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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; | |
43539c38 EB |
28 | /* Update callback used to cope with buggy hardware */ |
29 | ht_irq_update_t *update; | |
8b955b0d EB |
30 | unsigned pos; |
31 | unsigned idx; | |
ec68307c | 32 | struct ht_irq_msg msg; |
8b955b0d EB |
33 | }; |
34 | ||
8b955b0d | 35 | |
ec68307c | 36 | void write_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg) |
8b955b0d EB |
37 | { |
38 | struct ht_irq_cfg *cfg = get_irq_data(irq); | |
39 | unsigned long flags; | |
8b955b0d | 40 | spin_lock_irqsave(&ht_irq_lock, flags); |
ec68307c EB |
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 | } | |
43539c38 EB |
49 | if (cfg->update) |
50 | cfg->update(cfg->dev, irq, msg); | |
8b955b0d | 51 | spin_unlock_irqrestore(&ht_irq_lock, flags); |
ec68307c | 52 | cfg->msg = *msg; |
8b955b0d EB |
53 | } |
54 | ||
ec68307c | 55 | void fetch_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg) |
8b955b0d EB |
56 | { |
57 | struct ht_irq_cfg *cfg = get_irq_data(irq); | |
ec68307c | 58 | *msg = cfg->msg; |
8b955b0d EB |
59 | } |
60 | ||
61 | void mask_ht_irq(unsigned int irq) | |
62 | { | |
63 | struct ht_irq_cfg *cfg; | |
ec68307c | 64 | struct ht_irq_msg msg; |
8b955b0d EB |
65 | |
66 | cfg = get_irq_data(irq); | |
67 | ||
ec68307c EB |
68 | msg = cfg->msg; |
69 | msg.address_lo |= 1; | |
70 | write_ht_irq_msg(irq, &msg); | |
8b955b0d EB |
71 | } |
72 | ||
73 | void unmask_ht_irq(unsigned int irq) | |
74 | { | |
75 | struct ht_irq_cfg *cfg; | |
ec68307c | 76 | struct ht_irq_msg msg; |
8b955b0d EB |
77 | |
78 | cfg = get_irq_data(irq); | |
79 | ||
ec68307c EB |
80 | msg = cfg->msg; |
81 | msg.address_lo &= ~1; | |
82 | write_ht_irq_msg(irq, &msg); | |
8b955b0d EB |
83 | } |
84 | ||
85 | /** | |
43539c38 | 86 | * __ht_create_irq - create an irq and attach it to a device. |
8b955b0d EB |
87 | * @dev: The hypertransport device to find the irq capability on. |
88 | * @idx: Which of the possible irqs to attach to. | |
43539c38 | 89 | * @update: Function to be called when changing the htirq message |
8b955b0d EB |
90 | * |
91 | * The irq number of the new irq or a negative error value is returned. | |
92 | */ | |
43539c38 | 93 | int __ht_create_irq(struct pci_dev *dev, int idx, ht_irq_update_t *update) |
8b955b0d EB |
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 | ||
120a50df | 102 | pos = pci_find_ht_capability(dev, HT_CAPTYPE_IRQ); |
8b955b0d EB |
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; | |
43539c38 | 121 | cfg->update = update; |
8b955b0d EB |
122 | cfg->pos = pos; |
123 | cfg->idx = 0x10 + (idx * 2); | |
ec68307c EB |
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; | |
8b955b0d EB |
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 | ||
43539c38 EB |
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 | */ | |
153 | int ht_create_irq(struct pci_dev *dev, int idx) | |
154 | { | |
155 | return __ht_create_irq(dev, idx, NULL); | |
156 | } | |
157 | ||
8b955b0d EB |
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 | */ | |
164 | void 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 | ||
43539c38 | 176 | EXPORT_SYMBOL(__ht_create_irq); |
8b955b0d EB |
177 | EXPORT_SYMBOL(ht_create_irq); |
178 | EXPORT_SYMBOL(ht_destroy_irq); |