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/htirq.h> 14 15/* Global ht irq lock. 16 * 17 * This is needed to serialize access to the data port in hypertransport 18 * irq capability. 19 * 20 * With multiple simultaneous hypertransport irq devices it might pay 21 * to make this more fine grained. But start with simple, stupid, and correct. 22 */ 23static DEFINE_SPINLOCK(ht_irq_lock); 24 25struct ht_irq_cfg { 26 struct pci_dev *dev; 27 /* Update callback used to cope with buggy hardware */ 28 ht_irq_update_t *update; 29 unsigned pos; 30 unsigned idx; 31 struct ht_irq_msg msg; 32}; 33 34 35void write_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg) 36{ 37 struct ht_irq_cfg *cfg = get_irq_data(irq); 38 unsigned long flags; 39 spin_lock_irqsave(&ht_irq_lock, flags); 40 if (cfg->msg.address_lo != msg->address_lo) { 41 pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx); 42 pci_write_config_dword(cfg->dev, cfg->pos + 4, msg->address_lo); 43 } 44 if (cfg->msg.address_hi != msg->address_hi) { 45 pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx + 1); 46 pci_write_config_dword(cfg->dev, cfg->pos + 4, msg->address_hi); 47 } 48 if (cfg->update) 49 cfg->update(cfg->dev, irq, msg); 50 spin_unlock_irqrestore(&ht_irq_lock, flags); 51 cfg->msg = *msg; 52} 53 54void fetch_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg) 55{ 56 struct ht_irq_cfg *cfg = get_irq_data(irq); 57 *msg = cfg->msg; 58} 59 60void mask_ht_irq(unsigned int irq) 61{ 62 struct ht_irq_cfg *cfg; 63 struct ht_irq_msg msg; 64 65 cfg = get_irq_data(irq); 66 67 msg = cfg->msg; 68 msg.address_lo |= 1; 69 write_ht_irq_msg(irq, &msg); 70} 71 72void unmask_ht_irq(unsigned int irq) 73{ 74 struct ht_irq_cfg *cfg; 75 struct ht_irq_msg msg; 76 77 cfg = get_irq_data(irq); 78 79 msg = cfg->msg; 80 msg.address_lo &= ~1; 81 write_ht_irq_msg(irq, &msg); 82} 83 84/** 85 * __ht_create_irq - create an irq and attach it to a device. 86 * @dev: The hypertransport device to find the irq capability on. 87 * @idx: Which of the possible irqs to attach to. 88 * @update: Function to be called when changing the htirq message 89 * 90 * The irq number of the new irq or a negative error value is returned. 91 */ 92int __ht_create_irq(struct pci_dev *dev, int idx, ht_irq_update_t *update) 93{ 94 struct ht_irq_cfg *cfg; 95 unsigned long flags; 96 u32 data; 97 int max_irq; 98 int pos; 99 int irq; 100 int node; 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 node = dev_to_node(&dev->dev); 129 irq = create_irq_nr(0, node); 130 131 if (irq <= 0) { 132 kfree(cfg); 133 return -EBUSY; 134 } 135 set_irq_data(irq, cfg); 136 137 if (arch_setup_ht_irq(irq, dev) < 0) { 138 ht_destroy_irq(irq); 139 return -EBUSY; 140 } 141 142 return irq; 143} 144 145/** 146 * ht_create_irq - create an irq and attach it to a device. 147 * @dev: The hypertransport device to find the irq capability on. 148 * @idx: Which of the possible irqs to attach to. 149 * 150 * ht_create_irq needs to be called for all hypertransport devices 151 * that generate irqs. 152 * 153 * The irq number of the new irq or a negative error value is returned. 154 */ 155int ht_create_irq(struct pci_dev *dev, int idx) 156{ 157 return __ht_create_irq(dev, idx, NULL); 158} 159 160/** 161 * ht_destroy_irq - destroy an irq created with ht_create_irq 162 * @irq: irq to be destroyed 163 * 164 * This reverses ht_create_irq removing the specified irq from 165 * existence. The irq should be free before this happens. 166 */ 167void ht_destroy_irq(unsigned int irq) 168{ 169 struct ht_irq_cfg *cfg; 170 171 cfg = get_irq_data(irq); 172 set_irq_chip(irq, NULL); 173 set_irq_data(irq, NULL); 174 destroy_irq(irq); 175 176 kfree(cfg); 177} 178 179EXPORT_SYMBOL(__ht_create_irq); 180EXPORT_SYMBOL(ht_create_irq); 181EXPORT_SYMBOL(ht_destroy_irq); 182