xref: /openbmc/linux/arch/powerpc/kernel/dbell.c (revision 52beb1fc)
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 	trace_doorbell_entry(regs);
27 
28 	ppc_msgsync();
29 
30 	if (should_hard_irq_enable())
31 		do_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 
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 */
48