti X-Patchwork-Id: 3521991 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 6F0059F1C3 for ; Wed, 22 Jan 2014 07:12:09 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7177220155 for ; Wed, 22 Jan 2014 07:12:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 69E2B2012E for ; Wed, 22 Jan 2014 07:12:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753382AbaAVHMA (ORCPT ); Wed, 22 Jan 2014 02:12:00 -0500 Received: from e35.co.us.ibm.com ([32.97.110.153]:47617 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754005AbaAVHL5 (ORCPT ); Wed, 22 Jan 2014 02:11:57 -0500 Received: from /spool/local by e35.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 22 Jan 2014 00:11:54 -0700 Received: from b03cxnp07028.gho.boulder.ibm.com (b03cxnp07028.gho.boulder.ibm.com [9.17.130.15]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id 6A0C83E4003F; Wed, 22 Jan 2014 00:11:54 -0700 (MST) Received: from d03av06.boulder.ibm.com (d03av06.boulder.ibm.com [9.17.195.245]) by b03cxnp07028.gho.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s0M7BahN8257840; Wed, 22 Jan 2014 08:11:36 +0100 Received: from d03av06.boulder.ibm.com (loopback [127.0.0.1]) by d03av06.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id s0M7F9jn008691; Wed, 22 Jan 2014 00:15:12 -0700 Received: from preeti.in.ibm.com (preeti.in.ibm.com [9.124.31.42] (may be forged)) by d03av06.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id s0M7F0HZ008318; Wed, 22 Jan 2014 00:15:01 -0700 Subject: [RESEND PATCH V5 2/8] powerpc: Implement tick broadcast IPI as a fixed IPI message To: peterz@infradead.org, fweisbec@gmail.com, paul.gortmaker@windriver.com, paulus@samba.org, mingo@kernel.org, mikey@neuling.org, shangw@linux.vnet.ibm.com, rafael.j.wysocki@intel.com, galak@kernel.crashing.org, =daniel.lezcano@linaro.org, benh@kernel.crashing.org, paulmck@linux.vnet.ibm.com, --to=agraf@suse.de, arnd@arndb.de, linux-pm@vger.kernel.org, rostedt@goodmis.org, michael@ellerman.id.au, john.stultz@linaro.org, anton@samba.org, tglx@linutronix.de, chenhui.zhao@freescale.com, deepthi@linux.vnet.ibm.com, r58472@freescale.com, geoff@infradead.org, linux-kernel@vger.kernel.org, srivatsa.bhat@linux.vnet.ibm.com, schwidefsky@de.ibm.com, svaidy@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org From: Preeti U Murthy Date: Wed, 22 Jan 2014 12:38:19 +0530 Message-ID: <20140122070819.30650.49100.stgit@preeti.in.ibm.com> In-Reply-To: <20140122065918.30650.22437.stgit@preeti.in.ibm.com> References: <20140122065918.30650.22437.stgit@preeti.in.ibm.com> User-Agent: StGit/0.16-38-g167d MIME-Version: 1.0 X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14012207-6688-0000-0000-000005C0FD38 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Srivatsa S. Bhat For scalability and performance reasons, we want the tick broadcast IPIs to be handled as efficiently as possible. Fixed IPI messages are one of the most efficient mechanisms available - they are faster than the smp_call_function mechanism because the IPI handlers are fixed and hence they don't involve costly operations such as adding IPI handlers to the target CPU's function queue, acquiring locks for synchronization etc. Luckily we have an unused IPI message slot, so use that to implement tick broadcast IPIs efficiently. Signed-off-by: Srivatsa S. Bhat [Functions renamed to tick_broadcast* and Changelog modified by Preeti U. Murthy] Signed-off-by: Preeti U. Murthy Acked-by: Geoff Levand [For the PS3 part] --- arch/powerpc/include/asm/smp.h | 2 +- arch/powerpc/include/asm/time.h | 1 + arch/powerpc/kernel/smp.c | 19 +++++++++++++++---- arch/powerpc/kernel/time.c | 5 +++++ arch/powerpc/platforms/cell/interrupt.c | 2 +- arch/powerpc/platforms/ps3/smp.c | 2 +- 6 files changed, 24 insertions(+), 7 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h index 9f7356b..ff51046 100644 --- a/arch/powerpc/include/asm/smp.h +++ b/arch/powerpc/include/asm/smp.h @@ -120,7 +120,7 @@ extern int cpu_to_core_id(int cpu); * in /proc/interrupts will be wrong!!! --Troy */ #define PPC_MSG_CALL_FUNCTION 0 #define PPC_MSG_RESCHEDULE 1 -#define PPC_MSG_UNUSED 2 +#define PPC_MSG_TICK_BROADCAST 2 #define PPC_MSG_DEBUGGER_BREAK 3 /* for irq controllers that have dedicated ipis per message (4) */ diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h index c1f2676..1d428e6 100644 --- a/arch/powerpc/include/asm/time.h +++ b/arch/powerpc/include/asm/time.h @@ -28,6 +28,7 @@ extern struct clock_event_device decrementer_clockevent; struct rtc_time; extern void to_tm(int tim, struct rtc_time * tm); extern void GregorianDay(struct rtc_time *tm); +extern void tick_broadcast_ipi_handler(void); extern void generic_calibrate_decr(void); diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index ee7d76b..6f06f05 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include #include @@ -145,9 +146,9 @@ static irqreturn_t reschedule_action(int irq, void *data) return IRQ_HANDLED; } -static irqreturn_t unused_action(int irq, void *data) +static irqreturn_t tick_broadcast_ipi_action(int irq, void *data) { - /* This slot is unused and hence available for use, if needed */ + tick_broadcast_ipi_handler(); return IRQ_HANDLED; } @@ -168,14 +169,14 @@ static irqreturn_t debug_ipi_action(int irq, void *data) static irq_handler_t smp_ipi_action[] = { [PPC_MSG_CALL_FUNCTION] = call_function_action, [PPC_MSG_RESCHEDULE] = reschedule_action, - [PPC_MSG_UNUSED] = unused_action, + [PPC_MSG_TICK_BROADCAST] = tick_broadcast_ipi_action, [PPC_MSG_DEBUGGER_BREAK] = debug_ipi_action, }; const char *smp_ipi_name[] = { [PPC_MSG_CALL_FUNCTION] = "ipi call function", [PPC_MSG_RESCHEDULE] = "ipi reschedule", - [PPC_MSG_UNUSED] = "ipi unused", + [PPC_MSG_TICK_BROADCAST] = "ipi tick-broadcast", [PPC_MSG_DEBUGGER_BREAK] = "ipi debugger", }; @@ -251,6 +252,8 @@ irqreturn_t smp_ipi_demux(void) generic_smp_call_function_interrupt(); if (all & IPI_MESSAGE(PPC_MSG_RESCHEDULE)) scheduler_ipi(); + if (all & IPI_MESSAGE(PPC_MSG_TICK_BROADCAST)) + tick_broadcast_ipi_handler(); if (all & IPI_MESSAGE(PPC_MSG_DEBUGGER_BREAK)) debug_ipi_action(0, NULL); } while (info->messages); @@ -289,6 +292,14 @@ void arch_send_call_function_ipi_mask(const struct cpumask *mask) do_message_pass(cpu, PPC_MSG_CALL_FUNCTION); } +void tick_broadcast(const struct cpumask *mask) +{ + unsigned int cpu; + + for_each_cpu(cpu, mask) + do_message_pass(cpu, PPC_MSG_TICK_BROADCAST); +} + #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC) void smp_send_debugger_break(void) { diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index b3dab20..3ff97db 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -825,6 +825,11 @@ static void decrementer_set_mode(enum clock_event_mode mode, decrementer_set_next_event(DECREMENTER_MAX, dev); } +/* Interrupt handler for the timer broadcast IPI */ +void tick_broadcast_ipi_handler(void) +{ +} + static void register_decrementer_clockevent(int cpu) { struct clock_event_device *dec = &per_cpu(decrementers, cpu); diff --git a/arch/powerpc/platforms/cell/interrupt.c b/arch/powerpc/platforms/cell/interrupt.c index adf3726..8a106b4 100644 --- a/arch/powerpc/platforms/cell/interrupt.c +++ b/arch/powerpc/platforms/cell/interrupt.c @@ -215,7 +215,7 @@ void iic_request_IPIs(void) { iic_request_ipi(PPC_MSG_CALL_FUNCTION); iic_request_ipi(PPC_MSG_RESCHEDULE); - iic_request_ipi(PPC_MSG_UNUSED); + iic_request_ipi(PPC_MSG_TICK_BROADCAST); iic_request_ipi(PPC_MSG_DEBUGGER_BREAK); } diff --git a/arch/powerpc/platforms/ps3/smp.c b/arch/powerpc/platforms/ps3/smp.c index 00d1a7c..b358bec 100644 --- a/arch/powerpc/platforms/ps3/smp.c +++ b/arch/powerpc/platforms/ps3/smp.c @@ -76,7 +76,7 @@ static int __init ps3_smp_probe(void) BUILD_BUG_ON(PPC_MSG_CALL_FUNCTION != 0); BUILD_BUG_ON(PPC_MSG_RESCHEDULE != 1); - BUILD_BUG_ON(PPC_MSG_UNUSED != 2); + BUILD_BUG_ON(PPC_MSG_TICK_BROADCAST != 2); BUILD_BUG_ON(PPC_MSG_DEBUGGER_BREAK != 3); for (i = 0; i < MSG_COUNT; i++) {