2874c5fd28
Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
103 lines
2.3 KiB
C
103 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Author: Kumar Gala <galak@kernel.crashing.org>
|
|
*
|
|
* Copyright 2009 Freescale Semiconductor Inc.
|
|
*/
|
|
|
|
#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>
|
|
#include <asm/trace.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, 1);
|
|
/* 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, 1);
|
|
/* 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();
|
|
trace_doorbell_entry(regs);
|
|
|
|
ppc_msgsync();
|
|
|
|
may_hard_irq_enable();
|
|
|
|
kvmppc_set_host_ipi(smp_processor_id(), 0);
|
|
__this_cpu_inc(irq_stat.doorbell_irqs);
|
|
|
|
smp_ipi_demux_relaxed(); /* already performed the barrier */
|
|
|
|
trace_doorbell_exit(regs);
|
|
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 */
|
|
|