xref: /linux/arch/powerpc/kernel/dbell.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
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 
21 #ifdef CONFIG_SMP
22 void doorbell_setup_this_cpu(void)
23 {
24 	unsigned long tag = mfspr(SPRN_PIR) & 0x3fff;
25 
26 	smp_muxed_ipi_set_data(smp_processor_id(), tag);
27 }
28 
29 void doorbell_cause_ipi(int cpu, unsigned long data)
30 {
31 	ppc_msgsnd(PPC_DBELL, 0, data);
32 }
33 
34 void doorbell_exception(struct pt_regs *regs)
35 {
36 	struct pt_regs *old_regs = set_irq_regs(regs);
37 
38 	irq_enter();
39 
40 	smp_ipi_demux();
41 
42 	irq_exit();
43 	set_irq_regs(old_regs);
44 }
45 #else /* CONFIG_SMP */
46 void doorbell_exception(struct pt_regs *regs)
47 {
48 	printk(KERN_WARNING "Received doorbell on non-smp system\n");
49 }
50 #endif /* CONFIG_SMP */
51 
52