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(num); 19 20 spin_lock_irqsave(&bmp->lock, flags); 21 22 offset = bitmap_find_next_zero_area(bmp->bitmap, bmp->irq_count, 0, 23 num, (1 << order) - 1); 24 if (offset > bmp->irq_count) 25 goto err; 26 27 bitmap_set(bmp->bitmap, offset, num); 28 spin_unlock_irqrestore(&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(&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(bmp->bitmap, offset, num); 49 spin_unlock_irqrestore(&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(bmp->bitmap, hwirq, 0); 61 spin_unlock_irqrestore(&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(bmp->of_node, "msi-available-ranges", &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(bmp->bitmap, 0, get_count_order(bmp->irq_count)); 97 98 spin_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(bmp->bitmap, *p + j, 0); 105 } 106 107 spin_unlock(&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_or_panic(size, SMP_CACHE_BYTES); 128 /* the bitmap won't be freed from memblock allocator */ 129 kmemleak_not_leak(bmp->bitmap); 130 } 131 132 if (!bmp->bitmap) { 133 pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n"); 134 return -ENOMEM; 135 } 136 137 /* We zalloc'ed the bitmap, so all irqs are free by default */ 138 spin_lock_init(&bmp->lock); 139 bmp->of_node = of_node_get(of_node); 140 bmp->irq_count = irq_count; 141 142 return 0; 143 } 144 145 void msi_bitmap_free(struct msi_bitmap *bmp) 146 { 147 if (bmp->bitmap_from_slab) 148 kfree(bmp->bitmap); 149 of_node_put(bmp->of_node); 150 bmp->bitmap = NULL; 151 } 152 153 #ifdef CONFIG_MSI_BITMAP_SELFTEST 154 155 static void __init test_basics(void) 156 { 157 struct msi_bitmap bmp; 158 int rc, i, size = 512; 159 160 /* Can't allocate a bitmap of 0 irqs */ 161 WARN_ON(msi_bitmap_alloc(&bmp, 0, NULL) == 0); 162 163 /* of_node may be NULL */ 164 WARN_ON(msi_bitmap_alloc(&bmp, size, NULL)); 165 166 /* Should all be free by default */ 167 WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size))); 168 bitmap_release_region(bmp.bitmap, 0, get_count_order(size)); 169 170 /* With no node, there's no msi-available-ranges, so expect > 0 */ 171 WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0); 172 173 /* Should all still be free */ 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)); 176 177 /* Check we can fill it up and then no more */ 178 for (i = 0; i < size; i++) 179 WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0); 180 181 WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0); 182 183 /* Should all be allocated */ 184 WARN_ON(bitmap_find_free_region(bmp.bitmap, size, 0) >= 0); 185 186 /* And if we free one we can then allocate another */ 187 msi_bitmap_free_hwirqs(&bmp, size / 2, 1); 188 WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) != size / 2); 189 190 /* Free most of them for the alignment tests */ 191 msi_bitmap_free_hwirqs(&bmp, 3, size - 3); 192 193 /* Check we get a naturally aligned offset */ 194 rc = msi_bitmap_alloc_hwirqs(&bmp, 2); 195 WARN_ON(rc < 0 && rc % 2 != 0); 196 rc = msi_bitmap_alloc_hwirqs(&bmp, 4); 197 WARN_ON(rc < 0 && rc % 4 != 0); 198 rc = msi_bitmap_alloc_hwirqs(&bmp, 8); 199 WARN_ON(rc < 0 && rc % 8 != 0); 200 rc = msi_bitmap_alloc_hwirqs(&bmp, 9); 201 WARN_ON(rc < 0 && rc % 16 != 0); 202 rc = msi_bitmap_alloc_hwirqs(&bmp, 3); 203 WARN_ON(rc < 0 && rc % 4 != 0); 204 rc = msi_bitmap_alloc_hwirqs(&bmp, 7); 205 WARN_ON(rc < 0 && rc % 8 != 0); 206 rc = msi_bitmap_alloc_hwirqs(&bmp, 121); 207 WARN_ON(rc < 0 && rc % 128 != 0); 208 209 msi_bitmap_free(&bmp); 210 211 /* Clients may WARN_ON bitmap == NULL for "not-allocated" */ 212 WARN_ON(bmp.bitmap != NULL); 213 } 214 215 static void __init test_of_node(void) 216 { 217 u32 prop_data[] = { 10, 10, 25, 3, 40, 1, 100, 100, 200, 20 }; 218 const char *expected_str = "0-9,20-24,28-39,41-99,220-255"; 219 char *prop_name = "msi-available-ranges"; 220 char *node_name = "/fakenode"; 221 struct device_node of_node; 222 struct property prop; 223 struct msi_bitmap bmp; 224 #define SIZE_EXPECTED 256 225 DECLARE_BITMAP(expected, SIZE_EXPECTED); 226 227 /* There should really be a struct device_node allocator */ 228 memset(&of_node, 0, sizeof(of_node)); 229 of_node_init(&of_node); 230 of_node.full_name = node_name; 231 232 WARN_ON(msi_bitmap_alloc(&bmp, SIZE_EXPECTED, &of_node)); 233 234 /* No msi-available-ranges, so expect > 0 */ 235 WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0); 236 237 /* Should all still be free */ 238 WARN_ON(bitmap_find_free_region(bmp.bitmap, SIZE_EXPECTED, 239 get_count_order(SIZE_EXPECTED))); 240 bitmap_release_region(bmp.bitmap, 0, get_count_order(SIZE_EXPECTED)); 241 242 /* Now create a fake msi-available-ranges property */ 243 244 /* There should really .. oh whatever */ 245 memset(&prop, 0, sizeof(prop)); 246 prop.name = prop_name; 247 prop.value = &prop_data; 248 prop.length = sizeof(prop_data); 249 250 of_node.properties = ∝ 251 252 /* msi-available-ranges, so expect == 0 */ 253 WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp)); 254 255 /* Check we got the expected result */ 256 WARN_ON(bitmap_parselist(expected_str, expected, SIZE_EXPECTED)); 257 WARN_ON(!bitmap_equal(expected, bmp.bitmap, SIZE_EXPECTED)); 258 259 msi_bitmap_free(&bmp); 260 kfree(bmp.bitmap); 261 } 262 263 static int __init msi_bitmap_selftest(void) 264 { 265 printk(KERN_DEBUG "Running MSI bitmap self-tests ...\n"); 266 267 test_basics(); 268 test_of_node(); 269 270 return 0; 271 } 272 late_initcall(msi_bitmap_selftest); 273 #endif /* CONFIG_MSI_BITMAP_SELFTEST */ 274