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 <asm/msi_bitmap.h> 12 #include <asm/setup.h> 13 14 int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num) 15 { 16 unsigned long flags; 17 int offset, order = get_count_order(num); 18 19 spin_lock_irqsave(&bmp->lock, flags); 20 21 offset = bitmap_find_next_zero_area(bmp->bitmap, bmp->irq_count, 0, 22 num, (1 << order) - 1); 23 if (offset > bmp->irq_count) 24 goto err; 25 26 bitmap_set(bmp->bitmap, offset, num); 27 spin_unlock_irqrestore(&bmp->lock, flags); 28 29 pr_debug("msi_bitmap: allocated 0x%x at offset 0x%x\n", num, offset); 30 31 return offset; 32 err: 33 spin_unlock_irqrestore(&bmp->lock, flags); 34 return -ENOMEM; 35 } 36 EXPORT_SYMBOL(msi_bitmap_alloc_hwirqs); 37 38 void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset, 39 unsigned int num) 40 { 41 unsigned long flags; 42 43 pr_debug("msi_bitmap: freeing 0x%x at offset 0x%x\n", 44 num, offset); 45 46 spin_lock_irqsave(&bmp->lock, flags); 47 bitmap_clear(bmp->bitmap, offset, num); 48 spin_unlock_irqrestore(&bmp->lock, flags); 49 } 50 EXPORT_SYMBOL(msi_bitmap_free_hwirqs); 51 52 void msi_bitmap_reserve_hwirq(struct msi_bitmap *bmp, unsigned int hwirq) 53 { 54 unsigned long flags; 55 56 pr_debug("msi_bitmap: reserving hwirq 0x%x\n", hwirq); 57 58 spin_lock_irqsave(&bmp->lock, flags); 59 bitmap_allocate_region(bmp->bitmap, hwirq, 0); 60 spin_unlock_irqrestore(&bmp->lock, flags); 61 } 62 63 /** 64 * msi_bitmap_reserve_dt_hwirqs - Reserve irqs specified in the device tree. 65 * @bmp: pointer to the MSI bitmap. 66 * 67 * Looks in the device tree to see if there is a property specifying which 68 * irqs can be used for MSI. If found those irqs reserved in the device tree 69 * are reserved in the bitmap. 70 * 71 * Returns 0 for success, < 0 if there was an error, and > 0 if no property 72 * was found in the device tree. 73 **/ 74 int msi_bitmap_reserve_dt_hwirqs(struct msi_bitmap *bmp) 75 { 76 int i, j, len; 77 const u32 *p; 78 79 if (!bmp->of_node) 80 return 1; 81 82 p = of_get_property(bmp->of_node, "msi-available-ranges", &len); 83 if (!p) { 84 pr_debug("msi_bitmap: no msi-available-ranges property " \ 85 "found on %pOF\n", bmp->of_node); 86 return 1; 87 } 88 89 if (len % (2 * sizeof(u32)) != 0) { 90 printk(KERN_WARNING "msi_bitmap: Malformed msi-available-ranges" 91 " property on %pOF\n", bmp->of_node); 92 return -EINVAL; 93 } 94 95 bitmap_allocate_region(bmp->bitmap, 0, get_count_order(bmp->irq_count)); 96 97 spin_lock(&bmp->lock); 98 99 /* Format is: (<u32 start> <u32 count>)+ */ 100 len /= 2 * sizeof(u32); 101 for (i = 0; i < len; i++, p += 2) { 102 for (j = 0; j < *(p + 1); j++) 103 bitmap_release_region(bmp->bitmap, *p + j, 0); 104 } 105 106 spin_unlock(&bmp->lock); 107 108 return 0; 109 } 110 111 int __ref msi_bitmap_alloc(struct msi_bitmap *bmp, unsigned int irq_count, 112 struct device_node *of_node) 113 { 114 int size; 115 116 if (!irq_count) 117 return -EINVAL; 118 119 size = BITS_TO_LONGS(irq_count) * sizeof(long); 120 pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n", size); 121 122 bmp->bitmap_from_slab = slab_is_available(); 123 if (bmp->bitmap_from_slab) 124 bmp->bitmap = kzalloc(size, GFP_KERNEL); 125 else { 126 bmp->bitmap = memblock_alloc(size, SMP_CACHE_BYTES); 127 if (!bmp->bitmap) 128 panic("%s: Failed to allocate %u bytes\n", __func__, 129 size); 130 /* the bitmap won't be freed from memblock allocator */ 131 kmemleak_not_leak(bmp->bitmap); 132 } 133 134 if (!bmp->bitmap) { 135 pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n"); 136 return -ENOMEM; 137 } 138 139 /* We zalloc'ed the bitmap, so all irqs are free by default */ 140 spin_lock_init(&bmp->lock); 141 bmp->of_node = of_node_get(of_node); 142 bmp->irq_count = irq_count; 143 144 return 0; 145 } 146 147 void msi_bitmap_free(struct msi_bitmap *bmp) 148 { 149 if (bmp->bitmap_from_slab) 150 kfree(bmp->bitmap); 151 of_node_put(bmp->of_node); 152 bmp->bitmap = NULL; 153 } 154 155 #ifdef CONFIG_MSI_BITMAP_SELFTEST 156 157 static void __init test_basics(void) 158 { 159 struct msi_bitmap bmp; 160 int rc, i, size = 512; 161 162 /* Can't allocate a bitmap of 0 irqs */ 163 WARN_ON(msi_bitmap_alloc(&bmp, 0, NULL) == 0); 164 165 /* of_node may be NULL */ 166 WARN_ON(msi_bitmap_alloc(&bmp, size, NULL)); 167 168 /* Should all be free by default */ 169 WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size))); 170 bitmap_release_region(bmp.bitmap, 0, get_count_order(size)); 171 172 /* With no node, there's no msi-available-ranges, so expect > 0 */ 173 WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0); 174 175 /* Should all still be free */ 176 WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size))); 177 bitmap_release_region(bmp.bitmap, 0, get_count_order(size)); 178 179 /* Check we can fill it up and then no more */ 180 for (i = 0; i < size; i++) 181 WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) < 0); 182 183 WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) >= 0); 184 185 /* Should all be allocated */ 186 WARN_ON(bitmap_find_free_region(bmp.bitmap, size, 0) >= 0); 187 188 /* And if we free one we can then allocate another */ 189 msi_bitmap_free_hwirqs(&bmp, size / 2, 1); 190 WARN_ON(msi_bitmap_alloc_hwirqs(&bmp, 1) != size / 2); 191 192 /* Free most of them for the alignment tests */ 193 msi_bitmap_free_hwirqs(&bmp, 3, size - 3); 194 195 /* Check we get a naturally aligned offset */ 196 rc = msi_bitmap_alloc_hwirqs(&bmp, 2); 197 WARN_ON(rc < 0 && rc % 2 != 0); 198 rc = msi_bitmap_alloc_hwirqs(&bmp, 4); 199 WARN_ON(rc < 0 && rc % 4 != 0); 200 rc = msi_bitmap_alloc_hwirqs(&bmp, 8); 201 WARN_ON(rc < 0 && rc % 8 != 0); 202 rc = msi_bitmap_alloc_hwirqs(&bmp, 9); 203 WARN_ON(rc < 0 && rc % 16 != 0); 204 rc = msi_bitmap_alloc_hwirqs(&bmp, 3); 205 WARN_ON(rc < 0 && rc % 4 != 0); 206 rc = msi_bitmap_alloc_hwirqs(&bmp, 7); 207 WARN_ON(rc < 0 && rc % 8 != 0); 208 rc = msi_bitmap_alloc_hwirqs(&bmp, 121); 209 WARN_ON(rc < 0 && rc % 128 != 0); 210 211 msi_bitmap_free(&bmp); 212 213 /* Clients may WARN_ON bitmap == NULL for "not-allocated" */ 214 WARN_ON(bmp.bitmap != NULL); 215 } 216 217 static void __init test_of_node(void) 218 { 219 u32 prop_data[] = { 10, 10, 25, 3, 40, 1, 100, 100, 200, 20 }; 220 const char *expected_str = "0-9,20-24,28-39,41-99,220-255"; 221 char *prop_name = "msi-available-ranges"; 222 char *node_name = "/fakenode"; 223 struct device_node of_node; 224 struct property prop; 225 struct msi_bitmap bmp; 226 #define SIZE_EXPECTED 256 227 DECLARE_BITMAP(expected, SIZE_EXPECTED); 228 229 /* There should really be a struct device_node allocator */ 230 memset(&of_node, 0, sizeof(of_node)); 231 of_node_init(&of_node); 232 of_node.full_name = node_name; 233 234 WARN_ON(msi_bitmap_alloc(&bmp, SIZE_EXPECTED, &of_node)); 235 236 /* No msi-available-ranges, so expect > 0 */ 237 WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0); 238 239 /* Should all still be free */ 240 WARN_ON(bitmap_find_free_region(bmp.bitmap, SIZE_EXPECTED, 241 get_count_order(SIZE_EXPECTED))); 242 bitmap_release_region(bmp.bitmap, 0, get_count_order(SIZE_EXPECTED)); 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_EXPECTED)); 259 WARN_ON(!bitmap_equal(expected, bmp.bitmap, SIZE_EXPECTED)); 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