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	bool exec_callback;
 30	void (*callback)(void *);
 31	void *private;
 32};
 33
 34void kmem_cache_set_callback(struct kmem_cache *cachep, void (*callback)(void *))
 35{
 36	cachep->callback = callback;
 37}
 38
 39void kmem_cache_set_private(struct kmem_cache *cachep, void *private)
 40{
 41	cachep->private = private;
 42}
 43
 44void kmem_cache_set_non_kernel(struct kmem_cache *cachep, unsigned int val)
 45{
 46	cachep->non_kernel = val;
 47}
 48
 49unsigned long kmem_cache_get_alloc(struct kmem_cache *cachep)
 50{
 51	return cachep->size * cachep->nr_allocated;
 52}
 53
 54unsigned long kmem_cache_nr_allocated(struct kmem_cache *cachep)
 55{
 56	return cachep->nr_allocated;
 57}
 58
 59unsigned long kmem_cache_nr_tallocated(struct kmem_cache *cachep)
 60{
 61	return cachep->nr_tallocated;
 62}
 63
 64void kmem_cache_zero_nr_tallocated(struct kmem_cache *cachep)
 65{
 66	cachep->nr_tallocated = 0;
 67}
 68
 69void *kmem_cache_alloc_lru(struct kmem_cache *cachep, struct list_lru *lru,
 70		int gfp)
 71{
 72	void *p;
 73
 74	if (cachep->exec_callback) {
 75		if (cachep->callback)
 76			cachep->callback(cachep->private);
 77		cachep->exec_callback = false;
 78	}
 79
 80	if (!(gfp & __GFP_DIRECT_RECLAIM)) {
 81		if (!cachep->non_kernel) {
 82			cachep->exec_callback = true;
 83			return NULL;
 84		}
 85
 86		cachep->non_kernel--;
 87	}
 88
 89	pthread_mutex_lock(&cachep->lock);
 90	if (cachep->nr_objs) {
 91		struct radix_tree_node *node = cachep->objs;
 92		cachep->nr_objs--;
 93		cachep->objs = node->parent;
 94		pthread_mutex_unlock(&cachep->lock);
 95		node->parent = NULL;
 96		p = node;
 97	} else {
 98		pthread_mutex_unlock(&cachep->lock);
 99		if (cachep->align) {
100			if (posix_memalign(&p, cachep->align, cachep->size) < 0)
101				return NULL;
102		} else {
103			p = malloc(cachep->size);
104		}
105
106		if (cachep->ctor)
107			cachep->ctor(p);
108		else if (gfp & __GFP_ZERO)
109			memset(p, 0, cachep->size);
110	}
111
112	uatomic_inc(&cachep->nr_allocated);
113	uatomic_inc(&nr_allocated);
114	uatomic_inc(&cachep->nr_tallocated);
115	if (kmalloc_verbose)
116		printf("Allocating %p from slab\n", p);
117	return p;
118}
119
120void __kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
121{
122	assert(objp);
123	if (cachep->nr_objs > 10 || cachep->align) {
124		memset(objp, POISON_FREE, cachep->size);
125		free(objp);
126	} else {
127		struct radix_tree_node *node = objp;
128		cachep->nr_objs++;
129		node->parent = cachep->objs;
130		cachep->objs = node;
131	}
132}
133
134void kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
135{
136	uatomic_dec(&nr_allocated);
137	uatomic_dec(&cachep->nr_allocated);
138	if (kmalloc_verbose)
139		printf("Freeing %p to slab\n", objp);
140	__kmem_cache_free_locked(cachep, objp);
141}
142
143void kmem_cache_free(struct kmem_cache *cachep, void *objp)
144{
145	pthread_mutex_lock(&cachep->lock);
146	kmem_cache_free_locked(cachep, objp);
147	pthread_mutex_unlock(&cachep->lock);
148}
149
150void kmem_cache_free_bulk(struct kmem_cache *cachep, size_t size, void **list)
151{
152	if (kmalloc_verbose)
153		pr_debug("Bulk free %p[0-%lu]\n", list, size - 1);
154
155	pthread_mutex_lock(&cachep->lock);
156	for (int i = 0; i < size; i++)
157		kmem_cache_free_locked(cachep, list[i]);
158	pthread_mutex_unlock(&cachep->lock);
159}
160
161void kmem_cache_shrink(struct kmem_cache *cachep)
162{
163}
164
165int kmem_cache_alloc_bulk(struct kmem_cache *cachep, gfp_t gfp, size_t size,
166			  void **p)
167{
168	size_t i;
169
170	if (kmalloc_verbose)
171		pr_debug("Bulk alloc %lu\n", size);
172
173	pthread_mutex_lock(&cachep->lock);
174	if (cachep->nr_objs >= size) {
175		struct radix_tree_node *node;
176
177		for (i = 0; i < size; i++) {
178			if (!(gfp & __GFP_DIRECT_RECLAIM)) {
179				if (!cachep->non_kernel)
180					break;
181				cachep->non_kernel--;
182			}
183
184			node = cachep->objs;
185			cachep->nr_objs--;
186			cachep->objs = node->parent;
187			p[i] = node;
188			node->parent = NULL;
189		}
190		pthread_mutex_unlock(&cachep->lock);
191	} else {
192		pthread_mutex_unlock(&cachep->lock);
193		for (i = 0; i < size; i++) {
194			if (!(gfp & __GFP_DIRECT_RECLAIM)) {
195				if (!cachep->non_kernel)
196					break;
197				cachep->non_kernel--;
198			}
199
200			if (cachep->align) {
201				if (posix_memalign(&p[i], cachep->align,
202					       cachep->size) < 0)
203					break;
204			} else {
205				p[i] = malloc(cachep->size);
206				if (!p[i])
207					break;
208			}
209			if (cachep->ctor)
210				cachep->ctor(p[i]);
211			else if (gfp & __GFP_ZERO)
212				memset(p[i], 0, cachep->size);
213		}
214	}
215
216	if (i < size) {
217		size = i;
218		pthread_mutex_lock(&cachep->lock);
219		for (i = 0; i < size; i++)
220			__kmem_cache_free_locked(cachep, p[i]);
221		pthread_mutex_unlock(&cachep->lock);
222		return 0;
223	}
224
225	for (i = 0; i < size; i++) {
226		uatomic_inc(&nr_allocated);
227		uatomic_inc(&cachep->nr_allocated);
228		uatomic_inc(&cachep->nr_tallocated);
229		if (kmalloc_verbose)
230			printf("Allocating %p from slab\n", p[i]);
231	}
232
233	return size;
234}
235
236struct kmem_cache *
237kmem_cache_create(const char *name, unsigned int size, unsigned int align,
238		unsigned int flags, void (*ctor)(void *))
239{
240	struct kmem_cache *ret = malloc(sizeof(*ret));
241
242	pthread_mutex_init(&ret->lock, NULL);
243	ret->size = size;
244	ret->align = align;
245	ret->nr_objs = 0;
246	ret->nr_allocated = 0;
247	ret->nr_tallocated = 0;
248	ret->objs = NULL;
249	ret->ctor = ctor;
250	ret->non_kernel = 0;
251	ret->exec_callback = false;
252	ret->callback = NULL;
253	ret->private = NULL;
254	return ret;
255}
256
257/*
258 * Test the test infrastructure for kem_cache_alloc/free and bulk counterparts.
259 */
260void test_kmem_cache_bulk(void)
261{
262	int i;
263	void *list[12];
264	static struct kmem_cache *test_cache, *test_cache2;
265
266	/*
267	 * Testing the bulk allocators without aligned kmem_cache to force the
268	 * bulk alloc/free to reuse
269	 */
270	test_cache = kmem_cache_create("test_cache", 256, 0, SLAB_PANIC, NULL);
271
272	for (i = 0; i < 5; i++)
273		list[i] = kmem_cache_alloc(test_cache, __GFP_DIRECT_RECLAIM);
274
275	for (i = 0; i < 5; i++)
276		kmem_cache_free(test_cache, list[i]);
277	assert(test_cache->nr_objs == 5);
278
279	kmem_cache_alloc_bulk(test_cache, __GFP_DIRECT_RECLAIM, 5, list);
280	kmem_cache_free_bulk(test_cache, 5, list);
281
282	for (i = 0; i < 12 ; i++)
283		list[i] = kmem_cache_alloc(test_cache, __GFP_DIRECT_RECLAIM);
284
285	for (i = 0; i < 12; i++)
286		kmem_cache_free(test_cache, list[i]);
287
288	/* The last free will not be kept around */
289	assert(test_cache->nr_objs == 11);
290
291	/* Aligned caches will immediately free */
292	test_cache2 = kmem_cache_create("test_cache2", 128, 128, SLAB_PANIC, NULL);
293
294	kmem_cache_alloc_bulk(test_cache2, __GFP_DIRECT_RECLAIM, 10, list);
295	kmem_cache_free_bulk(test_cache2, 10, list);
296	assert(!test_cache2->nr_objs);
297
298
299}