![Nicholas Piggin](/assets/img/avatar_default.png)
When the NMI IPI lock is contended, spin at low SMT priority, using loads only, and with interrupts enabled (where possible). This improves behaviour under high contention (e.g., a system crash when a number of CPUs are trying to enter the debugger). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
1065 lines
24 KiB
C
1065 lines
24 KiB
C
/*
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* SMP support for ppc.
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*
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* Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great
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* deal of code from the sparc and intel versions.
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*
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* Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
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*
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* PowerPC-64 Support added by Dave Engebretsen, Peter Bergner, and
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* Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#undef DEBUG
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/sched/mm.h>
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#include <linux/sched/topology.h>
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#include <linux/smp.h>
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#include <linux/interrupt.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/cache.h>
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#include <linux/err.h>
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#include <linux/device.h>
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#include <linux/cpu.h>
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#include <linux/notifier.h>
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#include <linux/topology.h>
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#include <linux/profile.h>
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#include <linux/processor.h>
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#include <asm/ptrace.h>
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#include <linux/atomic.h>
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#include <asm/irq.h>
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#include <asm/hw_irq.h>
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#include <asm/kvm_ppc.h>
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#include <asm/dbell.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/prom.h>
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#include <asm/smp.h>
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#include <asm/time.h>
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#include <asm/machdep.h>
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#include <asm/cputhreads.h>
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#include <asm/cputable.h>
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#include <asm/mpic.h>
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#include <asm/vdso_datapage.h>
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#ifdef CONFIG_PPC64
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#include <asm/paca.h>
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#endif
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#include <asm/vdso.h>
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#include <asm/debug.h>
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#include <asm/kexec.h>
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#include <asm/asm-prototypes.h>
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#include <asm/cpu_has_feature.h>
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#ifdef DEBUG
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#include <asm/udbg.h>
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#define DBG(fmt...) udbg_printf(fmt)
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#else
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#define DBG(fmt...)
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#endif
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#ifdef CONFIG_HOTPLUG_CPU
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/* State of each CPU during hotplug phases */
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static DEFINE_PER_CPU(int, cpu_state) = { 0 };
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#endif
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struct thread_info *secondary_ti;
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DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
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DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
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EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
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EXPORT_PER_CPU_SYMBOL(cpu_core_map);
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/* SMP operations for this machine */
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struct smp_ops_t *smp_ops;
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/* Can't be static due to PowerMac hackery */
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volatile unsigned int cpu_callin_map[NR_CPUS];
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int smt_enabled_at_boot = 1;
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/*
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* Returns 1 if the specified cpu should be brought up during boot.
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* Used to inhibit booting threads if they've been disabled or
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* limited on the command line
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*/
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int smp_generic_cpu_bootable(unsigned int nr)
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{
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/* Special case - we inhibit secondary thread startup
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* during boot if the user requests it.
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*/
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if (system_state < SYSTEM_RUNNING && cpu_has_feature(CPU_FTR_SMT)) {
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if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
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return 0;
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if (smt_enabled_at_boot
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&& cpu_thread_in_core(nr) >= smt_enabled_at_boot)
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return 0;
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}
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return 1;
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}
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#ifdef CONFIG_PPC64
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int smp_generic_kick_cpu(int nr)
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{
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if (nr < 0 || nr >= nr_cpu_ids)
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return -EINVAL;
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/*
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* The processor is currently spinning, waiting for the
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* cpu_start field to become non-zero After we set cpu_start,
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* the processor will continue on to secondary_start
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*/
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if (!paca[nr].cpu_start) {
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paca[nr].cpu_start = 1;
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smp_mb();
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return 0;
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}
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#ifdef CONFIG_HOTPLUG_CPU
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/*
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* Ok it's not there, so it might be soft-unplugged, let's
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* try to bring it back
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*/
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generic_set_cpu_up(nr);
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smp_wmb();
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smp_send_reschedule(nr);
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#endif /* CONFIG_HOTPLUG_CPU */
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return 0;
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}
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#endif /* CONFIG_PPC64 */
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static irqreturn_t call_function_action(int irq, void *data)
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{
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generic_smp_call_function_interrupt();
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return IRQ_HANDLED;
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}
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static irqreturn_t reschedule_action(int irq, void *data)
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{
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scheduler_ipi();
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return IRQ_HANDLED;
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}
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static irqreturn_t tick_broadcast_ipi_action(int irq, void *data)
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{
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tick_broadcast_ipi_handler();
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return IRQ_HANDLED;
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}
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#ifdef CONFIG_NMI_IPI
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static irqreturn_t nmi_ipi_action(int irq, void *data)
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{
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smp_handle_nmi_ipi(get_irq_regs());
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return IRQ_HANDLED;
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}
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#endif
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static irq_handler_t smp_ipi_action[] = {
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[PPC_MSG_CALL_FUNCTION] = call_function_action,
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[PPC_MSG_RESCHEDULE] = reschedule_action,
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[PPC_MSG_TICK_BROADCAST] = tick_broadcast_ipi_action,
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#ifdef CONFIG_NMI_IPI
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[PPC_MSG_NMI_IPI] = nmi_ipi_action,
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#endif
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};
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/*
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* The NMI IPI is a fallback and not truly non-maskable. It is simpler
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* than going through the call function infrastructure, and strongly
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* serialized, so it is more appropriate for debugging.
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*/
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const char *smp_ipi_name[] = {
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[PPC_MSG_CALL_FUNCTION] = "ipi call function",
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[PPC_MSG_RESCHEDULE] = "ipi reschedule",
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[PPC_MSG_TICK_BROADCAST] = "ipi tick-broadcast",
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[PPC_MSG_NMI_IPI] = "nmi ipi",
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};
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/* optional function to request ipi, for controllers with >= 4 ipis */
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int smp_request_message_ipi(int virq, int msg)
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{
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int err;
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if (msg < 0 || msg > PPC_MSG_NMI_IPI)
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return -EINVAL;
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#ifndef CONFIG_NMI_IPI
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if (msg == PPC_MSG_NMI_IPI)
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return 1;
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#endif
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err = request_irq(virq, smp_ipi_action[msg],
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IRQF_PERCPU | IRQF_NO_THREAD | IRQF_NO_SUSPEND,
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smp_ipi_name[msg], NULL);
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WARN(err < 0, "unable to request_irq %d for %s (rc %d)\n",
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virq, smp_ipi_name[msg], err);
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return err;
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}
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#ifdef CONFIG_PPC_SMP_MUXED_IPI
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struct cpu_messages {
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long messages; /* current messages */
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};
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static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_messages, ipi_message);
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void smp_muxed_ipi_set_message(int cpu, int msg)
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{
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struct cpu_messages *info = &per_cpu(ipi_message, cpu);
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char *message = (char *)&info->messages;
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/*
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* Order previous accesses before accesses in the IPI handler.
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*/
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smp_mb();
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message[msg] = 1;
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}
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void smp_muxed_ipi_message_pass(int cpu, int msg)
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{
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smp_muxed_ipi_set_message(cpu, msg);
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/*
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* cause_ipi functions are required to include a full barrier
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* before doing whatever causes the IPI.
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*/
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smp_ops->cause_ipi(cpu);
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}
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#ifdef __BIG_ENDIAN__
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#define IPI_MESSAGE(A) (1uL << ((BITS_PER_LONG - 8) - 8 * (A)))
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#else
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#define IPI_MESSAGE(A) (1uL << (8 * (A)))
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#endif
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irqreturn_t smp_ipi_demux(void)
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{
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mb(); /* order any irq clear */
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return smp_ipi_demux_relaxed();
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}
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/* sync-free variant. Callers should ensure synchronization */
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irqreturn_t smp_ipi_demux_relaxed(void)
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{
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struct cpu_messages *info;
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unsigned long all;
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info = this_cpu_ptr(&ipi_message);
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do {
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all = xchg(&info->messages, 0);
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#if defined(CONFIG_KVM_XICS) && defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE)
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/*
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* Must check for PPC_MSG_RM_HOST_ACTION messages
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* before PPC_MSG_CALL_FUNCTION messages because when
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* a VM is destroyed, we call kick_all_cpus_sync()
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* to ensure that any pending PPC_MSG_RM_HOST_ACTION
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* messages have completed before we free any VCPUs.
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*/
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if (all & IPI_MESSAGE(PPC_MSG_RM_HOST_ACTION))
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kvmppc_xics_ipi_action();
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#endif
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if (all & IPI_MESSAGE(PPC_MSG_CALL_FUNCTION))
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generic_smp_call_function_interrupt();
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if (all & IPI_MESSAGE(PPC_MSG_RESCHEDULE))
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scheduler_ipi();
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if (all & IPI_MESSAGE(PPC_MSG_TICK_BROADCAST))
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tick_broadcast_ipi_handler();
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#ifdef CONFIG_NMI_IPI
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if (all & IPI_MESSAGE(PPC_MSG_NMI_IPI))
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nmi_ipi_action(0, NULL);
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#endif
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} while (info->messages);
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return IRQ_HANDLED;
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}
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#endif /* CONFIG_PPC_SMP_MUXED_IPI */
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static inline void do_message_pass(int cpu, int msg)
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{
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if (smp_ops->message_pass)
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smp_ops->message_pass(cpu, msg);
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#ifdef CONFIG_PPC_SMP_MUXED_IPI
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else
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smp_muxed_ipi_message_pass(cpu, msg);
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#endif
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}
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void smp_send_reschedule(int cpu)
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{
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if (likely(smp_ops))
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do_message_pass(cpu, PPC_MSG_RESCHEDULE);
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}
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EXPORT_SYMBOL_GPL(smp_send_reschedule);
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void arch_send_call_function_single_ipi(int cpu)
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{
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do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
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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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unsigned int cpu;
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for_each_cpu(cpu, mask)
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do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
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}
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#ifdef CONFIG_NMI_IPI
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/*
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* "NMI IPI" system.
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*
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* NMI IPIs may not be recoverable, so should not be used as ongoing part of
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* a running system. They can be used for crash, debug, halt/reboot, etc.
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*
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* NMI IPIs are globally single threaded. No more than one in progress at
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* any time.
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*
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* The IPI call waits with interrupts disabled until all targets enter the
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* NMI handler, then the call returns.
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*
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* No new NMI can be initiated until targets exit the handler.
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*
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* The IPI call may time out without all targets entering the NMI handler.
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* In that case, there is some logic to recover (and ignore subsequent
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* NMI interrupts that may eventually be raised), but the platform interrupt
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* handler may not be able to distinguish this from other exception causes,
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* which may cause a crash.
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*/
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static atomic_t __nmi_ipi_lock = ATOMIC_INIT(0);
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static struct cpumask nmi_ipi_pending_mask;
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static int nmi_ipi_busy_count = 0;
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static void (*nmi_ipi_function)(struct pt_regs *) = NULL;
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static void nmi_ipi_lock_start(unsigned long *flags)
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{
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raw_local_irq_save(*flags);
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hard_irq_disable();
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while (atomic_cmpxchg(&__nmi_ipi_lock, 0, 1) == 1) {
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raw_local_irq_restore(*flags);
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spin_until_cond(atomic_read(&__nmi_ipi_lock) == 0);
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raw_local_irq_save(*flags);
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hard_irq_disable();
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}
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}
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static void nmi_ipi_lock(void)
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{
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while (atomic_cmpxchg(&__nmi_ipi_lock, 0, 1) == 1)
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spin_until_cond(atomic_read(&__nmi_ipi_lock) == 0);
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}
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static void nmi_ipi_unlock(void)
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{
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smp_mb();
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WARN_ON(atomic_read(&__nmi_ipi_lock) != 1);
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atomic_set(&__nmi_ipi_lock, 0);
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}
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static void nmi_ipi_unlock_end(unsigned long *flags)
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{
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nmi_ipi_unlock();
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raw_local_irq_restore(*flags);
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}
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/*
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* Platform NMI handler calls this to ack
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*/
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int smp_handle_nmi_ipi(struct pt_regs *regs)
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{
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void (*fn)(struct pt_regs *);
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unsigned long flags;
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int me = raw_smp_processor_id();
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int ret = 0;
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/*
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* Unexpected NMIs are possible here because the interrupt may not
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* be able to distinguish NMI IPIs from other types of NMIs, or
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* because the caller may have timed out.
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*/
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nmi_ipi_lock_start(&flags);
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if (!nmi_ipi_busy_count)
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goto out;
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if (!cpumask_test_cpu(me, &nmi_ipi_pending_mask))
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goto out;
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fn = nmi_ipi_function;
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if (!fn)
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goto out;
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cpumask_clear_cpu(me, &nmi_ipi_pending_mask);
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nmi_ipi_busy_count++;
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nmi_ipi_unlock();
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ret = 1;
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fn(regs);
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nmi_ipi_lock();
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nmi_ipi_busy_count--;
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out:
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nmi_ipi_unlock_end(&flags);
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return ret;
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}
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static void do_smp_send_nmi_ipi(int cpu)
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{
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if (smp_ops->cause_nmi_ipi && smp_ops->cause_nmi_ipi(cpu))
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return;
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if (cpu >= 0) {
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do_message_pass(cpu, PPC_MSG_NMI_IPI);
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} else {
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int c;
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for_each_online_cpu(c) {
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if (c == raw_smp_processor_id())
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continue;
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do_message_pass(c, PPC_MSG_NMI_IPI);
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}
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}
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}
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void smp_flush_nmi_ipi(u64 delay_us)
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{
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unsigned long flags;
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nmi_ipi_lock_start(&flags);
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while (nmi_ipi_busy_count) {
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nmi_ipi_unlock_end(&flags);
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udelay(1);
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if (delay_us) {
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delay_us--;
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if (!delay_us)
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return;
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}
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nmi_ipi_lock_start(&flags);
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}
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nmi_ipi_unlock_end(&flags);
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}
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/*
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* - cpu is the target CPU (must not be this CPU), or NMI_IPI_ALL_OTHERS.
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* - fn is the target callback function.
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* - delay_us > 0 is the delay before giving up waiting for targets to
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* enter the handler, == 0 specifies indefinite delay.
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*/
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int smp_send_nmi_ipi(int cpu, void (*fn)(struct pt_regs *), u64 delay_us)
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{
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unsigned long flags;
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int me = raw_smp_processor_id();
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int ret = 1;
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BUG_ON(cpu == me);
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BUG_ON(cpu < 0 && cpu != NMI_IPI_ALL_OTHERS);
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if (unlikely(!smp_ops))
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return 0;
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/* Take the nmi_ipi_busy count/lock with interrupts hard disabled */
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nmi_ipi_lock_start(&flags);
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while (nmi_ipi_busy_count) {
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nmi_ipi_unlock_end(&flags);
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spin_until_cond(nmi_ipi_busy_count == 0);
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nmi_ipi_lock_start(&flags);
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}
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nmi_ipi_function = fn;
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if (cpu < 0) {
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/* ALL_OTHERS */
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cpumask_copy(&nmi_ipi_pending_mask, cpu_online_mask);
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cpumask_clear_cpu(me, &nmi_ipi_pending_mask);
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} else {
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/* cpumask starts clear */
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cpumask_set_cpu(cpu, &nmi_ipi_pending_mask);
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}
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nmi_ipi_busy_count++;
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nmi_ipi_unlock();
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do_smp_send_nmi_ipi(cpu);
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while (!cpumask_empty(&nmi_ipi_pending_mask)) {
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udelay(1);
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if (delay_us) {
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delay_us--;
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if (!delay_us)
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break;
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}
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}
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nmi_ipi_lock();
|
|
if (!cpumask_empty(&nmi_ipi_pending_mask)) {
|
|
/* Could not gather all CPUs */
|
|
ret = 0;
|
|
cpumask_clear(&nmi_ipi_pending_mask);
|
|
}
|
|
nmi_ipi_busy_count--;
|
|
nmi_ipi_unlock_end(&flags);
|
|
|
|
return ret;
|
|
}
|
|
#endif /* CONFIG_NMI_IPI */
|
|
|
|
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
|
|
void tick_broadcast(const struct cpumask *mask)
|
|
{
|
|
unsigned int cpu;
|
|
|
|
for_each_cpu(cpu, mask)
|
|
do_message_pass(cpu, PPC_MSG_TICK_BROADCAST);
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_DEBUGGER
|
|
void debugger_ipi_callback(struct pt_regs *regs)
|
|
{
|
|
debugger_ipi(regs);
|
|
}
|
|
|
|
void smp_send_debugger_break(void)
|
|
{
|
|
smp_send_nmi_ipi(NMI_IPI_ALL_OTHERS, debugger_ipi_callback, 1000000);
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_KEXEC_CORE
|
|
void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
|
|
{
|
|
smp_send_nmi_ipi(NMI_IPI_ALL_OTHERS, crash_ipi_callback, 1000000);
|
|
}
|
|
#endif
|
|
|
|
static void stop_this_cpu(void *dummy)
|
|
{
|
|
/* Remove this CPU */
|
|
set_cpu_online(smp_processor_id(), false);
|
|
|
|
local_irq_disable();
|
|
while (1)
|
|
;
|
|
}
|
|
|
|
void smp_send_stop(void)
|
|
{
|
|
smp_call_function(stop_this_cpu, NULL, 0);
|
|
}
|
|
|
|
struct thread_info *current_set[NR_CPUS];
|
|
|
|
static void smp_store_cpu_info(int id)
|
|
{
|
|
per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
|
|
#ifdef CONFIG_PPC_FSL_BOOK3E
|
|
per_cpu(next_tlbcam_idx, id)
|
|
= (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
|
|
#endif
|
|
}
|
|
|
|
void __init smp_prepare_cpus(unsigned int max_cpus)
|
|
{
|
|
unsigned int cpu;
|
|
|
|
DBG("smp_prepare_cpus\n");
|
|
|
|
/*
|
|
* setup_cpu may need to be called on the boot cpu. We havent
|
|
* spun any cpus up but lets be paranoid.
|
|
*/
|
|
BUG_ON(boot_cpuid != smp_processor_id());
|
|
|
|
/* Fixup boot cpu */
|
|
smp_store_cpu_info(boot_cpuid);
|
|
cpu_callin_map[boot_cpuid] = 1;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu),
|
|
GFP_KERNEL, cpu_to_node(cpu));
|
|
zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
|
|
GFP_KERNEL, cpu_to_node(cpu));
|
|
/*
|
|
* numa_node_id() works after this.
|
|
*/
|
|
if (cpu_present(cpu)) {
|
|
set_cpu_numa_node(cpu, numa_cpu_lookup_table[cpu]);
|
|
set_cpu_numa_mem(cpu,
|
|
local_memory_node(numa_cpu_lookup_table[cpu]));
|
|
}
|
|
}
|
|
|
|
cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid));
|
|
cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
|
|
|
|
if (smp_ops && smp_ops->probe)
|
|
smp_ops->probe();
|
|
}
|
|
|
|
void smp_prepare_boot_cpu(void)
|
|
{
|
|
BUG_ON(smp_processor_id() != boot_cpuid);
|
|
#ifdef CONFIG_PPC64
|
|
paca[boot_cpuid].__current = current;
|
|
#endif
|
|
set_numa_node(numa_cpu_lookup_table[boot_cpuid]);
|
|
current_set[boot_cpuid] = task_thread_info(current);
|
|
}
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
|
|
int generic_cpu_disable(void)
|
|
{
|
|
unsigned int cpu = smp_processor_id();
|
|
|
|
if (cpu == boot_cpuid)
|
|
return -EBUSY;
|
|
|
|
set_cpu_online(cpu, false);
|
|
#ifdef CONFIG_PPC64
|
|
vdso_data->processorCount--;
|
|
#endif
|
|
/* Update affinity of all IRQs previously aimed at this CPU */
|
|
irq_migrate_all_off_this_cpu();
|
|
|
|
/*
|
|
* Depending on the details of the interrupt controller, it's possible
|
|
* that one of the interrupts we just migrated away from this CPU is
|
|
* actually already pending on this CPU. If we leave it in that state
|
|
* the interrupt will never be EOI'ed, and will never fire again. So
|
|
* temporarily enable interrupts here, to allow any pending interrupt to
|
|
* be received (and EOI'ed), before we take this CPU offline.
|
|
*/
|
|
local_irq_enable();
|
|
mdelay(1);
|
|
local_irq_disable();
|
|
|
|
return 0;
|
|
}
|
|
|
|
void generic_cpu_die(unsigned int cpu)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < 100; i++) {
|
|
smp_rmb();
|
|
if (is_cpu_dead(cpu))
|
|
return;
|
|
msleep(100);
|
|
}
|
|
printk(KERN_ERR "CPU%d didn't die...\n", cpu);
|
|
}
|
|
|
|
void generic_set_cpu_dead(unsigned int cpu)
|
|
{
|
|
per_cpu(cpu_state, cpu) = CPU_DEAD;
|
|
}
|
|
|
|
/*
|
|
* The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
|
|
* the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
|
|
* which makes the delay in generic_cpu_die() not happen.
|
|
*/
|
|
void generic_set_cpu_up(unsigned int cpu)
|
|
{
|
|
per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
|
|
}
|
|
|
|
int generic_check_cpu_restart(unsigned int cpu)
|
|
{
|
|
return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
|
|
}
|
|
|
|
int is_cpu_dead(unsigned int cpu)
|
|
{
|
|
return per_cpu(cpu_state, cpu) == CPU_DEAD;
|
|
}
|
|
|
|
static bool secondaries_inhibited(void)
|
|
{
|
|
return kvm_hv_mode_active();
|
|
}
|
|
|
|
#else /* HOTPLUG_CPU */
|
|
|
|
#define secondaries_inhibited() 0
|
|
|
|
#endif
|
|
|
|
static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
|
|
{
|
|
struct thread_info *ti = task_thread_info(idle);
|
|
|
|
#ifdef CONFIG_PPC64
|
|
paca[cpu].__current = idle;
|
|
paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
|
|
#endif
|
|
ti->cpu = cpu;
|
|
secondary_ti = current_set[cpu] = ti;
|
|
}
|
|
|
|
int __cpu_up(unsigned int cpu, struct task_struct *tidle)
|
|
{
|
|
int rc, c;
|
|
|
|
/*
|
|
* Don't allow secondary threads to come online if inhibited
|
|
*/
|
|
if (threads_per_core > 1 && secondaries_inhibited() &&
|
|
cpu_thread_in_subcore(cpu))
|
|
return -EBUSY;
|
|
|
|
if (smp_ops == NULL ||
|
|
(smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
|
|
return -EINVAL;
|
|
|
|
cpu_idle_thread_init(cpu, tidle);
|
|
|
|
/*
|
|
* The platform might need to allocate resources prior to bringing
|
|
* up the CPU
|
|
*/
|
|
if (smp_ops->prepare_cpu) {
|
|
rc = smp_ops->prepare_cpu(cpu);
|
|
if (rc)
|
|
return rc;
|
|
}
|
|
|
|
/* Make sure callin-map entry is 0 (can be leftover a CPU
|
|
* hotplug
|
|
*/
|
|
cpu_callin_map[cpu] = 0;
|
|
|
|
/* The information for processor bringup must
|
|
* be written out to main store before we release
|
|
* the processor.
|
|
*/
|
|
smp_mb();
|
|
|
|
/* wake up cpus */
|
|
DBG("smp: kicking cpu %d\n", cpu);
|
|
rc = smp_ops->kick_cpu(cpu);
|
|
if (rc) {
|
|
pr_err("smp: failed starting cpu %d (rc %d)\n", cpu, rc);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* wait to see if the cpu made a callin (is actually up).
|
|
* use this value that I found through experimentation.
|
|
* -- Cort
|
|
*/
|
|
if (system_state < SYSTEM_RUNNING)
|
|
for (c = 50000; c && !cpu_callin_map[cpu]; c--)
|
|
udelay(100);
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
else
|
|
/*
|
|
* CPUs can take much longer to come up in the
|
|
* hotplug case. Wait five seconds.
|
|
*/
|
|
for (c = 5000; c && !cpu_callin_map[cpu]; c--)
|
|
msleep(1);
|
|
#endif
|
|
|
|
if (!cpu_callin_map[cpu]) {
|
|
printk(KERN_ERR "Processor %u is stuck.\n", cpu);
|
|
return -ENOENT;
|
|
}
|
|
|
|
DBG("Processor %u found.\n", cpu);
|
|
|
|
if (smp_ops->give_timebase)
|
|
smp_ops->give_timebase();
|
|
|
|
/* Wait until cpu puts itself in the online & active maps */
|
|
spin_until_cond(cpu_online(cpu));
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Return the value of the reg property corresponding to the given
|
|
* logical cpu.
|
|
*/
|
|
int cpu_to_core_id(int cpu)
|
|
{
|
|
struct device_node *np;
|
|
const __be32 *reg;
|
|
int id = -1;
|
|
|
|
np = of_get_cpu_node(cpu, NULL);
|
|
if (!np)
|
|
goto out;
|
|
|
|
reg = of_get_property(np, "reg", NULL);
|
|
if (!reg)
|
|
goto out;
|
|
|
|
id = be32_to_cpup(reg);
|
|
out:
|
|
of_node_put(np);
|
|
return id;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpu_to_core_id);
|
|
|
|
/* Helper routines for cpu to core mapping */
|
|
int cpu_core_index_of_thread(int cpu)
|
|
{
|
|
return cpu >> threads_shift;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpu_core_index_of_thread);
|
|
|
|
int cpu_first_thread_of_core(int core)
|
|
{
|
|
return core << threads_shift;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);
|
|
|
|
static void traverse_siblings_chip_id(int cpu, bool add, int chipid)
|
|
{
|
|
const struct cpumask *mask;
|
|
struct device_node *np;
|
|
int i, plen;
|
|
const __be32 *prop;
|
|
|
|
mask = add ? cpu_online_mask : cpu_present_mask;
|
|
for_each_cpu(i, mask) {
|
|
np = of_get_cpu_node(i, NULL);
|
|
if (!np)
|
|
continue;
|
|
prop = of_get_property(np, "ibm,chip-id", &plen);
|
|
if (prop && plen == sizeof(int) &&
|
|
of_read_number(prop, 1) == chipid) {
|
|
if (add) {
|
|
cpumask_set_cpu(cpu, cpu_core_mask(i));
|
|
cpumask_set_cpu(i, cpu_core_mask(cpu));
|
|
} else {
|
|
cpumask_clear_cpu(cpu, cpu_core_mask(i));
|
|
cpumask_clear_cpu(i, cpu_core_mask(cpu));
|
|
}
|
|
}
|
|
of_node_put(np);
|
|
}
|
|
}
|
|
|
|
/* Must be called when no change can occur to cpu_present_mask,
|
|
* i.e. during cpu online or offline.
|
|
*/
|
|
static struct device_node *cpu_to_l2cache(int cpu)
|
|
{
|
|
struct device_node *np;
|
|
struct device_node *cache;
|
|
|
|
if (!cpu_present(cpu))
|
|
return NULL;
|
|
|
|
np = of_get_cpu_node(cpu, NULL);
|
|
if (np == NULL)
|
|
return NULL;
|
|
|
|
cache = of_find_next_cache_node(np);
|
|
|
|
of_node_put(np);
|
|
|
|
return cache;
|
|
}
|
|
|
|
static void traverse_core_siblings(int cpu, bool add)
|
|
{
|
|
struct device_node *l2_cache, *np;
|
|
const struct cpumask *mask;
|
|
int i, chip, plen;
|
|
const __be32 *prop;
|
|
|
|
/* First see if we have ibm,chip-id properties in cpu nodes */
|
|
np = of_get_cpu_node(cpu, NULL);
|
|
if (np) {
|
|
chip = -1;
|
|
prop = of_get_property(np, "ibm,chip-id", &plen);
|
|
if (prop && plen == sizeof(int))
|
|
chip = of_read_number(prop, 1);
|
|
of_node_put(np);
|
|
if (chip >= 0) {
|
|
traverse_siblings_chip_id(cpu, add, chip);
|
|
return;
|
|
}
|
|
}
|
|
|
|
l2_cache = cpu_to_l2cache(cpu);
|
|
mask = add ? cpu_online_mask : cpu_present_mask;
|
|
for_each_cpu(i, mask) {
|
|
np = cpu_to_l2cache(i);
|
|
if (!np)
|
|
continue;
|
|
if (np == l2_cache) {
|
|
if (add) {
|
|
cpumask_set_cpu(cpu, cpu_core_mask(i));
|
|
cpumask_set_cpu(i, cpu_core_mask(cpu));
|
|
} else {
|
|
cpumask_clear_cpu(cpu, cpu_core_mask(i));
|
|
cpumask_clear_cpu(i, cpu_core_mask(cpu));
|
|
}
|
|
}
|
|
of_node_put(np);
|
|
}
|
|
of_node_put(l2_cache);
|
|
}
|
|
|
|
/* Activate a secondary processor. */
|
|
void start_secondary(void *unused)
|
|
{
|
|
unsigned int cpu = smp_processor_id();
|
|
int i, base;
|
|
|
|
mmgrab(&init_mm);
|
|
current->active_mm = &init_mm;
|
|
|
|
smp_store_cpu_info(cpu);
|
|
set_dec(tb_ticks_per_jiffy);
|
|
preempt_disable();
|
|
cpu_callin_map[cpu] = 1;
|
|
|
|
if (smp_ops->setup_cpu)
|
|
smp_ops->setup_cpu(cpu);
|
|
if (smp_ops->take_timebase)
|
|
smp_ops->take_timebase();
|
|
|
|
secondary_cpu_time_init();
|
|
|
|
#ifdef CONFIG_PPC64
|
|
if (system_state == SYSTEM_RUNNING)
|
|
vdso_data->processorCount++;
|
|
|
|
vdso_getcpu_init();
|
|
#endif
|
|
/* Update sibling maps */
|
|
base = cpu_first_thread_sibling(cpu);
|
|
for (i = 0; i < threads_per_core; i++) {
|
|
if (cpu_is_offline(base + i) && (cpu != base + i))
|
|
continue;
|
|
cpumask_set_cpu(cpu, cpu_sibling_mask(base + i));
|
|
cpumask_set_cpu(base + i, cpu_sibling_mask(cpu));
|
|
|
|
/* cpu_core_map should be a superset of
|
|
* cpu_sibling_map even if we don't have cache
|
|
* information, so update the former here, too.
|
|
*/
|
|
cpumask_set_cpu(cpu, cpu_core_mask(base + i));
|
|
cpumask_set_cpu(base + i, cpu_core_mask(cpu));
|
|
}
|
|
traverse_core_siblings(cpu, true);
|
|
|
|
set_numa_node(numa_cpu_lookup_table[cpu]);
|
|
set_numa_mem(local_memory_node(numa_cpu_lookup_table[cpu]));
|
|
|
|
smp_wmb();
|
|
notify_cpu_starting(cpu);
|
|
set_cpu_online(cpu, true);
|
|
|
|
local_irq_enable();
|
|
|
|
cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
|
|
|
|
BUG();
|
|
}
|
|
|
|
int setup_profiling_timer(unsigned int multiplier)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_SCHED_SMT
|
|
/* cpumask of CPUs with asymetric SMT dependancy */
|
|
static int powerpc_smt_flags(void)
|
|
{
|
|
int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
|
|
|
|
if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
|
|
printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
|
|
flags |= SD_ASYM_PACKING;
|
|
}
|
|
return flags;
|
|
}
|
|
#endif
|
|
|
|
static struct sched_domain_topology_level powerpc_topology[] = {
|
|
#ifdef CONFIG_SCHED_SMT
|
|
{ cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
|
|
#endif
|
|
{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
|
|
{ NULL, },
|
|
};
|
|
|
|
void __init smp_cpus_done(unsigned int max_cpus)
|
|
{
|
|
/*
|
|
* We are running pinned to the boot CPU, see rest_init().
|
|
*/
|
|
if (smp_ops && smp_ops->setup_cpu)
|
|
smp_ops->setup_cpu(boot_cpuid);
|
|
|
|
if (smp_ops && smp_ops->bringup_done)
|
|
smp_ops->bringup_done();
|
|
|
|
dump_numa_cpu_topology();
|
|
|
|
set_sched_topology(powerpc_topology);
|
|
}
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
int __cpu_disable(void)
|
|
{
|
|
int cpu = smp_processor_id();
|
|
int base, i;
|
|
int err;
|
|
|
|
if (!smp_ops->cpu_disable)
|
|
return -ENOSYS;
|
|
|
|
err = smp_ops->cpu_disable();
|
|
if (err)
|
|
return err;
|
|
|
|
/* Update sibling maps */
|
|
base = cpu_first_thread_sibling(cpu);
|
|
for (i = 0; i < threads_per_core && base + i < nr_cpu_ids; i++) {
|
|
cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
|
|
cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
|
|
cpumask_clear_cpu(cpu, cpu_core_mask(base + i));
|
|
cpumask_clear_cpu(base + i, cpu_core_mask(cpu));
|
|
}
|
|
traverse_core_siblings(cpu, false);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void __cpu_die(unsigned int cpu)
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|
{
|
|
if (smp_ops->cpu_die)
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|
smp_ops->cpu_die(cpu);
|
|
}
|
|
|
|
void cpu_die(void)
|
|
{
|
|
if (ppc_md.cpu_die)
|
|
ppc_md.cpu_die();
|
|
|
|
/* If we return, we re-enter start_secondary */
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|
start_secondary_resume();
|
|
}
|
|
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|
#endif
|