1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #include <stdlib.h>
3*4882a593Smuzhiyun #include <string.h>
4*4882a593Smuzhiyun #include <malloc.h>
5*4882a593Smuzhiyun #include <pthread.h>
6*4882a593Smuzhiyun #include <unistd.h>
7*4882a593Smuzhiyun #include <assert.h>
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include <linux/gfp.h>
10*4882a593Smuzhiyun #include <linux/poison.h>
11*4882a593Smuzhiyun #include <linux/slab.h>
12*4882a593Smuzhiyun #include <linux/radix-tree.h>
13*4882a593Smuzhiyun #include <urcu/uatomic.h>
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun int nr_allocated;
16*4882a593Smuzhiyun int preempt_count;
17*4882a593Smuzhiyun int kmalloc_verbose;
18*4882a593Smuzhiyun int test_verbose;
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun struct kmem_cache {
21*4882a593Smuzhiyun pthread_mutex_t lock;
22*4882a593Smuzhiyun unsigned int size;
23*4882a593Smuzhiyun unsigned int align;
24*4882a593Smuzhiyun int nr_objs;
25*4882a593Smuzhiyun void *objs;
26*4882a593Smuzhiyun void (*ctor)(void *);
27*4882a593Smuzhiyun };
28*4882a593Smuzhiyun
kmem_cache_alloc(struct kmem_cache * cachep,int gfp)29*4882a593Smuzhiyun void *kmem_cache_alloc(struct kmem_cache *cachep, int gfp)
30*4882a593Smuzhiyun {
31*4882a593Smuzhiyun void *p;
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun if (!(gfp & __GFP_DIRECT_RECLAIM))
34*4882a593Smuzhiyun return NULL;
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun pthread_mutex_lock(&cachep->lock);
37*4882a593Smuzhiyun if (cachep->nr_objs) {
38*4882a593Smuzhiyun struct radix_tree_node *node = cachep->objs;
39*4882a593Smuzhiyun cachep->nr_objs--;
40*4882a593Smuzhiyun cachep->objs = node->parent;
41*4882a593Smuzhiyun pthread_mutex_unlock(&cachep->lock);
42*4882a593Smuzhiyun node->parent = NULL;
43*4882a593Smuzhiyun p = node;
44*4882a593Smuzhiyun } else {
45*4882a593Smuzhiyun pthread_mutex_unlock(&cachep->lock);
46*4882a593Smuzhiyun if (cachep->align)
47*4882a593Smuzhiyun posix_memalign(&p, cachep->align, cachep->size);
48*4882a593Smuzhiyun else
49*4882a593Smuzhiyun p = malloc(cachep->size);
50*4882a593Smuzhiyun if (cachep->ctor)
51*4882a593Smuzhiyun cachep->ctor(p);
52*4882a593Smuzhiyun else if (gfp & __GFP_ZERO)
53*4882a593Smuzhiyun memset(p, 0, cachep->size);
54*4882a593Smuzhiyun }
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun uatomic_inc(&nr_allocated);
57*4882a593Smuzhiyun if (kmalloc_verbose)
58*4882a593Smuzhiyun printf("Allocating %p from slab\n", p);
59*4882a593Smuzhiyun return p;
60*4882a593Smuzhiyun }
61*4882a593Smuzhiyun
kmem_cache_free(struct kmem_cache * cachep,void * objp)62*4882a593Smuzhiyun void kmem_cache_free(struct kmem_cache *cachep, void *objp)
63*4882a593Smuzhiyun {
64*4882a593Smuzhiyun assert(objp);
65*4882a593Smuzhiyun uatomic_dec(&nr_allocated);
66*4882a593Smuzhiyun if (kmalloc_verbose)
67*4882a593Smuzhiyun printf("Freeing %p to slab\n", objp);
68*4882a593Smuzhiyun pthread_mutex_lock(&cachep->lock);
69*4882a593Smuzhiyun if (cachep->nr_objs > 10 || cachep->align) {
70*4882a593Smuzhiyun memset(objp, POISON_FREE, cachep->size);
71*4882a593Smuzhiyun free(objp);
72*4882a593Smuzhiyun } else {
73*4882a593Smuzhiyun struct radix_tree_node *node = objp;
74*4882a593Smuzhiyun cachep->nr_objs++;
75*4882a593Smuzhiyun node->parent = cachep->objs;
76*4882a593Smuzhiyun cachep->objs = node;
77*4882a593Smuzhiyun }
78*4882a593Smuzhiyun pthread_mutex_unlock(&cachep->lock);
79*4882a593Smuzhiyun }
80*4882a593Smuzhiyun
kmalloc(size_t size,gfp_t gfp)81*4882a593Smuzhiyun void *kmalloc(size_t size, gfp_t gfp)
82*4882a593Smuzhiyun {
83*4882a593Smuzhiyun void *ret;
84*4882a593Smuzhiyun
85*4882a593Smuzhiyun if (!(gfp & __GFP_DIRECT_RECLAIM))
86*4882a593Smuzhiyun return NULL;
87*4882a593Smuzhiyun
88*4882a593Smuzhiyun ret = malloc(size);
89*4882a593Smuzhiyun uatomic_inc(&nr_allocated);
90*4882a593Smuzhiyun if (kmalloc_verbose)
91*4882a593Smuzhiyun printf("Allocating %p from malloc\n", ret);
92*4882a593Smuzhiyun if (gfp & __GFP_ZERO)
93*4882a593Smuzhiyun memset(ret, 0, size);
94*4882a593Smuzhiyun return ret;
95*4882a593Smuzhiyun }
96*4882a593Smuzhiyun
kfree(void * p)97*4882a593Smuzhiyun void kfree(void *p)
98*4882a593Smuzhiyun {
99*4882a593Smuzhiyun if (!p)
100*4882a593Smuzhiyun return;
101*4882a593Smuzhiyun uatomic_dec(&nr_allocated);
102*4882a593Smuzhiyun if (kmalloc_verbose)
103*4882a593Smuzhiyun printf("Freeing %p to malloc\n", p);
104*4882a593Smuzhiyun free(p);
105*4882a593Smuzhiyun }
106*4882a593Smuzhiyun
107*4882a593Smuzhiyun struct kmem_cache *
kmem_cache_create(const char * name,unsigned int size,unsigned int align,unsigned int flags,void (* ctor)(void *))108*4882a593Smuzhiyun kmem_cache_create(const char *name, unsigned int size, unsigned int align,
109*4882a593Smuzhiyun unsigned int flags, void (*ctor)(void *))
110*4882a593Smuzhiyun {
111*4882a593Smuzhiyun struct kmem_cache *ret = malloc(sizeof(*ret));
112*4882a593Smuzhiyun
113*4882a593Smuzhiyun pthread_mutex_init(&ret->lock, NULL);
114*4882a593Smuzhiyun ret->size = size;
115*4882a593Smuzhiyun ret->align = align;
116*4882a593Smuzhiyun ret->nr_objs = 0;
117*4882a593Smuzhiyun ret->objs = NULL;
118*4882a593Smuzhiyun ret->ctor = ctor;
119*4882a593Smuzhiyun return ret;
120*4882a593Smuzhiyun }
121