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7e302869 ME |
1 | /* |
2 | * Copyright 2006-2008, Michael Ellerman, IBM Corporation. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; version 2 of the | |
7 | * License. | |
8 | * | |
9 | */ | |
10 | ||
5a0e3ad6 | 11 | #include <linux/slab.h> |
7e302869 ME |
12 | #include <linux/kernel.h> |
13 | #include <linux/bitmap.h> | |
14 | #include <asm/msi_bitmap.h> | |
ae3a197e | 15 | #include <asm/setup.h> |
7e302869 ME |
16 | |
17 | int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num) | |
18 | { | |
19 | unsigned long flags; | |
20 | int offset, order = get_count_order(num); | |
21 | ||
22 | spin_lock_irqsave(&bmp->lock, flags); | |
23 | /* | |
24 | * This is fast, but stricter than we need. We might want to add | |
25 | * a fallback routine which does a linear search with no alignment. | |
26 | */ | |
27 | offset = bitmap_find_free_region(bmp->bitmap, bmp->irq_count, order); | |
28 | spin_unlock_irqrestore(&bmp->lock, flags); | |
29 | ||
30 | pr_debug("msi_bitmap: allocated 0x%x (2^%d) at offset 0x%x\n", | |
31 | num, order, offset); | |
32 | ||
33 | return offset; | |
34 | } | |
35 | ||
36 | void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset, | |
37 | unsigned int num) | |
38 | { | |
39 | unsigned long flags; | |
40 | int order = get_count_order(num); | |
41 | ||
42 | pr_debug("msi_bitmap: freeing 0x%x (2^%d) at offset 0x%x\n", | |
43 | num, order, offset); | |
44 | ||
45 | spin_lock_irqsave(&bmp->lock, flags); | |
46 | bitmap_release_region(bmp->bitmap, offset, order); | |
47 | spin_unlock_irqrestore(&bmp->lock, flags); | |
48 | } | |
49 | ||
50 | void msi_bitmap_reserve_hwirq(struct msi_bitmap *bmp, unsigned int hwirq) | |
51 | { | |
52 | unsigned long flags; | |
53 | ||
54 | pr_debug("msi_bitmap: reserving hwirq 0x%x\n", hwirq); | |
55 | ||
56 | spin_lock_irqsave(&bmp->lock, flags); | |
57 | bitmap_allocate_region(bmp->bitmap, hwirq, 0); | |
58 | spin_unlock_irqrestore(&bmp->lock, flags); | |
59 | } | |
60 | ||
61 | /** | |
62 | * msi_bitmap_reserve_dt_hwirqs - Reserve irqs specified in the device tree. | |
63 | * @bmp: pointer to the MSI bitmap. | |
64 | * | |
65 | * Looks in the device tree to see if there is a property specifying which | |
66 | * irqs can be used for MSI. If found those irqs reserved in the device tree | |
67 | * are reserved in the bitmap. | |
68 | * | |
69 | * Returns 0 for success, < 0 if there was an error, and > 0 if no property | |
70 | * was found in the device tree. | |
71 | **/ | |
72 | int msi_bitmap_reserve_dt_hwirqs(struct msi_bitmap *bmp) | |
73 | { | |
74 | int i, j, len; | |
75 | const u32 *p; | |
76 | ||
77 | if (!bmp->of_node) | |
78 | return 1; | |
79 | ||
80 | p = of_get_property(bmp->of_node, "msi-available-ranges", &len); | |
81 | if (!p) { | |
82 | pr_debug("msi_bitmap: no msi-available-ranges property " \ | |
83 | "found on %s\n", bmp->of_node->full_name); | |
84 | return 1; | |
85 | } | |
86 | ||
87 | if (len % (2 * sizeof(u32)) != 0) { | |
88 | printk(KERN_WARNING "msi_bitmap: Malformed msi-available-ranges" | |
89 | " property on %s\n", bmp->of_node->full_name); | |
90 | return -EINVAL; | |
91 | } | |
92 | ||
93 | bitmap_allocate_region(bmp->bitmap, 0, get_count_order(bmp->irq_count)); | |
94 | ||
95 | spin_lock(&bmp->lock); | |
96 | ||
97 | /* Format is: (<u32 start> <u32 count>)+ */ | |
98 | len /= 2 * sizeof(u32); | |
99 | for (i = 0; i < len; i++, p += 2) { | |
100 | for (j = 0; j < *(p + 1); j++) | |
101 | bitmap_release_region(bmp->bitmap, *p + j, 0); | |
102 | } | |
103 | ||
104 | spin_unlock(&bmp->lock); | |
105 | ||
106 | return 0; | |
107 | } | |
108 | ||
109 | int msi_bitmap_alloc(struct msi_bitmap *bmp, unsigned int irq_count, | |
110 | struct device_node *of_node) | |
111 | { | |
112 | int size; | |
113 | ||
114 | if (!irq_count) | |
115 | return -EINVAL; | |
116 | ||
117 | size = BITS_TO_LONGS(irq_count) * sizeof(long); | |
118 | pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n", size); | |
119 | ||
120 | bmp->bitmap = zalloc_maybe_bootmem(size, GFP_KERNEL); | |
121 | if (!bmp->bitmap) { | |
122 | pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n"); | |
123 | return -ENOMEM; | |
124 | } | |
125 | ||
126 | /* We zalloc'ed the bitmap, so all irqs are free by default */ | |
127 | spin_lock_init(&bmp->lock); | |
128 | bmp->of_node = of_node_get(of_node); | |
129 | bmp->irq_count = irq_count; | |
130 | ||
131 | return 0; | |
132 | } | |
133 | ||
134 | void msi_bitmap_free(struct msi_bitmap *bmp) | |
135 | { | |
136 | /* we can't free the bitmap we don't know if it's bootmem etc. */ | |
137 | of_node_put(bmp->of_node); | |
138 | bmp->bitmap = NULL; | |
139 | } | |
140 | ||
141 | #ifdef CONFIG_MSI_BITMAP_SELFTEST | |
142 | ||
143 | #define check(x) \ | |
144 | if (!(x)) printk("msi_bitmap: test failed at line %d\n", __LINE__); | |
145 | ||
097529f3 | 146 | void __init test_basics(void) |
7e302869 ME |
147 | { |
148 | struct msi_bitmap bmp; | |
149 | int i, size = 512; | |
150 | ||
151 | /* Can't allocate a bitmap of 0 irqs */ | |
152 | check(msi_bitmap_alloc(&bmp, 0, NULL) != 0); | |
153 | ||
154 | /* of_node may be NULL */ | |
155 | check(0 == msi_bitmap_alloc(&bmp, size, NULL)); | |
156 | ||
157 | /* Should all be free by default */ | |
158 | check(0 == bitmap_find_free_region(bmp.bitmap, size, | |
159 | get_count_order(size))); | |
160 | bitmap_release_region(bmp.bitmap, 0, get_count_order(size)); | |
161 | ||
162 | /* With no node, there's no msi-available-ranges, so expect > 0 */ | |
163 | check(msi_bitmap_reserve_dt_hwirqs(&bmp) > 0); | |
164 | ||
165 | /* Should all still be free */ | |
166 | check(0 == bitmap_find_free_region(bmp.bitmap, size, | |
167 | get_count_order(size))); | |
168 | bitmap_release_region(bmp.bitmap, 0, get_count_order(size)); | |
169 | ||
170 | /* Check we can fill it up and then no more */ | |
171 | for (i = 0; i < size; i++) | |
172 | check(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0); | |
173 | ||
174 | check(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0); | |
175 | ||
176 | /* Should all be allocated */ | |
177 | check(bitmap_find_free_region(bmp.bitmap, size, 0) < 0); | |
178 | ||
179 | /* And if we free one we can then allocate another */ | |
180 | msi_bitmap_free_hwirqs(&bmp, size / 2, 1); | |
181 | check(msi_bitmap_alloc_hwirqs(&bmp, 1) == size / 2); | |
182 | ||
183 | msi_bitmap_free(&bmp); | |
184 | ||
185 | /* Clients may check bitmap == NULL for "not-allocated" */ | |
186 | check(bmp.bitmap == NULL); | |
187 | ||
188 | kfree(bmp.bitmap); | |
189 | } | |
190 | ||
097529f3 | 191 | void __init test_of_node(void) |
7e302869 ME |
192 | { |
193 | u32 prop_data[] = { 10, 10, 25, 3, 40, 1, 100, 100, 200, 20 }; | |
194 | const char *expected_str = "0-9,20-24,28-39,41-99,220-255"; | |
195 | char *prop_name = "msi-available-ranges"; | |
196 | char *node_name = "/fakenode"; | |
197 | struct device_node of_node; | |
198 | struct property prop; | |
199 | struct msi_bitmap bmp; | |
200 | int size = 256; | |
201 | DECLARE_BITMAP(expected, size); | |
202 | ||
203 | /* There should really be a struct device_node allocator */ | |
204 | memset(&of_node, 0, sizeof(of_node)); | |
205 | kref_init(&of_node.kref); | |
206 | of_node.full_name = node_name; | |
207 | ||
208 | check(0 == msi_bitmap_alloc(&bmp, size, &of_node)); | |
209 | ||
210 | /* No msi-available-ranges, so expect > 0 */ | |
211 | check(msi_bitmap_reserve_dt_hwirqs(&bmp) > 0); | |
212 | ||
213 | /* Should all still be free */ | |
214 | check(0 == bitmap_find_free_region(bmp.bitmap, size, | |
215 | get_count_order(size))); | |
216 | bitmap_release_region(bmp.bitmap, 0, get_count_order(size)); | |
217 | ||
218 | /* Now create a fake msi-available-ranges property */ | |
219 | ||
220 | /* There should really .. oh whatever */ | |
221 | memset(&prop, 0, sizeof(prop)); | |
222 | prop.name = prop_name; | |
223 | prop.value = &prop_data; | |
224 | prop.length = sizeof(prop_data); | |
225 | ||
226 | of_node.properties = ∝ | |
227 | ||
228 | /* msi-available-ranges, so expect == 0 */ | |
229 | check(msi_bitmap_reserve_dt_hwirqs(&bmp) == 0); | |
230 | ||
231 | /* Check we got the expected result */ | |
232 | check(0 == bitmap_parselist(expected_str, expected, size)); | |
233 | check(bitmap_equal(expected, bmp.bitmap, size)); | |
234 | ||
235 | msi_bitmap_free(&bmp); | |
236 | kfree(bmp.bitmap); | |
237 | } | |
238 | ||
097529f3 | 239 | int __init msi_bitmap_selftest(void) |
7e302869 ME |
240 | { |
241 | printk(KERN_DEBUG "Running MSI bitmap self-tests ...\n"); | |
242 | ||
243 | test_basics(); | |
244 | test_of_node(); | |
245 | ||
246 | return 0; | |
247 | } | |
248 | late_initcall(msi_bitmap_selftest); | |
249 | #endif /* CONFIG_MSI_BITMAP_SELFTEST */ |