[POWERPC] Celleb: support interrupts

/*

 * Celleb/Beat Interrupt controller

 *

 * (C) Copyright 2006-2007 TOSHIBA CORPORATION

 *

 * 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.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, write to the Free Software Foundation, Inc.,

 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#include <linux/init.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/percpu.h>

#include <linux/types.h>

#include <asm/machdep.h>

#include "interrupt.h"

#include "beat_wrapper.h"

#define	MAX_IRQS	NR_IRQS

static DEFINE_SPINLOCK(beatic_irq_mask_lock);

static uint64_t	beatic_irq_mask_enable[(MAX_IRQS+255)/64];

static uint64_t	beatic_irq_mask_ack[(MAX_IRQS+255)/64];

static struct irq_host *beatic_host = NULL;

/*

 * In this implementation, "virq" == "IRQ plug number",

 * "(irq_hw_number_t)hwirq" == "IRQ outlet number".

 */

/* assumption: locked */

static inline void beatic_update_irq_mask(unsigned int irq_plug)

{

	int off;

	unsigned long masks[4];

	off = (irq_plug / 256) * 4;

	masks[0] = beatic_irq_mask_enable[off + 0]

	           & beatic_irq_mask_ack[off + 0];

	masks[1] = beatic_irq_mask_enable[off + 1]

	           & beatic_irq_mask_ack[off + 1];

	masks[2] = beatic_irq_mask_enable[off + 2]

	           & beatic_irq_mask_ack[off + 2];

	masks[3] = beatic_irq_mask_enable[off + 3]

	           & beatic_irq_mask_ack[off + 3];

	if (beat_set_interrupt_mask(irq_plug&~255UL,

		masks[0], masks[1], masks[2], masks[3]) != 0)

		panic("Failed to set mask IRQ!");

}

static void beatic_mask_irq(unsigned int irq_plug)

{

	unsigned long flags;

	spin_lock_irqsave(&beatic_irq_mask_lock, flags);

	beatic_irq_mask_enable[irq_plug/64] &= ~(1UL << (63 - (irq_plug%64)));

	beatic_update_irq_mask(irq_plug);

	spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);

}

static void beatic_unmask_irq(unsigned int irq_plug)

{

	unsigned long flags;

	spin_lock_irqsave(&beatic_irq_mask_lock, flags);

	beatic_irq_mask_enable[irq_plug/64] |= 1UL << (63 - (irq_plug%64));

	beatic_update_irq_mask(irq_plug);

	spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);

}

static void beatic_ack_irq(unsigned int irq_plug)

{

	unsigned long flags;

	spin_lock_irqsave(&beatic_irq_mask_lock, flags);

	beatic_irq_mask_ack[irq_plug/64] &= ~(1UL << (63 - (irq_plug%64)));

	beatic_update_irq_mask(irq_plug);

	spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);

}

static void beatic_end_irq(unsigned int irq_plug)

{

	s64 err;

	unsigned long flags;

	if ((err = beat_downcount_of_interrupt(irq_plug)) != 0) {

		if ((err & 0xFFFFFFFF) != 0xFFFFFFF5) /* -11: wrong state */

			panic("Failed to downcount IRQ! Error = %16lx", err);

		printk(KERN_ERR "IRQ over-downcounted, plug %d\n", irq_plug);

	}

	spin_lock_irqsave(&beatic_irq_mask_lock, flags);

	beatic_irq_mask_ack[irq_plug/64] |= 1UL << (63 - (irq_plug%64));

	beatic_update_irq_mask(irq_plug);

	spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);

}

static struct irq_chip beatic_pic = {

	.typename = " CELL-BEAT ",

	.unmask = beatic_unmask_irq,

	.mask = beatic_mask_irq,

	.eoi = beatic_end_irq,

};

/*

 * Dispose binding hardware IRQ number (hw) and Virtuql IRQ number (virq),

 * update flags.

 *

 * Note that the number (virq) is already assigned at upper layer.

 */

static void beatic_pic_host_unmap(struct irq_host *h, unsigned int virq)

{

	beat_destruct_irq_plug(virq);

}

/*

 * Create or update binding hardware IRQ number (hw) and Virtuql

 * IRQ number (virq). This is called only once for a given mapping.

 *

 * Note that the number (virq) is already assigned at upper layer.

 */

static int beatic_pic_host_map(struct irq_host *h, unsigned int virq,

			       irq_hw_number_t hw)

{

	struct irq_desc *desc = get_irq_desc(virq);

	int64_t	err;

	if ((err = beat_construct_and_connect_irq_plug(virq, hw)) < 0)

		return -EIO;

	desc->status |= IRQ_LEVEL;

	set_irq_chip_and_handler(virq, &beatic_pic, handle_fasteoi_irq);

	return 0;

}

/*

 * Update binding hardware IRQ number (hw) and Virtuql

 * IRQ number (virq). This is called only once for a given mapping.

 */

static void beatic_pic_host_remap(struct irq_host *h, unsigned int virq,

			       irq_hw_number_t hw)

{

	beat_construct_and_connect_irq_plug(virq, hw);

}

/*

 * Translate device-tree interrupt spec to irq_hw_number_t style (ulong),

 * to pass away to irq_create_mapping().

 *

 * Called from irq_create_of_mapping() only.

 * Note: We have only 1 entry to translate.

 */

static int beatic_pic_host_xlate(struct irq_host *h, struct device_node *ct,

				 u32 *intspec, unsigned int intsize,

				 irq_hw_number_t *out_hwirq,

				 unsigned int *out_flags)

{

	u64 *intspec2 = (u64 *)intspec;

	*out_hwirq = *intspec2;

	*out_flags |= IRQ_TYPE_LEVEL_LOW;

	return 0;

}

static struct irq_host_ops beatic_pic_host_ops = {

	.map = beatic_pic_host_map,

	.remap = beatic_pic_host_remap,

	.unmap = beatic_pic_host_unmap,

	.xlate = beatic_pic_host_xlate,

};

/*

 * Get an IRQ number

 * Note: returns VIRQ

 */

static inline unsigned int beatic_get_irq_plug(void)

{

	int i;

	uint64_t	pending[4], ub;

	for (i = 0; i < MAX_IRQS; i += 256) {

		beat_detect_pending_interrupts(i, pending);

		__asm__ ("cntlzd %0,%1":"=r"(ub):

			"r"(pending[0] & beatic_irq_mask_enable[i/64+0]

			               & beatic_irq_mask_ack[i/64+0]));

		if (ub != 64)

			return i + ub + 0;

		__asm__ ("cntlzd %0,%1":"=r"(ub):

			"r"(pending[1] & beatic_irq_mask_enable[i/64+1]

			               & beatic_irq_mask_ack[i/64+1]));

		if (ub != 64)

			return i + ub + 64;

		__asm__ ("cntlzd %0,%1":"=r"(ub):

			"r"(pending[2] & beatic_irq_mask_enable[i/64+2]

			               & beatic_irq_mask_ack[i/64+2]));

		if (ub != 64)

			return i + ub + 128;

		__asm__ ("cntlzd %0,%1":"=r"(ub):

			"r"(pending[3] & beatic_irq_mask_enable[i/64+3]

			               & beatic_irq_mask_ack[i/64+3]));

		if (ub != 64)

			return i + ub + 192;

	}

	return NO_IRQ;

}

unsigned int beatic_get_irq(void)

{

	unsigned int ret;

	ret = beatic_get_irq_plug();

	if (ret != NO_IRQ)

		beatic_ack_irq(ret);

	return ret;

}

/*

 */

void __init beatic_init_IRQ(void)

{

	int	i;

	memset(beatic_irq_mask_enable, 0, sizeof(beatic_irq_mask_enable));

	memset(beatic_irq_mask_ack, 255, sizeof(beatic_irq_mask_ack));

	for (i = 0; i < MAX_IRQS; i += 256)

		beat_set_interrupt_mask(i, 0L, 0L, 0L, 0L);

	/* Set out get_irq function */

	ppc_md.get_irq = beatic_get_irq;

	/* Allocate an irq host */

	beatic_host = irq_alloc_host(IRQ_HOST_MAP_NOMAP, 0,

					 &beatic_pic_host_ops,

					 0);

	BUG_ON(beatic_host == NULL);

	irq_set_default_host(beatic_host);

}

#ifdef CONFIG_SMP

/* Nullified to compile with SMP mode */

void beatic_setup_cpu(int cpu)

{

}

void beatic_cause_IPI(int cpu, int mesg)

{

}

void beatic_request_IPIs(void)

{

}

#endif /* CONFIG_SMP */

void beatic_deinit_IRQ(void)

{

	int	i;

	for (i = 1; i < NR_IRQS; i++)

		beat_destruct_irq_plug(i);

}

/*

 * Celleb/Beat Interrupt controller

 *

 * (C) Copyright 2006 TOSHIBA CORPORATION

 *

 * 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.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, write to the Free Software Foundation, Inc.,

 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#ifndef ASM_BEAT_PIC_H

#define ASM_BEAT_PIC_H

#ifdef __KERNEL__

extern void beatic_init_IRQ(void);

extern unsigned int beatic_get_irq(void);

extern void beatic_cause_IPI(int cpu, int mesg);

extern void beatic_request_IPIs(void);

extern void beatic_setup_cpu(int);

extern void beatic_deinit_IRQ(void);

#endif

#endif /* ASM_BEAT_PIC_H */