ubuntu-linux-kernel/arch/s390/boot/compressed/misc.c

177 lines
3.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Definitions and wrapper functions for kernel decompressor
*
* Copyright IBM Corp. 2010
*
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
*/
#include <linux/uaccess.h>
#include <asm/page.h>
#include <asm/sclp.h>
#include <asm/ipl.h>
#include "sizes.h"
/*
* gzip declarations
*/
#define STATIC static
#undef memset
#undef memcpy
#undef memmove
#define memmove memmove
#define memzero(s, n) memset((s), 0, (n))
/* Symbols defined by linker scripts */
extern char input_data[];
extern int input_len;
extern char _text, _end;
extern char _bss, _ebss;
static void error(char *m);
static unsigned long free_mem_ptr;
static unsigned long free_mem_end_ptr;
#ifdef CONFIG_HAVE_KERNEL_BZIP2
#define HEAP_SIZE 0x400000
#else
#define HEAP_SIZE 0x10000
#endif
#ifdef CONFIG_KERNEL_GZIP
#include "../../../../lib/decompress_inflate.c"
#endif
#ifdef CONFIG_KERNEL_BZIP2
#include "../../../../lib/decompress_bunzip2.c"
#endif
#ifdef CONFIG_KERNEL_LZ4
#include "../../../../lib/decompress_unlz4.c"
#endif
#ifdef CONFIG_KERNEL_LZMA
#include "../../../../lib/decompress_unlzma.c"
#endif
#ifdef CONFIG_KERNEL_LZO
#include "../../../../lib/decompress_unlzo.c"
#endif
#ifdef CONFIG_KERNEL_XZ
#include "../../../../lib/decompress_unxz.c"
#endif
static int puts(const char *s)
{
sclp_early_printk(s);
return 0;
}
void *memset(void *s, int c, size_t n)
{
char *xs;
xs = s;
while (n--)
*xs++ = c;
return s;
}
void *memcpy(void *dest, const void *src, size_t n)
{
const char *s = src;
char *d = dest;
while (n--)
*d++ = *s++;
return dest;
}
void *memmove(void *dest, const void *src, size_t n)
{
const char *s = src;
char *d = dest;
if (d <= s) {
while (n--)
*d++ = *s++;
} else {
d += n;
s += n;
while (n--)
*--d = *--s;
}
return dest;
}
static void error(char *x)
{
unsigned long long psw = 0x000a0000deadbeefULL;
puts("\n\n");
puts(x);
puts("\n\n -- System halted");
asm volatile("lpsw %0" : : "Q" (psw));
}
/*
* Safe guard the ipl parameter block against a memory area that will be
* overwritten. The validity check for the ipl parameter block is complex
* (see cio_get_iplinfo and ipl_save_parameters) but if the pointer to
* the ipl parameter block intersects with the passed memory area we can
* safely assume that we can read from that memory. In that case just copy
* the memory to IPL_PARMBLOCK_ORIGIN even if there is no ipl parameter
* block.
*/
static void check_ipl_parmblock(void *start, unsigned long size)
{
void *src, *dst;
src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
if (src + PAGE_SIZE <= start || src >= start + size)
return;
dst = (void *) IPL_PARMBLOCK_ORIGIN;
memmove(dst, src, PAGE_SIZE);
S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
}
unsigned long decompress_kernel(void)
{
void *output, *kernel_end;
output = (void *) ALIGN((unsigned long) &_end + HEAP_SIZE, PAGE_SIZE);
kernel_end = output + SZ__bss_start;
check_ipl_parmblock((void *) 0, (unsigned long) kernel_end);
#ifdef CONFIG_BLK_DEV_INITRD
/*
* Move the initrd right behind the end of the decompressed
* kernel image. This also prevents initrd corruption caused by
* bss clearing since kernel_end will always be located behind the
* current bss section..
*/
if (INITRD_START && INITRD_SIZE && kernel_end > (void *) INITRD_START) {
check_ipl_parmblock(kernel_end, INITRD_SIZE);
memmove(kernel_end, (void *) INITRD_START, INITRD_SIZE);
INITRD_START = (unsigned long) kernel_end;
}
#endif
/*
* Clear bss section. free_mem_ptr and free_mem_end_ptr need to be
* initialized afterwards since they reside in bss.
*/
memset(&_bss, 0, &_ebss - &_bss);
free_mem_ptr = (unsigned long) &_end;
free_mem_end_ptr = free_mem_ptr + HEAP_SIZE;
__decompress(input_data, input_len, NULL, NULL, output, 0, NULL, error);
return (unsigned long) output;
}