From 34f361ade2fb4a869f6a7714d01c04ce4cfa75d9 Mon Sep 17 00:00:00 2001 From: Ashok Raj Date: Sat, 25 Mar 2006 03:08:18 -0800 Subject: [PATCH] [PATCH] Check if cpu can be onlined before calling smp_prepare_cpu() - Moved check for online cpu out of smp_prepare_cpu() - Moved default declaration of smp_prepare_cpu() to kernel/cpu.c - Removed lock_cpu_hotplug() from smp_prepare_cpu() to around it, since its called from cpu_up() as well now. - Removed clearing from cpu_present_map during cpu_offline as it breaks using cpu_up() directly during a subsequent online operation. Signed-off-by: Ashok Raj Cc: Srivatsa Vaddagiri Cc: "Li, Shaohua" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/smpboot.c | 33 ++++++++++++++++++--------------- drivers/base/cpu.c | 9 +-------- include/linux/cpu.h | 1 - kernel/power/smp.c | 4 +--- 4 files changed, 20 insertions(+), 27 deletions(-) diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c index 4c470e99a742..82371d83bfa9 100644 --- a/arch/i386/kernel/smpboot.c +++ b/arch/i386/kernel/smpboot.c @@ -1003,7 +1003,6 @@ void cpu_exit_clear(void) cpu_clear(cpu, cpu_callout_map); cpu_clear(cpu, cpu_callin_map); - cpu_clear(cpu, cpu_present_map); cpu_clear(cpu, smp_commenced_mask); unmap_cpu_to_logical_apicid(cpu); @@ -1015,31 +1014,20 @@ struct warm_boot_cpu_info { int cpu; }; -static void __devinit do_warm_boot_cpu(void *p) +static void __cpuinit do_warm_boot_cpu(void *p) { struct warm_boot_cpu_info *info = p; do_boot_cpu(info->apicid, info->cpu); complete(info->complete); } -int __devinit smp_prepare_cpu(int cpu) +static int __cpuinit __smp_prepare_cpu(int cpu) { DECLARE_COMPLETION(done); struct warm_boot_cpu_info info; struct work_struct task; int apicid, ret; - lock_cpu_hotplug(); - - /* - * On x86, CPU0 is never offlined. Trying to bring up an - * already-booted CPU will hang. So check for that case. - */ - if (cpu_online(cpu)) { - ret = -EINVAL; - goto exit; - } - apicid = x86_cpu_to_apicid[cpu]; if (apicid == BAD_APICID) { ret = -ENODEV; @@ -1064,7 +1052,6 @@ int __devinit smp_prepare_cpu(int cpu) zap_low_mappings(); ret = 0; exit: - unlock_cpu_hotplug(); return ret; } #endif @@ -1392,6 +1379,22 @@ void __cpu_die(unsigned int cpu) int __devinit __cpu_up(unsigned int cpu) { +#ifdef CONFIG_HOTPLUG_CPU + int ret=0; + + /* + * We do warm boot only on cpus that had booted earlier + * Otherwise cold boot is all handled from smp_boot_cpus(). + * cpu_callin_map is set during AP kickstart process. Its reset + * when a cpu is taken offline from cpu_exit_clear(). + */ + if (!cpu_isset(cpu, cpu_callin_map)) + ret = __smp_prepare_cpu(cpu); + + if (ret) + return -EIO; +#endif + /* In case one didn't come up */ if (!cpu_isset(cpu, cpu_callin_map)) { printk(KERN_DEBUG "skipping cpu%d, didn't come online\n", cpu); diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 29f3d7504da1..dd712b24ec91 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -19,11 +19,6 @@ EXPORT_SYMBOL(cpu_sysdev_class); static struct sys_device *cpu_sys_devices[NR_CPUS]; #ifdef CONFIG_HOTPLUG_CPU -int __attribute__((weak)) smp_prepare_cpu (int cpu) -{ - return 0; -} - static ssize_t show_online(struct sys_device *dev, char *buf) { struct cpu *cpu = container_of(dev, struct cpu, sysdev); @@ -44,9 +39,7 @@ static ssize_t store_online(struct sys_device *dev, const char *buf, kobject_uevent(&dev->kobj, KOBJ_OFFLINE); break; case '1': - ret = smp_prepare_cpu(cpu->sysdev.id); - if (!ret) - ret = cpu_up(cpu->sysdev.id); + ret = cpu_up(cpu->sysdev.id); if (!ret) kobject_uevent(&dev->kobj, KOBJ_ONLINE); break; diff --git a/include/linux/cpu.h b/include/linux/cpu.h index d612b89dce33..08d50c53aab4 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -74,7 +74,6 @@ extern int lock_cpu_hotplug_interruptible(void); register_cpu_notifier(&fn##_nb); \ } int cpu_down(unsigned int cpu); -extern int __attribute__((weak)) smp_prepare_cpu(int cpu); #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) #else #define lock_cpu_hotplug() do { } while (0) diff --git a/kernel/power/smp.c b/kernel/power/smp.c index 911fc62b8225..5957312b2d68 100644 --- a/kernel/power/smp.c +++ b/kernel/power/smp.c @@ -49,9 +49,7 @@ void enable_nonboot_cpus(void) printk("Thawing cpus ...\n"); for_each_cpu_mask(cpu, frozen_cpus) { - error = smp_prepare_cpu(cpu); - if (!error) - error = cpu_up(cpu); + error = cpu_up(cpu); if (!error) { printk("CPU%d is up\n", cpu); continue;