3 * Purpose: Hypertransport Interrupt Capability
5 * Copyright (C) 2006 Linux Networx
6 * Copyright (C) Eric Biederman <ebiederman@lnxi.com>
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>
16 /* Global ht irq lock.
18 * This is needed to serialize access to the data port in hypertransport
21 * With multiple simultaneous hypertransport irq devices it might pay
22 * to make this more fine grained. But start with simple, stupid, and correct.
24 static DEFINE_SPINLOCK(ht_irq_lock);
30 struct ht_irq_msg msg;
34 void write_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg)
36 struct ht_irq_cfg *cfg = get_irq_data(irq);
38 spin_lock_irqsave(&ht_irq_lock, flags);
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);
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);
47 spin_unlock_irqrestore(&ht_irq_lock, flags);
51 void fetch_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg)
53 struct ht_irq_cfg *cfg = get_irq_data(irq);
57 void mask_ht_irq(unsigned int irq)
59 struct ht_irq_cfg *cfg;
60 struct ht_irq_msg msg;
62 cfg = get_irq_data(irq);
66 write_ht_irq_msg(irq, &msg);
69 void unmask_ht_irq(unsigned int irq)
71 struct ht_irq_cfg *cfg;
72 struct ht_irq_msg msg;
74 cfg = get_irq_data(irq);
78 write_ht_irq_msg(irq, &msg);
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.
86 * ht_create_irq is needs to be called for all hypertransport devices
89 * The irq number of the new irq or a negative error value is returned.
91 int ht_create_irq(struct pci_dev *dev, int idx)
93 struct ht_irq_cfg *cfg;
100 pos = pci_find_capability(dev, PCI_CAP_ID_HT);
103 pci_read_config_byte(dev, pos + 3, &subtype);
104 if (subtype == HT_CAPTYPE_IRQ)
106 pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_HT);
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);
117 max_irq = (data >> 16) & 0xff;
121 cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
127 cfg->idx = 0x10 + (idx * 2);
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;
137 set_irq_data(irq, cfg);
139 if (arch_setup_ht_irq(irq, dev) < 0) {
148 * ht_destroy_irq - destroy an irq created with ht_create_irq
150 * This reverses ht_create_irq removing the specified irq from
151 * existence. The irq should be free before this happens.
153 void ht_destroy_irq(unsigned int irq)
155 struct ht_irq_cfg *cfg;
157 cfg = get_irq_data(irq);
158 set_irq_chip(irq, NULL);
159 set_irq_data(irq, NULL);
165 EXPORT_SYMBOL(ht_create_irq);
166 EXPORT_SYMBOL(ht_destroy_irq);