123 lines
2.8 KiB
C
123 lines
2.8 KiB
C
/*
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* Smp support for CHRP machines.
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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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*/
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#include <linux/config.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/smp.h>
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#include <linux/smp_lock.h>
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#include <linux/interrupt.h>
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#include <linux/kernel_stat.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 <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/sections.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/residual.h>
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#include <asm/time.h>
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#include <asm/open_pic.h>
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#include <asm/machdep.h>
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#include <asm/smp.h>
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#include <asm/mpic.h>
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extern unsigned long smp_chrp_cpu_nr;
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static int __init smp_chrp_probe(void)
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{
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struct device_node *cpus = NULL;
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unsigned int *reg;
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int reglen;
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int ncpus = 0;
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int cpuid;
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unsigned int phys;
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/* Count CPUs in the device-tree */
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cpuid = 1; /* the boot cpu is logical cpu 0 */
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while ((cpus = of_find_node_by_type(cpus, "cpu")) != NULL) {
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phys = ncpus;
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reg = (unsigned int *) get_property(cpus, "reg", ®len);
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if (reg && reglen >= sizeof(unsigned int))
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/* hmmm, not having a reg property would be bad */
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phys = *reg;
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if (phys != boot_cpuid_phys) {
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set_hard_smp_processor_id(cpuid, phys);
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++cpuid;
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}
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++ncpus;
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}
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printk(KERN_INFO "CHRP SMP probe found %d cpus\n", ncpus);
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/* Nothing more to do if less than 2 of them */
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if (ncpus <= 1)
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return 1;
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mpic_request_ipis();
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return ncpus;
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}
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static void __devinit smp_chrp_kick_cpu(int nr)
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{
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*(unsigned long *)KERNELBASE = nr;
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asm volatile("dcbf 0,%0"::"r"(KERNELBASE):"memory");
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}
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static void __devinit smp_chrp_setup_cpu(int cpu_nr)
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{
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mpic_setup_this_cpu();
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}
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static DEFINE_SPINLOCK(timebase_lock);
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static unsigned int timebase_upper = 0, timebase_lower = 0;
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void __devinit smp_chrp_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_upper = get_tbu();
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timebase_lower = get_tbl();
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spin_unlock(&timebase_lock);
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while (timebase_upper || timebase_lower)
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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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void __devinit smp_chrp_take_timebase(void)
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{
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while (!(timebase_upper || timebase_lower))
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barrier();
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spin_lock(&timebase_lock);
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set_tb(timebase_upper, timebase_lower);
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timebase_upper = 0;
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timebase_lower = 0;
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spin_unlock(&timebase_lock);
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printk("CPU %i taken timebase\n", smp_processor_id());
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}
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/* CHRP with openpic */
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struct smp_ops_t chrp_smp_ops = {
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.message_pass = smp_mpic_message_pass,
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.probe = smp_chrp_probe,
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.kick_cpu = smp_chrp_kick_cpu,
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.setup_cpu = smp_chrp_setup_cpu,
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.give_timebase = smp_chrp_give_timebase,
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.take_timebase = smp_chrp_take_timebase,
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};
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