1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright 2006-2008, Michael Ellerman, IBM Corporation. |
4 | */ |
5 | |
6 | #include <linux/slab.h> |
7 | #include <linux/kernel.h> |
8 | #include <linux/kmemleak.h> |
9 | #include <linux/bitmap.h> |
10 | #include <linux/memblock.h> |
11 | #include <linux/of.h> |
12 | #include <asm/msi_bitmap.h> |
13 | #include <asm/setup.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(count: num); |
19 | |
20 | spin_lock_irqsave(&bmp->lock, flags); |
21 | |
22 | offset = bitmap_find_next_zero_area(map: bmp->bitmap, size: bmp->irq_count, start: 0, |
23 | nr: num, align_mask: (1 << order) - 1); |
24 | if (offset > bmp->irq_count) |
25 | goto err; |
26 | |
27 | bitmap_set(map: bmp->bitmap, start: offset, nbits: num); |
28 | spin_unlock_irqrestore(lock: &bmp->lock, flags); |
29 | |
30 | pr_debug("msi_bitmap: allocated 0x%x at offset 0x%x\n" , num, offset); |
31 | |
32 | return offset; |
33 | err: |
34 | spin_unlock_irqrestore(lock: &bmp->lock, flags); |
35 | return -ENOMEM; |
36 | } |
37 | EXPORT_SYMBOL(msi_bitmap_alloc_hwirqs); |
38 | |
39 | void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset, |
40 | unsigned int num) |
41 | { |
42 | unsigned long flags; |
43 | |
44 | pr_debug("msi_bitmap: freeing 0x%x at offset 0x%x\n" , |
45 | num, offset); |
46 | |
47 | spin_lock_irqsave(&bmp->lock, flags); |
48 | bitmap_clear(map: bmp->bitmap, start: offset, nbits: num); |
49 | spin_unlock_irqrestore(lock: &bmp->lock, flags); |
50 | } |
51 | EXPORT_SYMBOL(msi_bitmap_free_hwirqs); |
52 | |
53 | void msi_bitmap_reserve_hwirq(struct msi_bitmap *bmp, unsigned int hwirq) |
54 | { |
55 | unsigned long flags; |
56 | |
57 | pr_debug("msi_bitmap: reserving hwirq 0x%x\n" , hwirq); |
58 | |
59 | spin_lock_irqsave(&bmp->lock, flags); |
60 | bitmap_allocate_region(bitmap: bmp->bitmap, pos: hwirq, order: 0); |
61 | spin_unlock_irqrestore(lock: &bmp->lock, flags); |
62 | } |
63 | |
64 | /** |
65 | * msi_bitmap_reserve_dt_hwirqs - Reserve irqs specified in the device tree. |
66 | * @bmp: pointer to the MSI bitmap. |
67 | * |
68 | * Looks in the device tree to see if there is a property specifying which |
69 | * irqs can be used for MSI. If found those irqs reserved in the device tree |
70 | * are reserved in the bitmap. |
71 | * |
72 | * Returns 0 for success, < 0 if there was an error, and > 0 if no property |
73 | * was found in the device tree. |
74 | **/ |
75 | int msi_bitmap_reserve_dt_hwirqs(struct msi_bitmap *bmp) |
76 | { |
77 | int i, j, len; |
78 | const u32 *p; |
79 | |
80 | if (!bmp->of_node) |
81 | return 1; |
82 | |
83 | p = of_get_property(node: bmp->of_node, name: "msi-available-ranges" , lenp: &len); |
84 | if (!p) { |
85 | pr_debug("msi_bitmap: no msi-available-ranges property " \ |
86 | "found on %pOF\n" , bmp->of_node); |
87 | return 1; |
88 | } |
89 | |
90 | if (len % (2 * sizeof(u32)) != 0) { |
91 | printk(KERN_WARNING "msi_bitmap: Malformed msi-available-ranges" |
92 | " property on %pOF\n" , bmp->of_node); |
93 | return -EINVAL; |
94 | } |
95 | |
96 | bitmap_allocate_region(bitmap: bmp->bitmap, pos: 0, order: get_count_order(count: bmp->irq_count)); |
97 | |
98 | spin_lock(lock: &bmp->lock); |
99 | |
100 | /* Format is: (<u32 start> <u32 count>)+ */ |
101 | len /= 2 * sizeof(u32); |
102 | for (i = 0; i < len; i++, p += 2) { |
103 | for (j = 0; j < *(p + 1); j++) |
104 | bitmap_release_region(bitmap: bmp->bitmap, pos: *p + j, order: 0); |
105 | } |
106 | |
107 | spin_unlock(lock: &bmp->lock); |
108 | |
109 | return 0; |
110 | } |
111 | |
112 | int __ref msi_bitmap_alloc(struct msi_bitmap *bmp, unsigned int irq_count, |
113 | struct device_node *of_node) |
114 | { |
115 | int size; |
116 | |
117 | if (!irq_count) |
118 | return -EINVAL; |
119 | |
120 | size = BITS_TO_LONGS(irq_count) * sizeof(long); |
121 | pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n" , size); |
122 | |
123 | bmp->bitmap_from_slab = slab_is_available(); |
124 | if (bmp->bitmap_from_slab) |
125 | bmp->bitmap = kzalloc(size, GFP_KERNEL); |
126 | else { |
127 | bmp->bitmap = memblock_alloc(size, SMP_CACHE_BYTES); |
128 | if (!bmp->bitmap) |
129 | panic(fmt: "%s: Failed to allocate %u bytes\n" , __func__, |
130 | size); |
131 | /* the bitmap won't be freed from memblock allocator */ |
132 | kmemleak_not_leak(ptr: 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(node: of_node); |
143 | bmp->irq_count = irq_count; |
144 | |
145 | return 0; |
146 | } |
147 | |
148 | void msi_bitmap_free(struct msi_bitmap *bmp) |
149 | { |
150 | if (bmp->bitmap_from_slab) |
151 | kfree(objp: bmp->bitmap); |
152 | of_node_put(node: bmp->of_node); |
153 | bmp->bitmap = NULL; |
154 | } |
155 | |
156 | #ifdef CONFIG_MSI_BITMAP_SELFTEST |
157 | |
158 | static 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 | |
218 | static 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 | #define SIZE_EXPECTED 256 |
228 | DECLARE_BITMAP(expected, SIZE_EXPECTED); |
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_EXPECTED, &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_EXPECTED, |
242 | get_count_order(SIZE_EXPECTED))); |
243 | bitmap_release_region(bmp.bitmap, 0, get_count_order(SIZE_EXPECTED)); |
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_EXPECTED)); |
260 | WARN_ON(!bitmap_equal(expected, bmp.bitmap, SIZE_EXPECTED)); |
261 | |
262 | msi_bitmap_free(&bmp); |
263 | kfree(bmp.bitmap); |
264 | } |
265 | |
266 | static 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 | } |
275 | late_initcall(msi_bitmap_selftest); |
276 | #endif /* CONFIG_MSI_BITMAP_SELFTEST */ |
277 | |