Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
#include <stdlib.h>
#include <string.h>
#include <malloc.h>
#include <pthread.h>
#include <unistd.h>
#include <assert.h>
 
#include <linux/gfp.h>
#include <linux/poison.h>
#include <linux/slab.h>
#include <linux/radix-tree.h>
#include <urcu/uatomic.h>
 
int nr_allocated;
int preempt_count;
int kmalloc_verbose;
int test_verbose;
 
struct kmem_cache {
<------>pthread_mutex_t lock;
<------>unsigned int size;
<------>unsigned int align;
<------>int nr_objs;
<------>void *objs;
<------>void (*ctor)(void *);
};
 
void *kmem_cache_alloc(struct kmem_cache *cachep, int gfp)
{
<------>void *p;
 
<------>if (!(gfp & __GFP_DIRECT_RECLAIM))
<------><------>return NULL;
 
<------>pthread_mutex_lock(&cachep->lock);
<------>if (cachep->nr_objs) {
<------><------>struct radix_tree_node *node = cachep->objs;
<------><------>cachep->nr_objs--;
<------><------>cachep->objs = node->parent;
<------><------>pthread_mutex_unlock(&cachep->lock);
<------><------>node->parent = NULL;
<------><------>p = node;
<------>} else {
<------><------>pthread_mutex_unlock(&cachep->lock);
<------><------>if (cachep->align)
<------><------><------>posix_memalign(&p, cachep->align, cachep->size);
<------><------>else
<------><------><------>p = malloc(cachep->size);
<------><------>if (cachep->ctor)
<------><------><------>cachep->ctor(p);
<------><------>else if (gfp & __GFP_ZERO)
<------><------><------>memset(p, 0, cachep->size);
<------>}
 
<------>uatomic_inc(&nr_allocated);
<------>if (kmalloc_verbose)
<------><------>printf("Allocating %p from slab\n", p);
<------>return p;
}
 
void kmem_cache_free(struct kmem_cache *cachep, void *objp)
{
<------>assert(objp);
<------>uatomic_dec(&nr_allocated);
<------>if (kmalloc_verbose)
<------><------>printf("Freeing %p to slab\n", objp);
<------>pthread_mutex_lock(&cachep->lock);
<------>if (cachep->nr_objs > 10 || cachep->align) {
<------><------>memset(objp, POISON_FREE, cachep->size);
<------><------>free(objp);
<------>} else {
<------><------>struct radix_tree_node *node = objp;
<------><------>cachep->nr_objs++;
<------><------>node->parent = cachep->objs;
<------><------>cachep->objs = node;
<------>}
<------>pthread_mutex_unlock(&cachep->lock);
}
 
void *kmalloc(size_t size, gfp_t gfp)
{
<------>void *ret;
 
<------>if (!(gfp & __GFP_DIRECT_RECLAIM))
<------><------>return NULL;
 
<------>ret = malloc(size);
<------>uatomic_inc(&nr_allocated);
<------>if (kmalloc_verbose)
<------><------>printf("Allocating %p from malloc\n", ret);
<------>if (gfp & __GFP_ZERO)
<------><------>memset(ret, 0, size);
<------>return ret;
}
 
void kfree(void *p)
{
<------>if (!p)
<------><------>return;
<------>uatomic_dec(&nr_allocated);
<------>if (kmalloc_verbose)
<------><------>printf("Freeing %p to malloc\n", p);
<------>free(p);
}
 
struct kmem_cache *
kmem_cache_create(const char *name, unsigned int size, unsigned int align,
<------><------>unsigned int flags, void (*ctor)(void *))
{
<------>struct kmem_cache *ret = malloc(sizeof(*ret));
 
<------>pthread_mutex_init(&ret->lock, NULL);
<------>ret->size = size;
<------>ret->align = align;
<------>ret->nr_objs = 0;
<------>ret->objs = NULL;
<------>ret->ctor = ctor;
<------>return ret;
}