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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 <linux/bootmem.h>
15#include <asm/msi_bitmap.h>
16#include <asm/setup.h>
17
18int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num)
19{
20 unsigned long flags;
21 int offset, order = get_count_order(num);
22
23 spin_lock_irqsave(&bmp->lock, flags);
24
25 offset = bitmap_find_next_zero_area(bmp->bitmap, bmp->irq_count, 0,
26 num, (1 << order) - 1);
27 if (offset > bmp->irq_count)
28 goto err;
29
30 bitmap_set(bmp->bitmap, offset, num);
31 spin_unlock_irqrestore(&bmp->lock, flags);
32
33 pr_debug("msi_bitmap: allocated 0x%x at offset 0x%x\n", num, offset);
34
35 return offset;
36err:
37 spin_unlock_irqrestore(&bmp->lock, flags);
38 return -ENOMEM;
39}
40EXPORT_SYMBOL(msi_bitmap_alloc_hwirqs);
41
42void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset,
43 unsigned int num)
44{
45 unsigned long flags;
46
47 pr_debug("msi_bitmap: freeing 0x%x at offset 0x%x\n",
48 num, offset);
49
50 spin_lock_irqsave(&bmp->lock, flags);
51 bitmap_clear(bmp->bitmap, offset, num);
52 spin_unlock_irqrestore(&bmp->lock, flags);
53}
54EXPORT_SYMBOL(msi_bitmap_free_hwirqs);
55
56void msi_bitmap_reserve_hwirq(struct msi_bitmap *bmp, unsigned int hwirq)
57{
58 unsigned long flags;
59
60 pr_debug("msi_bitmap: reserving hwirq 0x%x\n", hwirq);
61
62 spin_lock_irqsave(&bmp->lock, flags);
63 bitmap_allocate_region(bmp->bitmap, hwirq, 0);
64 spin_unlock_irqrestore(&bmp->lock, flags);
65}
66
67/**
68 * msi_bitmap_reserve_dt_hwirqs - Reserve irqs specified in the device tree.
69 * @bmp: pointer to the MSI bitmap.
70 *
71 * Looks in the device tree to see if there is a property specifying which
72 * irqs can be used for MSI. If found those irqs reserved in the device tree
73 * are reserved in the bitmap.
74 *
75 * Returns 0 for success, < 0 if there was an error, and > 0 if no property
76 * was found in the device tree.
77 **/
78int msi_bitmap_reserve_dt_hwirqs(struct msi_bitmap *bmp)
79{
80 int i, j, len;
81 const u32 *p;
82
83 if (!bmp->of_node)
84 return 1;
85
86 p = of_get_property(bmp->of_node, "msi-available-ranges", &len);
87 if (!p) {
88 pr_debug("msi_bitmap: no msi-available-ranges property " \
89 "found on %s\n", bmp->of_node->full_name);
90 return 1;
91 }
92
93 if (len % (2 * sizeof(u32)) != 0) {
94 printk(KERN_WARNING "msi_bitmap: Malformed msi-available-ranges"
95 " property on %s\n", bmp->of_node->full_name);
96 return -EINVAL;
97 }
98
99 bitmap_allocate_region(bmp->bitmap, 0, get_count_order(bmp->irq_count));
100
101 spin_lock(&bmp->lock);
102
103 /* Format is: (<u32 start> <u32 count>)+ */
104 len /= 2 * sizeof(u32);
105 for (i = 0; i < len; i++, p += 2) {
106 for (j = 0; j < *(p + 1); j++)
107 bitmap_release_region(bmp->bitmap, *p + j, 0);
108 }
109
110 spin_unlock(&bmp->lock);
111
112 return 0;
113}
114
115int __init_refok msi_bitmap_alloc(struct msi_bitmap *bmp, unsigned int irq_count,
116 struct device_node *of_node)
117{
118 int size;
119
120 if (!irq_count)
121 return -EINVAL;
122
123 size = BITS_TO_LONGS(irq_count) * sizeof(long);
124 pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n", size);
125
126 bmp->bitmap_from_slab = slab_is_available();
127 if (bmp->bitmap_from_slab)
128 bmp->bitmap = kzalloc(size, GFP_KERNEL);
129 else {
130 bmp->bitmap = memblock_virt_alloc(size, 0);
131 /* the bitmap won't be freed from memblock allocator */
132 kmemleak_not_leak(bmp->bitmap);
133 }
134
135 if (!bmp->bitmap) {
136 pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n");
137 return -ENOMEM;
138 }
139
140 /* We zalloc'ed the bitmap, so all irqs are free by default */
141 spin_lock_init(&bmp->lock);
142 bmp->of_node = of_node_get(of_node);
143 bmp->irq_count = irq_count;
144
145 return 0;
146}
147
148void msi_bitmap_free(struct msi_bitmap *bmp)
149{
150 if (bmp->bitmap_from_slab)
151 kfree(bmp->bitmap);
152 of_node_put(bmp->of_node);
153 bmp->bitmap = NULL;
154}
155
156#ifdef CONFIG_MSI_BITMAP_SELFTEST
157
158static void __init test_basics(void)
159{
160 struct msi_bitmap bmp;
161 int rc, i, size = 512;
162
163 /* Can't allocate a bitmap of 0 irqs */
164 WARN_ON(msi_bitmap_alloc(&bmp, 0, NULL) == 0);
165
166 /* of_node may be NULL */
167 WARN_ON(msi_bitmap_alloc(&bmp, size, NULL));
168
169 /* Should all be free by default */
170 WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
171 bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
172
173 /* With no node, there's no msi-available-ranges, so expect > 0 */
174 WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);
175
176 /* Should all still be free */
177 WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
178 bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
179
180 /* Check we can fill it up and then no more */
181 for (i = 0; i < size; i++)
182 WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0);
183
184 WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0);
185
186 /* Should all be allocated */
187 WARN_ON(bitmap_find_free_region(bmp.bitmap, size, 0) >= 0);
188
189 /* And if we free one we can then allocate another */
190 msi_bitmap_free_hwirqs(&bmp, size / 2, 1);
191 WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) != size / 2);
192
193 /* Free most of them for the alignment tests */
194 msi_bitmap_free_hwirqs(&bmp, 3, size - 3);
195
196 /* Check we get a naturally aligned offset */
197 rc = msi_bitmap_alloc_hwirqs(&bmp, 2);
198 WARN_ON(rc < 0 && rc % 2 != 0);
199 rc = msi_bitmap_alloc_hwirqs(&bmp, 4);
200 WARN_ON(rc < 0 && rc % 4 != 0);
201 rc = msi_bitmap_alloc_hwirqs(&bmp, 8);
202 WARN_ON(rc < 0 && rc % 8 != 0);
203 rc = msi_bitmap_alloc_hwirqs(&bmp, 9);
204 WARN_ON(rc < 0 && rc % 16 != 0);
205 rc = msi_bitmap_alloc_hwirqs(&bmp, 3);
206 WARN_ON(rc < 0 && rc % 4 != 0);
207 rc = msi_bitmap_alloc_hwirqs(&bmp, 7);
208 WARN_ON(rc < 0 && rc % 8 != 0);
209 rc = msi_bitmap_alloc_hwirqs(&bmp, 121);
210 WARN_ON(rc < 0 && rc % 128 != 0);
211
212 msi_bitmap_free(&bmp);
213
214 /* Clients may WARN_ON bitmap == NULL for "not-allocated" */
215 WARN_ON(bmp.bitmap != NULL);
216}
217
218static void __init test_of_node(void)
219{
220 u32 prop_data[] = { 10, 10, 25, 3, 40, 1, 100, 100, 200, 20 };
221 const char *expected_str = "0-9,20-24,28-39,41-99,220-255";
222 char *prop_name = "msi-available-ranges";
223 char *node_name = "/fakenode";
224 struct device_node of_node;
225 struct property prop;
226 struct msi_bitmap bmp;
227 int size = 256;
228 DECLARE_BITMAP(expected, size);
229
230 /* There should really be a struct device_node allocator */
231 memset(&of_node, 0, sizeof(of_node));
232 of_node_init(&of_node);
233 of_node.full_name = node_name;
234
235 WARN_ON(msi_bitmap_alloc(&bmp, size, &of_node));
236
237 /* No msi-available-ranges, so expect > 0 */
238 WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);
239
240 /* Should all still be free */
241 WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
242 bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
243
244 /* Now create a fake msi-available-ranges property */
245
246 /* There should really .. oh whatever */
247 memset(&prop, 0, sizeof(prop));
248 prop.name = prop_name;
249 prop.value = &prop_data;
250 prop.length = sizeof(prop_data);
251
252 of_node.properties = ∝
253
254 /* msi-available-ranges, so expect == 0 */
255 WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp));
256
257 /* Check we got the expected result */
258 WARN_ON(bitmap_parselist(expected_str, expected, size));
259 WARN_ON(!bitmap_equal(expected, bmp.bitmap, size));
260
261 msi_bitmap_free(&bmp);
262 kfree(bmp.bitmap);
263}
264
265static int __init msi_bitmap_selftest(void)
266{
267 printk(KERN_DEBUG "Running MSI bitmap self-tests ...\n");
268
269 test_basics();
270 test_of_node();
271
272 return 0;
273}
274late_initcall(msi_bitmap_selftest);
275#endif /* CONFIG_MSI_BITMAP_SELFTEST */