1// SPDX-License-Identifier: GPL-2.0
2#include <stdlib.h>
3#include <string.h>
4#include <malloc.h>
5#include <pthread.h>
6#include <unistd.h>
7#include <assert.h>
8
9#include <linux/gfp.h>
10#include <linux/poison.h>
11#include <linux/slab.h>
12#include <linux/radix-tree.h>
13#include <urcu/uatomic.h>
14
15int nr_allocated;
16int preempt_count;
17int test_verbose;
18
19struct kmem_cache {
20	pthread_mutex_t lock;
21	unsigned int size;
22	unsigned int align;
23	int nr_objs;
24	void *objs;
25	void (*ctor)(void *);
26	unsigned int non_kernel;
27	unsigned long nr_allocated;
28	unsigned long nr_tallocated;
29};
30
31void kmem_cache_set_non_kernel(struct kmem_cache *cachep, unsigned int val)
32{
33	cachep->non_kernel = val;
34}
35
36unsigned long kmem_cache_get_alloc(struct kmem_cache *cachep)
37{
38	return cachep->size * cachep->nr_allocated;
39}
40
41unsigned long kmem_cache_nr_allocated(struct kmem_cache *cachep)
42{
43	return cachep->nr_allocated;
44}
45
46unsigned long kmem_cache_nr_tallocated(struct kmem_cache *cachep)
47{
48	return cachep->nr_tallocated;
49}
50
51void kmem_cache_zero_nr_tallocated(struct kmem_cache *cachep)
52{
53	cachep->nr_tallocated = 0;
54}
55
56void *kmem_cache_alloc_lru(struct kmem_cache *cachep, struct list_lru *lru,
57		int gfp)
58{
59	void *p;
60
61	if (!(gfp & __GFP_DIRECT_RECLAIM)) {
62		if (!cachep->non_kernel)
63			return NULL;
64
65		cachep->non_kernel--;
66	}
67
68	pthread_mutex_lock(&cachep->lock);
69	if (cachep->nr_objs) {
70		struct radix_tree_node *node = cachep->objs;
71		cachep->nr_objs--;
72		cachep->objs = node->parent;
73		pthread_mutex_unlock(&cachep->lock);
74		node->parent = NULL;
75		p = node;
76	} else {
77		pthread_mutex_unlock(&cachep->lock);
78		if (cachep->align)
79			posix_memalign(&p, cachep->align, cachep->size);
80		else
81			p = malloc(cachep->size);
82		if (cachep->ctor)
83			cachep->ctor(p);
84		else if (gfp & __GFP_ZERO)
85			memset(p, 0, cachep->size);
86	}
87
88	uatomic_inc(&cachep->nr_allocated);
89	uatomic_inc(&nr_allocated);
90	uatomic_inc(&cachep->nr_tallocated);
91	if (kmalloc_verbose)
92		printf("Allocating %p from slab\n", p);
93	return p;
94}
95
96void kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
97{
98	assert(objp);
99	uatomic_dec(&nr_allocated);
100	uatomic_dec(&cachep->nr_allocated);
101	if (kmalloc_verbose)
102		printf("Freeing %p to slab\n", objp);
103	if (cachep->nr_objs > 10 || cachep->align) {
104		memset(objp, POISON_FREE, cachep->size);
105		free(objp);
106	} else {
107		struct radix_tree_node *node = objp;
108		cachep->nr_objs++;
109		node->parent = cachep->objs;
110		cachep->objs = node;
111	}
112}
113
114void kmem_cache_free(struct kmem_cache *cachep, void *objp)
115{
116	pthread_mutex_lock(&cachep->lock);
117	kmem_cache_free_locked(cachep, objp);
118	pthread_mutex_unlock(&cachep->lock);
119}
120
121void kmem_cache_free_bulk(struct kmem_cache *cachep, size_t size, void **list)
122{
123	if (kmalloc_verbose)
124		pr_debug("Bulk free %p[0-%lu]\n", list, size - 1);
125
126	pthread_mutex_lock(&cachep->lock);
127	for (int i = 0; i < size; i++)
128		kmem_cache_free_locked(cachep, list[i]);
129	pthread_mutex_unlock(&cachep->lock);
130}
131
132void kmem_cache_shrink(struct kmem_cache *cachep)
133{
134}
135
136int kmem_cache_alloc_bulk(struct kmem_cache *cachep, gfp_t gfp, size_t size,
137			  void **p)
138{
139	size_t i;
140
141	if (kmalloc_verbose)
142		pr_debug("Bulk alloc %lu\n", size);
143
144	if (!(gfp & __GFP_DIRECT_RECLAIM)) {
145		if (cachep->non_kernel < size)
146			return 0;
147
148		cachep->non_kernel -= size;
149	}
150
151	pthread_mutex_lock(&cachep->lock);
152	if (cachep->nr_objs >= size) {
153		struct radix_tree_node *node;
154
155		for (i = 0; i < size; i++) {
156			node = cachep->objs;
157			cachep->nr_objs--;
158			cachep->objs = node->parent;
159			p[i] = node;
160			node->parent = NULL;
161		}
162		pthread_mutex_unlock(&cachep->lock);
163	} else {
164		pthread_mutex_unlock(&cachep->lock);
165		for (i = 0; i < size; i++) {
166			if (cachep->align) {
167				posix_memalign(&p[i], cachep->align,
168					       cachep->size * size);
169			} else {
170				p[i] = malloc(cachep->size * size);
171			}
172			if (cachep->ctor)
173				cachep->ctor(p[i]);
174			else if (gfp & __GFP_ZERO)
175				memset(p[i], 0, cachep->size);
176		}
177	}
178
179	for (i = 0; i < size; i++) {
180		uatomic_inc(&nr_allocated);
181		uatomic_inc(&cachep->nr_allocated);
182		uatomic_inc(&cachep->nr_tallocated);
183		if (kmalloc_verbose)
184			printf("Allocating %p from slab\n", p[i]);
185	}
186
187	return size;
188}
189
190struct kmem_cache *
191kmem_cache_create(const char *name, unsigned int size, unsigned int align,
192		unsigned int flags, void (*ctor)(void *))
193{
194	struct kmem_cache *ret = malloc(sizeof(*ret));
195
196	pthread_mutex_init(&ret->lock, NULL);
197	ret->size = size;
198	ret->align = align;
199	ret->nr_objs = 0;
200	ret->nr_allocated = 0;
201	ret->nr_tallocated = 0;
202	ret->objs = NULL;
203	ret->ctor = ctor;
204	ret->non_kernel = 0;
205	return ret;
206}
207
208/*
209 * Test the test infrastructure for kem_cache_alloc/free and bulk counterparts.
210 */
211void test_kmem_cache_bulk(void)
212{
213	int i;
214	void *list[12];
215	static struct kmem_cache *test_cache, *test_cache2;
216
217	/*
218	 * Testing the bulk allocators without aligned kmem_cache to force the
219	 * bulk alloc/free to reuse
220	 */
221	test_cache = kmem_cache_create("test_cache", 256, 0, SLAB_PANIC, NULL);
222
223	for (i = 0; i < 5; i++)
224		list[i] = kmem_cache_alloc(test_cache, __GFP_DIRECT_RECLAIM);
225
226	for (i = 0; i < 5; i++)
227		kmem_cache_free(test_cache, list[i]);
228	assert(test_cache->nr_objs == 5);
229
230	kmem_cache_alloc_bulk(test_cache, __GFP_DIRECT_RECLAIM, 5, list);
231	kmem_cache_free_bulk(test_cache, 5, list);
232
233	for (i = 0; i < 12 ; i++)
234		list[i] = kmem_cache_alloc(test_cache, __GFP_DIRECT_RECLAIM);
235
236	for (i = 0; i < 12; i++)
237		kmem_cache_free(test_cache, list[i]);
238
239	/* The last free will not be kept around */
240	assert(test_cache->nr_objs == 11);
241
242	/* Aligned caches will immediately free */
243	test_cache2 = kmem_cache_create("test_cache2", 128, 128, SLAB_PANIC, NULL);
244
245	kmem_cache_alloc_bulk(test_cache2, __GFP_DIRECT_RECLAIM, 10, list);
246	kmem_cache_free_bulk(test_cache2, 10, list);
247	assert(!test_cache2->nr_objs);
248
249
250}
251