2 * CMA DebugFS Interface
4 * Copyright (c) 2015 Sasha Levin <sasha.levin@oracle.com>
8 #include <linux/debugfs.h>
10 #include <linux/list.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/mm_types.h>
18 struct hlist_node node;
23 static struct dentry *cma_debugfs_root;
25 static int cma_debugfs_get(void *data, u64 *val)
27 unsigned long *p = data;
34 DEFINE_SIMPLE_ATTRIBUTE(cma_debugfs_fops, cma_debugfs_get, NULL, "%llu\n");
36 static int cma_used_get(void *data, u64 *val)
38 struct cma *cma = data;
41 mutex_lock(&cma->lock);
42 /* pages counter is smaller than sizeof(int) */
43 used = bitmap_weight(cma->bitmap, (int)cma->count);
44 mutex_unlock(&cma->lock);
45 *val = (u64)used << cma->order_per_bit;
50 DEFINE_SIMPLE_ATTRIBUTE(cma_used_fops, cma_used_get, NULL, "%llu\n");
52 static int cma_maxchunk_get(void *data, u64 *val)
54 struct cma *cma = data;
55 unsigned long maxchunk = 0;
56 unsigned long start, end = 0;
58 mutex_lock(&cma->lock);
60 start = find_next_zero_bit(cma->bitmap, cma->count, end);
61 if (start >= cma->count)
63 end = find_next_bit(cma->bitmap, cma->count, start);
64 maxchunk = max(end - start, maxchunk);
66 mutex_unlock(&cma->lock);
67 *val = (u64)maxchunk << cma->order_per_bit;
72 DEFINE_SIMPLE_ATTRIBUTE(cma_maxchunk_fops, cma_maxchunk_get, NULL, "%llu\n");
74 static void cma_add_to_cma_mem_list(struct cma *cma, struct cma_mem *mem)
76 spin_lock(&cma->mem_head_lock);
77 hlist_add_head(&mem->node, &cma->mem_head);
78 spin_unlock(&cma->mem_head_lock);
81 static struct cma_mem *cma_get_entry_from_list(struct cma *cma)
83 struct cma_mem *mem = NULL;
85 spin_lock(&cma->mem_head_lock);
86 if (!hlist_empty(&cma->mem_head)) {
87 mem = hlist_entry(cma->mem_head.first, struct cma_mem, node);
88 hlist_del_init(&mem->node);
90 spin_unlock(&cma->mem_head_lock);
95 static int cma_free_mem(struct cma *cma, int count)
97 struct cma_mem *mem = NULL;
100 mem = cma_get_entry_from_list(cma);
104 if (mem->n <= count) {
105 cma_release(cma, mem->p, mem->n);
108 } else if (cma->order_per_bit == 0) {
109 cma_release(cma, mem->p, count);
113 cma_add_to_cma_mem_list(cma, mem);
115 pr_debug("cma: cannot release partial block when order_per_bit != 0\n");
116 cma_add_to_cma_mem_list(cma, mem);
125 static int cma_free_write(void *data, u64 val)
128 struct cma *cma = data;
130 return cma_free_mem(cma, pages);
133 DEFINE_SIMPLE_ATTRIBUTE(cma_free_fops, NULL, cma_free_write, "%llu\n");
135 static int cma_alloc_mem(struct cma *cma, int count)
140 mem = kzalloc(sizeof(*mem), GFP_KERNEL);
144 p = cma_alloc(cma, count, 0);
153 cma_add_to_cma_mem_list(cma, mem);
158 static int cma_alloc_write(void *data, u64 val)
161 struct cma *cma = data;
163 return cma_alloc_mem(cma, pages);
166 DEFINE_SIMPLE_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n");
168 static void cma_debugfs_add_one(struct cma *cma, int idx)
174 sprintf(name, "cma-%d", idx);
176 tmp = debugfs_create_dir(name, cma_debugfs_root);
178 debugfs_create_file("alloc", S_IWUSR, cma_debugfs_root, cma,
181 debugfs_create_file("free", S_IWUSR, cma_debugfs_root, cma,
184 debugfs_create_file("base_pfn", S_IRUGO, tmp,
185 &cma->base_pfn, &cma_debugfs_fops);
186 debugfs_create_file("count", S_IRUGO, tmp,
187 &cma->count, &cma_debugfs_fops);
188 debugfs_create_file("order_per_bit", S_IRUGO, tmp,
189 &cma->order_per_bit, &cma_debugfs_fops);
190 debugfs_create_file("used", S_IRUGO, tmp, cma, &cma_used_fops);
191 debugfs_create_file("maxchunk", S_IRUGO, tmp, cma, &cma_maxchunk_fops);
193 u32s = DIV_ROUND_UP(cma_bitmap_maxno(cma), BITS_PER_BYTE * sizeof(u32));
194 debugfs_create_u32_array("bitmap", S_IRUGO, tmp, (u32*)cma->bitmap, u32s);
197 static int __init cma_debugfs_init(void)
201 cma_debugfs_root = debugfs_create_dir("cma", NULL);
202 if (!cma_debugfs_root)
205 for (i = 0; i < cma_area_count; i++)
206 cma_debugfs_add_one(&cma_areas[i], i);
210 late_initcall(cma_debugfs_init);