1  /* SPDX-License-Identifier: GPL-2.0-only */
 2  
 3  #include <console/console.h>
 4  #include <stdlib.h>
 5  #include <string.h>
 6  
 7  #if CONFIG(DEBUG_MALLOC)
 8  #define MALLOCDBG(x...) printk(BIOS_SPEW, x)
 9  #else
10  #define MALLOCDBG(x...)
11  #endif
12  
13  extern unsigned char _heap, _eheap;
14  static void *free_mem_ptr = &_heap;		/* Start of heap */
15  static void *free_mem_end_ptr = &_eheap;	/* End of heap */
16  static void *free_last_alloc_ptr = &_heap;	/* End of heap before
17  						   last allocation */
18  
19  /* We don't restrict the boundary. This is firmware,
20   * you are supposed to know what you are doing.
21   */
22  void *memalign(size_t boundary, size_t size)
23  {
24  	void *p;
25  
26  	MALLOCDBG("%s Enter, boundary %zu, size %zu, free_mem_ptr %p\n",
27  		__func__, boundary, size, free_mem_ptr);
28  
29  	free_mem_ptr = (void *)ALIGN_UP((unsigned long)free_mem_ptr, boundary);
30  
31  	p = free_mem_ptr;
32  	free_mem_ptr += size;
33  	/*
34  	 * Store last allocation pointer after ALIGN, as malloc() will
35  	 * return it. This may cause n bytes of gap between allocations
36  	 * where n < boundary.
37  	 */
38  	free_last_alloc_ptr = p;
39  
40  	if (free_mem_ptr >= free_mem_end_ptr) {
41  		printk(BIOS_ERR, "%s(boundary=%zu, size=%zu): failed: ",
42  				__func__, boundary, size);
43  		printk(BIOS_ERR, "Tried to round up free_mem_ptr %p to %p\n",
44  				p, free_mem_ptr);
45  		printk(BIOS_ERR, "but free_mem_end_ptr is %p\n",
46  				free_mem_end_ptr);
47  		printk(BIOS_ERR, "Error! %s: Out of memory "
48  				"(free_mem_ptr >= free_mem_end_ptr)",
49  				__func__);
50  		return NULL;
51  	}
52  
53  	MALLOCDBG("%s %p\n", __func__, p);
54  
55  	return p;
56  }
57  
58  void *malloc(size_t size)
59  {
60  	return memalign(sizeof(u64), size);
61  }
62  
63  void *calloc(size_t nitems, size_t size)
64  {
65  	void *p = malloc(nitems * size);
66  	if (p)
67  		memset(p, 0, nitems * size);
68  
69  	return p;
70  }
71  
72  void free(void *ptr)
73  {
74  	if (ptr == NULL)
75  		return;
76  
77  	if (ptr < (void *)&_heap || ptr >= free_mem_end_ptr) {
78  		printk(BIOS_WARNING, "Pointer passed to %s is not "
79  					"pointing to the heap\n", __func__);
80  		return;
81  	}
82  
83  	/*
84  	 * Rewind the heap pointer to the end of heap
85  	 * before the last successful malloc().
86  	 */
87  	if (ptr == free_last_alloc_ptr) {
88  		free_mem_ptr = free_last_alloc_ptr;
89  		free_last_alloc_ptr = NULL;
90  	}
91  }