Currently the size of the per-cpu region reserved to save crash notes is
set by the per-architecture value MAX_NOTE_BYTES.  Which in turn is
currently set to 1024 on all supported architectures.

While testing ia64 I recently discovered that this value is in fact too
small.  The particular setup I was using actually needs 1172 bytes.  This
lead to very tedious failure mode where the tail of one elf note would
overwrite the head of another if they ended up being alocated sequentially
by kmalloc, which was often the case.

It seems to me that a far better approach is to caclculate the size that
the area needs to be.  This patch does just that.

If a simpler stop-gap patch for ia64 to be squeezed into 2.6.21(.X) is
needed then this should be as easy as making MAX_NOTE_BYTES larger in
arch/asm-ia64/kexec.h.  Perhaps 2048 would be a good choice.  However, I
think that the approach in this patch is a much more robust idea.

Acked-by:  Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Add kexec support to ARM.

Improvements like commandline handling could be made but this patch gives
basic functional support. It uses the next available syscall number, 347.

Once the syscall number is known, userspace support will be
finalised/submitted to kexec-tools, various patches already exist.

Originally based on a patch by Maxim Syrchin but updated and forward
ported by various people.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

* 'release' of master.kernel.org:/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] replace kmalloc+memset with kzalloc
  [IA64] resolve name clash by renaming is_available_memory()
  [IA64] Need export for csum_ipv6_magic
  [IA64] Fix DISCONTIGMEM without VIRTUAL_MEM_MAP
  [PATCH] Add support for type argument in PAL_GET_PSTATE
  [IA64] tidy up return value of ip_fast_csum
  [IA64] implement csum_ipv6_magic for ia64.
  [IA64] More Itanium PAL spec updates
  [IA64] Update processor_info features
  [IA64] Add se bit to Processor State Parameter structure
  [IA64] Add dp bit to cache and bus check structs
  [IA64] SN: Correctly update smp_affinty mask
  [IA64] sparse cleanups
  [IA64] IA64 Kexec/kdump

Changes and updates.

1. Remove fake rendz path and related code according to discuss with Khalid Aziz.
2. fc.i offset fix in relocate_kernel.S.
3. iospic shutdown code eoi and mask race fix from Fujitsu.
4. Warm boot hook in machine_kexec to SN SAL code from Jack Steiner.
5. Send slave to SAL slave loop patch from Jay Lan.
6. Kdump on non-recoverable MCA event patch from Jay Lan
7. Use CTL_UNNUMBERED in kdump_on_init sysctl.

Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

The elf note saving code is currently duplicated over several
architectures.  This cleanup patch simply adds code to a common file and
then replaces the arch-specific code with calls to the newly added code.

The only drawback with this approach is that s390 doesn't fully support
kexec-on-panic which for that arch leads to introduction of unused code.

Signed-off-by: Magnus Damm <magnus@valinux.co.jp>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

A tiny userland application loading the kernel and invoking kexec_load for 
mips is available here:

http://chac.le-poulpe.net/~nico/kexec/kexec-2006-10-18.tar.gz

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Create two files in /sys/kernel, kexec_loaded and kexec_crash_loaded.  Each
file contains a simple boolean value indicating whether the relevant kernel
has been loaded into memory.  The motivation for this is geared around
support.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

It is possible that the reserved crashkernel region can be overlapped with
initrd since the bootloader sets the initrd location.  When the initrd
region is freed, the second kernel memory will not be contiguous.  The
Kexec_load can cause an oops since there is no contiguous memory to write
the second kernel or this memory could be used in the first kernel itself
and may not be part of the dump.  For example, on powerpc, the initrd is
located at 36MB and the crashkernel starts at 32MB.  The kexec_load caused
panic since writing into non-allocated memory (after 36MB).  We could see
the similar issue even on other archs.

One possibility is to move the initrd outside of crashkernel region.  But,
the initrd region will be freed anyway before the system is up.  This patch
fixes this issue and frees only regions that are not part of crashkernel
memory in case overlaps.

Signed-off-by: Haren Myneni <haren@us.ibm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This adds kexec() support for SH.

Signed-off-by: kogiidena <kogiidena@eggplant.ddo.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: <fastboot@lists.osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

)

From: Vivek Goyal <vgoyal@in.ibm.com>

- In some cases, the number of segments, on a kexec load, exceeds the
  existing cap of 8.  This patch increases the KEXEC_SEGMENT_MAX limit from 8
  to 16.

Signed-off-by: Rachita Kothiyal <rachita@in.ibm.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>