Fixes hibernation bugs on x86-32 system

From: Zhimin Gu <[email protected]>

Currently there are mainly three bugs in x86-32 system when doing hibernation:
1. The page copy code is not running in safe page, which might cause hang during resume.
2. There's no text mapping for the final jump address
of the original kernel, which might cause the system jumping into illegal address and causes system hang during resume.
3. The restore kernel switches to its own kernel page table(swapper_pg_dir) rather than the original kernel page table after all the pages been copied back, which might cause invalid virtual-physical mapping issue during resume.

To solve these problems:

1. Copy the code core_restore_code to a safe page, to avoid the instruction code be overwriten when image kernel pages are being copied.
2. Set up temporary text mapping for the image kernel's jump address, so that after all the pages have been copied back, the system could jump to this address.
3. Switch to the original kernel page table during resume.

Furthermore, MD5 hash check for e820 map is also backported from 64bits

Zhimin Gu (3):
x86, hibernate: Fix nosave_regions setup for hibernation x86, hibernate: Extract the common code of 64/32 bit system x86, hibernate: Backport several fixes from 64bits to 32bits
hibernation

 arch/x86/Kconfig                  |   2 +-
 arch/x86/include/asm/suspend_32.h |   4 +
 arch/x86/kernel/setup.c           |   2 +-
 arch/x86/power/hibernate.c        | 253 ++++++++++++++++++++++++++++++++++++++
 arch/x86/power/hibernate_32.c     |  76 ++++++++----
 arch/x86/power/hibernate_64.c     | 241 +-----------------------------------
 arch/x86/power/hibernate_asm_32.S |  49 ++++++--
 arch/x86/power/hibernate_asm_64.S |   2 +-
 8 files changed, 353 insertions(+), 276 deletions(-)
 create mode 100644 arch/x86/power/hibernate.c

2.7.4