/*
|
* Author: Kumar Gala <galak@kernel.crashing.org>
|
*
|
* 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>
|
#include <asm/kvm_ppc.h>
|
|
#ifdef CONFIG_SMP
|
|
/*
|
* Doorbells must only be used if CPU_FTR_DBELL is available.
|
* msgsnd is used in HV, and msgsndp is used in !HV.
|
*
|
* These should be used by platform code that is aware of restrictions.
|
* Other arch code should use ->cause_ipi.
|
*
|
* doorbell_global_ipi() sends a dbell to any target CPU.
|
* Must be used only by architectures that address msgsnd target
|
* by PIR/get_hard_smp_processor_id.
|
*/
|
void doorbell_global_ipi(int cpu)
|
{
|
u32 tag = get_hard_smp_processor_id(cpu);
|
|
kvmppc_set_host_ipi(cpu);
|
/* Order previous accesses vs. msgsnd, which is treated as a store */
|
ppc_msgsnd_sync();
|
ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag);
|
}
|
|
/*
|
* doorbell_core_ipi() sends a dbell to a target CPU in the same core.
|
* Must be used only by architectures that address msgsnd target
|
* by TIR/cpu_thread_in_core.
|
*/
|
void doorbell_core_ipi(int cpu)
|
{
|
u32 tag = cpu_thread_in_core(cpu);
|
|
kvmppc_set_host_ipi(cpu);
|
/* Order previous accesses vs. msgsnd, which is treated as a store */
|
ppc_msgsnd_sync();
|
ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag);
|
}
|
|
/*
|
* Attempt to cause a core doorbell if destination is on the same core.
|
* Returns 1 on success, 0 on failure.
|
*/
|
int doorbell_try_core_ipi(int cpu)
|
{
|
int this_cpu = get_cpu();
|
int ret = 0;
|
|
if (cpumask_test_cpu(cpu, cpu_sibling_mask(this_cpu))) {
|
doorbell_core_ipi(cpu);
|
ret = 1;
|
}
|
|
put_cpu();
|
|
return ret;
|
}
|
|
void doorbell_exception(struct pt_regs *regs)
|
{
|
struct pt_regs *old_regs = set_irq_regs(regs);
|
|
irq_enter();
|
|
ppc_msgsync();
|
|
may_hard_irq_enable();
|
|
kvmppc_clear_host_ipi(smp_processor_id());
|
__this_cpu_inc(irq_stat.doorbell_irqs);
|
|
smp_ipi_demux_relaxed(); /* already performed the barrier */
|
|
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 */
|
