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517 lines
12 KiB
517 lines
12 KiB
/*
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* SMP support for pSeries and BPA machines.
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*
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* 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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* Plus various changes from other IBM teams...
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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/config.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/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/sysdev.h>
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#include <linux/cpu.h>
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#include <asm/ptrace.h>
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#include <asm/atomic.h>
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#include <asm/irq.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/io.h>
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#include <asm/prom.h>
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#include <asm/smp.h>
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#include <asm/paca.h>
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#include <asm/time.h>
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#include <asm/machdep.h>
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#include <asm/xics.h>
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#include <asm/cputable.h>
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#include <asm/firmware.h>
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#include <asm/system.h>
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#include <asm/rtas.h>
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#include <asm/plpar_wrappers.h>
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#include <asm/pSeries_reconfig.h>
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#include "mpic.h"
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#include "bpa_iic.h"
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#ifdef DEBUG
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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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/*
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* The primary thread of each non-boot processor is recorded here before
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* smp init.
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*/
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static cpumask_t of_spin_map;
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extern void pSeries_secondary_smp_init(unsigned long);
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#ifdef CONFIG_HOTPLUG_CPU
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/* Get state of physical CPU.
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* Return codes:
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* 0 - The processor is in the RTAS stopped state
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* 1 - stop-self is in progress
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* 2 - The processor is not in the RTAS stopped state
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* -1 - Hardware Error
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* -2 - Hardware Busy, Try again later.
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*/
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static int query_cpu_stopped(unsigned int pcpu)
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{
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int cpu_status;
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int status, qcss_tok;
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qcss_tok = rtas_token("query-cpu-stopped-state");
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if (qcss_tok == RTAS_UNKNOWN_SERVICE)
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return -1;
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status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu);
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if (status != 0) {
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printk(KERN_ERR
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"RTAS query-cpu-stopped-state failed: %i\n", status);
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return status;
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}
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return cpu_status;
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}
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int pSeries_cpu_disable(void)
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{
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int cpu = smp_processor_id();
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cpu_clear(cpu, cpu_online_map);
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systemcfg->processorCount--;
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/*fix boot_cpuid here*/
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if (cpu == boot_cpuid)
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boot_cpuid = any_online_cpu(cpu_online_map);
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/* FIXME: abstract this to not be platform specific later on */
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xics_migrate_irqs_away();
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return 0;
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}
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void pSeries_cpu_die(unsigned int cpu)
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{
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int tries;
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int cpu_status;
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unsigned int pcpu = get_hard_smp_processor_id(cpu);
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for (tries = 0; tries < 25; tries++) {
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cpu_status = query_cpu_stopped(pcpu);
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if (cpu_status == 0 || cpu_status == -1)
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break;
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msleep(200);
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}
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if (cpu_status != 0) {
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printk("Querying DEAD? cpu %i (%i) shows %i\n",
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cpu, pcpu, cpu_status);
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}
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/* Isolation and deallocation are definatly done by
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* drslot_chrp_cpu. If they were not they would be
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* done here. Change isolate state to Isolate and
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* change allocation-state to Unusable.
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*/
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paca[cpu].cpu_start = 0;
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}
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/*
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* Update cpu_present_map and paca(s) for a new cpu node. The wrinkle
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* here is that a cpu device node may represent up to two logical cpus
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* in the SMT case. We must honor the assumption in other code that
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* the logical ids for sibling SMT threads x and y are adjacent, such
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* that x^1 == y and y^1 == x.
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*/
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static int pSeries_add_processor(struct device_node *np)
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{
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unsigned int cpu;
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cpumask_t candidate_map, tmp = CPU_MASK_NONE;
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int err = -ENOSPC, len, nthreads, i;
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u32 *intserv;
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intserv = (u32 *)get_property(np, "ibm,ppc-interrupt-server#s", &len);
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if (!intserv)
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return 0;
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nthreads = len / sizeof(u32);
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for (i = 0; i < nthreads; i++)
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cpu_set(i, tmp);
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lock_cpu_hotplug();
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BUG_ON(!cpus_subset(cpu_present_map, cpu_possible_map));
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/* Get a bitmap of unoccupied slots. */
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cpus_xor(candidate_map, cpu_possible_map, cpu_present_map);
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if (cpus_empty(candidate_map)) {
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/* If we get here, it most likely means that NR_CPUS is
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* less than the partition's max processors setting.
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*/
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printk(KERN_ERR "Cannot add cpu %s; this system configuration"
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" supports %d logical cpus.\n", np->full_name,
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cpus_weight(cpu_possible_map));
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goto out_unlock;
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}
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while (!cpus_empty(tmp))
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if (cpus_subset(tmp, candidate_map))
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/* Found a range where we can insert the new cpu(s) */
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break;
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else
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cpus_shift_left(tmp, tmp, nthreads);
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if (cpus_empty(tmp)) {
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printk(KERN_ERR "Unable to find space in cpu_present_map for"
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" processor %s with %d thread(s)\n", np->name,
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nthreads);
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goto out_unlock;
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}
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for_each_cpu_mask(cpu, tmp) {
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BUG_ON(cpu_isset(cpu, cpu_present_map));
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cpu_set(cpu, cpu_present_map);
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set_hard_smp_processor_id(cpu, *intserv++);
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}
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err = 0;
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out_unlock:
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unlock_cpu_hotplug();
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return err;
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}
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/*
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* Update the present map for a cpu node which is going away, and set
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* the hard id in the paca(s) to -1 to be consistent with boot time
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* convention for non-present cpus.
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*/
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static void pSeries_remove_processor(struct device_node *np)
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{
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unsigned int cpu;
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int len, nthreads, i;
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u32 *intserv;
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intserv = (u32 *)get_property(np, "ibm,ppc-interrupt-server#s", &len);
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if (!intserv)
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return;
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nthreads = len / sizeof(u32);
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lock_cpu_hotplug();
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for (i = 0; i < nthreads; i++) {
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for_each_present_cpu(cpu) {
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if (get_hard_smp_processor_id(cpu) != intserv[i])
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continue;
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BUG_ON(cpu_online(cpu));
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cpu_clear(cpu, cpu_present_map);
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set_hard_smp_processor_id(cpu, -1);
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break;
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}
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if (cpu == NR_CPUS)
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printk(KERN_WARNING "Could not find cpu to remove "
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"with physical id 0x%x\n", intserv[i]);
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}
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unlock_cpu_hotplug();
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}
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static int pSeries_smp_notifier(struct notifier_block *nb, unsigned long action, void *node)
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{
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int err = NOTIFY_OK;
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switch (action) {
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case PSERIES_RECONFIG_ADD:
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if (pSeries_add_processor(node))
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err = NOTIFY_BAD;
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break;
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case PSERIES_RECONFIG_REMOVE:
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pSeries_remove_processor(node);
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break;
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default:
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err = NOTIFY_DONE;
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break;
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}
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return err;
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}
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static struct notifier_block pSeries_smp_nb = {
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.notifier_call = pSeries_smp_notifier,
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};
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#endif /* CONFIG_HOTPLUG_CPU */
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/**
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* smp_startup_cpu() - start the given cpu
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*
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* At boot time, there is nothing to do for primary threads which were
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* started from Open Firmware. For anything else, call RTAS with the
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* appropriate start location.
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*
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* Returns:
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* 0 - failure
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* 1 - success
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*/
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static inline int __devinit smp_startup_cpu(unsigned int lcpu)
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{
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int status;
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unsigned long start_here = __pa((u32)*((unsigned long *)
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pSeries_secondary_smp_init));
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unsigned int pcpu;
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int start_cpu;
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if (cpu_isset(lcpu, of_spin_map))
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/* Already started by OF and sitting in spin loop */
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return 1;
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pcpu = get_hard_smp_processor_id(lcpu);
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/* Fixup atomic count: it exited inside IRQ handler. */
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paca[lcpu].__current->thread_info->preempt_count = 0;
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/*
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* If the RTAS start-cpu token does not exist then presume the
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* cpu is already spinning.
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*/
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start_cpu = rtas_token("start-cpu");
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if (start_cpu == RTAS_UNKNOWN_SERVICE)
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return 1;
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status = rtas_call(start_cpu, 3, 1, NULL, pcpu, start_here, lcpu);
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if (status != 0) {
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printk(KERN_ERR "start-cpu failed: %i\n", status);
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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_XICS
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static inline void smp_xics_do_message(int cpu, int msg)
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{
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set_bit(msg, &xics_ipi_message[cpu].value);
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mb();
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xics_cause_IPI(cpu);
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}
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static void smp_xics_message_pass(int target, int msg)
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{
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unsigned int i;
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if (target < NR_CPUS) {
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smp_xics_do_message(target, msg);
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} else {
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for_each_online_cpu(i) {
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if (target == MSG_ALL_BUT_SELF
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&& i == smp_processor_id())
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continue;
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smp_xics_do_message(i, msg);
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}
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}
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}
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static int __init smp_xics_probe(void)
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{
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xics_request_IPIs();
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return cpus_weight(cpu_possible_map);
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}
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static void __devinit smp_xics_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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if (firmware_has_feature(FW_FEATURE_SPLPAR))
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vpa_init(cpu);
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cpu_clear(cpu, of_spin_map);
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}
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#endif /* CONFIG_XICS */
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#ifdef CONFIG_BPA_IIC
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static void smp_iic_message_pass(int target, int msg)
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{
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unsigned int i;
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if (target < NR_CPUS) {
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iic_cause_IPI(target, msg);
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} else {
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for_each_online_cpu(i) {
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if (target == MSG_ALL_BUT_SELF
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&& i == smp_processor_id())
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continue;
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iic_cause_IPI(i, msg);
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}
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}
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}
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static int __init smp_iic_probe(void)
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{
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iic_request_IPIs();
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return cpus_weight(cpu_possible_map);
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}
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static void __devinit smp_iic_setup_cpu(int cpu)
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{
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if (cpu != boot_cpuid)
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iic_setup_cpu();
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}
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#endif /* CONFIG_BPA_IIC */
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static DEFINE_SPINLOCK(timebase_lock);
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static unsigned long timebase = 0;
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static void __devinit pSeries_give_timebase(void)
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{
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spin_lock(&timebase_lock);
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rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
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timebase = get_tb();
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spin_unlock(&timebase_lock);
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while (timebase)
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barrier();
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rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
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}
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static void __devinit pSeries_take_timebase(void)
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{
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while (!timebase)
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barrier();
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spin_lock(&timebase_lock);
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set_tb(timebase >> 32, timebase & 0xffffffff);
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timebase = 0;
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spin_unlock(&timebase_lock);
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}
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static void __devinit smp_pSeries_kick_cpu(int nr)
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{
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BUG_ON(nr < 0 || nr >= NR_CPUS);
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if (!smp_startup_cpu(nr))
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return;
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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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paca[nr].cpu_start = 1;
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}
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static int smp_pSeries_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. Odd-numbered
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* cpus are assumed to be secondary threads.
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*/
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if (system_state < SYSTEM_RUNNING &&
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cpu_has_feature(CPU_FTR_SMT) &&
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!smt_enabled_at_boot && nr % 2 != 0)
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return 0;
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return 1;
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}
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#ifdef CONFIG_MPIC
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static struct smp_ops_t pSeries_mpic_smp_ops = {
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.message_pass = smp_mpic_message_pass,
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.probe = smp_mpic_probe,
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.kick_cpu = smp_pSeries_kick_cpu,
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.setup_cpu = smp_mpic_setup_cpu,
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};
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#endif
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#ifdef CONFIG_XICS
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static struct smp_ops_t pSeries_xics_smp_ops = {
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.message_pass = smp_xics_message_pass,
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.probe = smp_xics_probe,
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.kick_cpu = smp_pSeries_kick_cpu,
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.setup_cpu = smp_xics_setup_cpu,
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.cpu_bootable = smp_pSeries_cpu_bootable,
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};
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#endif
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#ifdef CONFIG_BPA_IIC
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static struct smp_ops_t bpa_iic_smp_ops = {
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.message_pass = smp_iic_message_pass,
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.probe = smp_iic_probe,
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.kick_cpu = smp_pSeries_kick_cpu,
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.setup_cpu = smp_iic_setup_cpu,
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.cpu_bootable = smp_pSeries_cpu_bootable,
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};
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#endif
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/* This is called very early */
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void __init smp_init_pSeries(void)
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{
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int i;
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DBG(" -> smp_init_pSeries()\n");
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switch (ppc64_interrupt_controller) {
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#ifdef CONFIG_MPIC
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case IC_OPEN_PIC:
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smp_ops = &pSeries_mpic_smp_ops;
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break;
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#endif
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#ifdef CONFIG_XICS
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case IC_PPC_XIC:
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smp_ops = &pSeries_xics_smp_ops;
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break;
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#endif
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#ifdef CONFIG_BPA_IIC
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case IC_BPA_IIC:
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smp_ops = &bpa_iic_smp_ops;
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break;
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#endif
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default:
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panic("Invalid interrupt controller");
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}
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#ifdef CONFIG_HOTPLUG_CPU
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smp_ops->cpu_disable = pSeries_cpu_disable;
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smp_ops->cpu_die = pSeries_cpu_die;
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/* Processors can be added/removed only on LPAR */
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if (systemcfg->platform == PLATFORM_PSERIES_LPAR)
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pSeries_reconfig_notifier_register(&pSeries_smp_nb);
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#endif
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/* Mark threads which are still spinning in hold loops. */
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if (cpu_has_feature(CPU_FTR_SMT)) {
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for_each_present_cpu(i) {
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if (i % 2 == 0)
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/*
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* Even-numbered logical cpus correspond to
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* primary threads.
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*/
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cpu_set(i, of_spin_map);
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}
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} else {
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of_spin_map = cpu_present_map;
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}
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cpu_clear(boot_cpuid, of_spin_map);
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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 = pSeries_give_timebase;
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smp_ops->take_timebase = pSeries_take_timebase;
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}
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DBG(" <- smp_init_pSeries()\n");
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}
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