1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * linux/compr_mm.h
4  *
5  * Memory management for pre-boot and ramdisk uncompressors
6  *
7  * Authors: Alain Knaff <alain@knaff.lu>
8  *
9  */
10 
11 #ifndef DECOMPR_MM_H
12 #define DECOMPR_MM_H
13 
14 #ifdef STATIC
15 
16 /* Code active when included from pre-boot environment: */
17 
18 /*
19  * Some architectures want to ensure there is no local data in their
20  * pre-boot environment, so that data can arbitrarily relocated (via
21  * GOT references).  This is achieved by defining STATIC_RW_DATA to
22  * be null.
23  */
24 #ifndef STATIC_RW_DATA
25 #define STATIC_RW_DATA static
26 #endif
27 
28 /* A trivial malloc implementation, adapted from
29  *  malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
30  */
31 STATIC_RW_DATA unsigned long malloc_ptr;
32 STATIC_RW_DATA int malloc_count;
33 
malloc(int size)34 static void *malloc(int size)
35 {
36 	void *p;
37 
38 	if (size < 0)
39 		return NULL;
40 	if (!malloc_ptr)
41 		malloc_ptr = free_mem_ptr;
42 
43 	malloc_ptr = (malloc_ptr + 3) & ~3;     /* Align */
44 
45 	p = (void *)malloc_ptr;
46 	malloc_ptr += size;
47 
48 	if (free_mem_end_ptr && malloc_ptr >= free_mem_end_ptr)
49 		return NULL;
50 
51 	malloc_count++;
52 	return p;
53 }
54 
free(void * where)55 static void free(void *where)
56 {
57 	malloc_count--;
58 	if (!malloc_count)
59 		malloc_ptr = free_mem_ptr;
60 }
61 
62 #define large_malloc(a) malloc(a)
63 #define large_free(a) free(a)
64 
65 #define INIT
66 
67 #else /* STATIC */
68 
69 /* Code active when compiled standalone for use when loading ramdisk: */
70 
71 #include <linux/kernel.h>
72 #include <linux/fs.h>
73 #include <linux/string.h>
74 #include <linux/slab.h>
75 #include <linux/vmalloc.h>
76 
77 /* Use defines rather than static inline in order to avoid spurious
78  * warnings when not needed (indeed large_malloc / large_free are not
79  * needed by inflate */
80 
81 #define malloc(a) kmalloc(a, GFP_KERNEL)
82 #define free(a) kfree(a)
83 
84 #define large_malloc(a) vmalloc(a)
85 #define large_free(a) vfree(a)
86 
87 #define INIT __init
88 #define STATIC
89 
90 #include <linux/init.h>
91 
92 #endif /* STATIC */
93 
94 #endif /* DECOMPR_MM_H */
95