LXR linux/arch/mips/paravirt/paravirt-smp.c

   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * Copyright (C) 2013 Cavium, Inc.
   7 */
   8
   9#include <linux/interrupt.h>
  10#include <linux/cpumask.h>
  11#include <linux/kernel.h>
  12#include <linux/sched.h>
  13
  14#include <asm/mipsregs.h>
  15#include <asm/setup.h>
  16#include <asm/time.h>
  17#include <asm/smp.h>
  18
  19/*
  20 * Writing the sp releases the CPU, so writes must be ordered, gp
  21 * first, then sp.
  22 */
  23unsigned long paravirt_smp_sp[NR_CPUS];
  24unsigned long paravirt_smp_gp[NR_CPUS];
  25
  26static int numcpus = 1;
  27
  28static int __init set_numcpus(char *str)
  29{
  30        int newval;
  31
  32        if (get_option(&str, &newval)) {
  33                if (newval < 1 || newval >= NR_CPUS)
  34                        goto bad;
  35                numcpus = newval;
  36                return 0;
  37        }
  38bad:
  39        return -EINVAL;
  40}
  41early_param("numcpus", set_numcpus);
  42
  43
  44static void paravirt_smp_setup(void)
  45{
  46        int id;
  47        unsigned int cpunum = get_ebase_cpunum();
  48
  49        if (WARN_ON(cpunum >= NR_CPUS))
  50                return;
  51
  52        /* The present CPUs are initially just the boot cpu (CPU 0). */
  53        for (id = 0; id < NR_CPUS; id++) {
  54                set_cpu_possible(id, id == 0);
  55                set_cpu_present(id, id == 0);
  56        }
  57        __cpu_number_map[cpunum] = 0;
  58        __cpu_logical_map[0] = cpunum;
  59
  60        for (id = 0; id < numcpus; id++) {
  61                set_cpu_possible(id, true);
  62                set_cpu_present(id, true);
  63                __cpu_number_map[id] = id;
  64                __cpu_logical_map[id] = id;
  65        }
  66}
  67
  68void irq_mbox_ipi(int cpu, unsigned int actions);
  69static void paravirt_send_ipi_single(int cpu, unsigned int action)
  70{
  71        irq_mbox_ipi(cpu, action);
  72}
  73
  74static void paravirt_send_ipi_mask(const struct cpumask *mask, unsigned int action)
  75{
  76        unsigned int cpu;
  77
  78        for_each_cpu(cpu, mask)
  79                paravirt_send_ipi_single(cpu, action);
  80}
  81
  82static void paravirt_init_secondary(void)
  83{
  84        unsigned int sr;
  85
  86        sr = set_c0_status(ST0_BEV);
  87        write_c0_ebase((u32)ebase);
  88
  89        sr |= STATUSF_IP2; /* Interrupt controller on IP2 */
  90        write_c0_status(sr);
  91
  92        irq_cpu_online();
  93}
  94
  95static void paravirt_smp_finish(void)
  96{
  97        /* to generate the first CPU timer interrupt */
  98        write_c0_compare(read_c0_count() + mips_hpt_frequency / HZ);
  99        local_irq_enable();
 100}
 101
 102static void paravirt_boot_secondary(int cpu, struct task_struct *idle)
 103{
 104        paravirt_smp_gp[cpu] = (unsigned long)task_thread_info(idle);
 105        smp_wmb();
 106        paravirt_smp_sp[cpu] = __KSTK_TOS(idle);
 107}
 108
 109static irqreturn_t paravirt_reched_interrupt(int irq, void *dev_id)
 110{
 111        scheduler_ipi();
 112        return IRQ_HANDLED;
 113}
 114
 115static irqreturn_t paravirt_function_interrupt(int irq, void *dev_id)
 116{
 117        generic_smp_call_function_interrupt();
 118        return IRQ_HANDLED;
 119}
 120
 121static void paravirt_prepare_cpus(unsigned int max_cpus)
 122{
 123        if (request_irq(MIPS_IRQ_MBOX0, paravirt_reched_interrupt,
 124                        IRQF_PERCPU | IRQF_NO_THREAD, "Scheduler",
 125                        paravirt_reched_interrupt)) {
 126                panic("Cannot request_irq for SchedulerIPI");
 127        }
 128        if (request_irq(MIPS_IRQ_MBOX1, paravirt_function_interrupt,
 129                        IRQF_PERCPU | IRQF_NO_THREAD, "SMP-Call",
 130                        paravirt_function_interrupt)) {
 131                panic("Cannot request_irq for SMP-Call");
 132        }
 133}
 134
 135struct plat_smp_ops paravirt_smp_ops = {
 136        .send_ipi_single        = paravirt_send_ipi_single,
 137        .send_ipi_mask          = paravirt_send_ipi_mask,
 138        .init_secondary         = paravirt_init_secondary,
 139        .smp_finish             = paravirt_smp_finish,
 140        .boot_secondary         = paravirt_boot_secondary,
 141        .smp_setup              = paravirt_smp_setup,
 142        .prepare_cpus           = paravirt_prepare_cpus,
 143};
 144