/*
 *  PS3 interrupt routines.
 *
 *  Copyright (C) 2006 Sony Computer Entertainment Inc.
 *  Copyright 2006 Sony Corp.
 *
 *  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; version 2 of the License.
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/irq.h>

#include <asm/machdep.h>
#include <asm/udbg.h>
#include <asm/lv1call.h>

#include "platform.h"

#if defined(DEBUG)
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...) do{if(0)printk(fmt);}while(0)
#endif

/**
 * struct ps3_bmp - a per cpu irq status and mask bitmap structure
 * @status: 256 bit status bitmap indexed by plug
 * @unused_1:
 * @mask: 256 bit mask bitmap indexed by plug
 * @unused_2:
 * @lock:
 * @ipi_debug_brk_mask:
 *
 * The HV mantains per SMT thread mappings of HV outlet to HV plug on
 * behalf of the guest.  These mappings are implemented as 256 bit guest
 * supplied bitmaps indexed by plug number.  The addresses of the bitmaps
 * are registered with the HV through lv1_configure_irq_state_bitmap().
 * The HV requires that the 512 bits of status + mask not cross a page
 * boundary.  PS3_BMP_MINALIGN is used to define this minimal 64 byte
 * alignment.
 *
 * The HV supports 256 plugs per thread, assigned as {0..255}, for a total
 * of 512 plugs supported on a processor.  To simplify the logic this
 * implementation equates HV plug value to Linux virq value, constrains each
 * interrupt to have a system wide unique plug number, and limits the range
 * of the plug values to map into the first dword of the bitmaps.  This
 * gives a usable range of plug values of  {NUM_ISA_INTERRUPTS..63}.  Note
 * that there is no constraint on how many in this set an individual thread
 * can acquire.
 */

#define PS3_BMP_MINALIGN 64

struct ps3_bmp {
	struct {
		u64 status;
		u64 unused_1[3];
		u64 mask;
		u64 unused_2[3];
	};
	u64 ipi_debug_brk_mask;
	spinlock_t lock;
};

/**
 * struct ps3_private - a per cpu data structure
 * @bmp: ps3_bmp structure
 * @node: HV logical_ppe_id
 * @cpu: HV thread_id
 */

struct ps3_private {
	struct ps3_bmp bmp __attribute__ ((aligned (PS3_BMP_MINALIGN)));
	u64 node;
	unsigned int cpu;
};

static DEFINE_PER_CPU(struct ps3_private, ps3_private);

int ps3_alloc_irq(enum ps3_cpu_binding cpu, unsigned long outlet,
	unsigned int *virq)
{
	int result;
	struct ps3_private *pd;

	/* This defines the default interrupt distribution policy. */

	if (cpu == PS3_BINDING_CPU_ANY)
		cpu = 0;

	pd = &per_cpu(ps3_private, cpu);

	*virq = irq_create_mapping(NULL, outlet);

	if (*virq == NO_IRQ) {
		pr_debug("%s:%d: irq_create_mapping failed: outlet %lu\n",
			__func__, __LINE__, outlet);
		result = -ENOMEM;
		goto fail_create;
	}

	/* Binds outlet to cpu + virq. */

	result = lv1_connect_irq_plug_ext(pd->node, pd->cpu, *virq, outlet, 0);

	if (result) {
		pr_info("%s:%d: lv1_connect_irq_plug_ext failed: %s\n",
		__func__, __LINE__, ps3_result(result));
		result = -EPERM;
		goto fail_connect;
	}

	pr_debug("%s:%d: outlet %lu => cpu %u, virq %u\n", __func__, __LINE__,
		outlet, cpu, *virq);

	result = set_irq_chip_data(*virq, pd);

	if (result) {
		pr_debug("%s:%d: set_irq_chip_data failed\n",
			__func__, __LINE__);
		goto fail_set;
	}

	return result;

fail_set:
	lv1_disconnect_irq_plug_ext(pd->node, pd->cpu, *virq);
fail_connect:
	irq_dispose_mapping(*virq);
fail_create:
	return result;
}
EXPORT_SYMBOL_GPL(ps3_alloc_irq);

int ps3_free_irq(unsigned int virq)
{
	int result;
	const struct ps3_private *pd = get_irq_chip_data(virq);

	pr_debug("%s:%d: node %lu, cpu %d, virq %u\n", __func__, __LINE__,
		pd->node, pd->cpu, virq);

	result = lv1_disconnect_irq_plug_ext(pd->node, pd->cpu, virq);

	if (result)
		pr_info("%s:%d: lv1_disconnect_irq_plug_ext failed: %s\n",
		__func__, __LINE__, ps3_result(result));

	set_irq_chip_data(virq, NULL);
	irq_dispose_mapping(virq);
	return result;
}
EXPORT_SYMBOL_GPL(ps3_free_irq);

/**
 * ps3_alloc_io_irq - Assign a virq to a system bus device.
 * @cpu: enum ps3_cpu_binding indicating the cpu the interrupt should be
 * serviced on.
 * @interrupt_id: The device interrupt id read from the system repository.
 * @virq: The assigned Linux virq.
 *
 * An io irq represents a non-virtualized device interrupt.  interrupt_id
 * coresponds to the interrupt number of the interrupt controller.
 */

int ps3_alloc_io_irq(enum ps3_cpu_binding cpu, unsigned int interrupt_id,
	unsigned int *virq)
{
	int result;
	unsigned long outlet;

	result = lv1_construct_io_irq_outlet(interrupt_id, &outlet);

	if (result) {
		pr_debug("%s:%d: lv1_construct_io_irq_outlet failed: %s\n",
			__func__, __LINE__, ps3_result(result));
		return result;
	}

	result = ps3_alloc_irq(cpu, outlet, virq);
	BUG_ON(result);

	return result;
}
EXPORT_SYMBOL_GPL(ps3_alloc_io_irq);

int ps3_free_io_irq(unsigned int virq)
{
	int result;

	result = lv1_destruct_io_irq_outlet(virq_to_hw(virq));

	if (result)
		pr_debug("%s:%d: lv1_destruct_io_irq_outlet failed: %s\n",
			__func__, __LINE__, ps3_result(result));

	ps3_free_irq(virq);

	return result;
}
EXPORT_SYMBOL_GPL(ps3_free_io_irq);

/**
 * ps3_alloc_event_irq - Allocate a virq for use with a system event.
 * @cpu: enum ps3_cpu_binding indicating the cpu the interrupt should be
 * serviced on.
 * @virq: The assigned Linux virq.
 *
 * The virq can be used with lv1_connect_interrupt_event_receive_port() to
 * arrange to receive events, or with ps3_send_event_locally() to signal
 * events.
 */

int ps3_alloc_event_irq(enum ps3_cpu_binding cpu, unsigned int *virq)
{
	int result;
	unsigned long outlet;

	result = lv1_construct_event_receive_port(&outlet);

	if (result) {
		pr_debug("%s:%d: lv1_construct_event_receive_port failed: %s\n",
			__func__, __LINE__, ps3_result(result));
		*virq = NO_IRQ;
		return result;
	}

	result = ps3_alloc_irq(cpu, outlet, virq);
	BUG_ON(result);

	return result;
}

int ps3_free_event_irq(unsigned int virq)
{
	int result;

	pr_debug(" -> %s:%d\n", __func__, __LINE__);

	result = lv1_destruct_event_receive_port(virq_to_hw(virq));

	if (result)
		pr_debug("%s:%d: lv1_destruct_event_receive_port failed: %s\n",
			__func__, __LINE__, ps3_result(result));

	ps3_free_irq(virq);

	pr_debug(" <- %s:%d\n", __func__, __LINE__);
	return result;
}

int ps3_send_event_locally(unsigned int virq)
{
	return lv1_send_event_locally(virq_to_hw(virq));
}

/**
 * ps3_connect_event_irq - Assign a virq to a system bus device.
 * @cpu: enum ps3_cpu_binding indicating the cpu the interrupt should be
 * serviced on.
 * @did: The HV device identifier read from the system repository.
 * @interrupt_id: The device interrupt id read from the system repository.
 * @virq: The assigned Linux virq.
 *
 * An event irq represents a virtual device interrupt.  The interrupt_id
 * coresponds to the software interrupt number.
 */

int ps3_connect_event_irq(enum ps3_cpu_binding cpu,
	const struct ps3_device_id *did, unsigned int interrupt_id,
	unsigned int *virq)
{
	int result;

	result = ps3_alloc_event_irq(cpu, virq);

	if (result)
		return result;

	result = lv1_connect_interrupt_event_receive_port(did->bus_id,
		did->dev_id, virq_to_hw(*virq), interrupt_id);

	if (result) {
		pr_debug("%s:%d: lv1_connect_interrupt_event_receive_port"
			" failed: %s\n", __func__, __LINE__,
			ps3_result(result));
		ps3_free_event_irq(*virq);
		*virq = NO_IRQ;
		return result;
	}

	pr_debug("%s:%d: interrupt_id %u, virq %u\n", __func__, __LINE__,
		interrupt_id, *virq);

	return 0;
}

int ps3_disconnect_event_irq(const struct ps3_device_id *did,
	unsigned int interrupt_id, unsigned int virq)
{
	int result;

	pr_debug(" -> %s:%d: interrupt_id %u, virq %u\n", __func__, __LINE__,
		interrupt_id, virq);

	result = lv1_disconnect_interrupt_event_receive_port(did->bus_id,
		did->dev_id, virq_to_hw(virq), interrupt_id);

	if (result)
		pr_debug("%s:%d: lv1_disconnect_interrupt_event_receive_port"
			" failed: %s\n", __func__, __LINE__,
			ps3_result(result));

	ps3_free_event_irq(virq);

	pr_debug(" <- %s:%d\n", __func__, __LINE__);
	return result;
}

/**
 * ps3_alloc_vuart_irq - Configure the system virtual uart virq.
 * @cpu: enum ps3_cpu_binding indicating the cpu the interrupt should be
 * serviced on.
 * @virt_addr_bmp: The caller supplied virtual uart interrupt bitmap.
 * @virq: The assigned Linux virq.
 *
 * The system supports only a single virtual uart, so multiple calls without
 * freeing the interrupt will return a wrong state error.
 */

int ps3_alloc_vuart_irq(enum ps3_cpu_binding cpu, void* virt_addr_bmp,
	unsigned int *virq)
{
	int result;
	unsigned long outlet;
	u64 lpar_addr;

	BUG_ON(!is_kernel_addr((u64)virt_addr_bmp));

	lpar_addr = ps3_mm_phys_to_lpar(__pa(virt_addr_bmp));

	result = lv1_configure_virtual_uart_irq(lpar_addr, &outlet);

	if (result) {
		pr_debug("%s:%d: lv1_configure_virtual_uart_irq failed: %s\n",
			__func__, __LINE__, ps3_result(result));
		return result;
	}

	result = ps3_alloc_irq(cpu, outlet, virq);
	BUG_ON(result);

	return result;
}

int ps3_free_vuart_irq(unsigned int virq)
{
	int result;

	result = lv1_deconfigure_virtual_uart_irq();

	if (result) {
		pr_debug("%s:%d: lv1_configure_virtual_uart_irq failed: %s\n",
			__func__, __LINE__, ps3_result(result));
		return result;
	}

	ps3_free_irq(virq);

	return result;
}

/**
 * ps3_alloc_spe_irq - Configure an spe virq.
 * @cpu: enum ps3_cpu_binding indicating the cpu the interrupt should be
 * serviced on.
 * @spe_id: The spe_id returned from lv1_construct_logical_spe().
 * @class: The spe interrupt class {0,1,2}.
 * @virq: The assigned Linux virq.
 *
 */

int ps3_alloc_spe_irq(enum ps3_cpu_binding cpu, unsigned long spe_id,
	unsigned int class, unsigned int *virq)
{
	int result;
	unsigned long outlet;

	BUG_ON(class > 2);

	result = lv1_get_spe_irq_outlet(spe_id, class, &outlet);

	if (result) {
		pr_debug("%s:%d: lv1_get_spe_irq_outlet failed: %s\n",
			__func__, __LINE__, ps3_result(result));
		return result;
	}

	result = ps3_alloc_irq(cpu, outlet, virq);
	BUG_ON(result);

	return result;
}

int ps3_free_spe_irq(unsigned int virq)
{
	ps3_free_irq(virq);
	return 0;
}


#define PS3_INVALID_OUTLET ((irq_hw_number_t)-1)
#define PS3_PLUG_MAX 63

#if defined(DEBUG)
static void _dump_64_bmp(const char *header, const u64 *p, unsigned cpu,
	const char* func, int line)
{
	pr_debug("%s:%d: %s %u {%04lx_%04lx_%04lx_%04lx}\n",
		func, line, header, cpu,
		*p >> 48, (*p >> 32) & 0xffff, (*p >> 16) & 0xffff,
		*p & 0xffff);
}

static void __attribute__ ((unused)) _dump_256_bmp(const char *header,
	const u64 *p, unsigned cpu, const char* func, int line)
{
	pr_debug("%s:%d: %s %u {%016lx:%016lx:%016lx:%016lx}\n",
		func, line, header, cpu, p[0], p[1], p[2], p[3]);
}

#define dump_bmp(_x) _dump_bmp(_x, __func__, __LINE__)
static void _dump_bmp(struct ps3_private* pd, const char* func, int line)
{
	unsigned long flags;

	spin_lock_irqsave(&pd->bmp.lock, flags);
	_dump_64_bmp("stat", &pd->bmp.status, pd->cpu, func, line);
	_dump_64_bmp("mask", &pd->bmp.mask, pd->cpu, func, line);
	spin_unlock_irqrestore(&pd->bmp.lock, flags);
}

#define dump_mask(_x) _dump_mask(_x, __func__, __LINE__)
static void __attribute__ ((unused)) _dump_mask(struct ps3_private* pd,
	const char* func, int line)
{
	unsigned long flags;

	spin_lock_irqsave(&pd->bmp.lock, flags);
	_dump_64_bmp("mask", &pd->bmp.mask, pd->cpu, func, line);
	spin_unlock_irqrestore(&pd->bmp.lock, flags);
}
#else
static void dump_bmp(struct ps3_private* pd) {};
#endif /* defined(DEBUG) */

static void ps3_chip_mask(unsigned int virq)
{
	struct ps3_private *pd = get_irq_chip_data(virq);
	u64 bit = 0x8000000000000000UL >> virq;
	u64 *p = &pd->bmp.mask;
	u64 old;
	unsigned long flags;

	pr_debug("%s:%d: cpu %u, virq %d\n", __func__, __LINE__, pd->cpu, virq);

	local_irq_save(flags);
	asm volatile(
		     "1:	ldarx %0,0,%3\n"
		     "andc	%0,%0,%2\n"
		     "stdcx.	%0,0,%3\n"
		     "bne-	1b"
		     : "=&r" (old), "+m" (*p)
		     : "r" (bit), "r" (p)
		     : "cc" );

	lv1_did_update_interrupt_mask(pd->node, pd->cpu);
	local_irq_restore(flags);
}

static void ps3_chip_unmask(unsigned int virq)
{
	struct ps3_private *pd = get_irq_chip_data(virq);
	u64 bit = 0x8000000000000000UL >> virq;
	u64 *p = &pd->bmp.mask;
	u64 old;
	unsigned long flags;

	pr_debug("%s:%d: cpu %u, virq %d\n", __func__, __LINE__, pd->cpu, virq);

	local_irq_save(flags);
	asm volatile(
		     "1:	ldarx %0,0,%3\n"
		     "or	%0,%0,%2\n"
		     "stdcx.	%0,0,%3\n"
		     "bne-	1b"
		     : "=&r" (old), "+m" (*p)
		     : "r" (bit), "r" (p)
		     : "cc" );

	lv1_did_update_interrupt_mask(pd->node, pd->cpu);
	local_irq_restore(flags);
}

static void ps3_chip_eoi(unsigned int virq)
{
	const struct ps3_private *pd = get_irq_chip_data(virq);
	lv1_end_of_interrupt_ext(pd->node, pd->cpu, virq);
}

static struct irq_chip irq_chip = {
	.typename = "ps3",
	.mask = ps3_chip_mask,
	.unmask = ps3_chip_unmask,
	.eoi = ps3_chip_eoi,
};

static void ps3_host_unmap(struct irq_host *h, unsigned int virq)
{
	set_irq_chip_data(virq, NULL);
}

static int ps3_host_map(struct irq_host *h, unsigned int virq,
	irq_hw_number_t hwirq)
{
	pr_debug("%s:%d: hwirq %lu, virq %u\n", __func__, __LINE__, hwirq,
		virq);

	set_irq_chip_and_handler(virq, &irq_chip, handle_fasteoi_irq);

	return 0;
}

static struct irq_host_ops ps3_host_ops = {
	.map = ps3_host_map,
	.unmap = ps3_host_unmap,
};

void __init ps3_register_ipi_debug_brk(unsigned int cpu, unsigned int virq)
{
	struct ps3_private *pd = &per_cpu(ps3_private, cpu);

	pd->bmp.ipi_debug_brk_mask = 0x8000000000000000UL >> virq;

	pr_debug("%s:%d: cpu %u, virq %u, mask %lxh\n", __func__, __LINE__,
		cpu, virq, pd->bmp.ipi_debug_brk_mask);
}

unsigned int ps3_get_irq(void)
{
	struct ps3_private *pd = &__get_cpu_var(ps3_private);
	u64 x = (pd->bmp.status & pd->bmp.mask);
	unsigned int plug;

	/* check for ipi break first to stop this cpu ASAP */

	if (x & pd->bmp.ipi_debug_brk_mask)
		x &= pd->bmp.ipi_debug_brk_mask;

	asm volatile("cntlzd %0,%1" : "=r" (plug) : "r" (x));
	plug &= 0x3f;

	if (unlikely(plug) == NO_IRQ) {
		pr_debug("%s:%d: no plug found: cpu %u\n", __func__, __LINE__,
			pd->cpu);
		dump_bmp(&per_cpu(ps3_private, 0));
		dump_bmp(&per_cpu(ps3_private, 1));
		return NO_IRQ;
	}

#if defined(DEBUG)
	if (unlikely(plug < NUM_ISA_INTERRUPTS || plug > PS3_PLUG_MAX)) {
		dump_bmp(&per_cpu(ps3_private, 0));
		dump_bmp(&per_cpu(ps3_private, 1));
		BUG();
	}
#endif
	return plug;
}

void __init ps3_init_IRQ(void)
{
	int result;
	unsigned cpu;
	struct irq_host *host;

	host = irq_alloc_host(IRQ_HOST_MAP_NOMAP, 0, &ps3_host_ops,
		PS3_INVALID_OUTLET);
	irq_set_default_host(host);
	irq_set_virq_count(PS3_PLUG_MAX + 1);

	for_each_possible_cpu(cpu) {
		struct ps3_private *pd = &per_cpu(ps3_private, cpu);

		lv1_get_logical_ppe_id(&pd->node);
		pd->cpu = get_hard_smp_processor_id(cpu);
		spin_lock_init(&pd->bmp.lock);

		pr_debug("%s:%d: node %lu, cpu %d, bmp %lxh\n", __func__,
			__LINE__, pd->node, pd->cpu,
			ps3_mm_phys_to_lpar(__pa(&pd->bmp)));

		result = lv1_configure_irq_state_bitmap(pd->node, pd->cpu,
			ps3_mm_phys_to_lpar(__pa(&pd->bmp)));

		if (result)
			pr_debug("%s:%d: lv1_configure_irq_state_bitmap failed:"
				" %s\n", __func__, __LINE__,
				ps3_result(result));
	}

	ppc_md.get_irq = ps3_get_irq;
}