[GitHub/mt8127/android_kernel_alcatel_ttab.git] / 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/percpu.h>

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

#ifdef CONFIG_SMP
struct doorbell_cpu_info {
	unsigned long	messages;	/* current messages bits */
	unsigned int	tag;		/* tag value */
};

static DEFINE_PER_CPU(struct doorbell_cpu_info, doorbell_cpu_info);

void doorbell_setup_this_cpu(void)
{
	struct doorbell_cpu_info *info = &__get_cpu_var(doorbell_cpu_info);

	info->messages = 0;
	info->tag = mfspr(SPRN_PIR) & 0x3fff;
}

void doorbell_message_pass(int target, int msg)
{
	struct doorbell_cpu_info *info;
	int i;

	if (target < NR_CPUS) {
		info = &per_cpu(doorbell_cpu_info, target);
		set_bit(msg, &info->messages);
		ppc_msgsnd(PPC_DBELL, 0, info->tag);
	}
	else if (target == MSG_ALL_BUT_SELF) {
		for_each_online_cpu(i) {
			if (i == smp_processor_id())
				continue;
			info = &per_cpu(doorbell_cpu_info, i);
			set_bit(msg, &info->messages);
			ppc_msgsnd(PPC_DBELL, 0, info->tag);
		}
	}
	else { /* target == MSG_ALL */
		for_each_online_cpu(i) {
			info = &per_cpu(doorbell_cpu_info, i);
			set_bit(msg, &info->messages);
		}
		ppc_msgsnd(PPC_DBELL, PPC_DBELL_MSG_BRDCAST, 0);
	}
}

void doorbell_exception(struct pt_regs *regs)
{
	struct pt_regs *old_regs = set_irq_regs(regs);
	struct doorbell_cpu_info *info = &__get_cpu_var(doorbell_cpu_info);
	int msg;

	/* Warning: regs can be NULL when called from irq enable */

	if (!info->messages || (num_online_cpus() < 2))
		goto out;

	for (msg = 0; msg < 4; msg++)
		if (test_and_clear_bit(msg, &info->messages))
			smp_message_recv(msg);

out:
	set_irq_regs(old_regs);
}

void doorbell_check_self(void)
{
	struct doorbell_cpu_info *info = &__get_cpu_var(doorbell_cpu_info);

	if (!info->messages)
		return;

	ppc_msgsnd(PPC_DBELL, 0, info->tag);
}

#else /* CONFIG_SMP */
void doorbell_exception(struct pt_regs *regs)
{
	printk(KERN_WARNING "Received doorbell on non-smp system\n");
}
#endif /* CONFIG_SMP */
Commit	Line	Data
620165f9 KG	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>
b9f1cd71	16	#include <linux/percpu.h>
620165f9 KG	17
620165f9 KG	18	#include <asm/dbell.h>
0e37d259	19	#include <asm/irq_regs.h>
620165f9 KG	20
620165f9 KG	21	#ifdef CONFIG_SMP
b9f1cd71 BH	22	struct doorbell_cpu_info {
	23	unsigned long messages; /* current messages bits */
	24	unsigned int tag; /* tag value */
	25	};
620165f9	26
b9f1cd71 BH	27	static DEFINE_PER_CPU(struct doorbell_cpu_info, doorbell_cpu_info);
	28
	29	void doorbell_setup_this_cpu(void)
	30	{
	31	struct doorbell_cpu_info *info = &__get_cpu_var(doorbell_cpu_info);
	32
	33	info->messages = 0;
	34	info->tag = mfspr(SPRN_PIR) & 0x3fff;
	35	}
	36
	37	void doorbell_message_pass(int target, int msg)
620165f9	38	{
b9f1cd71	39	struct doorbell_cpu_info *info;
620165f9 KG	40	int i;
620165f9 KG	41
b9f1cd71 BH	42	if (target < NR_CPUS) {
	43	info = &per_cpu(doorbell_cpu_info, target);
	44	set_bit(msg, &info->messages);
	45	ppc_msgsnd(PPC_DBELL, 0, info->tag);
620165f9	46	}
b9f1cd71	47	else if (target == MSG_ALL_BUT_SELF) {
620165f9 KG	48	for_each_online_cpu(i) {
	49	if (i == smp_processor_id())
	50	continue;
b9f1cd71 BH	51	info = &per_cpu(doorbell_cpu_info, i);
	52	set_bit(msg, &info->messages);
	53	ppc_msgsnd(PPC_DBELL, 0, info->tag);
620165f9 KG	54	}
	55	}
	56	else { /* target == MSG_ALL */
b9f1cd71 BH	57	for_each_online_cpu(i) {
	58	info = &per_cpu(doorbell_cpu_info, i);
	59	set_bit(msg, &info->messages);
	60	}
620165f9 KG	61	ppc_msgsnd(PPC_DBELL, PPC_DBELL_MSG_BRDCAST, 0);
	62	}
	63	}
e3145b38 BH	64
	65	void doorbell_exception(struct pt_regs *regs)
	66	{
0e37d259	67	struct pt_regs *old_regs = set_irq_regs(regs);
b9f1cd71	68	struct doorbell_cpu_info *info = &__get_cpu_var(doorbell_cpu_info);
e3145b38 BH	69	int msg;
e3145b38 BH	70
b9f1cd71 BH	71	/* Warning: regs can be NULL when called from irq enable */
	72
	73	if (!info->messages \|\| (num_online_cpus() < 2))
0e37d259	74	goto out;
e3145b38 BH	75
e3145b38 BH	76	for (msg = 0; msg < 4; msg++)
b9f1cd71	77	if (test_and_clear_bit(msg, &info->messages))
e3145b38	78	smp_message_recv(msg);
0e37d259 DG	79
	80	out:
	81	set_irq_regs(old_regs);
e3145b38 BH	82	}
e3145b38 BH	83
850f22d5 ME	84	void doorbell_check_self(void)
	85	{
	86	struct doorbell_cpu_info *info = &__get_cpu_var(doorbell_cpu_info);
	87
	88	if (!info->messages)
	89	return;
	90
	91	ppc_msgsnd(PPC_DBELL, 0, info->tag);
	92	}
	93
e3145b38 BH	94	#else /* CONFIG_SMP */
	95	void doorbell_exception(struct pt_regs *regs)
	96	{
	97	printk(KERN_WARNING "Received doorbell on non-smp system\n");
	98	}
	99	#endif /* CONFIG_SMP */
	100