LXR linux/include/linux/decompress/mm.h

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