2 files changed, 87 insertions, 83 deletions

diff --git a/Documentation/s390/crypto/crypto-API.txt b/Documentation/s390/crypto/crypto-API.txt
deleted file mode 100644
index 71ae6ca9f2c2..000000000000
--- a/Documentation/s390/crypto/crypto-API.txt
+++ /dev/null
@@ -1,83 +0,0 @@
-crypto-API support for z990 Message Security Assist (MSA) instructions
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-AUTHOR: Thomas Spatzier (tspat@de.ibm.com)
-
-
-1. Introduction crypto-API
-~~~~~~~~~~~~~~~~~~~~~~~~~~
-See Documentation/crypto/api-intro.txt for an introduction/description of the
-kernel crypto API.
-According to api-intro.txt support for z990 crypto instructions has been added
-in the algorithm api layer of the crypto API. Several files containing z990
-optimized implementations of crypto algorithms are placed in the
-arch/s390/crypto directory.
-
-
-2. Probing for availability of MSA
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-It should be possible to use Kernels with the z990 crypto implementations both
-on machines with MSA available and on those without MSA (pre z990 or z990
-without MSA). Therefore a simple probing mechanism has been implemented:
-In the init function of each crypto module the availability of MSA and of the
-respective crypto algorithm in particular will be tested. If the algorithm is
-available the module will load and register its algorithm with the crypto API.
-
-If the respective crypto algorithm is not available, the init function will
-return -ENOSYS. In that case a fallback to the standard software implementation
-of the crypto algorithm must be taken ( -> the standard crypto modules are
-also built when compiling the kernel).
-
-
-3. Ensuring z990 crypto module preference
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-If z990 crypto instructions are available the optimized modules should be
-preferred instead of standard modules.
-
-3.1. compiled-in modules
-~~~~~~~~~~~~~~~~~~~~~~~~
-For compiled-in modules it has to be ensured that the z990 modules are linked
-before the standard crypto modules. Then, on system startup the init functions
-of z990 crypto modules will be called first and query for availability of z990
-crypto instructions. If instruction is available, the z990 module will register
-its crypto algorithm implementation -> the load of the standard module will fail
-since the algorithm is already registered.
-If z990 crypto instruction is not available the load of the z990 module will
-fail -> the standard module will load and register its algorithm.
-
-3.2. dynamic modules
-~~~~~~~~~~~~~~~~~~~~
-A system administrator has to take care of giving preference to z990 crypto
-modules. If MSA is available appropriate lines have to be added to
-/etc/modprobe.conf.
-
-Example:        z990 crypto instruction for SHA1 algorithm is available
-
-                add the following line to /etc/modprobe.conf (assuming the
-                z990 crypto modules for SHA1 is called sha1_z990):
-
-                alias sha1 sha1_z990
-
-                -> when the sha1 algorithm is requested through the crypto API
-                (which has a module autoloader) the z990 module will be loaded.
-
-TBD:    a userspace module probing mechanism
-        something like 'probe sha1 sha1_z990 sha1' in modprobe.conf
-        -> try module sha1_z990, if it fails to load standard module sha1
-        the 'probe' statement is currently not supported in modprobe.conf
-
-
-4. Currently implemented z990 crypto algorithms
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-The following crypto algorithms with z990 MSA support are currently implemented.
-The name of each algorithm under which it is registered in crypto API and the
-name of the respective module is given in square brackets.
-
-- SHA1 Digest Algorithm [sha1 -> sha1_z990]
-- DES Encrypt/Decrypt Algorithm (64bit key) [des -> des_z990]
-- Triple DES Encrypt/Decrypt Algorithm (128bit key) [des3_ede128 -> des_z990]
-- Triple DES Encrypt/Decrypt Algorithm (192bit key) [des3_ede -> des_z990]
-
-In order to load, for example, the sha1_z990 module when the sha1 algorithm is
-requested (see 3.2.) add 'alias sha1 sha1_z990' to /etc/modprobe.conf.
-
diff --git a/Documentation/s390/zfcpdump.txt b/Documentation/s390/zfcpdump.txt
new file mode 100644
index 000000000000..cf45d27c4608
--- /dev/null
+++ b/Documentation/s390/zfcpdump.txt
@@ -0,0 +1,87 @@
+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 userspace 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_ZFCPDUMP 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.
+
+The userspace application of zfcpdump can reside e.g. in an intitramfs or an
+initrd. It reads from zcore/mem and writes the system dump to a file on a
+SCSI disk.
+
+To build a zfcpdump kernel use the following settings in your kernel
+configuration:
+ * CONFIG_ZFCPDUMP=y
+ * Enable ZFCP driver
+ * Enable SCSI driver
+ * Enable ext2 and ext3 filesystems
+ * Disable as many features as possible to keep the kernel small.
+   E.g. network support is not needed at all.
+
+To use the zfcpdump userspace application in an initramfs you have to do the
+following:
+
+ * Copy the zfcpdump executable somewhere into your Linux tree.
+   E.g. to "arch/s390/boot/zfcpdump. If you do not want to include
+   shared libraries, compile the tool with the "-static" gcc option.
+ * If you want to include e2fsck, add it to your source tree, too. The zfcpdump
+   application attempts to start /sbin/e2fsck from the ramdisk.
+ * Use an initramfs config file like the following:
+
+   dir /dev 755 0 0
+   nod /dev/console 644 0 0 c 5 1
+   nod /dev/null 644 0 0 c 1 3
+   nod /dev/sda1 644 0 0 b 8 1
+   nod /dev/sda2 644 0 0 b 8 2
+   nod /dev/sda3 644 0 0 b 8 3
+   nod /dev/sda4 644 0 0 b 8 4
+   nod /dev/sda5 644 0 0 b 8 5
+   nod /dev/sda6 644 0 0 b 8 6
+   nod /dev/sda7 644 0 0 b 8 7
+   nod /dev/sda8 644 0 0 b 8 8
+   nod /dev/sda9 644 0 0 b 8 9
+   nod /dev/sda10 644 0 0 b 8 10
+   nod /dev/sda11 644 0 0 b 8 11
+   nod /dev/sda12 644 0 0 b 8 12
+   nod /dev/sda13 644 0 0 b 8 13
+   nod /dev/sda14 644 0 0 b 8 14
+   nod /dev/sda15 644 0 0 b 8 15
+   file /init arch/s390/boot/zfcpdump 755 0 0
+   file /sbin/e2fsck arch/s390/boot/e2fsck 755 0 0
+   dir /proc 755 0 0
+   dir /sys 755 0 0
+   dir /mnt 755 0 0
+   dir /sbin 755 0 0
+
+ * Issue "make image" to build the zfcpdump image with initramfs.
+
+In a Linux distribution the zfcpdump enabled kernel image must be copied to
+/usr/share/zfcpdump/zfcpdump.image, where the s390 zipl tool is looking for the
+dump kernel when preparing a SCSI dump disk.
+
+If you use a ramdisk copy it to "/usr/share/zfcpdump/zfcpdump.rd".
+
+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.