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> 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 = get_irq_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 = get_irq_data(irq); 58 *msg = cfg->msg; 59} 60 61void mask_ht_irq(unsigned int irq) 62{ 63 struct ht_irq_cfg *cfg; 64 struct ht_irq_msg msg; 65 66 cfg = get_irq_data(irq); 67 68 msg = cfg->msg; 69 msg.address_lo |= 1; 70 write_ht_irq_msg(irq, &msg); 71} 72 73void unmask_ht_irq(unsigned int irq) 74{ 75 struct ht_irq_cfg *cfg; 76 struct ht_irq_msg msg; 77 78 cfg = get_irq_data(irq); 79 80 msg = cfg->msg; 81 msg.address_lo &= ~1; 82 write_ht_irq_msg(irq, &msg); 83} 84 85/** 86 * __ht_create_irq - create an irq and attach it to a device. 87 * @dev: The hypertransport device to find the irq capability on. 88 * @idx: Which of the possible irqs to attach to. 89 * @update: Function to be called when changing the htirq message 90 * 91 * The irq number of the new irq or a negative error value is returned. 92 */ 93int __ht_create_irq(struct pci_dev *dev, int idx, ht_irq_update_t *update) 94{ 95 struct ht_irq_cfg *cfg; 96 unsigned long flags; 97 u32 data; 98 int max_irq; 99 int pos; 100 int irq; 101 102 pos = pci_find_ht_capability(dev, HT_CAPTYPE_IRQ); 103 if (!pos) 104 return -EINVAL; 105 106 /* Verify the idx I want to use is in range */ 107 spin_lock_irqsave(&ht_irq_lock, flags); 108 pci_write_config_byte(dev, pos + 2, 1); 109 pci_read_config_dword(dev, pos + 4, &data); 110 spin_unlock_irqrestore(&ht_irq_lock, flags); 111 112 max_irq = (data >> 16) & 0xff; 113 if ( idx > max_irq) 114 return -EINVAL; 115 116 cfg = kmalloc(sizeof(*cfg), GFP_KERNEL); 117 if (!cfg) 118 return -ENOMEM; 119 120 cfg->dev = dev; 121 cfg->update = update; 122 cfg->pos = pos; 123 cfg->idx = 0x10 + (idx * 2); 124 /* Initialize msg to a value that will never match the first write. */ 125 cfg->msg.address_lo = 0xffffffff; 126 cfg->msg.address_hi = 0xffffffff; 127 128 irq = create_irq(); 129 if (irq < 0) { 130 kfree(cfg); 131 return -EBUSY; 132 } 133 set_irq_data(irq, cfg); 134 135 if (arch_setup_ht_irq(irq, dev) < 0) { 136 ht_destroy_irq(irq); 137 return -EBUSY; 138 } 139 140 return irq; 141} 142 143/** 144 * ht_create_irq - create an irq and attach it to a device. 145 * @dev: The hypertransport device to find the irq capability on. 146 * @idx: Which of the possible irqs to attach to. 147 * 148 * ht_create_irq needs to be called for all hypertransport devices 149 * that generate irqs. 150 * 151 * The irq number of the new irq or a negative error value is returned. 152 */ 153int ht_create_irq(struct pci_dev *dev, int idx) 154{ 155 return __ht_create_irq(dev, idx, NULL); 156} 157 158/** 159 * ht_destroy_irq - destroy an irq created with ht_create_irq 160 * 161 * This reverses ht_create_irq removing the specified irq from 162 * existence. The irq should be free before this happens. 163 */ 164void ht_destroy_irq(unsigned int irq) 165{ 166 struct ht_irq_cfg *cfg; 167 168 cfg = get_irq_data(irq); 169 set_irq_chip(irq, NULL); 170 set_irq_data(irq, NULL); 171 destroy_irq(irq); 172 173 kfree(cfg); 174} 175 176EXPORT_SYMBOL(__ht_create_irq); 177EXPORT_SYMBOL(ht_create_irq); 178EXPORT_SYMBOL(ht_destroy_irq); 179