![Thomas Gleixner](/assets/img/avatar_default.png)
Let the non boot cpus call into idle with the corresponding hotplug state, so the hotplug core can handle the further bringup. That's a first step to convert the boot side of the hotplugged cpus to do all the synchronization with the other side through the state machine. For now it'll only start the hotplug thread and kick the full bringup of the cpu. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: Rik van Riel <riel@redhat.com> Cc: Rafael Wysocki <rafael.j.wysocki@intel.com> Cc: "Srivatsa S. Bhat" <srivatsa@mit.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: http://lkml.kernel.org/r/20160226182341.614102639@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
428 lines
9.4 KiB
C
428 lines
9.4 KiB
C
/*
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** SMP Support
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**
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** Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
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** Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
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** Copyright (C) 2001,2004 Grant Grundler <grundler@parisc-linux.org>
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**
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** Lots of stuff stolen from arch/alpha/kernel/smp.c
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** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^)
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**
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** Thanks to John Curry and Ullas Ponnadi. I learned a lot from their work.
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** -grant (1/12/2001)
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**
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** This program is free software; you can redistribute it and/or modify
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** it under the terms of the GNU General Public License as published by
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** the Free Software Foundation; either version 2 of the License, or
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** (at your option) any later version.
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*/
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#include <linux/types.h>
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#include <linux/spinlock.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/smp.h>
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#include <linux/kernel_stat.h>
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#include <linux/mm.h>
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#include <linux/err.h>
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#include <linux/delay.h>
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#include <linux/bitops.h>
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#include <linux/ftrace.h>
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#include <linux/cpu.h>
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#include <linux/atomic.h>
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#include <asm/current.h>
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#include <asm/delay.h>
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#include <asm/tlbflush.h>
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#include <asm/io.h>
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#include <asm/irq.h> /* for CPU_IRQ_REGION and friends */
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#include <asm/mmu_context.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/processor.h>
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#include <asm/ptrace.h>
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#include <asm/unistd.h>
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#include <asm/cacheflush.h>
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#undef DEBUG_SMP
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#ifdef DEBUG_SMP
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static int smp_debug_lvl = 0;
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#define smp_debug(lvl, printargs...) \
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if (lvl >= smp_debug_lvl) \
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printk(printargs);
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#else
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#define smp_debug(lvl, ...) do { } while(0)
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#endif /* DEBUG_SMP */
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volatile struct task_struct *smp_init_current_idle_task;
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/* track which CPU is booting */
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static volatile int cpu_now_booting;
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static int parisc_max_cpus = 1;
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static DEFINE_PER_CPU(spinlock_t, ipi_lock);
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enum ipi_message_type {
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IPI_NOP=0,
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IPI_RESCHEDULE=1,
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IPI_CALL_FUNC,
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IPI_CPU_START,
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IPI_CPU_STOP,
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IPI_CPU_TEST
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};
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/********** SMP inter processor interrupt and communication routines */
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#undef PER_CPU_IRQ_REGION
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#ifdef PER_CPU_IRQ_REGION
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/* XXX REVISIT Ignore for now.
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** *May* need this "hook" to register IPI handler
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** once we have perCPU ExtIntr switch tables.
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*/
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static void
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ipi_init(int cpuid)
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{
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#error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region
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if(cpu_online(cpuid) )
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{
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switch_to_idle_task(current);
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}
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return;
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}
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#endif
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/*
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** Yoink this CPU from the runnable list...
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**
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*/
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static void
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halt_processor(void)
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{
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/* REVISIT : redirect I/O Interrupts to another CPU? */
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/* REVISIT : does PM *know* this CPU isn't available? */
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set_cpu_online(smp_processor_id(), false);
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local_irq_disable();
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for (;;)
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;
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}
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irqreturn_t __irq_entry
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ipi_interrupt(int irq, void *dev_id)
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{
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int this_cpu = smp_processor_id();
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struct cpuinfo_parisc *p = &per_cpu(cpu_data, this_cpu);
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unsigned long ops;
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unsigned long flags;
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for (;;) {
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spinlock_t *lock = &per_cpu(ipi_lock, this_cpu);
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spin_lock_irqsave(lock, flags);
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ops = p->pending_ipi;
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p->pending_ipi = 0;
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spin_unlock_irqrestore(lock, flags);
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mb(); /* Order bit clearing and data access. */
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if (!ops)
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break;
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while (ops) {
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unsigned long which = ffz(~ops);
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ops &= ~(1 << which);
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switch (which) {
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case IPI_NOP:
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smp_debug(100, KERN_DEBUG "CPU%d IPI_NOP\n", this_cpu);
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break;
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case IPI_RESCHEDULE:
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smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu);
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inc_irq_stat(irq_resched_count);
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scheduler_ipi();
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break;
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case IPI_CALL_FUNC:
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smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu);
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generic_smp_call_function_interrupt();
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break;
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case IPI_CPU_START:
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smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_START\n", this_cpu);
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break;
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case IPI_CPU_STOP:
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smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_STOP\n", this_cpu);
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halt_processor();
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break;
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case IPI_CPU_TEST:
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smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu);
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break;
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default:
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printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
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this_cpu, which);
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return IRQ_NONE;
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} /* Switch */
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/* let in any pending interrupts */
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local_irq_enable();
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local_irq_disable();
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} /* while (ops) */
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}
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return IRQ_HANDLED;
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}
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static inline void
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ipi_send(int cpu, enum ipi_message_type op)
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{
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struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpu);
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spinlock_t *lock = &per_cpu(ipi_lock, cpu);
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unsigned long flags;
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spin_lock_irqsave(lock, flags);
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p->pending_ipi |= 1 << op;
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gsc_writel(IPI_IRQ - CPU_IRQ_BASE, p->hpa);
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spin_unlock_irqrestore(lock, flags);
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}
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static void
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send_IPI_mask(const struct cpumask *mask, enum ipi_message_type op)
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{
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int cpu;
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for_each_cpu(cpu, mask)
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ipi_send(cpu, op);
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}
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static inline void
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send_IPI_single(int dest_cpu, enum ipi_message_type op)
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{
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BUG_ON(dest_cpu == NO_PROC_ID);
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ipi_send(dest_cpu, op);
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}
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static inline void
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send_IPI_allbutself(enum ipi_message_type op)
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{
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int i;
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for_each_online_cpu(i) {
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if (i != smp_processor_id())
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send_IPI_single(i, op);
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}
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}
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inline void
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smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }
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void
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smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
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void
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smp_send_all_nop(void)
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{
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send_IPI_allbutself(IPI_NOP);
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}
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void arch_send_call_function_ipi_mask(const struct cpumask *mask)
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{
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send_IPI_mask(mask, IPI_CALL_FUNC);
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}
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void arch_send_call_function_single_ipi(int cpu)
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{
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send_IPI_single(cpu, IPI_CALL_FUNC);
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}
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/*
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* Called by secondaries to update state and initialize CPU registers.
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*/
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static void __init
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smp_cpu_init(int cpunum)
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{
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extern int init_per_cpu(int); /* arch/parisc/kernel/processor.c */
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extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */
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extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
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/* Set modes and Enable floating point coprocessor */
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(void) init_per_cpu(cpunum);
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disable_sr_hashing();
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mb();
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/* Well, support 2.4 linux scheme as well. */
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if (cpu_online(cpunum)) {
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extern void machine_halt(void); /* arch/parisc.../process.c */
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printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum);
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machine_halt();
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}
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notify_cpu_starting(cpunum);
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set_cpu_online(cpunum, true);
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/* Initialise the idle task for this CPU */
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atomic_inc(&init_mm.mm_count);
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current->active_mm = &init_mm;
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BUG_ON(current->mm);
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enter_lazy_tlb(&init_mm, current);
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init_IRQ(); /* make sure no IRQs are enabled or pending */
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start_cpu_itimer();
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}
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/*
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* Slaves start using C here. Indirectly called from smp_slave_stext.
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* Do what start_kernel() and main() do for boot strap processor (aka monarch)
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*/
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void __init smp_callin(void)
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{
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int slave_id = cpu_now_booting;
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smp_cpu_init(slave_id);
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preempt_disable();
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flush_cache_all_local(); /* start with known state */
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flush_tlb_all_local(NULL);
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local_irq_enable(); /* Interrupts have been off until now */
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cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
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/* NOTREACHED */
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panic("smp_callin() AAAAaaaaahhhh....\n");
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}
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/*
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* Bring one cpu online.
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*/
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int smp_boot_one_cpu(int cpuid, struct task_struct *idle)
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{
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const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
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long timeout;
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task_thread_info(idle)->cpu = cpuid;
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/* Let _start know what logical CPU we're booting
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** (offset into init_tasks[],cpu_data[])
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*/
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cpu_now_booting = cpuid;
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/*
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** boot strap code needs to know the task address since
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** it also contains the process stack.
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*/
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smp_init_current_idle_task = idle ;
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mb();
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printk(KERN_INFO "Releasing cpu %d now, hpa=%lx\n", cpuid, p->hpa);
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/*
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** This gets PDC to release the CPU from a very tight loop.
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**
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** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
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** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
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** is executed after receiving the rendezvous signal (an interrupt to
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** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
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** contents of memory are valid."
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*/
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gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, p->hpa);
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mb();
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/*
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* OK, wait a bit for that CPU to finish staggering about.
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* Slave will set a bit when it reaches smp_cpu_init().
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* Once the "monarch CPU" sees the bit change, it can move on.
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*/
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for (timeout = 0; timeout < 10000; timeout++) {
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if(cpu_online(cpuid)) {
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/* Which implies Slave has started up */
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cpu_now_booting = 0;
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smp_init_current_idle_task = NULL;
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goto alive ;
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}
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udelay(100);
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barrier();
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}
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printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
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return -1;
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alive:
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/* Remember the Slave data */
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smp_debug(100, KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
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cpuid, timeout * 100);
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return 0;
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}
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void __init smp_prepare_boot_cpu(void)
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{
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int bootstrap_processor = per_cpu(cpu_data, 0).cpuid;
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/* Setup BSP mappings */
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printk(KERN_INFO "SMP: bootstrap CPU ID is %d\n", bootstrap_processor);
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set_cpu_online(bootstrap_processor, true);
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set_cpu_present(bootstrap_processor, true);
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}
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/*
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** inventory.c:do_inventory() hasn't yet been run and thus we
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** don't 'discover' the additional CPUs until later.
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*/
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void __init smp_prepare_cpus(unsigned int max_cpus)
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{
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int cpu;
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for_each_possible_cpu(cpu)
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spin_lock_init(&per_cpu(ipi_lock, cpu));
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init_cpu_present(cpumask_of(0));
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parisc_max_cpus = max_cpus;
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if (!max_cpus)
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printk(KERN_INFO "SMP mode deactivated.\n");
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}
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void smp_cpus_done(unsigned int cpu_max)
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{
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return;
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}
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int __cpu_up(unsigned int cpu, struct task_struct *tidle)
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{
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if (cpu != 0 && cpu < parisc_max_cpus)
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smp_boot_one_cpu(cpu, tidle);
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return cpu_online(cpu) ? 0 : -ENOSYS;
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}
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#ifdef CONFIG_PROC_FS
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int __init
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setup_profiling_timer(unsigned int multiplier)
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{
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return -EINVAL;
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}
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#endif
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