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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; | |
28 | unsigned pos; | |
29 | unsigned idx; | |
30 | }; | |
31 | ||
32 | void write_ht_irq_low(unsigned int irq, u32 data) | |
33 | { | |
34 | struct ht_irq_cfg *cfg = get_irq_data(irq); | |
35 | unsigned long flags; | |
36 | spin_lock_irqsave(&ht_irq_lock, flags); | |
37 | pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx); | |
38 | pci_write_config_dword(cfg->dev, cfg->pos + 4, data); | |
39 | spin_unlock_irqrestore(&ht_irq_lock, flags); | |
40 | } | |
41 | ||
42 | void write_ht_irq_high(unsigned int irq, u32 data) | |
43 | { | |
44 | struct ht_irq_cfg *cfg = get_irq_data(irq); | |
45 | unsigned long flags; | |
46 | spin_lock_irqsave(&ht_irq_lock, flags); | |
47 | pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx + 1); | |
48 | pci_write_config_dword(cfg->dev, cfg->pos + 4, data); | |
49 | spin_unlock_irqrestore(&ht_irq_lock, flags); | |
50 | } | |
51 | ||
52 | u32 read_ht_irq_low(unsigned int irq) | |
53 | { | |
54 | struct ht_irq_cfg *cfg = get_irq_data(irq); | |
55 | unsigned long flags; | |
56 | u32 data; | |
57 | spin_lock_irqsave(&ht_irq_lock, flags); | |
58 | pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx); | |
59 | pci_read_config_dword(cfg->dev, cfg->pos + 4, &data); | |
60 | spin_unlock_irqrestore(&ht_irq_lock, flags); | |
61 | return data; | |
62 | } | |
63 | ||
64 | u32 read_ht_irq_high(unsigned int irq) | |
65 | { | |
66 | struct ht_irq_cfg *cfg = get_irq_data(irq); | |
67 | unsigned long flags; | |
68 | u32 data; | |
69 | spin_lock_irqsave(&ht_irq_lock, flags); | |
70 | pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx + 1); | |
71 | pci_read_config_dword(cfg->dev, cfg->pos + 4, &data); | |
72 | spin_unlock_irqrestore(&ht_irq_lock, flags); | |
73 | return data; | |
74 | } | |
75 | ||
76 | void mask_ht_irq(unsigned int irq) | |
77 | { | |
78 | struct ht_irq_cfg *cfg; | |
79 | unsigned long flags; | |
80 | u32 data; | |
81 | ||
82 | cfg = get_irq_data(irq); | |
83 | ||
84 | spin_lock_irqsave(&ht_irq_lock, flags); | |
85 | pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx); | |
86 | pci_read_config_dword(cfg->dev, cfg->pos + 4, &data); | |
87 | data |= 1; | |
88 | pci_write_config_dword(cfg->dev, cfg->pos + 4, data); | |
89 | spin_unlock_irqrestore(&ht_irq_lock, flags); | |
90 | } | |
91 | ||
92 | void unmask_ht_irq(unsigned int irq) | |
93 | { | |
94 | struct ht_irq_cfg *cfg; | |
95 | unsigned long flags; | |
96 | u32 data; | |
97 | ||
98 | cfg = get_irq_data(irq); | |
99 | ||
100 | spin_lock_irqsave(&ht_irq_lock, flags); | |
101 | pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx); | |
102 | pci_read_config_dword(cfg->dev, cfg->pos + 4, &data); | |
103 | data &= ~1; | |
104 | pci_write_config_dword(cfg->dev, cfg->pos + 4, data); | |
105 | spin_unlock_irqrestore(&ht_irq_lock, flags); | |
106 | } | |
107 | ||
108 | /** | |
109 | * ht_create_irq - create an irq and attach it to a device. | |
110 | * @dev: The hypertransport device to find the irq capability on. | |
111 | * @idx: Which of the possible irqs to attach to. | |
112 | * | |
113 | * ht_create_irq is needs to be called for all hypertransport devices | |
114 | * that generate irqs. | |
115 | * | |
116 | * The irq number of the new irq or a negative error value is returned. | |
117 | */ | |
118 | int ht_create_irq(struct pci_dev *dev, int idx) | |
119 | { | |
120 | struct ht_irq_cfg *cfg; | |
121 | unsigned long flags; | |
122 | u32 data; | |
123 | int max_irq; | |
124 | int pos; | |
125 | int irq; | |
126 | ||
127 | pos = pci_find_capability(dev, PCI_CAP_ID_HT); | |
128 | while (pos) { | |
129 | u8 subtype; | |
130 | pci_read_config_byte(dev, pos + 3, &subtype); | |
131 | if (subtype == HT_CAPTYPE_IRQ) | |
132 | break; | |
133 | pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_HT); | |
134 | } | |
135 | if (!pos) | |
136 | return -EINVAL; | |
137 | ||
138 | /* Verify the idx I want to use is in range */ | |
139 | spin_lock_irqsave(&ht_irq_lock, flags); | |
140 | pci_write_config_byte(dev, pos + 2, 1); | |
141 | pci_read_config_dword(dev, pos + 4, &data); | |
142 | spin_unlock_irqrestore(&ht_irq_lock, flags); | |
143 | ||
144 | max_irq = (data >> 16) & 0xff; | |
145 | if ( idx > max_irq) | |
146 | return -EINVAL; | |
147 | ||
148 | cfg = kmalloc(sizeof(*cfg), GFP_KERNEL); | |
149 | if (!cfg) | |
150 | return -ENOMEM; | |
151 | ||
152 | cfg->dev = dev; | |
153 | cfg->pos = pos; | |
154 | cfg->idx = 0x10 + (idx * 2); | |
155 | ||
156 | irq = create_irq(); | |
157 | if (irq < 0) { | |
158 | kfree(cfg); | |
159 | return -EBUSY; | |
160 | } | |
161 | set_irq_data(irq, cfg); | |
162 | ||
163 | if (arch_setup_ht_irq(irq, dev) < 0) { | |
164 | ht_destroy_irq(irq); | |
165 | return -EBUSY; | |
166 | } | |
167 | ||
168 | return irq; | |
169 | } | |
170 | ||
171 | /** | |
172 | * ht_destroy_irq - destroy an irq created with ht_create_irq | |
173 | * | |
174 | * This reverses ht_create_irq removing the specified irq from | |
175 | * existence. The irq should be free before this happens. | |
176 | */ | |
177 | void ht_destroy_irq(unsigned int irq) | |
178 | { | |
179 | struct ht_irq_cfg *cfg; | |
180 | ||
181 | cfg = get_irq_data(irq); | |
182 | set_irq_chip(irq, NULL); | |
183 | set_irq_data(irq, NULL); | |
184 | destroy_irq(irq); | |
185 | ||
186 | kfree(cfg); | |
187 | } | |
188 | ||
189 | EXPORT_SYMBOL(ht_create_irq); | |
190 | EXPORT_SYMBOL(ht_destroy_irq); |