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/export.h> 13#include <linux/slab.h> 14#include <linux/htirq.h> 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 */ 24static DEFINE_SPINLOCK(ht_irq_lock); 25 26struct ht_irq_cfg { 27 struct pci_dev *dev; 28 /* Update callback used to cope with buggy hardware */ 29 ht_irq_update_t *update; 30 unsigned pos; 31 unsigned idx; 32 struct ht_irq_msg msg; 33}; 34 35 36void write_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg) 37{ 38 struct ht_irq_cfg *cfg = irq_get_handler_data(irq); 39 unsigned long flags; 40 spin_lock_irqsave(&ht_irq_lock, flags); 41 if (cfg->msg.address_lo != msg->address_lo) { 42 pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx); 43 pci_write_config_dword(cfg->dev, cfg->pos + 4, msg->address_lo); 44 } 45 if (cfg->msg.address_hi != msg->address_hi) { 46 pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx + 1); 47 pci_write_config_dword(cfg->dev, cfg->pos + 4, msg->address_hi); 48 } 49 if (cfg->update) 50 cfg->update(cfg->dev, irq, msg); 51 spin_unlock_irqrestore(&ht_irq_lock, flags); 52 cfg->msg = *msg; 53} 54 55void fetch_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg) 56{ 57 struct ht_irq_cfg *cfg = irq_get_handler_data(irq); 58 *msg = cfg->msg; 59} 60 61void mask_ht_irq(struct irq_data *data) 62{ 63 struct ht_irq_cfg *cfg = irq_data_get_irq_handler_data(data); 64 struct ht_irq_msg msg = cfg->msg; 65 66 msg.address_lo |= 1; 67 write_ht_irq_msg(data->irq, &msg); 68} 69 70void unmask_ht_irq(struct irq_data *data) 71{ 72 struct ht_irq_cfg *cfg = irq_data_get_irq_handler_data(data); 73 struct ht_irq_msg msg = cfg->msg; 74 75 msg.address_lo &= ~1; 76 write_ht_irq_msg(data->irq, &msg); 77} 78 79/** 80 * __ht_create_irq - create an irq and attach it to a device. 81 * @dev: The hypertransport device to find the irq capability on. 82 * @idx: Which of the possible irqs to attach to. 83 * @update: Function to be called when changing the htirq message 84 * 85 * The irq number of the new irq or a negative error value is returned. 86 */ 87int __ht_create_irq(struct pci_dev *dev, int idx, ht_irq_update_t *update) 88{ 89 struct ht_irq_cfg *cfg; 90 unsigned long flags; 91 u32 data; 92 int max_irq; 93 int pos; 94 int irq; 95 int node; 96 97 pos = pci_find_ht_capability(dev, HT_CAPTYPE_IRQ); 98 if (!pos) 99 return -EINVAL; 100 101 /* Verify the idx I want to use is in range */ 102 spin_lock_irqsave(&ht_irq_lock, flags); 103 pci_write_config_byte(dev, pos + 2, 1); 104 pci_read_config_dword(dev, pos + 4, &data); 105 spin_unlock_irqrestore(&ht_irq_lock, flags); 106 107 max_irq = (data >> 16) & 0xff; 108 if ( idx > max_irq) 109 return -EINVAL; 110 111 cfg = kmalloc(sizeof(*cfg), GFP_KERNEL); 112 if (!cfg) 113 return -ENOMEM; 114 115 cfg->dev = dev; 116 cfg->update = update; 117 cfg->pos = pos; 118 cfg->idx = 0x10 + (idx * 2); 119 /* Initialize msg to a value that will never match the first write. */ 120 cfg->msg.address_lo = 0xffffffff; 121 cfg->msg.address_hi = 0xffffffff; 122 123 node = dev_to_node(&dev->dev); 124 irq = create_irq_nr(0, node); 125 126 if (irq <= 0) { 127 kfree(cfg); 128 return -EBUSY; 129 } 130 irq_set_handler_data(irq, cfg); 131 132 if (arch_setup_ht_irq(irq, dev) < 0) { 133 ht_destroy_irq(irq); 134 return -EBUSY; 135 } 136 137 return irq; 138} 139 140/** 141 * ht_create_irq - create an irq and attach it to a device. 142 * @dev: The hypertransport device to find the irq capability on. 143 * @idx: Which of the possible irqs to attach to. 144 * 145 * ht_create_irq needs to be called for all hypertransport devices 146 * that generate irqs. 147 * 148 * The irq number of the new irq or a negative error value is returned. 149 */ 150int ht_create_irq(struct pci_dev *dev, int idx) 151{ 152 return __ht_create_irq(dev, idx, NULL); 153} 154 155/** 156 * ht_destroy_irq - destroy an irq created with ht_create_irq 157 * @irq: irq to be destroyed 158 * 159 * This reverses ht_create_irq removing the specified irq from 160 * existence. The irq should be free before this happens. 161 */ 162void ht_destroy_irq(unsigned int irq) 163{ 164 struct ht_irq_cfg *cfg; 165 166 cfg = irq_get_handler_data(irq); 167 irq_set_chip(irq, NULL); 168 irq_set_handler_data(irq, NULL); 169 destroy_irq(irq); 170 171 kfree(cfg); 172} 173 174EXPORT_SYMBOL(__ht_create_irq); 175EXPORT_SYMBOL(ht_create_irq); 176EXPORT_SYMBOL(ht_destroy_irq); 177