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 18 int 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; 36 err: 37 spin_unlock_irqrestore(&bmp->lock, flags); 38 return -ENOMEM; 39 } 40 EXPORT_SYMBOL(msi_bitmap_alloc_hwirqs); 41 42 void 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 } 54 EXPORT_SYMBOL(msi_bitmap_free_hwirqs); 55 56 void 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 **/ 78 int 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 } 114 115 int __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 } 147 148 void 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 157 158 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 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 } 264 265 static 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 } 274 late_initcall(msi_bitmap_selftest); 275 #endif /* CONFIG_MSI_BITMAP_SELFTEST */ 276