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 arbitrarily 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  */
  30 STATIC_RW_DATA unsigned long malloc_ptr;
  31 STATIC_RW_DATA int malloc_count;
  32
  33 static 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
  54 static 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 */