1/*
2 * Author: Kumar Gala <galak@kernel.crashing.org>
3 *
4 * Copyright 2009 Freescale Semiconductor Inc.
5 *
6 * This program is free software; you can redistribute  it and/or modify it
7 * under  the terms of  the GNU General  Public License as published by the
8 * Free Software Foundation;  either version 2 of the  License, or (at your
9 * option) any later version.
10 */
11
12#include <linux/stddef.h>
13#include <linux/kernel.h>
14#include <linux/smp.h>
15#include <linux/threads.h>
16#include <linux/hardirq.h>
17
18#include <asm/dbell.h>
19#include <asm/irq_regs.h>
20#include <asm/kvm_ppc.h>
21
22#ifdef CONFIG_SMP
23void doorbell_setup_this_cpu(void)
24{
25	unsigned long tag = mfspr(SPRN_DOORBELL_CPUTAG) & PPC_DBELL_TAG_MASK;
26
27	smp_muxed_ipi_set_data(smp_processor_id(), tag);
28}
29
30void doorbell_cause_ipi(int cpu, unsigned long data)
31{
32	/* Order previous accesses vs. msgsnd, which is treated as a store */
33	mb();
34	ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, data);
35}
36
37void doorbell_exception(struct pt_regs *regs)
38{
39	struct pt_regs *old_regs = set_irq_regs(regs);
40
41	irq_enter();
42
43	may_hard_irq_enable();
44
45	kvmppc_set_host_ipi(smp_processor_id(), 0);
46	__this_cpu_inc(irq_stat.doorbell_irqs);
47
48	smp_ipi_demux();
49
50	irq_exit();
51	set_irq_regs(old_regs);
52}
53#else /* CONFIG_SMP */
54void doorbell_exception(struct pt_regs *regs)
55{
56	printk(KERN_WARNING "Received doorbell on non-smp system\n");
57}
58#endif /* CONFIG_SMP */
59
60