arch/powerpc/kernel/dbell.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Author: Kumar Gala <galak@kernel.crashing.org>
   4  *
   5  * Copyright 2009 Freescale Semiconductor Inc.
   6  */
   7
   8 #include <linux/stddef.h>
   9 #include <linux/kernel.h>
  10 #include <linux/smp.h>
  11 #include <linux/threads.h>
  12 #include <linux/hardirq.h>
  13
  14 #include <asm/dbell.h>
  15 #include <asm/interrupt.h>
  16 #include <asm/irq_regs.h>
  17 #include <asm/kvm_ppc.h>
  18 #include <asm/trace.h>
  19
  20 #ifdef CONFIG_SMP
  21
  22 DEFINE_INTERRUPT_HANDLER_ASYNC(doorbell_exception)
  23 {
  24         struct pt_regs *old_regs = set_irq_regs(regs);
  25
  26         irq_enter();
  27         trace_doorbell_entry(regs);
  28
  29         ppc_msgsync();
  30
  31         may_hard_irq_enable();
  32
  33         kvmppc_clear_host_ipi(smp_processor_id());
  34         __this_cpu_inc(irq_stat.doorbell_irqs);
  35
  36         smp_ipi_demux_relaxed(); /* already performed the barrier */
  37
  38         trace_doorbell_exit(regs);
  39         irq_exit();
  40         set_irq_regs(old_regs);
  41 }
  42 #else /* CONFIG_SMP */
  43 DEFINE_INTERRUPT_HANDLER_ASYNC(doorbell_exception)
  44 {
  45         printk(KERN_WARNING "Received doorbell on non-smp system\n");
  46 }
  47 #endif /* CONFIG_SMP */