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