Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751811Ab3C0NfU (ORCPT ); Wed, 27 Mar 2013 09:35:20 -0400 Received: from service87.mimecast.com ([91.220.42.44]:53690 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750968Ab3C0NfT convert rfc822-to-8bit (ORCPT ); Wed, 27 Mar 2013 09:35:19 -0400 Message-ID: <5152F591.40201@arm.com> Date: Wed, 27 Mar 2013 13:35:13 +0000 From: Marc Zyngier User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: Stefano Stabellini CC: "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "arnd@arndb.de" , Will Deacon , "linux@arm.linux.org.uk" , "nico@linaro.org" Subject: Re: [PATCH v3] [RFC] arm: use PSCI if available References: <1364388639-11210-1-git-send-email-stefano.stabellini@eu.citrix.com> In-Reply-To: <1364388639-11210-1-git-send-email-stefano.stabellini@eu.citrix.com> X-Enigmail-Version: 1.4.6 X-OriginalArrivalTime: 27 Mar 2013 13:35:14.0512 (UTC) FILETIME=[E99AF500:01CE2AEF] X-MC-Unique: 113032713351704301 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5827 Lines: 192 On 27/03/13 12:50, Stefano Stabellini wrote: > Check for the presence of PSCI before setting smp_ops, use PSCI if it is > available. > > This is useful because at least when running on Xen it's possible to have a > PSCI node for example on a Versatile Express or an Exynos5 machine. In these > cases the PSCI SMP calls should be the ones to be called. > > Remove virt_smp_ops and platsmp.c from mach-virt because they aren't needed > anymore. > > > > This patch was originally part of this series: > > http://marc.info/?l=linux-arm-kernel&m=136430903110734&w=2 > > I am keeping it separate now since it is the only non-obvious change and > it is not Xen related. > > > > > Changes in v3: > - move the call to psci_init to setup_arch; > - export psci_smp_ops from psci.h; > - introduce psci_smp_available; > - introduce stub functions for psci_init and psci_smp_available ifndef > CONFIG_ARM_PSCI; > - only compile psci_smp functions ifdef CONFIG_SMP. > > > Signed-off-by: Stefano Stabellini > CC: will.deacon@arm.com > CC: arnd@arndb.de > CC: marc.zyngier@arm.com > CC: linux@arm.linux.org.uk > CC: nico@linaro.org > --- > arch/arm/include/asm/psci.h | 9 ++++ > arch/arm/kernel/psci.c | 97 ++++++++++++++++++++++++++++++++++-------- > arch/arm/kernel/setup.c | 7 +++- > arch/arm/mach-virt/Makefile | 1 - > arch/arm/mach-virt/platsmp.c | 58 ------------------------- > arch/arm/mach-virt/virt.c | 3 - > 6 files changed, 94 insertions(+), 81 deletions(-) > delete mode 100644 arch/arm/mach-virt/platsmp.c > > diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h > index ce0dbe7..ddef231 100644 > --- a/arch/arm/include/asm/psci.h > +++ b/arch/arm/include/asm/psci.h > @@ -32,5 +32,14 @@ struct psci_operations { > }; > > extern struct psci_operations psci_ops; > +extern struct smp_operations psci_smp_ops; > + > +#ifdef CONFIG_ARM_PSCI > +int psci_init(void); > +bool psci_smp_available(void); > +#else > +static inline int psci_init(void) { return -ENODEV; } > +static inline bool psci_smp_available(void) { return false; } > +#endif > > #endif /* __ASM_ARM_PSCI_H */ > diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c > index 3653164..90f0839 100644 > --- a/arch/arm/kernel/psci.c > +++ b/arch/arm/kernel/psci.c > @@ -16,6 +16,7 @@ > #define pr_fmt(fmt) "psci: " fmt > > #include > +#include > #include > > #include > @@ -23,8 +24,9 @@ > #include > #include > #include > +#include > > -struct psci_operations psci_ops; > +extern void secondary_startup(void); > > static int (*invoke_psci_fn)(u32, u32, u32, u32); > > @@ -36,7 +38,11 @@ enum psci_function { > PSCI_FN_MAX, > }; > > -static u32 psci_function_id[PSCI_FN_MAX]; > +struct psci_function_desc { > + enum psci_function func; > + bool valid; > +}; > +static struct psci_function_desc psci_function_id[PSCI_FN_MAX]; > > #define PSCI_RET_SUCCESS 0 > #define PSCI_RET_EOPNOTSUPP -1 > @@ -116,7 +122,10 @@ static int psci_cpu_suspend(struct psci_power_state state, > int err; > u32 fn, power_state; > > - fn = psci_function_id[PSCI_FN_CPU_SUSPEND]; > + if (!psci_function_id[PSCI_FN_CPU_SUSPEND].valid) > + return -ENOSYS; > + > + fn = psci_function_id[PSCI_FN_CPU_SUSPEND].func; > power_state = psci_power_state_pack(state); > err = invoke_psci_fn(fn, power_state, entry_point, 0); > return psci_to_linux_errno(err); > @@ -127,7 +136,10 @@ static int psci_cpu_off(struct psci_power_state state) > int err; > u32 fn, power_state; > > - fn = psci_function_id[PSCI_FN_CPU_OFF]; > + if (!psci_function_id[PSCI_FN_CPU_OFF].valid) > + return -ENOSYS; > + > + fn = psci_function_id[PSCI_FN_CPU_OFF].func; > power_state = psci_power_state_pack(state); > err = invoke_psci_fn(fn, power_state, 0, 0); > return psci_to_linux_errno(err); > @@ -138,7 +150,10 @@ static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point) > int err; > u32 fn; > > - fn = psci_function_id[PSCI_FN_CPU_ON]; > + if (!psci_function_id[PSCI_FN_CPU_ON].valid) > + return -ENOSYS; > + > + fn = psci_function_id[PSCI_FN_CPU_ON].func; > err = invoke_psci_fn(fn, cpuid, entry_point, 0); > return psci_to_linux_errno(err); > } > @@ -148,25 +163,64 @@ static int psci_migrate(unsigned long cpuid) > int err; > u32 fn; > > - fn = psci_function_id[PSCI_FN_MIGRATE]; > + if (!psci_function_id[PSCI_FN_MIGRATE].valid) > + return -ENOSYS; > + > + fn = psci_function_id[PSCI_FN_MIGRATE].func; > err = invoke_psci_fn(fn, cpuid, 0, 0); > return psci_to_linux_errno(err); > } > > +struct psci_operations psci_ops = { > + .cpu_suspend = psci_cpu_suspend, > + .cpu_off = psci_cpu_off, > + .cpu_on = psci_cpu_on, > + .migrate = psci_migrate, > +}; > + > +#ifdef CONFIG_SMP > +static void __init psci_smp_init_cpus(void) > +{ > +} > + > +static void __init psci_smp_prepare_cpus(unsigned int max_cpus) > +{ > +} > + > +static int __cpuinit psci_boot_secondary(unsigned int cpu, > + struct task_struct *idle) > +{ > + return psci_cpu_on(cpu_logical_map(cpu), __pa(secondary_startup)); > +} > + > +static void __cpuinit psci_secondary_init(unsigned int cpu) > +{ > + gic_secondary_init(0); > +} So here we end-up with a dependency between SMP, PSCI, and GIC. I really can't see that being a good idea, even I like the general direction of this series. M. -- Jazz is not dead. It just smells funny... -- 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/