From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudeep Holla Subject: Re: [PATCH v7 4/6] cpuidle: introduce HAVE_GENERIC_CPUIDLE_ENTER for ARM{32,64} platforms Date: Thu, 7 Jul 2016 14:34:36 +0100 Message-ID: <577E5A6C.9020007@arm.com> References: <1467122152-5604-1-git-send-email-sudeep.holla@arm.com> <1467122152-5604-5-git-send-email-sudeep.holla@arm.com> <1675585.udvKUofiJK@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1675585.udvKUofiJK@vostro.rjw.lan> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: "Rafael J. Wysocki" Cc: Lorenzo Pieralisi , Al Stone , PrashanthPrakash , Vikas Sajjan , Daniel Lezcano , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, Ashwin Chaugule , Sudeep Holla , linux-arm-kernel@lists.infradead.org, Sunil List-Id: linux-acpi@vger.kernel.org On 07/07/16 14:21, Rafael J. Wysocki wrote: > On Tuesday, June 28, 2016 02:55:50 PM Sudeep Holla wrote: >> The function arm_enter_idle_state is exactly the same in both generic >> ARM{32,64} CPUIdle driver and will be the same even on ARM64 backend >> for ACPI processor idle driver. So we can unify it and move it as >> generic_cpuidle_enter by introducing HAVE_GENERIC_CPUIDLE_ENTER and >> enabling the same on both ARM{32,64}. >> >> This is in preparation of reuse of the generic cpuidle entry function >> for ACPI LPI support on ARM64. >> >> Cc: "Rafael J. Wysocki" >> Cc: Daniel Lezcano >> Cc: Lorenzo Pieralisi >> Signed-off-by: Sudeep Holla >> --- >> arch/arm/Kconfig | 1 + >> arch/arm/kernel/cpuidle.c | 4 ++-- >> arch/arm64/Kconfig | 1 + >> arch/arm64/kernel/cpuidle.c | 6 +++--- >> drivers/cpuidle/Kconfig | 3 +++ >> drivers/cpuidle/cpuidle-arm.c | 21 +-------------------- >> drivers/cpuidle/cpuidle.c | 35 +++++++++++++++++++++++++++++++++++ >> include/linux/cpuidle.h | 8 ++++++++ >> 8 files changed, 54 insertions(+), 25 deletions(-) >> >> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig >> index 90542db1220d..52b3dca0381c 100644 >> --- a/arch/arm/Kconfig >> +++ b/arch/arm/Kconfig >> @@ -54,6 +54,7 @@ config ARM >> select HAVE_FTRACE_MCOUNT_RECORD if (!XIP_KERNEL) >> select HAVE_FUNCTION_GRAPH_TRACER if (!THUMB2_KERNEL) >> select HAVE_FUNCTION_TRACER if (!XIP_KERNEL) >> + select HAVE_GENERIC_CPUIDLE_ENTER > > That "generic" part in the name concerns me a bit, because the thing is not > really generic. It is "common on ARM" rather. > I agree and that's exactly what I told Daniel. It's rather just *ARM Generic*. Any preference on the name ? I had it header file under include/linu/cpuidle-arm.h in the previous version. Do you prefer that ? [..] >> @@ -255,6 +256,40 @@ int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) >> } >> >> /** >> + * cpuidle_generic_enter_state - enter into the specified idle state using the >> + * generic callback if implemented >> + * >> + * @index: the index in the idle state table >> + * >> + * Returns the index in the idle state, -1 in case of error. >> + */ >> +int cpuidle_generic_enter_state(int idx) >> +{ >> + int ret; >> + >> + if (!idx) { >> + cpu_do_idle(); >> + return idx; >> + } >> + >> + ret = cpu_pm_enter(); > > If you look at the users of cpu_pm_enter(), they are all ARM. Nobody else uses > it, so at least please put cpuidle_generic_enter_state() under a #ifdef to avoid > building it in vain on non-ARM. > Agreed, that should be taken care once I do the changes you are suggesting below. [...] >> @@ -246,6 +248,12 @@ static inline int cpuidle_register_governor(struct cpuidle_governor *gov) >> {return 0;} >> #endif >> >> +#ifdef CONFIG_HAVE_GENERIC_CPUIDLE_ENTER >> +extern int cpuidle_generic_enter(int idx); > > And if you put it under the #ifdef here, its definition also should go under > the same #ifdef. > Yes I will do that. -- Regards, Sudeep