[deliverable/linux.git] / drivers / pci / htirq.c

/*
 * File:	htirq.c
 * Purpose:	Hypertransport Interrupt Capability
 *
 * Copyright (C) 2006 Linux Networx
 * Copyright (C) Eric Biederman <ebiederman@lnxi.com>
 */

#include <linux/irq.h>
#include <linux/pci.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/gfp.h>
#include <linux/htirq.h>

/* Global ht irq lock.
 *
 * This is needed to serialize access to the data port in hypertransport
 * irq capability.
 *
 * With multiple simultaneous hypertransport irq devices it might pay
 * to make this more fine grained.  But start with simple, stupid, and correct.
 */
static DEFINE_SPINLOCK(ht_irq_lock);

struct ht_irq_cfg {
	struct pci_dev *dev;
	unsigned pos;
	unsigned idx;
	struct ht_irq_msg msg;
};


void write_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg)
{
	struct ht_irq_cfg *cfg = get_irq_data(irq);
	unsigned long flags;
	spin_lock_irqsave(&ht_irq_lock, flags);
	if (cfg->msg.address_lo != msg->address_lo) {
		pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx);
		pci_write_config_dword(cfg->dev, cfg->pos + 4, msg->address_lo);
	}
	if (cfg->msg.address_hi != msg->address_hi) {
		pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx + 1);
		pci_write_config_dword(cfg->dev, cfg->pos + 4, msg->address_hi);
	}
	spin_unlock_irqrestore(&ht_irq_lock, flags);
	cfg->msg = *msg;
}

void fetch_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg)
{
	struct ht_irq_cfg *cfg = get_irq_data(irq);
	*msg = cfg->msg;
}

void mask_ht_irq(unsigned int irq)
{
	struct ht_irq_cfg *cfg;
	struct ht_irq_msg msg;

	cfg = get_irq_data(irq);

	msg = cfg->msg;
	msg.address_lo |= 1;
	write_ht_irq_msg(irq, &msg);
}

void unmask_ht_irq(unsigned int irq)
{
	struct ht_irq_cfg *cfg;
	struct ht_irq_msg msg;

	cfg = get_irq_data(irq);

	msg = cfg->msg;
	msg.address_lo &= ~1;
	write_ht_irq_msg(irq, &msg);
}

/**
 * ht_create_irq - create an irq and attach it to a device.
 * @dev: The hypertransport device to find the irq capability on.
 * @idx: Which of the possible irqs to attach to.
 *
 * ht_create_irq is needs to be called for all hypertransport devices
 * that generate irqs.
 *
 * The irq number of the new irq or a negative error value is returned.
 */
int ht_create_irq(struct pci_dev *dev, int idx)
{
	struct ht_irq_cfg *cfg;
	unsigned long flags;
	u32 data;
	int max_irq;
	int pos;
	int irq;

	pos = pci_find_capability(dev, PCI_CAP_ID_HT);
	while (pos) {
		u8 subtype;
		pci_read_config_byte(dev, pos + 3, &subtype);
		if (subtype == HT_CAPTYPE_IRQ)
			break;
		pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_HT);
	}
	if (!pos)
		return -EINVAL;

	/* Verify the idx I want to use is in range */
	spin_lock_irqsave(&ht_irq_lock, flags);
	pci_write_config_byte(dev, pos + 2, 1);
	pci_read_config_dword(dev, pos + 4, &data);
	spin_unlock_irqrestore(&ht_irq_lock, flags);

	max_irq = (data >> 16) & 0xff;
	if ( idx > max_irq)
		return -EINVAL;

	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
	if (!cfg)
		return -ENOMEM;

	cfg->dev = dev;
	cfg->pos = pos;
	cfg->idx = 0x10 + (idx * 2);
	/* Initialize msg to a value that will never match the first write. */
	cfg->msg.address_lo = 0xffffffff;
	cfg->msg.address_hi = 0xffffffff;

	irq = create_irq();
	if (irq < 0) {
		kfree(cfg);
		return -EBUSY;
	}
	set_irq_data(irq, cfg);

	if (arch_setup_ht_irq(irq, dev) < 0) {
		ht_destroy_irq(irq);
		return -EBUSY;
	}

	return irq;
}

/**
 * ht_destroy_irq - destroy an irq created with ht_create_irq
 *
 * This reverses ht_create_irq removing the specified irq from
 * existence.  The irq should be free before this happens.
 */
void ht_destroy_irq(unsigned int irq)
{
	struct ht_irq_cfg *cfg;

	cfg = get_irq_data(irq);
	set_irq_chip(irq, NULL);
	set_irq_data(irq, NULL);
	destroy_irq(irq);

	kfree(cfg);
}

EXPORT_SYMBOL(ht_create_irq);
EXPORT_SYMBOL(ht_destroy_irq);
Commit	Line	Data
8b955b0d EB	1	/*
	2	* File: htirq.c
	3	* Purpose: Hypertransport Interrupt Capability
	4	*
	5	* Copyright (C) 2006 Linux Networx
	6	* Copyright (C) Eric Biederman <ebiederman@lnxi.com>
	7	*/
	8
	9	#include <linux/irq.h>
	10	#include <linux/pci.h>
	11	#include <linux/spinlock.h>
	12	#include <linux/slab.h>
	13	#include <linux/gfp.h>
95d77884	14	#include <linux/htirq.h>
8b955b0d EB	15
	16	/* Global ht irq lock.
	17	*
	18	* This is needed to serialize access to the data port in hypertransport
	19	* irq capability.
	20	*
	21	* With multiple simultaneous hypertransport irq devices it might pay
	22	* to make this more fine grained. But start with simple, stupid, and correct.
	23	*/
	24	static DEFINE_SPINLOCK(ht_irq_lock);
	25
	26	struct ht_irq_cfg {
	27	struct pci_dev *dev;
	28	unsigned pos;
	29	unsigned idx;
ec68307c	30	struct ht_irq_msg msg;
8b955b0d EB	31	};
8b955b0d EB	32
8b955b0d	33
ec68307c	34	void write_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg)
8b955b0d EB	35	{
	36	struct ht_irq_cfg *cfg = get_irq_data(irq);
	37	unsigned long flags;
8b955b0d	38	spin_lock_irqsave(&ht_irq_lock, flags);
ec68307c EB	39	if (cfg->msg.address_lo != msg->address_lo) {
	40	pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx);
	41	pci_write_config_dword(cfg->dev, cfg->pos + 4, msg->address_lo);
	42	}
	43	if (cfg->msg.address_hi != msg->address_hi) {
	44	pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx + 1);
	45	pci_write_config_dword(cfg->dev, cfg->pos + 4, msg->address_hi);
	46	}
8b955b0d	47	spin_unlock_irqrestore(&ht_irq_lock, flags);
ec68307c	48	cfg->msg = *msg;
8b955b0d EB	49	}
8b955b0d EB	50
ec68307c	51	void fetch_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg)
8b955b0d EB	52	{
8b955b0d EB	53	struct ht_irq_cfg *cfg = get_irq_data(irq);
ec68307c	54	*msg = cfg->msg;
8b955b0d EB	55	}
	56
	57	void mask_ht_irq(unsigned int irq)
	58	{
	59	struct ht_irq_cfg *cfg;
ec68307c	60	struct ht_irq_msg msg;
8b955b0d EB	61
	62	cfg = get_irq_data(irq);
	63
ec68307c EB	64	msg = cfg->msg;
	65	msg.address_lo \|= 1;
	66	write_ht_irq_msg(irq, &msg);
8b955b0d EB	67	}
	68
	69	void unmask_ht_irq(unsigned int irq)
	70	{
	71	struct ht_irq_cfg *cfg;
ec68307c	72	struct ht_irq_msg msg;
8b955b0d EB	73
	74	cfg = get_irq_data(irq);
	75
ec68307c EB	76	msg = cfg->msg;
	77	msg.address_lo &= ~1;
	78	write_ht_irq_msg(irq, &msg);
8b955b0d EB	79	}
	80
	81	/**
	82	* ht_create_irq - create an irq and attach it to a device.
	83	* @dev: The hypertransport device to find the irq capability on.
	84	* @idx: Which of the possible irqs to attach to.
	85	*
	86	* ht_create_irq is needs to be called for all hypertransport devices
	87	* that generate irqs.
	88	*
	89	* The irq number of the new irq or a negative error value is returned.
	90	*/
	91	int ht_create_irq(struct pci_dev *dev, int idx)
	92	{
	93	struct ht_irq_cfg *cfg;
	94	unsigned long flags;
	95	u32 data;
	96	int max_irq;
	97	int pos;
	98	int irq;
	99
	100	pos = pci_find_capability(dev, PCI_CAP_ID_HT);
	101	while (pos) {
	102	u8 subtype;
	103	pci_read_config_byte(dev, pos + 3, &subtype);
	104	if (subtype == HT_CAPTYPE_IRQ)
	105	break;
	106	pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_HT);
	107	}
	108	if (!pos)
	109	return -EINVAL;
	110
	111	/* Verify the idx I want to use is in range */
	112	spin_lock_irqsave(&ht_irq_lock, flags);
	113	pci_write_config_byte(dev, pos + 2, 1);
	114	pci_read_config_dword(dev, pos + 4, &data);
	115	spin_unlock_irqrestore(&ht_irq_lock, flags);
	116
	117	max_irq = (data >> 16) & 0xff;
	118	if ( idx > max_irq)
	119	return -EINVAL;
	120
	121	cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
	122	if (!cfg)
	123	return -ENOMEM;
	124
	125	cfg->dev = dev;
	126	cfg->pos = pos;
	127	cfg->idx = 0x10 + (idx * 2);
ec68307c EB	128	/* Initialize msg to a value that will never match the first write. */
	129	cfg->msg.address_lo = 0xffffffff;
	130	cfg->msg.address_hi = 0xffffffff;
8b955b0d EB	131
	132	irq = create_irq();
	133	if (irq < 0) {
	134	kfree(cfg);
	135	return -EBUSY;
	136	}
	137	set_irq_data(irq, cfg);
	138
	139	if (arch_setup_ht_irq(irq, dev) < 0) {
	140	ht_destroy_irq(irq);
	141	return -EBUSY;
	142	}
	143
	144	return irq;
	145	}
	146
	147	/**
	148	* ht_destroy_irq - destroy an irq created with ht_create_irq
	149	*
	150	* This reverses ht_create_irq removing the specified irq from
	151	* existence. The irq should be free before this happens.
	152	*/
	153	void ht_destroy_irq(unsigned int irq)
	154	{
	155	struct ht_irq_cfg *cfg;
	156
	157	cfg = get_irq_data(irq);
	158	set_irq_chip(irq, NULL);
	159	set_irq_data(irq, NULL);
	160	destroy_irq(irq);
	161
	162	kfree(cfg);
	163	}
	164
	165	EXPORT_SYMBOL(ht_create_irq);
	166	EXPORT_SYMBOL(ht_destroy_irq);