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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001// SPDX-License-Identifier: GPL-2.0
Sasha Levin28b24c12015-04-14 15:44:57 -07002/*
3 * CMA DebugFS Interface
4 *
5 * Copyright (c) 2015 Sasha Levin <sasha.levin@oracle.com>
6 */
7
8
9#include <linux/debugfs.h>
10#include <linux/cma.h>
Sasha Levin26b02a12015-04-14 15:44:59 -070011#include <linux/list.h>
12#include <linux/kernel.h>
13#include <linux/slab.h>
Sasha Levin83253302015-04-14 15:45:02 -070014#include <linux/mm_types.h>
Sasha Levin28b24c12015-04-14 15:44:57 -070015
16#include "cma.h"
17
Sasha Levin26b02a12015-04-14 15:44:59 -070018struct cma_mem {
19 struct hlist_node node;
20 struct page *p;
21 unsigned long n;
22};
23
Sasha Levin28b24c12015-04-14 15:44:57 -070024static struct dentry *cma_debugfs_root;
25
26static int cma_debugfs_get(void *data, u64 *val)
27{
28 unsigned long *p = data;
29
30 *val = *p;
31
32 return 0;
33}
Sasha Levin28b24c12015-04-14 15:44:57 -070034DEFINE_SIMPLE_ATTRIBUTE(cma_debugfs_fops, cma_debugfs_get, NULL, "%llu\n");
35
Dmitry Safonov2e32b942015-04-15 16:14:59 -070036static int cma_used_get(void *data, u64 *val)
37{
38 struct cma *cma = data;
39 unsigned long used;
40
41 mutex_lock(&cma->lock);
42 /* pages counter is smaller than sizeof(int) */
Joonsoo Kimd56e84b2015-07-17 16:24:23 -070043 used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));
Dmitry Safonov2e32b942015-04-15 16:14:59 -070044 mutex_unlock(&cma->lock);
45 *val = (u64)used << cma->order_per_bit;
46
47 return 0;
48}
Dmitry Safonov2e32b942015-04-15 16:14:59 -070049DEFINE_SIMPLE_ATTRIBUTE(cma_used_fops, cma_used_get, NULL, "%llu\n");
50
51static int cma_maxchunk_get(void *data, u64 *val)
52{
53 struct cma *cma = data;
54 unsigned long maxchunk = 0;
55 unsigned long start, end = 0;
Joonsoo Kimd56e84b2015-07-17 16:24:23 -070056 unsigned long bitmap_maxno = cma_bitmap_maxno(cma);
Dmitry Safonov2e32b942015-04-15 16:14:59 -070057
58 mutex_lock(&cma->lock);
59 for (;;) {
Joonsoo Kimd56e84b2015-07-17 16:24:23 -070060 start = find_next_zero_bit(cma->bitmap, bitmap_maxno, end);
Dmitry Safonov2e32b942015-04-15 16:14:59 -070061 if (start >= cma->count)
62 break;
Joonsoo Kimd56e84b2015-07-17 16:24:23 -070063 end = find_next_bit(cma->bitmap, bitmap_maxno, start);
Dmitry Safonov2e32b942015-04-15 16:14:59 -070064 maxchunk = max(end - start, maxchunk);
65 }
66 mutex_unlock(&cma->lock);
67 *val = (u64)maxchunk << cma->order_per_bit;
68
69 return 0;
70}
Dmitry Safonov2e32b942015-04-15 16:14:59 -070071DEFINE_SIMPLE_ATTRIBUTE(cma_maxchunk_fops, cma_maxchunk_get, NULL, "%llu\n");
72
Sasha Levin26b02a12015-04-14 15:44:59 -070073static void cma_add_to_cma_mem_list(struct cma *cma, struct cma_mem *mem)
74{
75 spin_lock(&cma->mem_head_lock);
76 hlist_add_head(&mem->node, &cma->mem_head);
77 spin_unlock(&cma->mem_head_lock);
78}
79
Sasha Levin83253302015-04-14 15:45:02 -070080static struct cma_mem *cma_get_entry_from_list(struct cma *cma)
81{
82 struct cma_mem *mem = NULL;
83
84 spin_lock(&cma->mem_head_lock);
85 if (!hlist_empty(&cma->mem_head)) {
86 mem = hlist_entry(cma->mem_head.first, struct cma_mem, node);
87 hlist_del_init(&mem->node);
88 }
89 spin_unlock(&cma->mem_head_lock);
90
91 return mem;
92}
93
94static int cma_free_mem(struct cma *cma, int count)
95{
96 struct cma_mem *mem = NULL;
97
98 while (count) {
99 mem = cma_get_entry_from_list(cma);
100 if (mem == NULL)
101 return 0;
102
103 if (mem->n <= count) {
104 cma_release(cma, mem->p, mem->n);
105 count -= mem->n;
106 kfree(mem);
107 } else if (cma->order_per_bit == 0) {
108 cma_release(cma, mem->p, count);
109 mem->p += count;
110 mem->n -= count;
111 count = 0;
112 cma_add_to_cma_mem_list(cma, mem);
113 } else {
114 pr_debug("cma: cannot release partial block when order_per_bit != 0\n");
115 cma_add_to_cma_mem_list(cma, mem);
116 break;
117 }
118 }
119
120 return 0;
121
122}
123
124static int cma_free_write(void *data, u64 val)
125{
126 int pages = val;
127 struct cma *cma = data;
128
129 return cma_free_mem(cma, pages);
130}
Sasha Levin83253302015-04-14 15:45:02 -0700131DEFINE_SIMPLE_ATTRIBUTE(cma_free_fops, NULL, cma_free_write, "%llu\n");
132
Sasha Levin26b02a12015-04-14 15:44:59 -0700133static int cma_alloc_mem(struct cma *cma, int count)
134{
135 struct cma_mem *mem;
136 struct page *p;
137
138 mem = kzalloc(sizeof(*mem), GFP_KERNEL);
139 if (!mem)
140 return -ENOMEM;
141
Marek Szyprowski65182022018-08-17 15:48:57 -0700142 p = cma_alloc(cma, count, 0, false);
Sasha Levin26b02a12015-04-14 15:44:59 -0700143 if (!p) {
144 kfree(mem);
145 return -ENOMEM;
146 }
147
148 mem->p = p;
149 mem->n = count;
150
151 cma_add_to_cma_mem_list(cma, mem);
152
153 return 0;
154}
155
156static int cma_alloc_write(void *data, u64 val)
157{
158 int pages = val;
159 struct cma *cma = data;
160
161 return cma_alloc_mem(cma, pages);
162}
Sasha Levin26b02a12015-04-14 15:44:59 -0700163DEFINE_SIMPLE_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n");
164
Sasha Levin28b24c12015-04-14 15:44:57 -0700165static void cma_debugfs_add_one(struct cma *cma, int idx)
166{
167 struct dentry *tmp;
168 char name[16];
169 int u32s;
170
Prakash Guptada094e42017-08-18 15:16:21 -0700171 scnprintf(name, sizeof(name), "cma-%s", cma->name);
Sasha Levin28b24c12015-04-14 15:44:57 -0700172
173 tmp = debugfs_create_dir(name, cma_debugfs_root);
174
Joe Perches0825a6f2018-06-14 15:27:58 -0700175 debugfs_create_file("alloc", 0200, tmp, cma, &cma_alloc_fops);
176 debugfs_create_file("free", 0200, tmp, cma, &cma_free_fops);
177 debugfs_create_file("base_pfn", 0444, tmp,
178 &cma->base_pfn, &cma_debugfs_fops);
179 debugfs_create_file("count", 0444, tmp, &cma->count, &cma_debugfs_fops);
180 debugfs_create_file("order_per_bit", 0444, tmp,
181 &cma->order_per_bit, &cma_debugfs_fops);
182 debugfs_create_file("used", 0444, tmp, cma, &cma_used_fops);
183 debugfs_create_file("maxchunk", 0444, tmp, cma, &cma_maxchunk_fops);
Sasha Levin28b24c12015-04-14 15:44:57 -0700184
185 u32s = DIV_ROUND_UP(cma_bitmap_maxno(cma), BITS_PER_BYTE * sizeof(u32));
Joe Perches0825a6f2018-06-14 15:27:58 -0700186 debugfs_create_u32_array("bitmap", 0444, tmp, (u32 *)cma->bitmap, u32s);
Sasha Levin28b24c12015-04-14 15:44:57 -0700187}
188
189static int __init cma_debugfs_init(void)
190{
191 int i;
192
193 cma_debugfs_root = debugfs_create_dir("cma", NULL);
194 if (!cma_debugfs_root)
195 return -ENOMEM;
196
197 for (i = 0; i < cma_area_count; i++)
198 cma_debugfs_add_one(&cma_areas[i], i);
199
200 return 0;
201}
202late_initcall(cma_debugfs_init);