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