dbell.c

Go to the documentation of this file.

/*
 * Author: Kumar Gala <[email protected]>
 *
 * Copyright 2009 Freescale Semiconductor Inc.
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/threads.h>
#include <linux/hardirq.h>

#include <asm/dbell.h>
#include <asm/irq_regs.h>

#ifdef CONFIG_SMP
void doorbell_setup_this_cpu(void)
{
    unsigned long tag = mfspr(SPRN_PIR) & 0x3fff;

    smp_muxed_ipi_set_data(smp_processor_id(), tag);
}

void doorbell_cause_ipi(int cpu, unsigned long data)
{
    /* Order previous accesses vs. msgsnd, which is treated as a store */
    mb();
    ppc_msgsnd(PPC_DBELL, 0, data);
}

void doorbell_exception(struct pt_regs *regs)
{
    struct pt_regs *old_regs = set_irq_regs(regs);

    irq_enter();

    may_hard_irq_enable();

    smp_ipi_demux();

    irq_exit();
    set_irq_regs(old_regs);
}
#else /* CONFIG_SMP */
void doorbell_exception(struct pt_regs *regs)
{
    printk(KERN_WARNING "Received doorbell on non-smp system\n");
}
#endif /* CONFIG_SMP */