Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754243AbZIALnE (ORCPT ); Tue, 1 Sep 2009 07:43:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754025AbZIALnD (ORCPT ); Tue, 1 Sep 2009 07:43:03 -0400 Received: from e28smtp05.in.ibm.com ([59.145.155.5]:43896 "EHLO e28smtp05.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754193AbZIALnB (ORCPT ); Tue, 1 Sep 2009 07:43:01 -0400 Date: Tue, 1 Sep 2009 17:12:55 +0530 From: Arun R Bharadwaj To: Joel Schopp , Benjamin Herrenschmidt , Paul Mackerras , Peter Zijlstra , Ingo Molnar , Vaidyanathan Srinivasan , Dipankar Sarma , Balbir Singh , Gautham R Shenoy , Arun Bharadwaj Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [v4 PATCH 5/5]: pSeries: Implement pSeries processor idle module. Message-ID: <20090901114255.GL7599@linux.vnet.ibm.com> Reply-To: arun@linux.vnet.ibm.com References: <20090901113704.GG7599@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20090901113704.GG7599@linux.vnet.ibm.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7355 Lines: 258 * Arun R Bharadwaj [2009-09-01 17:07:04]: This patch creates arch/powerpc/platforms/pseries/processor_idle.c, which implements the cpuidle infrastructure for pseries. It implements a pseries_cpuidle_loop() which would be the main idle loop called from cpu_idle(). It makes decision of entering either snooze or nap state based on the decision taken by the cpuidle governor. Signed-off-by: Arun R Bharadwaj --- arch/powerpc/platforms/pseries/Makefile | 1 arch/powerpc/platforms/pseries/processor_idle.c | 179 ++++++++++++++++++++++++ arch/powerpc/platforms/pseries/pseries.h | 14 + arch/powerpc/platforms/pseries/setup.c | 3 4 files changed, 194 insertions(+), 3 deletions(-) Index: linux.trees.git/arch/powerpc/platforms/pseries/Makefile =================================================================== --- linux.trees.git.orig/arch/powerpc/platforms/pseries/Makefile +++ linux.trees.git/arch/powerpc/platforms/pseries/Makefile @@ -26,3 +26,4 @@ obj-$(CONFIG_HCALL_STATS) += hvCall_inst obj-$(CONFIG_PHYP_DUMP) += phyp_dump.o obj-$(CONFIG_CMM) += cmm.o obj-$(CONFIG_DTL) += dtl.o +obj-$(CONFIG_PSERIES_PROCESSOR_IDLE) += processor_idle.o Index: linux.trees.git/arch/powerpc/platforms/pseries/pseries.h =================================================================== --- linux.trees.git.orig/arch/powerpc/platforms/pseries/pseries.h +++ linux.trees.git/arch/powerpc/platforms/pseries/pseries.h @@ -10,6 +10,8 @@ #ifndef _PSERIES_PSERIES_H #define _PSERIES_PSERIES_H +#include + extern void __init fw_feature_init(const char *hypertas, unsigned long len); struct pt_regs; @@ -40,4 +42,16 @@ extern unsigned long rtas_poweron_auto; extern void find_udbg_vterm(void); +DECLARE_PER_CPU(unsigned long, smt_snooze_delay); + +#ifdef CONFIG_PSERIES_PROCESSOR_IDLE +struct pseries_processor_power { + struct cpuidle_device dev; + int count; + int id; +}; + +extern struct cpuidle_driver pseries_idle_driver; +#endif + #endif /* _PSERIES_PSERIES_H */ Index: linux.trees.git/arch/powerpc/platforms/pseries/processor_idle.c =================================================================== --- /dev/null +++ linux.trees.git/arch/powerpc/platforms/pseries/processor_idle.c @@ -0,0 +1,179 @@ +/* + * processor_idle - idle state cpuidle driver. + * Adapted from drivers/acpi/processor_idle.c + * + * Arun R Bharadwaj + * + * Copyright (C) 2009 IBM Corporation. + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ + +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include "plpar_wrappers.h" +#include "pseries.h" + +MODULE_AUTHOR("Arun R Bharadwaj"); +MODULE_DESCRIPTION("pSeries Idle State Driver"); +MODULE_LICENSE("GPL"); + +struct cpuidle_driver pseries_idle_driver = { + .name = "pseries_idle", + .owner = THIS_MODULE, +}; + +DEFINE_PER_CPU(struct pseries_processor_power, power); + +#define IDLE_STATE_COUNT 2 + +static int pseries_idle_init(struct pseries_processor_power *power) +{ + return cpuidle_register_device(&power->dev); +} + +static void cede1(void) +{ + local_irq_enable(); + set_thread_flag(TIF_POLLING_NRFLAG); + while (!need_resched()) { + ppc64_runlatch_off(); + HMT_low(); + HMT_very_low(); + } + HMT_medium(); + clear_thread_flag(TIF_POLLING_NRFLAG); + smp_mb(); + local_irq_disable(); +} + +static void cede2(void) +{ + ppc64_runlatch_off(); + HMT_medium(); + cede_processor(); +} + +static int pseries_cpuidle_loop(struct cpuidle_device *dev, + struct cpuidle_state *st) +{ + ktime_t t1, t2; + s64 diff; + int ret; + unsigned long in_purr, out_purr; + + get_lppaca()->idle = 1; + get_lppaca()->donate_dedicated_cpu = 1; + in_purr = mfspr(SPRN_PURR); + + t1 = ktime_get(); + + if (strcmp(st->desc, "cede1") == 0) + cede1(); + else + cede2(); + + t2 = ktime_get(); + diff = ktime_to_us(ktime_sub(t2, t1)); + if (diff > INT_MAX) + diff = INT_MAX; + + ret = (int) diff; + + out_purr = mfspr(SPRN_PURR); + get_lppaca()->wait_state_cycles += out_purr - in_purr; + get_lppaca()->donate_dedicated_cpu = 0; + get_lppaca()->idle = 0; + + return ret; +} + +static int pseries_setup_cpuidle(struct pseries_processor_power *power) +{ + int i; + struct cpuidle_state *state; + struct cpuidle_device *dev = &power->dev; + + dev->cpu = power->id; + + dev->enabled = 0; + for (i = 0; i < IDLE_STATE_COUNT; i++) { + state = &dev->states[i]; + + snprintf(state->name, CPUIDLE_NAME_LEN, "IDLE%d", i); + state->enter = pseries_cpuidle_loop; + + switch (i) { + case 0: + strncpy(state->desc, "cede1", CPUIDLE_DESC_LEN); + state->exit_latency = 0; + state->target_residency = 0; + break; + + case 1: + strncpy(state->desc, "cede2", CPUIDLE_DESC_LEN); + state->exit_latency = 1; + state->target_residency = + __get_cpu_var(smt_snooze_delay); + break; + } + } + + power->dev.state_count = i; + return 0; +} + +static int pseries_get_power_info(struct pseries_processor_power *power, + int cpu) +{ + power->id = cpu; + power->count = IDLE_STATE_COUNT; + return 0; +} + +static int __init pseries_processor_idle_init(void) +{ + int cpu; + int result = cpuidle_register_driver(&pseries_idle_driver); + + if (result < 0) + return result; + + printk(KERN_DEBUG "pSeries idle driver registered\n"); + + for_each_online_cpu(cpu) { + pseries_get_power_info(&per_cpu(power, cpu), cpu); + pseries_setup_cpuidle(&per_cpu(power, cpu)); + pseries_idle_init(&per_cpu(power, cpu)); + } + + printk(KERN_DEBUG "Using cpuidle idle loop\n"); + + return 0; +} + +late_initcall(pseries_processor_idle_init); Index: linux.trees.git/arch/powerpc/platforms/pseries/setup.c =================================================================== --- linux.trees.git.orig/arch/powerpc/platforms/pseries/setup.c +++ linux.trees.git/arch/powerpc/platforms/pseries/setup.c @@ -509,9 +509,6 @@ static int __init pSeries_probe(void) return 1; } - -DECLARE_PER_CPU(unsigned long, smt_snooze_delay); - static void pseries_dedicated_idle_sleep(void) { unsigned int cpu = smp_processor_id(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/