From patchwork Wed Mar 27 04:37:49 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Horman X-Patchwork-Id: 2347561 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) by patchwork1.kernel.org (Postfix) with ESMTP id DCC0D3FD40 for ; Wed, 27 Mar 2013 04:37:56 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [IPv6:::1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 942EE8D1; Wed, 27 Mar 2013 04:37:56 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTP id 0B7518D1 for ; Wed, 27 Mar 2013 04:37:56 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from kirsty.vergenet.net (kirsty.vergenet.net [202.4.237.240]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 27D8220123 for ; Wed, 27 Mar 2013 04:37:54 +0000 (UTC) Received: from ayumi.akashicho.tokyo.vergenet.net (p8120-ipbfp1001kobeminato.hyogo.ocn.ne.jp [118.10.137.120]) by kirsty.vergenet.net (Postfix) with ESMTP id 3A0D525BF85; Wed, 27 Mar 2013 15:37:53 +1100 (EST) Received: by ayumi.akashicho.tokyo.vergenet.net (Postfix, from userid 7100) id D3E5AEDE139; Wed, 27 Mar 2013 13:37:51 +0900 (JST) From: Simon Horman To: ltsi-dev@lists.linuxfoundation.org Date: Wed, 27 Mar 2013 13:37:49 +0900 Message-Id: <1364359070-7002-2-git-send-email-horms+renesas@verge.net.au> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1364359070-7002-1-git-send-email-horms+renesas@verge.net.au> References: <1364359070-7002-1-git-send-email-horms+renesas@verge.net.au> X-Spam-Status: No, score=-3.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_LOW, RP_MATCHES_RCVD autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Subject: [LTSI-dev] [PATCH 1/2] ARM: SoC: add per-platform SMP operations X-BeenThere: ltsi-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "A list to discuss patches, development, and other things related to the LTSI project" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org From: Marc Zyngier This adds a 'struct smp_operations' to abstract the CPU initialization and hot plugging functions on SMP systems, which otherwise conflict in a multiplatform kernel. This also helps shmobile and potentially others that have more than one method to do these. To allow the kernel to continue building, the platform hooks are defined as weak symbols which are overrided by the platform code. Once all platforms are converted, the "weak" attribute will be removed and the function made static. Unlike the original version from Marc, this new version from Arnd does not use a generalized abstraction for per-soc data structures but only tries to solve the problem for the SMP operations. This way, we can collapse the previous four data structures into a single struct, which is less systematic but also easier to follow as a causal reader. Signed-off-by: Marc Zyngier Acked-by: Nicolas Pitre Signed-off-by: Arnd Bergmann (cherry picked from commit abcee5fb0dfbb248d883a2f6bdb4820abe3ac524) Conflicts: arch/arm/kernel/smp.c Signed-off-by: Simon Horman --- arch/arm/include/asm/mach/arch.h | 7 +++++ arch/arm/include/asm/smp.h | 33 ++++++++++++++++++++ arch/arm/kernel/setup.c | 4 ++- arch/arm/kernel/smp.c | 62 +++++++++++++++++++++++++++++++++++++- 4 files changed, 104 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/asm/mach/arch.h b/arch/arm/include/asm/mach/arch.h index 0b1c94b..917d4fc 100644 --- a/arch/arm/include/asm/mach/arch.h +++ b/arch/arm/include/asm/mach/arch.h @@ -14,6 +14,12 @@ struct tag; struct meminfo; struct sys_timer; struct pt_regs; +struct smp_operations; +#ifdef CONFIG_SMP +#define smp_ops(ops) (&(ops)) +#else +#define smp_ops(ops) (struct smp_operations *)NULL +#endif struct machine_desc { unsigned int nr; /* architecture number */ @@ -35,6 +41,7 @@ struct machine_desc { unsigned char reserve_lp1 :1; /* never has lp1 */ unsigned char reserve_lp2 :1; /* never has lp2 */ char restart_mode; /* default restart mode */ + struct smp_operations *smp; /* SMP operations */ void (*fixup)(struct tag *, char **, struct meminfo *); void (*reserve)(void);/* reserve mem blocks */ diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h index ae29293..f79a9f5 100644 --- a/arch/arm/include/asm/smp.h +++ b/arch/arm/include/asm/smp.h @@ -93,4 +93,37 @@ extern void platform_cpu_enable(unsigned int cpu); extern void arch_send_call_function_single_ipi(int cpu); extern void arch_send_call_function_ipi_mask(const struct cpumask *mask); +struct smp_operations { +#ifdef CONFIG_SMP + /* + * Setup the set of possible CPUs (via set_cpu_possible) + */ + void (*smp_init_cpus)(void); + /* + * Initialize cpu_possible map, and enable coherency + */ + void (*smp_prepare_cpus)(unsigned int max_cpus); + + /* + * Perform platform specific initialisation of the specified CPU. + */ + void (*smp_secondary_init)(unsigned int cpu); + /* + * Boot a secondary CPU, and assign it the specified idle task. + * This also gives us the initial stack to use for this CPU. + */ + int (*smp_boot_secondary)(unsigned int cpu, struct task_struct *idle); +#ifdef CONFIG_HOTPLUG_CPU + int (*cpu_kill)(unsigned int cpu); + void (*cpu_die)(unsigned int cpu); + int (*cpu_disable)(unsigned int cpu); +#endif +#endif +}; + +/* + * set platform specific SMP operations + */ +extern void smp_set_ops(struct smp_operations *); + #endif /* ifndef __ASM_ARM_SMP_H */ diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index e15d83b..467155b 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -977,8 +977,10 @@ void __init setup_arch(char **cmdline_p) unflatten_device_tree(); #ifdef CONFIG_SMP - if (is_smp()) + if (is_smp()) { + smp_set_ops(mdesc->smp); smp_init_cpus(); + } #endif reserve_crashkernel(); diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 8f14a1b..2c2f7ac 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -19,7 +19,6 @@ #include #include #include -#include #include #include #include @@ -27,6 +26,7 @@ #include #include +#include #include #include #include @@ -42,6 +42,7 @@ #include #include #include +#include /* * as from 2.5, kernels no longer have an init_tasks structure @@ -60,6 +61,14 @@ enum ipi_msg_type { static DECLARE_COMPLETION(cpu_running); +static struct smp_operations smp_ops; + +void __init smp_set_ops(struct smp_operations *ops) +{ + if (ops) + smp_ops = *ops; +}; + int __cpuinit __cpu_up(unsigned int cpu) { struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu); @@ -121,9 +130,60 @@ int __cpuinit __cpu_up(unsigned int cpu) return ret; } +/* platform specific SMP operations */ +void __attribute__((weak)) __init smp_init_cpus(void) +{ + if (smp_ops.smp_init_cpus) + smp_ops.smp_init_cpus(); +} + +void __attribute__((weak)) __init platform_smp_prepare_cpus(unsigned int max_cpus) +{ + if (smp_ops.smp_prepare_cpus) + smp_ops.smp_prepare_cpus(max_cpus); +} + +void __attribute__((weak)) __cpuinit platform_secondary_init(unsigned int cpu) +{ + if (smp_ops.smp_secondary_init) + smp_ops.smp_secondary_init(cpu); +} + +int __attribute__((weak)) __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle) +{ + if (smp_ops.smp_boot_secondary) + return smp_ops.smp_boot_secondary(cpu, idle); + return -ENOSYS; +} + #ifdef CONFIG_HOTPLUG_CPU static void percpu_timer_stop(void); +int __attribute__((weak)) platform_cpu_kill(unsigned int cpu) +{ + if (smp_ops.cpu_kill) + return smp_ops.cpu_kill(cpu); + return 1; +} + +void __attribute__((weak)) platform_cpu_die(unsigned int cpu) +{ + if (smp_ops.cpu_die) + smp_ops.cpu_die(cpu); +} + +int __attribute__((weak)) platform_cpu_disable(unsigned int cpu) +{ + if (smp_ops.cpu_disable) + return smp_ops.cpu_disable(cpu); + + /* + * By default, allow disabling all CPUs except the first one, + * since this is special on a lot of platforms, e.g. because + * of clock tick interrupts. + */ + return cpu == 0 ? -EPERM : 0; +} /* * __cpu_disable runs on the processor to be shutdown. */