linux-toradex.git/include/linux/kexec.h, branch v3.0-rc3

kdump: Allow shrinking of kdump region to be overridden

2011-04-01T05:14:30+00:00

On ppc64 the crashkernel region almost always overlaps an area of firmware.
This works fine except when using the sysfs interface to reduce the kdump
region. If we free the firmware area we are guaranteed to crash.

Rename free_reserved_phys_range to crash_free_reserved_phys_range and make
it a weak function so we can override it.

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt

percpu: add __percpu sparse annotations to core kernel subsystems

2010-02-17T02:17:38+00:00

Add __percpu sparse annotations to core subsystems.

These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors.  This patch doesn't affect normal builds.

Signed-off-by: Tejun Heo 
Reviewed-by: Christoph Lameter 
Acked-by: Paul E. McKenney 
Cc: Jens Axboe 
Cc: linux-mm@kvack.org
Cc: Rusty Russell 
Cc: Dipankar Sarma 
Cc: Peter Zijlstra 
Cc: Andrew Morton 
Cc: Eric Biederman

kexec: premit reduction of the reserved memory size

2009-12-16T15:20:13+00:00

Implement shrinking the reserved memory for crash kernel, if it is more
than enough.

For example, if you have already reserved 128M, now you just want 100M,
you can do:

# echo $((100*1024*1024)) > /sys/kernel/kexec_crash_size

Note, you can only do this before loading the crash kernel.

Signed-off-by: WANG Cong 
Cc: Neil Horman 
Acked-by: Eric W. Biederman 
Cc: Andi Kleen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

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