This is purely to save memory - each supported CPU adds
approximately eight kilobytes to the kernel image.
+config HOTPLUG_CPU
+ bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
+ depends on SMP && HOTPLUG && EXPERIMENTAL
+ help
+ Say Y here to experiment with turning CPUs off and on. CPUs
+ can be controlled through /sys/devices/system/cpu.
+
source "kernel/Kconfig.preempt"
config GUSA
#include <cpu/sh7786.h>
#include <asm/heartbeat.h>
#include <asm/sizes.h>
+#include <asm/smp-ops.h>
/*
* bit 1234 5678
printk(KERN_INFO "Renesas Technology Corp. Urquell support.\n");
pm_power_off = urquell_power_off;
+
+ register_smp_ops(&shx3_smp_ops);
}
/*
#include <asm/heartbeat.h>
#include <asm/sizes.h>
#include <asm/reboot.h>
+#include <asm/smp-ops.h>
static struct resource heartbeat_resource = {
.start = 0x07fff8b0,
machine_ops.restart = sdk7786_restart;
pm_power_off = sdk7786_power_off;
+
+ register_smp_ops(&shx3_smp_ops);
}
/*
#include <linux/usb/r8a66597.h>
#include <linux/usb/m66592.h>
#include <asm/ilsel.h>
+#include <asm/smp-ops.h>
static struct resource heartbeat_resources[] = {
[0] = {
__raw_writel(__raw_readl(0xfe410000) | (1 << 21), 0xfe410000);
}
+static void __init x3proto_setup(char **cmdline_p)
+{
+ register_smp_ops(&shx3_smp_ops);
+}
+
static struct sh_machine_vector mv_x3proto __initmv = {
.mv_name = "x3proto",
+ .mv_setup = x3proto_setup,
.mv_init_irq = x3proto_init_irq,
};
#ifndef __ASM_SH_IRQ_H
#define __ASM_SH_IRQ_H
+#include <linux/cpumask.h>
#include <asm/machvec.h>
/*
#define irq_demux(irq) sh_mv.mv_irq_demux(irq)
void init_IRQ(void);
+void migrate_irqs(void);
+
asmlinkage int do_IRQ(unsigned int irq, struct pt_regs *regs);
#ifdef CONFIG_IRQSTACKS
struct tlb_info itlb;
struct tlb_info dtlb;
+#ifdef CONFIG_SMP
+ struct task_struct *idle;
+#endif
+
unsigned long flags;
} __attribute__ ((aligned(L1_CACHE_BYTES)));
--- /dev/null
+#ifndef __ASM_SH_SMP_OPS_H
+#define __ASM_SH_SMP_OPS_H
+
+struct plat_smp_ops {
+ void (*smp_setup)(void);
+ unsigned int (*smp_processor_id)(void);
+ void (*prepare_cpus)(unsigned int max_cpus);
+ void (*start_cpu)(unsigned int cpu, unsigned long entry_point);
+ void (*send_ipi)(unsigned int cpu, unsigned int message);
+ int (*cpu_disable)(unsigned int cpu);
+ void (*cpu_die)(unsigned int cpu);
+ void (*play_dead)(void);
+};
+
+extern struct plat_smp_ops *mp_ops;
+extern struct plat_smp_ops shx3_smp_ops;
+
+#ifdef CONFIG_SMP
+
+static inline void plat_smp_setup(void)
+{
+ BUG_ON(!mp_ops);
+ mp_ops->smp_setup();
+}
+
+static inline void play_dead(void)
+{
+ mp_ops->play_dead();
+}
+
+extern void register_smp_ops(struct plat_smp_ops *ops);
+
+#else
+
+static inline void plat_smp_setup(void)
+{
+ /* UP, nothing to do ... */
+}
+
+static inline void register_smp_ops(struct plat_smp_ops *ops)
+{
+}
+
+static inline void play_dead(void)
+{
+ BUG();
+}
+
+#endif /* CONFIG_SMP */
+
+#endif /* __ASM_SH_SMP_OPS_H */
#include <linux/bitops.h>
#include <linux/cpumask.h>
+#include <asm/smp-ops.h>
#ifdef CONFIG_SMP
#include <linux/spinlock.h>
#include <asm/atomic.h>
#include <asm/current.h>
+#include <asm/percpu.h>
#define raw_smp_processor_id() (current_thread_info()->cpu)
-#define hard_smp_processor_id() plat_smp_processor_id()
/* Map from cpu id to sequential logical cpu number. */
extern int __cpu_number_map[NR_CPUS];
SMP_MSG_NR, /* must be last */
};
+DECLARE_PER_CPU(int, cpu_state);
+
void smp_message_recv(unsigned int msg);
void smp_timer_broadcast(const struct cpumask *mask);
void local_timer_interrupt(void);
void local_timer_setup(unsigned int cpu);
-
-void plat_smp_setup(void);
-void plat_prepare_cpus(unsigned int max_cpus);
-int plat_smp_processor_id(void);
-void plat_start_cpu(unsigned int cpu, unsigned long entry_point);
-void plat_send_ipi(unsigned int cpu, unsigned int message);
+void local_timer_stop(unsigned int cpu);
void arch_send_call_function_single_ipi(int cpu);
-extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
+void arch_send_call_function_ipi_mask(const struct cpumask *mask);
+
+void native_play_dead(void);
+void native_cpu_die(unsigned int cpu);
+int native_cpu_disable(unsigned int cpu);
+
+#ifdef CONFIG_HOTPLUG_CPU
+void play_dead_common(void);
+extern int __cpu_disable(void);
+
+static inline void __cpu_die(unsigned int cpu)
+{
+ extern struct plat_smp_ops *mp_ops; /* private */
+
+ mp_ops->cpu_die(cpu);
+}
+#endif
+
+static inline int hard_smp_processor_id(void)
+{
+ extern struct plat_smp_ops *mp_ops; /* private */
+
+ if (!mp_ops)
+ return 0; /* boot CPU */
+
+ return mp_ops->smp_processor_id();
+}
#else
/*
* SH-X3 SMP
*
- * Copyright (C) 2007 - 2008 Paul Mundt
+ * Copyright (C) 2007 - 2010 Paul Mundt
* Copyright (C) 2007 Magnus Damm
*
* This file is subject to the terms and conditions of the GNU General Public
* for more details.
*/
#include <linux/init.h>
+#include <linux/kernel.h>
#include <linux/cpumask.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/io.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/cpu.h>
+#include <asm/sections.h>
#define STBCR_REG(phys_id) (0xfe400004 | (phys_id << 12))
#define RESET_REG(phys_id) (0xfe400008 | (phys_id << 12))
#define STBCR_MSTP 0x00000001
#define STBCR_RESET 0x00000002
+#define STBCR_SLEEP 0x00000004
#define STBCR_LTSLP 0x80000000
static irqreturn_t ipi_interrupt_handler(int irq, void *arg)
return IRQ_HANDLED;
}
-void __init plat_smp_setup(void)
+static void shx3_smp_setup(void)
{
unsigned int cpu = 0;
int i, num;
printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
}
-void __init plat_prepare_cpus(unsigned int max_cpus)
+static void shx3_prepare_cpus(unsigned int max_cpus)
{
int i;
for (i = 0; i < SMP_MSG_NR; i++)
request_irq(104 + i, ipi_interrupt_handler,
IRQF_DISABLED | IRQF_PERCPU, "IPI", (void *)(long)i);
+
+ for (i = 0; i < max_cpus; i++)
+ set_cpu_present(i, true);
}
-void plat_start_cpu(unsigned int cpu, unsigned long entry_point)
+static void shx3_start_cpu(unsigned int cpu, unsigned long entry_point)
{
if (__in_29bit_mode())
__raw_writel(entry_point, RESET_REG(cpu));
__raw_writel(STBCR_RESET | STBCR_LTSLP, STBCR_REG(cpu));
}
-int plat_smp_processor_id(void)
+static unsigned int shx3_smp_processor_id(void)
{
return __raw_readl(0xff000048); /* CPIDR */
}
-void plat_send_ipi(unsigned int cpu, unsigned int message)
+static void shx3_send_ipi(unsigned int cpu, unsigned int message)
{
unsigned long addr = 0xfe410070 + (cpu * 4);
__raw_writel(1 << (message << 2), addr); /* C0INTICI..CnINTICI */
}
+
+static void shx3_update_boot_vector(unsigned int cpu)
+{
+ __raw_writel(STBCR_MSTP, STBCR_REG(cpu));
+ while (!(__raw_readl(STBCR_REG(cpu)) & STBCR_MSTP))
+ cpu_relax();
+ __raw_writel(STBCR_RESET, STBCR_REG(cpu));
+}
+
+static int __cpuinit
+shx3_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (unsigned int)hcpu;
+
+ switch (action) {
+ case CPU_UP_PREPARE:
+ shx3_update_boot_vector(cpu);
+ break;
+ case CPU_ONLINE:
+ pr_info("CPU %u is now online\n", cpu);
+ break;
+ case CPU_DEAD:
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata shx3_cpu_notifier = {
+ .notifier_call = shx3_cpu_callback,
+};
+
+static int __cpuinit register_shx3_cpu_notifier(void)
+{
+ register_hotcpu_notifier(&shx3_cpu_notifier);
+ return 0;
+}
+late_initcall(register_shx3_cpu_notifier);
+
+struct plat_smp_ops shx3_smp_ops = {
+ .smp_setup = shx3_smp_setup,
+ .prepare_cpus = shx3_prepare_cpus,
+ .start_cpu = shx3_start_cpu,
+ .smp_processor_id = shx3_smp_processor_id,
+ .send_ipi = shx3_send_ipi,
+ .cpu_die = native_cpu_die,
+ .cpu_disable = native_cpu_disable,
+ .play_dead = native_play_dead,
+};
#include <asm/pgalloc.h>
#include <asm/system.h>
#include <asm/atomic.h>
+#include <asm/smp.h>
void (*pm_idle)(void) = NULL;
while (1) {
tick_nohz_stop_sched_tick(1);
- while (!need_resched() && cpu_online(cpu)) {
+ while (!need_resched()) {
check_pgt_cache();
rmb();
+ if (cpu_is_offline(cpu))
+ play_dead();
+
local_irq_disable();
/* Don't trace irqs off for idle */
stop_critical_timings();
void stop_this_cpu(void *unused)
{
local_irq_disable();
- cpu_clear(smp_processor_id(), cpu_online_map);
+ set_cpu_online(smp_processor_id(), false);
for (;;)
cpu_sleep();
#include <linux/kernel_stat.h>
#include <linux/seq_file.h>
#include <linux/ftrace.h>
+#include <linux/delay.h>
#include <asm/processor.h>
#include <asm/machvec.h>
#include <asm/uaccess.h>
return 0;
}
#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void route_irq(struct irq_desc *desc, unsigned int irq, unsigned int cpu)
+{
+ printk(KERN_INFO "IRQ%u: moving from cpu%u to cpu%u\n",
+ irq, desc->node, cpu);
+
+ raw_spin_lock_irq(&desc->lock);
+ desc->chip->set_affinity(irq, cpumask_of(cpu));
+ raw_spin_unlock_irq(&desc->lock);
+}
+
+/*
+ * The CPU has been marked offline. Migrate IRQs off this CPU. If
+ * the affinity settings do not allow other CPUs, force them onto any
+ * available CPU.
+ */
+void migrate_irqs(void)
+{
+ struct irq_desc *desc;
+ unsigned int irq, cpu = smp_processor_id();
+
+ for_each_irq_desc(irq, desc) {
+ if (desc->node == cpu) {
+ unsigned int newcpu = cpumask_any_and(desc->affinity,
+ cpu_online_mask);
+ if (newcpu >= nr_cpu_ids) {
+ if (printk_ratelimit())
+ printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n",
+ irq, cpu);
+
+ cpumask_setall(desc->affinity);
+ newcpu = cpumask_any_and(desc->affinity,
+ cpu_online_mask);
+ }
+
+ route_irq(desc, irq, newcpu);
+ }
+ }
+}
+#endif
{
}
-void __cpuinit local_timer_setup(unsigned int cpu)
+void local_timer_setup(unsigned int cpu)
{
struct clock_event_device *clk = &per_cpu(local_clockevent, cpu);
clockevents_register_device(clk);
}
+
+void local_timer_stop(unsigned int cpu)
+{
+}
#include <asm/irq.h>
#include <asm/setup.h>
#include <asm/clock.h>
+#include <asm/smp.h>
#include <asm/mmu_context.h>
/*
if (likely(sh_mv.mv_setup))
sh_mv.mv_setup(cmdline_p);
-#ifdef CONFIG_SMP
plat_smp_setup();
-#endif
}
/* processor boot mode configuration */
*
* SMP support for the SuperH processors.
*
- * Copyright (C) 2002 - 2008 Paul Mundt
+ * Copyright (C) 2002 - 2010 Paul Mundt
* Copyright (C) 2006 - 2007 Akio Idehara
*
* This file is subject to the terms and conditions of the GNU General Public
int __cpu_number_map[NR_CPUS]; /* Map physical to logical */
int __cpu_logical_map[NR_CPUS]; /* Map logical to physical */
-static inline void __init smp_store_cpu_info(unsigned int cpu)
+struct plat_smp_ops *mp_ops = NULL;
+
+/* State of each CPU */
+DEFINE_PER_CPU(int, cpu_state) = { 0 };
+
+void __cpuinit register_smp_ops(struct plat_smp_ops *ops)
+{
+ if (mp_ops)
+ printk(KERN_WARNING "Overriding previously set SMP ops\n");
+
+ mp_ops = ops;
+}
+
+static inline void __cpuinit smp_store_cpu_info(unsigned int cpu)
{
struct sh_cpuinfo *c = cpu_data + cpu;
init_new_context(current, &init_mm);
current_thread_info()->cpu = cpu;
- plat_prepare_cpus(max_cpus);
+ mp_ops->prepare_cpus(max_cpus);
#ifndef CONFIG_HOTPLUG_CPU
init_cpu_present(&cpu_possible_map);
#endif
}
-void __devinit smp_prepare_boot_cpu(void)
+void __init smp_prepare_boot_cpu(void)
{
unsigned int cpu = smp_processor_id();
set_cpu_online(cpu, true);
set_cpu_possible(cpu, true);
+
+ per_cpu(cpu_state, cpu) = CPU_ONLINE;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+void native_cpu_die(unsigned int cpu)
+{
+ unsigned int i;
+
+ for (i = 0; i < 10; i++) {
+ smp_rmb();
+ if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
+ if (system_state == SYSTEM_RUNNING)
+ pr_info("CPU %u is now offline\n", cpu);
+
+ return;
+ }
+
+ msleep(100);
+ }
+
+ pr_err("CPU %u didn't die...\n", cpu);
+}
+
+int native_cpu_disable(unsigned int cpu)
+{
+ return cpu == 0 ? -EPERM : 0;
+}
+
+void play_dead_common(void)
+{
+ idle_task_exit();
+ irq_ctx_exit(raw_smp_processor_id());
+ mb();
+
+ __get_cpu_var(cpu_state) = CPU_DEAD;
+ local_irq_disable();
+}
+
+void native_play_dead(void)
+{
+ play_dead_common();
}
+int __cpu_disable(void)
+{
+ unsigned int cpu = smp_processor_id();
+ struct task_struct *p;
+ int ret;
+
+ ret = mp_ops->cpu_disable(cpu);
+ if (ret)
+ return ret;
+
+ /*
+ * Take this CPU offline. Once we clear this, we can't return,
+ * and we must not schedule until we're ready to give up the cpu.
+ */
+ set_cpu_online(cpu, false);
+
+ /*
+ * OK - migrate IRQs away from this CPU
+ */
+ migrate_irqs();
+
+ /*
+ * Stop the local timer for this CPU.
+ */
+ local_timer_stop(cpu);
+
+ /*
+ * Flush user cache and TLB mappings, and then remove this CPU
+ * from the vm mask set of all processes.
+ */
+ flush_cache_all();
+ local_flush_tlb_all();
+
+ read_lock(&tasklist_lock);
+ for_each_process(p)
+ if (p->mm)
+ cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
+ read_unlock(&tasklist_lock);
+
+ return 0;
+}
+#else /* ... !CONFIG_HOTPLUG_CPU */
+int native_cpu_disable(void)
+{
+ return -ENOSYS;
+}
+
+void native_cpu_die(unsigned int cpu)
+{
+ /* We said "no" in __cpu_disable */
+ BUG();
+}
+
+void native_play_dead(void)
+{
+ BUG();
+}
+#endif
+
asmlinkage void __cpuinit start_secondary(void)
{
- unsigned int cpu;
+ unsigned int cpu = smp_processor_id();
struct mm_struct *mm = &init_mm;
enable_mmu();
atomic_inc(&mm->mm_count);
atomic_inc(&mm->mm_users);
current->active_mm = mm;
- BUG_ON(current->mm);
enter_lazy_tlb(mm, current);
+ local_flush_tlb_all();
per_cpu_trap_init();
preempt_disable();
- notify_cpu_starting(smp_processor_id());
+ notify_cpu_starting(cpu);
local_irq_enable();
- cpu = smp_processor_id();
-
/* Enable local timers */
local_timer_setup(cpu);
calibrate_delay();
smp_store_cpu_info(cpu);
- cpu_set(cpu, cpu_online_map);
+ set_cpu_online(cpu, true);
+ per_cpu(cpu_state, cpu) = CPU_ONLINE;
cpu_idle();
}
struct task_struct *tsk;
unsigned long timeout;
- tsk = fork_idle(cpu);
- if (IS_ERR(tsk)) {
- printk(KERN_ERR "Failed forking idle task for cpu %d\n", cpu);
- return PTR_ERR(tsk);
+ tsk = cpu_data[cpu].idle;
+ if (!tsk) {
+ tsk = fork_idle(cpu);
+ if (IS_ERR(tsk)) {
+ pr_err("Failed forking idle task for cpu %d\n", cpu);
+ return PTR_ERR(tsk);
+ }
+
+ cpu_data[cpu].idle = tsk;
}
+ per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
+
/* Fill in data in head.S for secondary cpus */
stack_start.sp = tsk->thread.sp;
stack_start.thread_info = tsk->stack;
(unsigned long)&stack_start + sizeof(stack_start));
wmb();
- plat_start_cpu(cpu, (unsigned long)_stext);
+ mp_ops->start_cpu(cpu, (unsigned long)_stext);
timeout = jiffies + HZ;
while (time_before(jiffies, timeout)) {
break;
udelay(10);
+ barrier();
}
if (cpu_online(cpu))
void smp_send_reschedule(int cpu)
{
- plat_send_ipi(cpu, SMP_MSG_RESCHEDULE);
+ mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
}
void smp_send_stop(void)
int cpu;
for_each_cpu(cpu, mask)
- plat_send_ipi(cpu, SMP_MSG_FUNCTION);
+ mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION);
}
void arch_send_call_function_single_ipi(int cpu)
{
- plat_send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
+ mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
}
void smp_timer_broadcast(const struct cpumask *mask)
int cpu;
for_each_cpu(cpu, mask)
- plat_send_ipi(cpu, SMP_MSG_TIMER);
+ mp_ops->send_ipi(cpu, SMP_MSG_TIMER);
}
static void ipi_timer(void)
* behalf of debugees, kswapd stealing pages from another process etc).
* Kanoj 07/00.
*/
-
void flush_tlb_mm(struct mm_struct *mm)
{
preempt_disable();
#endif
for_each_present_cpu(i) {
- ret = register_cpu(&per_cpu(cpu_devices, i), i);
+ struct cpu *c = &per_cpu(cpu_devices, i);
+
+ c->hotpluggable = 1;
+
+ ret = register_cpu(c, i);
if (unlikely(ret))
printk(KERN_WARNING "%s: register_cpu %d failed (%d)\n",
__func__, i, ret);
git.openpandora.org / pandora-kernel.git / commitdiff