Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752716Ab0DOLLt (ORCPT ); Thu, 15 Apr 2010 07:11:49 -0400 Received: from e23smtp08.au.ibm.com ([202.81.31.141]:34077 "EHLO e23smtp08.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752040Ab0DOLLr (ORCPT ); Thu, 15 Apr 2010 07:11:47 -0400 Date: Thu, 15 Apr 2010 16:41:36 +0530 From: Arun R Bharadwaj To: peterz@infradead.org Cc: Benjamin Herrenschmidt , Ingo Molnar , Vaidyanathan Srinivasan , Dipankar Sarma , Balbir Singh , Arun Bharadwaj , linux-kernel@vger.kernel.org Subject: [v12 PATCH 7/8]: pSeries: implement pSeries processor idle module. Message-ID: <20100415111136.GH16760@linux.vnet.ibm.com> Reply-To: arun@linux.vnet.ibm.com References: <20100415110046.GA16760@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20100415110046.GA16760@linux.vnet.ibm.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8477 Lines: 286 * Arun R Bharadwaj [2010-04-15 16:30:46]: 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 dedicated_snooze_loop or dedicated_cede_loop for dedicated lpar and shared_cede_loop for shared lpar processor based on the decision taken by the cpuidle governor. Signed-off-by: Arun R Bharadwaj --- arch/powerpc/include/asm/system.h | 6 arch/powerpc/kernel/sysfs.c | 2 arch/powerpc/platforms/pseries/Makefile | 1 arch/powerpc/platforms/pseries/processor_idle.c | 190 ++++++++++++++++++++++++ arch/powerpc/platforms/pseries/pseries.h | 6 5 files changed, 205 insertions(+) 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_CPU_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 +42,8 @@ extern unsigned long rtas_poweron_auto; extern void find_udbg_vterm(void); +DECLARE_PER_CPU(unsigned long, smt_snooze_delay); + +extern struct cpuidle_driver pseries_idle_driver; + #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 +1,190 @@ +/* + * 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 + +#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 IDLE_STATE_COUNT 2 + +/* pSeries Idle state Flags */ +#define PSERIES_DEDICATED_SNOOZE (0x01) +#define PSERIES_DEDICATED_CEDE (0x02) +#define PSERIES_SHARED_CEDE (0x03) + +static int pseries_idle_init(struct cpuidle_subsystem *subsys) +{ + return cpuidle_register_subsystem(subsys->state_count); +} + +static void shared_cede_loop(void) +{ + get_lppaca()->idle = 1; + cede_processor(); + get_lppaca()->idle = 0; +} + +static void dedicated_snooze_loop(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 dedicated_cede_loop(void) +{ + ppc64_runlatch_off(); + HMT_medium(); + cede_processor(); +} + +static int pseries_cpuidle_loop(struct cpuidle_state *st) +{ + unsigned long in_purr, out_purr; + + get_lppaca()->idle = 1; + get_lppaca()->donate_dedicated_cpu = 1; + in_purr = mfspr(SPRN_PURR); + + if (st->flags & PSERIES_SHARED_CEDE) + shared_cede_loop(); + else if (st->flags & PSERIES_DEDICATED_SNOOZE) + dedicated_snooze_loop(); + else + dedicated_cede_loop(); + + 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 0; +} + +static int pseries_setup_cpuidle(struct cpuidle_subsystem *subsys) +{ + int i; + struct cpuidle_state *state; + + if (get_lppaca()->shared_proc) { + state = &subsys->states[0]; + snprintf(state->name, CPUIDLE_NAME_LEN, "IDLE"); + state->enter = pseries_cpuidle_loop; + strncpy(state->desc, "shared_cede", CPUIDLE_DESC_LEN); + state->flags = PSERIES_SHARED_CEDE; + state->exit_latency = 0; + state->target_residency = 0; + subsys->state_count = 1; + return 0; + } + + for (i = 0; i < IDLE_STATE_COUNT; i++) { + state = &subsys->states[i]; + + snprintf(state->name, CPUIDLE_NAME_LEN, "CEDE%d", i); + state->enter = pseries_cpuidle_loop; + + switch (i) { + case 0: + strncpy(state->desc, "snooze", CPUIDLE_DESC_LEN); + state->flags = PSERIES_DEDICATED_SNOOZE; + state->exit_latency = 0; + state->target_residency = 0; + break; + + case 1: + strncpy(state->desc, "cede", CPUIDLE_DESC_LEN); + state->flags = PSERIES_DEDICATED_CEDE; + state->exit_latency = 1; + state->target_residency = + __get_cpu_var(smt_snooze_delay); + break; + } + } + subsys->state_count = i; + + return 0; +} + +void update_smt_snooze_delay(int snooze) +{ + cpuidle_subsys.states[0].target_residency = snooze; +} + +static int __init pseries_processor_idle_init(void) +{ + int result; + struct cpuidle_subsystem *pseries_subsys = &cpuidle_subsys; + + + result = cpuidle_register_driver(&pseries_idle_driver); + + if (result < 0) + return result; + + printk(KERN_DEBUG "pSeries idle driver registered\n"); + + if (!firmware_has_feature(FW_FEATURE_SPLPAR)) { + printk(KERN_DEBUG "Using default idle\n"); + return 0; + } + + pseries_setup_cpuidle(pseries_subsys); + pseries_idle_init(pseries_subsys); + + printk(KERN_DEBUG "Using cpuidle idle loop\n"); + + return 0; +} + +late_initcall(pseries_processor_idle_init); Index: linux.trees.git/arch/powerpc/include/asm/system.h =================================================================== --- linux.trees.git.orig/arch/powerpc/include/asm/system.h +++ linux.trees.git/arch/powerpc/include/asm/system.h @@ -554,5 +554,11 @@ extern struct dentry *powerpc_debugfs_ro void cpu_idle_wait(void); +#ifdef CONFIG_CPU_IDLE +extern void update_smt_snooze_delay(int snooze); +#else +static inline void update_smt_snooze_delay(int snooze) {} +#endif + #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_SYSTEM_H */ Index: linux.trees.git/arch/powerpc/kernel/sysfs.c =================================================================== --- linux.trees.git.orig/arch/powerpc/kernel/sysfs.c +++ linux.trees.git/arch/powerpc/kernel/sysfs.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "cacheinfo.h" @@ -51,6 +52,7 @@ static ssize_t store_smt_snooze_delay(st return -EINVAL; per_cpu(smt_snooze_delay, cpu->sysdev.id) = snooze; + update_smt_snooze_delay(snooze); return count; } -- 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/