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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 | // SPDX-License-Identifier: GPL-2.0 /* * CMA DebugFS Interface * * Copyright (c) 2015 Sasha Levin <sasha.levin@oracle.com> */ #include <linux/debugfs.h> #include <linux/cma.h> #include <linux/list.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/mm_types.h> #include "cma.h" struct cma_mem { struct hlist_node node; struct page *p; unsigned long n; }; static int cma_debugfs_get(void *data, u64 *val) { unsigned long *p = data; *val = *p; return 0; } DEFINE_DEBUGFS_ATTRIBUTE(cma_debugfs_fops, cma_debugfs_get, NULL, "%llu\n"); static int cma_used_get(void *data, u64 *val) { struct cma *cma = data; unsigned long used; spin_lock_irq(&cma->lock); /* pages counter is smaller than sizeof(int) */ used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma)); spin_unlock_irq(&cma->lock); *val = (u64)used << cma->order_per_bit; return 0; } DEFINE_DEBUGFS_ATTRIBUTE(cma_used_fops, cma_used_get, NULL, "%llu\n"); static int cma_maxchunk_get(void *data, u64 *val) { struct cma *cma = data; unsigned long maxchunk = 0; unsigned long start, end = 0; unsigned long bitmap_maxno = cma_bitmap_maxno(cma); spin_lock_irq(&cma->lock); for (;;) { start = find_next_zero_bit(cma->bitmap, bitmap_maxno, end); if (start >= bitmap_maxno) break; end = find_next_bit(cma->bitmap, bitmap_maxno, start); maxchunk = max(end - start, maxchunk); } spin_unlock_irq(&cma->lock); *val = (u64)maxchunk << cma->order_per_bit; return 0; } DEFINE_DEBUGFS_ATTRIBUTE(cma_maxchunk_fops, cma_maxchunk_get, NULL, "%llu\n"); static void cma_add_to_cma_mem_list(struct cma *cma, struct cma_mem *mem) { spin_lock(&cma->mem_head_lock); hlist_add_head(&mem->node, &cma->mem_head); spin_unlock(&cma->mem_head_lock); } static struct cma_mem *cma_get_entry_from_list(struct cma *cma) { struct cma_mem *mem = NULL; spin_lock(&cma->mem_head_lock); if (!hlist_empty(&cma->mem_head)) { mem = hlist_entry(cma->mem_head.first, struct cma_mem, node); hlist_del_init(&mem->node); } spin_unlock(&cma->mem_head_lock); return mem; } static int cma_free_mem(struct cma *cma, int count) { struct cma_mem *mem = NULL; while (count) { mem = cma_get_entry_from_list(cma); if (mem == NULL) return 0; if (mem->n <= count) { cma_release(cma, mem->p, mem->n); count -= mem->n; kfree(mem); } else if (cma->order_per_bit == 0) { cma_release(cma, mem->p, count); mem->p += count; mem->n -= count; count = 0; cma_add_to_cma_mem_list(cma, mem); } else { pr_debug("cma: cannot release partial block when order_per_bit != 0\n"); cma_add_to_cma_mem_list(cma, mem); break; } } return 0; } static int cma_free_write(void *data, u64 val) { int pages = val; struct cma *cma = data; return cma_free_mem(cma, pages); } DEFINE_DEBUGFS_ATTRIBUTE(cma_free_fops, NULL, cma_free_write, "%llu\n"); static int cma_alloc_mem(struct cma *cma, int count) { struct cma_mem *mem; struct page *p; mem = kzalloc(sizeof(*mem), GFP_KERNEL); if (!mem) return -ENOMEM; p = cma_alloc(cma, count, 0, false); if (!p) { kfree(mem); return -ENOMEM; } mem->p = p; mem->n = count; cma_add_to_cma_mem_list(cma, mem); return 0; } static int cma_alloc_write(void *data, u64 val) { int pages = val; struct cma *cma = data; return cma_alloc_mem(cma, pages); } DEFINE_DEBUGFS_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n"); static void cma_debugfs_add_one(struct cma *cma, struct dentry *root_dentry) { struct dentry *tmp; tmp = debugfs_create_dir(cma->name, root_dentry); debugfs_create_file("alloc", 0200, tmp, cma, &cma_alloc_fops); debugfs_create_file("free", 0200, tmp, cma, &cma_free_fops); debugfs_create_file("base_pfn", 0444, tmp, &cma->base_pfn, &cma_debugfs_fops); debugfs_create_file("count", 0444, tmp, &cma->count, &cma_debugfs_fops); debugfs_create_file("order_per_bit", 0444, tmp, &cma->order_per_bit, &cma_debugfs_fops); debugfs_create_file("used", 0444, tmp, cma, &cma_used_fops); debugfs_create_file("maxchunk", 0444, tmp, cma, &cma_maxchunk_fops); cma->dfs_bitmap.array = (u32 *)cma->bitmap; cma->dfs_bitmap.n_elements = DIV_ROUND_UP(cma_bitmap_maxno(cma), BITS_PER_BYTE * sizeof(u32)); debugfs_create_u32_array("bitmap", 0444, tmp, &cma->dfs_bitmap); } static int __init cma_debugfs_init(void) { struct dentry *cma_debugfs_root; int i; cma_debugfs_root = debugfs_create_dir("cma", NULL); for (i = 0; i < cma_area_count; i++) cma_debugfs_add_one(&cma_areas[i], cma_debugfs_root); return 0; } late_initcall(cma_debugfs_init); |