When unaligned accesses are required for uncompressing a kernel (such as
for LZO decompression on ARM in a patch that follows), including
<linux/kernel.h> causes issues as it brings in a lot of things that are
not available in the decompression environment.

linux/kernel.h brings at least:
extern int console_printk[];
extern const char hex_asc[];
which causes errors at link-time as they are not available when
compiling the pre-boot environement. There are also a few others:

  arch/arm/boot/compressed/misc.o: In function `valid_user_regs':
   arch/arm/include/asm/ptrace.h:158: undefined reference to `elf_hwcap'
  arch/arm/boot/compressed/misc.o: In function `console_silent':
   include/linux/kernel.h:292: undefined reference to `console_printk'
  arch/arm/boot/compressed/misc.o: In function `console_verbose':
   include/linux/kernel.h:297: undefined reference to `console_printk'
  arch/arm/boot/compressed/misc.o: In function `pack_hex_byte':
   include/linux/kernel.h:360: undefined reference to `hex_asc'
  arch/arm/boot/compressed/misc.o: In function `hweight_long':
   include/linux/bitops.h:45: undefined reference to `hweight32'
  arch/arm/boot/compressed/misc.o: In function `__cmpxchg_local_generic':
   include/asm-generic/cmpxchg-local.h:21: undefined reference to `wrong_size_cmpxchg'
   include/asm-generic/cmpxchg-local.h:42: undefined reference to `wrong_size_cmpxchg'
  arch/arm/boot/compressed/misc.o: In function `__xchg':
   arch/arm/include/asm/system.h:309: undefined reference to `__bad_xchg'

However, those files apparently use nothing from <linux/kernel.h>, all
they need is the declaration of types such as u32 or u64, so
<linux/types.h> should be enough

Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>