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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
21void 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 */
42void doorbell_exception(struct pt_regs *regs)
43{
44	printk(KERN_WARNING "Received doorbell on non-smp system\n");
45}
46#endif /* CONFIG_SMP */
47

 
  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
 23
 24/*
 25 * Doorbells must only be used if CPU_FTR_DBELL is available.
 26 * msgsnd is used in HV, and msgsndp is used in !HV.
 27 *
 28 * These should be used by platform code that is aware of restrictions.
 29 * Other arch code should use ->cause_ipi.
 30 *
 31 * doorbell_global_ipi() sends a dbell to any target CPU.
 32 * Must be used only by architectures that address msgsnd target
 33 * by PIR/get_hard_smp_processor_id.
 34 */
 35void doorbell_global_ipi(int cpu)
 36{
 37	u32 tag = get_hard_smp_processor_id(cpu);
 38
 39	kvmppc_set_host_ipi(cpu, 1);
 40	/* Order previous accesses vs. msgsnd, which is treated as a store */
 41	ppc_msgsnd_sync();
 42	ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag);
 43}
 44
 45/*
 46 * doorbell_core_ipi() sends a dbell to a target CPU in the same core.
 47 * Must be used only by architectures that address msgsnd target
 48 * by TIR/cpu_thread_in_core.
 49 */
 50void doorbell_core_ipi(int cpu)
 51{
 52	u32 tag = cpu_thread_in_core(cpu);
 53
 54	kvmppc_set_host_ipi(cpu, 1);
 55	/* Order previous accesses vs. msgsnd, which is treated as a store */
 56	ppc_msgsnd_sync();
 57	ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag);
 58}
 59
 60/*
 61 * Attempt to cause a core doorbell if destination is on the same core.
 62 * Returns 1 on success, 0 on failure.
 63 */
 64int doorbell_try_core_ipi(int cpu)
 65{
 66	int this_cpu = get_cpu();
 67	int ret = 0;
 68
 69	if (cpumask_test_cpu(cpu, cpu_sibling_mask(this_cpu))) {
 70		doorbell_core_ipi(cpu);
 71		ret = 1;
 72	}
 73
 74	put_cpu();
 75
 76	return ret;
 77}
 78
 79void doorbell_exception(struct pt_regs *regs)
 80{
 81	struct pt_regs *old_regs = set_irq_regs(regs);
 82
 83	irq_enter();
 
 84
 85	ppc_msgsync();
 86
 87	may_hard_irq_enable();
 88
 89	kvmppc_set_host_ipi(smp_processor_id(), 0);
 90	__this_cpu_inc(irq_stat.doorbell_irqs);
 91
 92	smp_ipi_demux_relaxed(); /* already performed the barrier */
 93
 
 94	irq_exit();
 95	set_irq_regs(old_regs);
 96}
 97#else /* CONFIG_SMP */
 98void doorbell_exception(struct pt_regs *regs)
 99{
100	printk(KERN_WARNING "Received doorbell on non-smp system\n");
101}
102#endif /* CONFIG_SMP */
103