174 строки
4.3 KiB
C
174 строки
4.3 KiB
C
/*
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* SMP support for PowerNV machines.
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*
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* Copyright 2011 IBM Corp.
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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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#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/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/cpu.h>
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#include <asm/irq.h>
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#include <asm/smp.h>
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#include <asm/paca.h>
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#include <asm/machdep.h>
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#include <asm/cputable.h>
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#include <asm/firmware.h>
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#include <asm/rtas.h>
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#include <asm/vdso_datapage.h>
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#include <asm/cputhreads.h>
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#include <asm/xics.h>
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#include <asm/opal.h>
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#include "powernv.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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static void __cpuinit pnv_smp_setup_cpu(int cpu)
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{
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if (cpu != boot_cpuid)
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xics_setup_cpu();
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}
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static int pnv_smp_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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int pnv_smp_kick_cpu(int nr)
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{
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unsigned int pcpu = get_hard_smp_processor_id(nr);
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unsigned long start_here = __pa(*((unsigned long *)
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generic_secondary_smp_init));
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long rc;
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BUG_ON(nr < 0 || nr >= NR_CPUS);
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/* On OPAL v2 the CPU are still spinning inside OPAL itself,
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* get them back now
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*/
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if (!paca[nr].cpu_start && firmware_has_feature(FW_FEATURE_OPALv2)) {
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pr_devel("OPAL: Starting CPU %d (HW 0x%x)...\n", nr, pcpu);
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rc = opal_start_cpu(pcpu, start_here);
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if (rc != OPAL_SUCCESS)
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pr_warn("OPAL Error %ld starting CPU %d\n",
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rc, nr);
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}
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return smp_generic_kick_cpu(nr);
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}
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#ifdef CONFIG_HOTPLUG_CPU
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static int pnv_smp_cpu_disable(void)
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{
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int cpu = smp_processor_id();
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/* This is identical to pSeries... might consolidate by
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* moving migrate_irqs_away to a ppc_md with default to
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* the generic fixup_irqs. --BenH.
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*/
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set_cpu_online(cpu, false);
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vdso_data->processorCount--;
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if (cpu == boot_cpuid)
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boot_cpuid = cpumask_any(cpu_online_mask);
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xics_migrate_irqs_away();
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return 0;
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}
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static void pnv_smp_cpu_kill_self(void)
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{
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unsigned int cpu;
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/* Standard hot unplug procedure */
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local_irq_disable();
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idle_task_exit();
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current->active_mm = NULL; /* for sanity */
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cpu = smp_processor_id();
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DBG("CPU%d offline\n", cpu);
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generic_set_cpu_dead(cpu);
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smp_wmb();
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/* We don't want to take decrementer interrupts while we are offline,
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* so clear LPCR:PECE1. We keep PECE2 enabled.
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*/
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mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1);
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while (!generic_check_cpu_restart(cpu)) {
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power7_nap();
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if (!generic_check_cpu_restart(cpu)) {
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DBG("CPU%d Unexpected exit while offline !\n", cpu);
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/* We may be getting an IPI, so we re-enable
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* interrupts to process it, it will be ignored
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* since we aren't online (hopefully)
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*/
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local_irq_enable();
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local_irq_disable();
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}
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}
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mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_PECE1);
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DBG("CPU%d coming online...\n", cpu);
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}
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#endif /* CONFIG_HOTPLUG_CPU */
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static struct smp_ops_t pnv_smp_ops = {
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.message_pass = smp_muxed_ipi_message_pass,
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.cause_ipi = NULL, /* Filled at runtime by xics_smp_probe() */
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.probe = xics_smp_probe,
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.kick_cpu = pnv_smp_kick_cpu,
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.setup_cpu = pnv_smp_setup_cpu,
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.cpu_bootable = pnv_smp_cpu_bootable,
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#ifdef CONFIG_HOTPLUG_CPU
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.cpu_disable = pnv_smp_cpu_disable,
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.cpu_die = generic_cpu_die,
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#endif /* CONFIG_HOTPLUG_CPU */
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};
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/* This is called very early during platform setup_arch */
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void __init pnv_smp_init(void)
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{
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smp_ops = &pnv_smp_ops;
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/* XXX We don't yet have a proper entry point from HAL, for
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* now we rely on kexec-style entry from BML
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*/
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#ifdef CONFIG_PPC_RTAS
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/* Non-lpar has additional take/give timebase */
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if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) {
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smp_ops->give_timebase = rtas_give_timebase;
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smp_ops->take_timebase = rtas_take_timebase;
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}
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#endif /* CONFIG_PPC_RTAS */
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#ifdef CONFIG_HOTPLUG_CPU
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ppc_md.cpu_die = pnv_smp_cpu_kill_self;
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#endif
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}
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