We have already had the relocatable kernel, so just remove
the TODO in the kdump document.
Signed-off-by: NZhang Yanfei <zhangyanfei@cn.fujitsu.com>
Acked-by: NRob Landley <rob@landley.net>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

In efi_init() memory aligns in IA64_GRANULE_SIZE(16M). If set "crashkernel=1024M-:600M"
and use sparse memory model, when crash kernel booting it changes [128M-728M] to [128M-720M].

But initrd memory is in [709M-727M], and virt_addr_valid() *can not* check the invalid pages
when freeing initrd memory, because there are some pages missed at the end of the section,
and this causes error.

...
Unpacking initramfs...
Freeing initrd memory: 19648kB freed
BUG: Bad page state in process swapper  pfn:02d00
page:e0000000102dd800 flags:(null) count:0 mapcount:1 mapping:(null) index:0

Call Trace:
 [<a000000100018dc0>] show_stack+0x80/0xa0
                                sp=e000000021e8fbd0 bsp=e000000021e81360
 [<a00000010090fcc0>] dump_stack+0x30/0x50
                                sp=e000000021e8fda0 bsp=e000000021e81348
 [<a0000001001a3180>] bad_page+0x280/0x380
                                sp=e000000021e8fda0 bsp=e000000021e81308
 [<a0000001001a8740>] free_hot_cold_page+0x3a0/0x5c0
                                sp=e000000021e8fda0 bsp=e000000021e812a0
 [<a0000001001a8a50>] free_hot_page+0x30/0x60
                                sp=e000000021e8fda0 bsp=e000000021e81280
 [<a0000001001a8b30>] __free_pages+0xb0/0xe0
                                sp=e000000021e8fda0 bsp=e000000021e81258
 [<a0000001001a8c00>] free_pages+0xa0/0xc0
                                sp=e000000021e8fda0 bsp=e000000021e81230
 [<a000000100bb40c0>] free_initrd_mem+0x230/0x290
                                sp=e000000021e8fda0 bsp=e000000021e811d8
 [<a000000100ba6620>] populate_rootfs+0x1c0/0x280
                                sp=e000000021e8fdb0 bsp=e000000021e811a0
 [<a00000010000ac30>] do_one_initcall+0x3b0/0x3e0
                                sp=e000000021e8fdb0 bsp=e000000021e81158
 [<a000000100ba0a90>] kernel_init+0x3f0/0x4b0
                                sp=e000000021e8fdb0 bsp=e000000021e81108
 [<a000000100016890>] kernel_thread_helper+0xd0/0x100
                                sp=e000000021e8fe30 bsp=e000000021e810e0
 [<a00000010000a4c0>] start_kernel_thread+0x20/0x40
                                sp=e000000021e8fe30 bsp=e000000021e810e0
...

In "http://marc.info/?l=linux-arch&m=136147092429314&w=2" Tony said:
"Perhaps in Documentation/kdump/kdump.txt (which the crashkernel entry
in kernel-parameters.txt points at).  The ia64 section of kdump.txt
notes that the start address will be rounded up to a GRANULE boundary,
but doesn't talk about restrictions on the size."

This patch add size restriction to the documentation of kdump.
Signed-off-by: NXishi Qiu <qiuxishi@huawei.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The referenced html file does not exist anymore. Replace the URL with
the current project homepage.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add s390x specific parts to kdump kernel documentation.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Fix various typos in documentation txts.
Signed-off-by: NMatt LaPlante <kernel1@cyberdogtech.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

This adds relocatable kernel support for kdump. With this one can
use the same regular kernel to capture the kdump. A signature (0xfeed1234)
is passed in r6 from panic code to the next kernel through kexec_sequence
and purgatory code. The signature is used to differentiate between
kdump kernel and non-kdump kernels.

The purgatory code compares the signature and sets the __kdump_flag in
head_64.S.  During the boot up, kernel code checks __kdump_flag and if it
is set, the kernel will behave as relocatable kdump kernel. This kernel
will boot at the address where it was loaded by kexec-tools ie. at the
address reserved through crashkernel boot parameter.

CONFIG_CRASH_DUMP depends on CONFIG_RELOCATABLE option to build kdump
kernel as relocatable. So the same kernel can be used as production and
kdump kernel.

This patch incorporates the changes suggested by Paul Mackerras to avoid
GOT use and to avoid two copies of the code.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NMohan Kumar M <mohan@in.ibm.com>
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NSimon Horman <horms@verge.net.au>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch fixes a small bug in documentation: x86_64 also has now
the ability to build a relocatable kernel.
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Cc: vgoyal@redhat.com
Cc: kexec@lists.infradead.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The extended crashkernel syntax is a little confusing in the way it handles
ranges.  eg:

 crashkernel=512M-2G:64M,2G-:128M

Means if the machine has between 512M and 2G of memory the crash region should
be 64M, and if the machine has 2G of memory the region should be 64M.  Only if
the machine has more than 2G memory will 128M be allocated.

Although that semantic is correct, it is somewhat baffling.  Instead I propose
that the end of the range means the first address past the end of the range,
ie: 512M up to but not including 2G.

[bwalle@suse.de: clarify inclusive/exclusive in crashkernel commandline in documentation]
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Acked-by: NBernhard Walle <bwalle@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Simon Horman <horms@verge.net.au>
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds the documentation for the extended crashkernel syntax into
Documentation/kdump/kdump.txt.
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This cleans up kdump documentation a bit. Plus I do not think we want
to mention Linux trademark in _every_ file in documentation....
Signed-off-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adds the "reset_devices" option (that's used only by one device
driver for now) to the recommended list of command line parameters for kdump.

Meaning (Documentation/kernel-parameters.txt):
    reset_devices   [KNL] Force drivers to reset the underlying device
                    during initialization.
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Haren Myneni <hbabu@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch reflects the
http://git.kernel.org/?p=linux/kernel/git/horms/kexec-tools-testing.git;a=commit;h=b9c3648e690ad0dad12389659673206213a09760
change in kexec-tools-testing also now in the kernel documentation.
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Haren Myneni <hbabu@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adapts the Documentation/kdump/kdump.txt file to express the fact
that the x86_64 kernel is now also relocatable.  This makes i386 and x86_64
now behave the same, simplifying the documentation.
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Haren Myneni <hbabu@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch from Mohan Kumar M to add the ppc64 portions of the kdump
documentation.

http://thread.gmane.org/gmane.linux.kernel/481689/focus=3375

Cc: Mohan Kumar M <mohan@in.ibm.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I've noticed that the boot options are not correct for in the documentation
for kdump.  The "init" keyword is not necessary, and causes a kernel panic
when booting with an initrd on Fedora 5.

[horms@verge.net.au: put original comment with the latest version of the patch]
Signed-off-by: NJudith Lebzeelter <judith@osdl.org>
Acked-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

this patch fills in the portions for ia64 kexec.
Signed-off-by: NSimon Horman <horms@verge.net.au>
Cc: "Zou, Nanhai" <nanhai.zou@intel.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Mohan Kumar suggested making kexec-tools-testing.tar.gz a link to the
latest version.  I have done this and this patch updates the documentation
accordingly.
Signed-off-by: NSimon Horman <horms@verge.net.au>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

o Kdump documentation update.
	- Update details for using relocatable kernel.
	- Start using kexec-tools-testing release as it is latest and old
	  kexec-tools can't load relocatable bzImage file.
	- Also add kdump on ia64 specific details.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Cc: Horms <horms@verge.net.au>
Cc: Mohan Kumar M <mohan@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove many duplicated words under Documentation/ and do other small
cleanups.

Examples:
        "and and" --> "and"
        "in in" --> "in"
        "the the" --> "the"
        "the the" --> "to the"
        ...
Signed-off-by: NPaolo Ornati <ornati@fastwebnet.it>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Update the kdump documentation to reflect the changes due to recent kernel
config option changes for kexec and kdump.
Signed-off-by: NManeesh Soni <maneesh@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Added clarification on the root device format to be used for second kernel,
as well as specifying initrd if drivers are built as modules.
Signed-off-by: NKishore Sampathkumar <kishore.sampathkumar@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

There are minor changes in command line options in kexec-tools for kdump.
This patch updates the documentation to reflect those changes.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

o Specify "irqpoll" command line option which loading second kernel. This
  helps in reducing driver initialization failures in second kernel due
  to shared interrupts.
o Enabled LAPIC/IOAPIC support for UP kernels in second kernel. This reduces
  the chances of devices sharing the irq and hence reduces the chances of
  driver initialization failures in second kernel.
o Build a UP capture kernel and disabled SMP support.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch contains the documentation for the kexec based crash dump tool.

Quick kdump-howto
================================================================

1) Download and build kexec-tools.

2) Download and build the latest kexec/kdump (-mm) kernel patchset.
   Two kernels need to be built in order to get this feature working.

  A) First kernel:
   a) Enable "kexec system call" feature:
	CONFIG_KEXEC=y
   b) Physical load address (use default):
	CONFIG_PHYSICAL_START=0x100000
   c) Enable "sysfs file system support":
	CONFIG_SYSFS=y
   d) Boot into first kernel with the command line parameter "crashkernel=Y@X":
      For example: "crashkernel=64M@16M".

  B) Second kernel:
   a) Enable "kernel crash dumps" feature:
	CONFIG_CRASH_DUMP=y
   b) Physical load addreess, use same load address as X in "crashkernel"
      kernel parameter in d) above, e.g., 16 MB or 0x1000000.
	CONFIG_PHYSICAL_START=0x1000000
   c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems).
	CONFIG_PROC_VMCORE=y

3) Boot into the first kernel.

4) Load the second kernel to be booted using:

   kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev>
   maxcpus=1 init 1"

5) System reboots into the second kernel when a panic occurs. A module can be
   written to force the panic, for testing purposes.

6) See Documentation/kdump.txt for how to read the first kernel's
   memory image and how to analyze it.
Signed-off-by: NHariprasad Nellitheertha <hari@in.ibm.com>
Signed-off-by: NEric Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Nrandy_dunlap <rdunlap@xenotime.net>
Signed-off-by: NManeesh Soni <maneesh@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>