linux-toradex.git/include/linux/kexec.h, branch tegra-10.7.1

kexec/i386: allocate page table pages dynamically

2008-10-31T09:01:56+00:00

Impact: save .text size when kexec is built in but not loaded

This patch adds an architecture specific struct kimage_arch into
struct kimage. The pointers to page table pages used by kexec are
added to struct kimage_arch. The page tables pages are dynamically
allocated in machine_kexec_prepare instead of statically from BSS
segment. This will save up to 20k memory when kexec image is not
loaded.

Signed-off-by: Huang Ying 
Signed-off-by: Ingo Molnar

kexec jump: rename KEXEC_CONTROL_CODE_SIZE to KEXEC_CONTROL_PAGE_SIZE

2008-08-15T15:35:42+00:00

Rename KEXEC_CONTROL_CODE_SIZE to KEXEC_CONTROL_PAGE_SIZE, because control
page is used for not only code on some platform.  For example in kexec
jump, it is used for data and stack too.

[akpm@linux-foundation.org: unbreak powerpc and arm, finish conversion]
Signed-off-by: Huang Ying 
Cc: Pavel Machek 
Cc: "Rafael J. Wysocki" 
Cc: "Eric W. Biederman" 
Cc: Vivek Goyal 
Cc: Ingo Molnar 
Cc: Russell King 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kdump: report actual value of VMCOREINFO_OSRELEASE in VMCOREINFO

2008-08-05T21:33:46+00:00

The current implementation reports the structure name as
VMCOREINFO_OSRELEASE in VMCOREINFO, e.g.

        VMCOREINFO_OSRELEASE=init_uts_ns.name.release

That doesn't make sense because it's always the same. Instead, use the
value, e.g.

        VMCOREINFO_OSRELEASE=2.6.26-rc3

That's also what the 'makedumpfile -g' does.

Signed-off-by: Bernhard Walle 
Cc: "Ken'ichi Ohmichi" 
Acked-by: Vivek Goyal 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kexec jump

2008-07-26T19:00:04+00:00

This patch provides an enhancement to kexec/kdump.  It implements the
following features:

- Backup/restore memory used by the original kernel before/after
  kexec.

- Save/restore CPU state before/after kexec.

The features of this patch can be used as a general method to call program in
physical mode (paging turning off).  This can be used to call BIOS code under
Linux.

kexec-tools needs to be patched to support kexec jump. The patches and
the precompiled kexec can be download from the following URL:

       source: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-src_git_kh10.tar.bz2
       patches: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-patches_git_kh10.tar.bz2
       binary: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec_git_kh10

Usage example of calling some physical mode code and return:

1. Compile and install patched kernel with following options selected:

CONFIG_X86_32=y
CONFIG_KEXEC=y
CONFIG_PM=y
CONFIG_KEXEC_JUMP=y

2. Build patched kexec-tool or download the pre-built one.

3. Build some physical mode executable named such as "phy_mode"

4. Boot kernel compiled in step 1.

5. Load physical mode executable with /sbin/kexec. The shell command
   line can be as follow:

   /sbin/kexec --load-preserve-context --args-none phy_mode

6. Call physical mode executable with following shell command line:

   /sbin/kexec -e

Implementation point:

To support jumping without reserving memory.  One shadow backup page (source
page) is allocated for each page used by kexeced code image (destination
page).  When do kexec_load, the image of kexeced code is loaded into source
pages, and before executing, the destination pages and the source pages are
swapped, so the contents of destination pages are backupped.  Before jumping
to the kexeced code image and after jumping back to the original kernel, the
destination pages and the source pages are swapped too.

C ABI (calling convention) is used as communication protocol between
kernel and called code.

A flag named KEXEC_PRESERVE_CONTEXT for sys_kexec_load is added to
indicate that the loaded kernel image is used for jumping back.

Now, only the i386 architecture is supported.

Signed-off-by: Huang Ying 
Acked-by: Vivek Goyal 
Cc: "Eric W. Biederman" 
Cc: Pavel Machek 
Cc: Nigel Cunningham 
Cc: "Rafael J. Wysocki" 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

vmcoreinfo: add "VMCOREINFO_" to all the call for vmcoreinfo_append_str()

2008-02-07T16:42:25+00:00

For readability, all the calls to vmcoreinfo_append_str() are changed to macros
having a prefix "VMCOREINFO_".

This discussion is the following:
http://www.ussg.iu.edu/hypermail/linux/kernel/0709.3/0584.html

Signed-off-by: Ken'ichi Ohmichi 
Acked-by: Simon Horman 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

vmcoreinfo: use the existing offsetof() for VMCOREINFO_OFFSET()

2008-02-07T16:42:25+00:00

It is better that the existing offsetof() is used for VMCOREINFO_OFFSET().

This discussion is the following:
http://www.ussg.iu.edu/hypermail/linux/kernel/0709.3/0584.html

Signed-off-by: Ken'ichi Ohmichi 
Acked-by: Simon Horman 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

vmcoreinfo: rename vmcoreinfo's macros returning the size

2008-02-07T16:42:25+00:00

This patchset is for the vmcoreinfo data.

The vmcoreinfo data has the minimum debugging information only for dump
filtering.  makedumpfile (dump filtering command) gets it to distinguish
unnecessary pages, and makedumpfile creates a small dumpfile.

This patch:

VMCOREINFO_SIZE() should be renamed VMCOREINFO_STRUCT_SIZE() since it's always
returning the size of the struct with a given name. This change would allow
VMCOREINFO_TYPEDEF_SIZE() to simply become VMCOREINFO_SIZE() since it need not
be used exclusively for typedefs.

This discussion is the following:
http://www.ussg.iu.edu/hypermail/linux/kernel/0709.3/0582.html

Signed-off-by: Ken'ichi Ohmichi 
Acked-by: David Rientjes 
Acked-by: Simon Horman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Extended crashkernel command line

2007-10-19T18:53:49+00:00

This patch adds a extended crashkernel syntax that makes the value of reserved
system RAM dependent on the system RAM itself:

    crashkernel=:[,:,...][@offset]
    range=start-[end]

For example:

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

The motivation comes from distributors that configure their crashkernel
command line automatically with some configuration tool (YaST, you know ;)).
Of course that tool knows the value of System RAM, but if the user removes
RAM, then the system becomes unbootable or at least unusable and error
handling is very difficult.

This series implements this change for i386, x86_64, ia64, ppc64 and sh.  That
should be all platforms that support kdump in current mainline.  I tested all
platforms except sh due to the lack of a sh processor.

This patch:

This is the generic part of the patch.  It adds a parse_crashkernel() function
in kernel/kexec.c that is called by the architecture specific code that
actually reserves the memory.  That function takes the whole command line and
looks itself for "crashkernel=" in it.

If there are multiple occurrences, then the last one is taken.  The advantage
is that if you have a bootloader like lilo or elilo which allows you to append
a command line parameter but not to remove one (like in GRUB), then you can
add another crashkernel value for testing at the boot command line and this
one overwrites the command line in the configuration then.

Signed-off-by: Bernhard Walle 
Cc: Andi Kleen 
Cc: "Luck, Tony" 
Cc: Paul Mackerras 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mundt 
Cc: Vivek Goyal 
Cc: "Eric W. Biederman" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

add-vmcore: add a prefix "VMCOREINFO_" to the vmcoreinfo macros

2007-10-17T15:42:54+00:00

Add a prefix "VMCOREINFO_" to the vmcoreinfo macros.  Old vmcoreinfo macros
were defined as generic names SYMBOL/SIZE/OFFSET /LENGTH/CONFIG, and it is
impossible to grep for them.  So these names should be changed.  This
discussion is the following:
http://www.ussg.iu.edu/hypermail/linux/kernel/0709.1/0415.html

Signed-off-by: Ken'ichi Ohmichi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

add-vmcore: add nodemask_t's size and NR_FREE_PAGES's value to vmcoreinfo_data

2007-10-17T15:42:54+00:00

[2/3] Add nodemask_t's size and NR_FREE_PAGES's value to vmcoreinfo_data.
  The dump filetering command 'makedumpfile'(v1.1.6 or before) had assumed
  the above values, and it was not good from the reliability viewpoint.
  So makedumpfile v1.2.0 came to need these values and I created the patch
  to let the kernel output them.
  makedumpfile site:
  https://sourceforge.net/projects/makedumpfile/

Signed-off-by: Ken'ichi Ohmichi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds