2 * Copyright 2006-2008, Michael Ellerman, IBM Corporation.
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
11 #include <linux/slab.h>
12 #include <linux/kernel.h>
13 #include <linux/kmemleak.h>
14 #include <linux/bitmap.h>
15 #include <linux/memblock.h>
16 #include <asm/msi_bitmap.h>
17 #include <asm/setup.h>
19 int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num)
22 int offset, order = get_count_order(num);
24 spin_lock_irqsave(&bmp->lock, flags);
26 offset = bitmap_find_next_zero_area(bmp->bitmap, bmp->irq_count, 0,
27 num, (1 << order) - 1);
28 if (offset > bmp->irq_count)
31 bitmap_set(bmp->bitmap, offset, num);
32 spin_unlock_irqrestore(&bmp->lock, flags);
34 pr_debug("msi_bitmap: allocated 0x%x at offset 0x%x\n", num, offset);
38 spin_unlock_irqrestore(&bmp->lock, flags);
41 EXPORT_SYMBOL(msi_bitmap_alloc_hwirqs);
43 void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset,
48 pr_debug("msi_bitmap: freeing 0x%x at offset 0x%x\n",
51 spin_lock_irqsave(&bmp->lock, flags);
52 bitmap_clear(bmp->bitmap, offset, num);
53 spin_unlock_irqrestore(&bmp->lock, flags);
55 EXPORT_SYMBOL(msi_bitmap_free_hwirqs);
57 void msi_bitmap_reserve_hwirq(struct msi_bitmap *bmp, unsigned int hwirq)
61 pr_debug("msi_bitmap: reserving hwirq 0x%x\n", hwirq);
63 spin_lock_irqsave(&bmp->lock, flags);
64 bitmap_allocate_region(bmp->bitmap, hwirq, 0);
65 spin_unlock_irqrestore(&bmp->lock, flags);
69 * msi_bitmap_reserve_dt_hwirqs - Reserve irqs specified in the device tree.
70 * @bmp: pointer to the MSI bitmap.
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.
76 * Returns 0 for success, < 0 if there was an error, and > 0 if no property
77 * was found in the device tree.
79 int msi_bitmap_reserve_dt_hwirqs(struct msi_bitmap *bmp)
87 p = of_get_property(bmp->of_node, "msi-available-ranges", &len);
89 pr_debug("msi_bitmap: no msi-available-ranges property " \
90 "found on %pOF\n", bmp->of_node);
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);
100 bitmap_allocate_region(bmp->bitmap, 0, get_count_order(bmp->irq_count));
102 spin_lock(&bmp->lock);
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);
111 spin_unlock(&bmp->lock);
116 int __ref msi_bitmap_alloc(struct msi_bitmap *bmp, unsigned int irq_count,
117 struct device_node *of_node)
124 size = BITS_TO_LONGS(irq_count) * sizeof(long);
125 pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n", size);
127 bmp->bitmap_from_slab = slab_is_available();
128 if (bmp->bitmap_from_slab)
129 bmp->bitmap = kzalloc(size, GFP_KERNEL);
131 bmp->bitmap = memblock_alloc(size, SMP_CACHE_BYTES);
133 panic("%s: Failed to allocate %u bytes\n", __func__,
135 /* the bitmap won't be freed from memblock allocator */
136 kmemleak_not_leak(bmp->bitmap);
140 pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n");
144 /* We zalloc'ed the bitmap, so all irqs are free by default */
145 spin_lock_init(&bmp->lock);
146 bmp->of_node = of_node_get(of_node);
147 bmp->irq_count = irq_count;
152 void msi_bitmap_free(struct msi_bitmap *bmp)
154 if (bmp->bitmap_from_slab)
156 of_node_put(bmp->of_node);
160 #ifdef CONFIG_MSI_BITMAP_SELFTEST
162 static void __init test_basics(void)
164 struct msi_bitmap bmp;
165 int rc, i, size = 512;
167 /* Can't allocate a bitmap of 0 irqs */
168 WARN_ON(msi_bitmap_alloc(&bmp, 0, NULL) == 0);
170 /* of_node may be NULL */
171 WARN_ON(msi_bitmap_alloc(&bmp, size, NULL));
173 /* Should all be free by default */
174 WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
175 bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
177 /* With no node, there's no msi-available-ranges, so expect > 0 */
178 WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);
180 /* Should all still be free */
181 WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size)));
182 bitmap_release_region(bmp.bitmap, 0, get_count_order(size));
184 /* Check we can fill it up and then no more */
185 for (i = 0; i < size; i++)
186 WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0);
188 WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0);
190 /* Should all be allocated */
191 WARN_ON(bitmap_find_free_region(bmp.bitmap, size, 0) >= 0);
193 /* And if we free one we can then allocate another */
194 msi_bitmap_free_hwirqs(&bmp, size / 2, 1);
195 WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) != size / 2);
197 /* Free most of them for the alignment tests */
198 msi_bitmap_free_hwirqs(&bmp, 3, size - 3);
200 /* Check we get a naturally aligned offset */
201 rc = msi_bitmap_alloc_hwirqs(&bmp, 2);
202 WARN_ON(rc < 0 && rc % 2 != 0);
203 rc = msi_bitmap_alloc_hwirqs(&bmp, 4);
204 WARN_ON(rc < 0 && rc % 4 != 0);
205 rc = msi_bitmap_alloc_hwirqs(&bmp, 8);
206 WARN_ON(rc < 0 && rc % 8 != 0);
207 rc = msi_bitmap_alloc_hwirqs(&bmp, 9);
208 WARN_ON(rc < 0 && rc % 16 != 0);
209 rc = msi_bitmap_alloc_hwirqs(&bmp, 3);
210 WARN_ON(rc < 0 && rc % 4 != 0);
211 rc = msi_bitmap_alloc_hwirqs(&bmp, 7);
212 WARN_ON(rc < 0 && rc % 8 != 0);
213 rc = msi_bitmap_alloc_hwirqs(&bmp, 121);
214 WARN_ON(rc < 0 && rc % 128 != 0);
216 msi_bitmap_free(&bmp);
218 /* Clients may WARN_ON bitmap == NULL for "not-allocated" */
219 WARN_ON(bmp.bitmap != NULL);
222 static void __init test_of_node(void)
224 u32 prop_data[] = { 10, 10, 25, 3, 40, 1, 100, 100, 200, 20 };
225 const char *expected_str = "0-9,20-24,28-39,41-99,220-255";
226 char *prop_name = "msi-available-ranges";
227 char *node_name = "/fakenode";
228 struct device_node of_node;
229 struct property prop;
230 struct msi_bitmap bmp;
231 #define SIZE_EXPECTED 256
232 DECLARE_BITMAP(expected, SIZE_EXPECTED);
234 /* There should really be a struct device_node allocator */
235 memset(&of_node, 0, sizeof(of_node));
236 of_node_init(&of_node);
237 of_node.full_name = node_name;
239 WARN_ON(msi_bitmap_alloc(&bmp, SIZE_EXPECTED, &of_node));
241 /* No msi-available-ranges, so expect > 0 */
242 WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0);
244 /* Should all still be free */
245 WARN_ON(bitmap_find_free_region(bmp.bitmap, SIZE_EXPECTED,
246 get_count_order(SIZE_EXPECTED)));
247 bitmap_release_region(bmp.bitmap, 0, get_count_order(SIZE_EXPECTED));
249 /* Now create a fake msi-available-ranges property */
251 /* There should really .. oh whatever */
252 memset(&prop, 0, sizeof(prop));
253 prop.name = prop_name;
254 prop.value = &prop_data;
255 prop.length = sizeof(prop_data);
257 of_node.properties = ∝
259 /* msi-available-ranges, so expect == 0 */
260 WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp));
262 /* Check we got the expected result */
263 WARN_ON(bitmap_parselist(expected_str, expected, SIZE_EXPECTED));
264 WARN_ON(!bitmap_equal(expected, bmp.bitmap, SIZE_EXPECTED));
266 msi_bitmap_free(&bmp);
270 static int __init msi_bitmap_selftest(void)
272 printk(KERN_DEBUG "Running MSI bitmap self-tests ...\n");
279 late_initcall(msi_bitmap_selftest);
280 #endif /* CONFIG_MSI_BITMAP_SELFTEST */