paravirt-smp.c
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2013 Cavium, Inc.
*/
#include <linux/interrupt.h>
#include <linux/cpumask.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <asm/mipsregs.h>
#include <asm/setup.h>
#include <asm/time.h>
#include <asm/smp.h>
/*
* Writing the sp releases the CPU, so writes must be ordered, gp
* first, then sp.
*/
unsigned long paravirt_smp_sp[NR_CPUS];
unsigned long paravirt_smp_gp[NR_CPUS];
static int numcpus = 1;
static int __init set_numcpus(char *str)
{
int newval;
if (get_option(&str, &newval)) {
if (newval < 1 || newval >= NR_CPUS)
goto bad;
numcpus = newval;
return 0;
}
bad:
return -EINVAL;
}
early_param("numcpus", set_numcpus);
static void paravirt_smp_setup(void)
{
int id;
unsigned int cpunum = get_ebase_cpunum();
if (WARN_ON(cpunum >= NR_CPUS))
return;
/* The present CPUs are initially just the boot cpu (CPU 0). */
for (id = 0; id < NR_CPUS; id++) {
set_cpu_possible(id, id == 0);
set_cpu_present(id, id == 0);
}
__cpu_number_map[cpunum] = 0;
__cpu_logical_map[0] = cpunum;
for (id = 0; id < numcpus; id++) {
set_cpu_possible(id, true);
set_cpu_present(id, true);
__cpu_number_map[id] = id;
__cpu_logical_map[id] = id;
}
}
void irq_mbox_ipi(int cpu, unsigned int actions);
static void paravirt_send_ipi_single(int cpu, unsigned int action)
{
irq_mbox_ipi(cpu, action);
}
static void paravirt_send_ipi_mask(const struct cpumask *mask, unsigned int action)
{
unsigned int cpu;
for_each_cpu(cpu, mask)
paravirt_send_ipi_single(cpu, action);
}
static void paravirt_init_secondary(void)
{
unsigned int sr;
sr = set_c0_status(ST0_BEV);
write_c0_ebase((u32)ebase);
sr |= STATUSF_IP2; /* Interrupt controller on IP2 */
write_c0_status(sr);
irq_cpu_online();
}
static void paravirt_smp_finish(void)
{
/* to generate the first CPU timer interrupt */
write_c0_compare(read_c0_count() + mips_hpt_frequency / HZ);
local_irq_enable();
}
static void paravirt_boot_secondary(int cpu, struct task_struct *idle)
{
paravirt_smp_gp[cpu] = (unsigned long)task_thread_info(idle);
smp_wmb();
paravirt_smp_sp[cpu] = __KSTK_TOS(idle);
}
static irqreturn_t paravirt_reched_interrupt(int irq, void *dev_id)
{
scheduler_ipi();
return IRQ_HANDLED;
}
static irqreturn_t paravirt_function_interrupt(int irq, void *dev_id)
{
generic_smp_call_function_interrupt();
return IRQ_HANDLED;
}
static void paravirt_prepare_cpus(unsigned int max_cpus)
{
if (request_irq(MIPS_IRQ_MBOX0, paravirt_reched_interrupt,
IRQF_PERCPU | IRQF_NO_THREAD, "Scheduler",
paravirt_reched_interrupt)) {
panic("Cannot request_irq for SchedulerIPI");
}
if (request_irq(MIPS_IRQ_MBOX1, paravirt_function_interrupt,
IRQF_PERCPU | IRQF_NO_THREAD, "SMP-Call",
paravirt_function_interrupt)) {
panic("Cannot request_irq for SMP-Call");
}
}
struct plat_smp_ops paravirt_smp_ops = {
.send_ipi_single = paravirt_send_ipi_single,
.send_ipi_mask = paravirt_send_ipi_mask,
.init_secondary = paravirt_init_secondary,
.smp_finish = paravirt_smp_finish,
.boot_secondary = paravirt_boot_secondary,
.smp_setup = paravirt_smp_setup,
.prepare_cpus = paravirt_prepare_cpus,
};