Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/kernel/Documentation/s390/zfcpdump.txt b/kernel/Documentation/s390/zfcpdump.txt
new file mode 100644
index 000000000..dc929be96
--- /dev/null
+++ b/kernel/Documentation/s390/zfcpdump.txt
@@ -0,0 +1,52 @@
+The s390 SCSI dump tool (zfcpdump)
+
+System z machines (z900 or higher) provide hardware support for creating system
+dumps on SCSI disks. The dump process is initiated by booting a dump tool, which
+has to create a dump of the current (probably crashed) Linux image. In order to
+not overwrite memory of the crashed Linux with data of the dump tool, the
+hardware saves some memory plus the register sets of the boot CPU before the
+dump tool is loaded. There exists an SCLP hardware interface to obtain the saved
+memory afterwards. Currently 32 MB are saved.
+
+This zfcpdump implementation consists of a Linux dump kernel together with
+a user space dump tool, which are loaded together into the saved memory region
+below 32 MB. zfcpdump is installed on a SCSI disk using zipl (as contained in
+the s390-tools package) to make the device bootable. The operator of a Linux
+system can then trigger a SCSI dump by booting the SCSI disk, where zfcpdump
+resides on.
+
+The kernel part of zfcpdump is implemented as a debugfs file under "zcore/mem",
+which exports memory and registers of the crashed Linux in an s390
+standalone dump format. It can be used in the same way as e.g. /dev/mem. The
+dump format defines a 4K header followed by plain uncompressed memory. The
+register sets are stored in the prefix pages of the respective CPUs. To build a
+dump enabled kernel with the zcore driver, the kernel config option
+CONFIG_CRASH_DUMP has to be set. When reading from "zcore/mem", the part of
+memory, which has been saved by hardware is read by the driver via the SCLP
+hardware interface. The second part is just copied from the non overwritten real
+memory.
+
+Since kernel version 3.12 also the /proc/vmcore file can also be used to access
+the dump.
+
+To get a valid zfcpdump kernel configuration use "make zfcpdump_defconfig".
+
+The s390 zipl tool looks for the zfcpdump kernel and optional initrd/initramfs
+under the following locations:
+
+* kernel:  <zfcpdump directory>/zfcpdump.image
+* ramdisk: <zfcpdump directory>/zfcpdump.rd
+
+The zfcpdump directory is defined in the s390-tools package.
+
+The user space application of zfcpdump can reside in an intitramfs or an
+initrd. It can also be included in a built-in kernel initramfs. The application
+reads from /proc/vmcore or zcore/mem and writes the system dump to a SCSI disk.
+
+The s390-tools package version 1.24.0 and above builds an external zfcpdump
+initramfs with a user space application that writes the dump to a SCSI
+partition.
+
+For more information on how to use zfcpdump refer to the s390 'Using the Dump
+Tools book', which is available from
+http://www.ibm.com/developerworks/linux/linux390.