release/src-rt-6.x.4708/linux/linux-2.6.36/arch/s390/boot/compressed/misc.c

   1 /*
   2  * Definitions and wrapper functions for kernel decompressor
   3  *
   4  * Copyright IBM Corp. 2010
   5  *
   6  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  */
   8
   9 #include <asm/uaccess.h>
  10 #include <asm/page.h>
  11 #include <asm/ipl.h>
  12 #include "sizes.h"
  13
  14 /*
  15  * gzip declarations
  16  */
  17 #define STATIC static
  18
  19 #undef memset
  20 #undef memcpy
  21 #undef memmove
  22 #define memzero(s, n) memset((s), 0, (n))
  23
  24 /* Symbols defined by linker scripts */
  25 extern char input_data[];
  26 extern int input_len;
  27 extern char _text, _end;
  28 extern char _bss, _ebss;
  29
  30 static void error(char *m);
  31
  32 static unsigned long free_mem_ptr;
  33 static unsigned long free_mem_end_ptr;
  34
  35 #ifdef CONFIG_HAVE_KERNEL_BZIP2
  36 #define HEAP_SIZE       0x400000
  37 #else
  38 #define HEAP_SIZE       0x10000
  39 #endif
  40
  41 #ifdef CONFIG_KERNEL_GZIP
  42 #include "../../../../lib/decompress_inflate.c"
  43 #endif
  44
  45 #ifdef CONFIG_KERNEL_BZIP2
  46 #include "../../../../lib/decompress_bunzip2.c"
  47 #endif
  48
  49 #ifdef CONFIG_KERNEL_LZMA
  50 #include "../../../../lib/decompress_unlzma.c"
  51 #endif
  52
  53 #ifdef CONFIG_KERNEL_LZO
  54 #include "../../../../lib/decompress_unlzo.c"
  55 #endif
  56
  57 extern _sclp_print_early(const char *);
  58
  59 int puts(const char *s)
  60 {
  61         _sclp_print_early(s);
  62         return 0;
  63 }
  64
  65 void *memset(void *s, int c, size_t n)
  66 {
  67         char *xs;
  68
  69         if (c == 0)
  70                 return __builtin_memset(s, 0, n);
  71
  72         xs = (char *) s;
  73         if (n > 0)
  74                 do {
  75                         *xs++ = c;
  76                 } while (--n > 0);
  77         return s;
  78 }
  79
  80 void *memcpy(void *__dest, __const void *__src, size_t __n)
  81 {
  82         return __builtin_memcpy(__dest, __src, __n);
  83 }
  84
  85 void *memmove(void *__dest, __const void *__src, size_t __n)
  86 {
  87         char *d;
  88         const char *s;
  89
  90         if (__dest <= __src)
  91                 return __builtin_memcpy(__dest, __src, __n);
  92         d = __dest + __n;
  93         s = __src + __n;
  94         while (__n--)
  95                 *--d = *--s;
  96         return __dest;
  97 }
  98
  99 static void error(char *x)
 100 {
 101         unsigned long long psw = 0x000a0000deadbeefULL;
 102
 103         puts("\n\n");
 104         puts(x);
 105         puts("\n\n -- System halted");
 106
 107         asm volatile("lpsw %0" : : "Q" (psw));
 108 }
 109
 110 /*
 111  * Safe guard the ipl parameter block against a memory area that will be
 112  * overwritten. The validity check for the ipl parameter block is complex
 113  * (see cio_get_iplinfo and ipl_save_parameters) but if the pointer to
 114  * the ipl parameter block intersects with the passed memory area we can
 115  * safely assume that we can read from that memory. In that case just copy
 116  * the memory to IPL_PARMBLOCK_ORIGIN even if there is no ipl parameter
 117  * block.
 118  */
 119 static void check_ipl_parmblock(void *start, unsigned long size)
 120 {
 121         void *src, *dst;
 122
 123         src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
 124         if (src + PAGE_SIZE <= start || src >= start + size)
 125                 return;
 126         dst = (void *) IPL_PARMBLOCK_ORIGIN;
 127         memmove(dst, src, PAGE_SIZE);
 128         S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
 129 }
 130
 131 unsigned long decompress_kernel(void)
 132 {
 133         unsigned long output_addr;
 134         unsigned char *output;
 135
 136         check_ipl_parmblock((void *) 0, (unsigned long) output + SZ__bss_start);
 137         memset(&_bss, 0, &_ebss - &_bss);
 138         free_mem_ptr = (unsigned long)&_end;
 139         free_mem_end_ptr = free_mem_ptr + HEAP_SIZE;
 140         output = (unsigned char *) ((free_mem_end_ptr + 4095UL) & -4096UL);
 141
 142 #ifdef CONFIG_BLK_DEV_INITRD
 143         /*
 144          * Move the initrd right behind the end of the decompressed
 145          * kernel image.
 146          */
 147         if (INITRD_START && INITRD_SIZE &&
 148             INITRD_START < (unsigned long) output + SZ__bss_start) {
 149                 check_ipl_parmblock(output + SZ__bss_start,
 150                                     INITRD_START + INITRD_SIZE);
 151                 memmove(output + SZ__bss_start,
 152                         (void *) INITRD_START, INITRD_SIZE);
 153                 INITRD_START = (unsigned long) output + SZ__bss_start;
 154         }
 155 #endif
 156
 157         puts("Uncompressing Linux... ");
 158         decompress(input_data, input_len, NULL, NULL, output, NULL, error);
 159         puts("Ok, booting the kernel.\n");
 160         return (unsigned long) output;
 161 }