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