Release 4.14 arch/powerpc/kernel/dbell.c

/*
 * Author: Kumar Gala <galak@kernel.crashing.org>
 *
 * Copyright 2009 Freescale Semiconductor Inc.
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/threads.h>
#include <linux/hardirq.h>

#include <asm/dbell.h>
#include <asm/irq_regs.h>
#include <asm/kvm_ppc.h>

#ifdef CONFIG_SMP

/*
 * Doorbells must only be used if CPU_FTR_DBELL is available.
 * msgsnd is used in HV, and msgsndp is used in !HV.
 *
 * These should be used by platform code that is aware of restrictions.
 * Other arch code should use ->cause_ipi.
 *
 * doorbell_global_ipi() sends a dbell to any target CPU.
 * Must be used only by architectures that address msgsnd target
 * by PIR/get_hard_smp_processor_id.
 */


void doorbell_global_ipi(int cpu)
{
	u32 tag = get_hard_smp_processor_id(cpu);

	kvmppc_set_host_ipi(cpu, 1);
	/* Order previous accesses vs. msgsnd, which is treated as a store */
	ppc_msgsnd_sync();
	ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Nicholas Piggin
20
55.56%
2
50.00%
Benjamin Herrenschmidt
9
25.00%
1
25.00%
Milton D. Miller II
7
19.44%
1
25.00%
Total
36
100.00%
4
100.00%

/*
 * doorbell_core_ipi() sends a dbell to a target CPU in the same core.
 * Must be used only by architectures that address msgsnd target
 * by TIR/cpu_thread_in_core.
 */


void doorbell_core_ipi(int cpu)
{
	u32 tag = cpu_thread_in_core(cpu);

	kvmppc_set_host_ipi(cpu, 1);
	/* Order previous accesses vs. msgsnd, which is treated as a store */
	ppc_msgsnd_sync();
	ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Nicholas Piggin
21
58.33%
2
33.33%
Kumar Gala
10
27.78%
1
16.67%
Paul Mackerras
3
8.33%
1
16.67%
Milton D. Miller II
1
2.78%
1
16.67%
Ian Munsie
1
2.78%
1
16.67%
Total
36
100.00%
6
100.00%

/*
 * Attempt to cause a core doorbell if destination is on the same core.
 * Returns 1 on success, 0 on failure.
 */


int doorbell_try_core_ipi(int cpu)
{
	int this_cpu = get_cpu();
	int ret = 0;

	if (cpumask_test_cpu(cpu, cpu_sibling_mask(this_cpu))) {
		doorbell_core_ipi(cpu);
		ret = 1;
	}

	put_cpu();

	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Nicholas Piggin
45
93.75%
1
50.00%
Kumar Gala
3
6.25%
1
50.00%
Total
48
100.00%
2
100.00%



void doorbell_exception(struct pt_regs *regs)
{
	struct pt_regs *old_regs = set_irq_regs(regs);

	irq_enter();

	ppc_msgsync();

	may_hard_irq_enable();

	kvmppc_set_host_ipi(smp_processor_id(), 0);
	__this_cpu_inc(irq_stat.doorbell_irqs);

	smp_ipi_demux_relaxed(); /* already performed the barrier */

	irq_exit();
	set_irq_regs(old_regs);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Benjamin Herrenschmidt
16
28.57%
3
33.33%
David Gibson
14
25.00%
1
11.11%
Paul Mackerras
8
14.29%
1
11.11%
Milton D. Miller II
6
10.71%
1
11.11%
Nicholas Piggin
5
8.93%
1
11.11%
Ian Munsie
5
8.93%
1
11.11%
Christoph Lameter
2
3.57%
1
11.11%
Total
56
100.00%
9
100.00%

#else /* CONFIG_SMP */


void doorbell_exception(struct pt_regs *regs)
{
	printk(KERN_WARNING "Received doorbell on non-smp system\n");
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Benjamin Herrenschmidt
16
100.00%
1
100.00%
Total
16
100.00%
1
100.00%

#endif /* CONFIG_SMP */

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Nicholas Piggin
94
41.05%
2
14.29%
Benjamin Herrenschmidt
47
20.52%
3
21.43%
Kumar Gala
34
14.85%
1
7.14%
David Gibson
17
7.42%
1
7.14%
Milton D. Miller II
15
6.55%
2
14.29%
Paul Mackerras
14
6.11%
2
14.29%
Ian Munsie
6
2.62%
2
14.29%
Christoph Lameter
2
0.87%
1
7.14%
Total
229
100.00%
14
100.00%
Directory: arch/powerpc/kernel

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.