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/irq_regs.h>
16 #include <asm/kvm_ppc.h>
17 #include <asm/trace.h>
18 
19 #ifdef CONFIG_SMP
20 
doorbell_exception(struct pt_regs * regs)21 void doorbell_exception(struct pt_regs *regs)
22 {
23 	struct pt_regs *old_regs = set_irq_regs(regs);
24 
25 	irq_enter();
26 	trace_doorbell_entry(regs);
27 
28 	ppc_msgsync();
29 
30 	may_hard_irq_enable();
31 
32 	kvmppc_clear_host_ipi(smp_processor_id());
33 	__this_cpu_inc(irq_stat.doorbell_irqs);
34 
35 	smp_ipi_demux_relaxed(); /* already performed the barrier */
36 
37 	trace_doorbell_exit(regs);
38 	irq_exit();
39 	set_irq_regs(old_regs);
40 }
41 #else /* CONFIG_SMP */
doorbell_exception(struct pt_regs * regs)42 void doorbell_exception(struct pt_regs *regs)
43 {
44 	printk(KERN_WARNING "Received doorbell on non-smp system\n");
45 }
46 #endif /* CONFIG_SMP */
47 
48