In MOTU FireWire series, MIDI messages are multiplexed to isochronous
packets as well as PCM frames, while the way is different from the one
in IEC 61883-6.

MIDI messages are put into a certain position in message chunks. One data
block can includes one byte of the MIDI messages. When data block includes
a MIDI byte, the block has a flag in a certain position of the message
chunk. These positions are unique depending on protocols.

Once a data block includes a MIDI byte, some following data blocks includes
no MIDI bytes. Next MIDI byte appears on a data block corresponding to
next cycle of physical MIDI bus. This seems to avoid buffer overflow caused
by bandwidth differences between IEEE 1394 bus and physical MIDI bus.

This commit adds MIDI functionality to transfer/receive MIDI messages.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

This commit adds PCM functionality to transmit/receive PCM samples.

When one of PCM substreams are running or external clock source is
selected, current sampling rate is used. Else, the sampling rate is
changed according to requests from a userspace application.

Available number of samples in a frame of PCM substream is determined at
open(2) to corresponding PCM character device. Later, packet streaming
starts by ioctl(2) with SNDRV_PCM_IOCTL_PREPARE. In theory, between them,
applications can change state of the unit by any write transaction to
change the number. In this case, this driver may fail packet streaming due
to wrong data format.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

This commit adds a proc node for debugging purpose.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

This commit adds a functionality to manage packet streaming for MOTU
FireWire series.

The streaming is not controlled by CMP, thus against IEC 61883-1. Write
transaction to certain addresses start/stop packet streaming.

Transactions to 0x'ffff'f000'0b00 results in isochronous channel number for
both directions and starting/stopping transmission of packets. The
isochronous channel number is represented in 6 bit field, thus units can
identify the channels up to 64, as IEEE 1394 bus specification described.

Transactions to 0x'ffff'f000'0b10 results in packet format for both
directions and transmission speed. When each of data block includes fixed
part of data chunks only, corresponding flags stand.

When bus reset occurs, the units continue to transmit packets with
non-contiguous data block counter. This causes discontinuity detection in
packet streaming engine and ALSA PCM applications receives EPIPE from any
I/O operation. In this case, typical applications manage to recover
corresponding PCM substream. This behaviour is kicked much earlier than
callback of bus reset handler by Linux FireWire subsystem, therefore
status of packet streaming is not changed in the handler.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

All models of MOTU FireWire series can be controlled by write transaction
to addresses in a range from 0x'ffff'f0000'0b00 to 0x'ffff'f000'0cff.

The models support asynchronous notification. This notification has 32 bit
field data, and is transferred when status of clock changes. Meaning of
the value is not enough clear yet.

Drivers can register its address to receive the notification. Write
transaction to 0x'ffff'f000'0b04 registers higher 16 bits of the address.
Write transaction to 0x'ffff'f0000'0b08 registers the rest of bits. The
address includes node ID, thus it should be registered every time of bus
reset.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

MOTU FireWire series uses blocking transmission for AMDTP packet streaming.
They transmit/receive 8,000 packets per second, to handle the same number
of data blocks as current sampling transmission frequency. Thus,
IEC 61883-1/6 packet streaming engine of ALSA firewire stack is available
for them.

However, the sequence of packet and data blocks includes some quirks.
Below sample is a sequence of CIP headers of packets received by 828mk2,
at 44.1kHz of sampling transmission frequency.

quads CIP1        CIP2
488   0x020F04E8  0x8222FFFF
  8   0x020F04F8  0x8222FFFF
488   0x020F0400  0x8222FFFF
488   0x020F0408  0x8222FFFF
  8   0x020F04E8  0x8222FFFF
488   0x020F04F0  0x8222FFFF
488   0x020F04F8  0x8222FFFF

The SID (source node ID), DBS (data block size), SPH (source packet header),
FMT (format ID), FDF (format dependent field) and SYT (time stamp) fields
are in IEC 61883-1. Especially, FMT is 0x02, FDF is 0x22 and SYT is 0xffff
to define MOTU specific protocol. In an aspect of dbc field, the value
represents accumulated number of data blocks included the packet. This
is against IEC 61883-1, because according to the specification this value
should be the number of data blocks already transferred.

In ALSA IEC 61883-1/6 engine, this quirk is already supported by
CIP_DBC_IS_END_EVENT flag, because Echo Audio Fireworks has.

Each data block includes SPH as its first quadlet field, to represent its
presentation time stamp. Actual value of SPH is compliant to IEC 61883-1;
lower 25 bits of 32 bits width consists of 13 bits cycle count and 12 bits
cycle offset.

The rest of each data block consists of 24 bit chunks. All of PCM samples,
MIDI messages, status and control messages are transferred by the chunks.
This is similar to '24-bit * 4 Audio Pack' in IEC 61883-6. The position of
each kind of data depends on generations of each model. The number of
whole chunks in a data block is a multiple of 4, to consists of
quadlet-aligned packets.

This commit adds data block processing layer specific for the MOTU
protocol. The remarkable point is the way to generate SPH header. Time
stamps for each data blocks are generated by below calculation:

 * Using pre-computed table for the number of ticks per event
  *  44,1kHz: (557 + 123/441)
  *  48.0kHz: (512 +   0/441)
  *  88.2kHz: (278 + 282/441)
  *  96.0kHz: (256 +   0/441)
  * 176.4kHz: (139 + 141/441)
  * 192.0kHz: (128 +   0/441)
 * Accumulate the ticks and set the value to SPH for every events.
 * This way makes sense only for blocking transmission because this mode
   transfers fixed number or none of events.

This calculation assumes that each data block has a PCM frame which is
sampled according to event timing clock. Current packet streaming layer
has the same assumption.

Although this sequence works fine for MOTU FireWire series at sampling
transmission frequency based on 48.0kHz, it is not enough at the frequency
based on 44.1kHz. The units generate choppy noise every few seconds.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Commit c8bdf49b("ALSA: fireworks/firewire-lib: Add a quirk for the
meaning of dbc") adds CIP_DBC_IS_END_EVENT flag just for tx packets.
However, MOTU FireWire series has this quirk for rx packets.

This commit allows both directions with the flag.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

In IEC 61883-1, CIP headers can have a SPH field. When a packet has 1 in
SPH field of its CIP header, the packet has a source packet headers. A
source packet header consists of 32 bit field (= 1 quadlet) and it
transfers time stamp, which is the same value as the lower 25 bits of the
IEEE 1394 CYCLE_TIMER register and the rest is zero.

This commit just supports source packet header field because IEC 61883-1
includes ambiguity the position of this header and its count. Each
protocol layer is allowed to have actual implementation according its
requirements.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Currently, packet streaming layer passes generated SYT value to data block
processing layer. However, this is not enough in a case that the data block
processing layer generates time stamps by its own ways.

For out-packet stream, the packet streaming layer guarantees 8,000 times
calls of data block processing layers per sec. Therefore, when cycle count
of the first packet is recorded, data block processing layers can calculate
own time stamps with the recorded value.

For the reason, this commit allows packet streaming layer to record the
first cycle count. Each data block processing layer can read the count by
accessing a member of structure for packet streaming layer.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

In an aspect of used protocols to communicate, models of MOTU FireWire
units are categorized to three generations.

This commit adds an abstraction layer of the protocols for features
related to packet streaming functionality. This layer includes 5
operations.

When configuring packet streaming functionality with sampling rate and
sampling transmission frequency, .get_clock_rate and .set_clock_rate are
called with proper arguments. MOTU FireWire series supports up to 192.0kHz.

When checking current source of sampling clock (not clock for packetization
layer), .get_clock_source is used. Enumeration is added to represent the
sources supported by this series. This operation can be used to expose
available sampling rate to user space applications when the unit is
configured to use any input signal as source of clock instead of crystal
clock.

In the protocols, the path between packet processing layer and digital
signal processing layer can be controlled. This looks a functionality to
'mute' the unit. For this feature, .switch_fetching_mode is added. This
can be used to suppress noises every time packet streaming starts/stops.

In a point of the size of data blocks at a certain sampling transmission
frequency, the most units accept several modes. This is due to usage of
optical interfaces. The size differs depending on which modes are
configured to the interfaces; None, S/PDIF and ADAT. Additionally, format
of packet is different depending on protocols. To cache current size of
data blocks and its format, .cache_packet_formats is added. This is used
by PCM functionality, packet streaming functionality and data block
processing layer.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

MOTU FireWire series doesn't tell drivers their capabilities, thus
the drivers should have and apply model-dependent parameters to detected
models.

This commit adds a structure to represent such parameters. Capabilities
are represented by enumeration except for the number of analog line
in/out. Identification name also be in the structure because the units has
no registers for this purpose.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Just after appearing on IEEE 1394 bus, this unit generates several bus
resets. This is due to loading firmware from on-board flash memory and
initialize hardware. It's better to postpone sound card registration.

This commit applies this idea.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

This commit adds an new driver for MOTU FireWire series. In this commit,
this driver just creates/removes card instance according to bus event.
More functionalities will be added in following commits.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The latest gcc-7.0.1 snapshot points out that we if nr_ch is zero, we never
initialize some variables:

sound/pci/au88x0/au88x0_core.c: In function 'vortex_adb_allocroute':
sound/pci/au88x0/au88x0_core.c:2304:68: error: 'mix[0]' may be used uninitialized in this function [-Werror=maybe-uninitialized]
sound/pci/au88x0/au88x0_core.c:2305:58: error: 'src[0]' may be used uninitialized in this function [-Werror=maybe-uninitialized]

I assume this can never happen in practice, but adding a check here doesn't
hurt either and avoids the warning. The code has been unchanged since
the start of git history.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The extra pairs of parantheses are not needed and causes clang to
generate warnings like this:

sound/pci/hda/patch_ca0132.c:1171:14: error: equality comparison with extraneous parentheses [-Werror,-Wparentheses-equality]
        if ((buffer == NULL))
             ~~~~~~~^~~~~~~
sound/pci/hda/patch_ca0132.c:1171:14: note: remove extraneous parentheses around the comparison to silence this warning
        if ((buffer == NULL))
            ~       ^      ~
sound/pci/hda/patch_ca0132.c:1171:14: note: use '=' to turn this equality comparison into an assignment
        if ((buffer == NULL))
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

There is no point in using sprintf() without a format string when
strcpy() can perform the same operation.
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

This tested patch adds missing initialization for Line-In/Out PINs for
the docking station for HP 840 G3.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

This tested patch adds missing initialization for Line-In/Out PINs for
the docking station for HP 820 G2.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

In the commit [15c75b09: ALSA: ctxfi: Fallback DMA mask to 32bit],
I forgot to put "!" at dam_set_mask() call check in cthw20k1.c (while
cthw20k2.c is OK).  This patch fixes that obvious bug.

(As a side note: although the original commit was completely wrong,
 it's still working for most of machines, as it sets to 32bit DMA mask
 in the end.  So the bug severity is low.)

Fixes: 15c75b09 ("ALSA: ctxfi: Fallback DMA mask to 32bit")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

This BUG_ON() triggered for me once at shutdown, and I don't see a
reason for the check.  The code correctly checks whether the swap slot
cache is usable or not, so an uninitialized swap slot cache is not
actually problematic afaik.

I've temporarily just switched the BUG_ON() to a WARN_ON_ONCE(), since
I'm not sure why that seemingly pointless check was there.  I suspect
the real fix is to just remove it entirely, but for now we'll warn about
it but not bring the machine down.

Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull more powerpc fixes from Michael Ellerman:
 "A couple of minor powerpc fixes for 4.11:

   - wire up statx() syscall

   - don't print a warning on memory hotplug when HPT resizing isn't
     available

  Thanks to: David Gibson, Chandan Rajendra"

* tag 'powerpc-4.11-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/pseries: Don't give a warning when HPT resizing isn't available
  powerpc: Wire up statx() syscall

Pull parisc fixes from Helge Deller:

 - Mikulas Patocka added support for R_PARISC_SECREL32 relocations in
   modules with CONFIG_MODVERSIONS.

 - Dave Anglin optimized the cache flushing for vmap ranges.

 - Arvind Yadav provided a fix for a potential NULL pointer dereference
   in the parisc perf code (and some code cleanups).

 - I wired up the new statx system call, fixed some compiler warnings
   with the access_ok() macro and fixed shutdown code to really halt a
   system at shutdown instead of crashing & rebooting.

* 'parisc-4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix system shutdown halt
  parisc: perf: Fix potential NULL pointer dereference
  parisc: Avoid compiler warnings with access_ok()
  parisc: Wire up statx system call
  parisc: Optimize flush_kernel_vmap_range and invalidate_kernel_vmap_range
  parisc: support R_PARISC_SECREL32 relocation in modules

Pull SCSI target fixes from Nicholas Bellinger:
 "The bulk of the changes are in qla2xxx target driver code to address
  various issues found during Cavium/QLogic's internal testing (stable
  CC's included), along with a few other stability and smaller
  miscellaneous improvements.

  There are also a couple of different patch sets from Mike Christie,
  which have been a result of his work to use target-core ALUA logic
  together with tcm-user backend driver.

  Finally, a patch to address some long standing issues with
  pass-through SCSI export of TYPE_TAPE + TYPE_MEDIUM_CHANGER devices,
  which will make folks using physical (or virtual) magnetic tape happy"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (28 commits)
  qla2xxx: Update driver version to 9.00.00.00-k
  qla2xxx: Fix delayed response to command for loop mode/direct connect.
  qla2xxx: Change scsi host lookup method.
  qla2xxx: Add DebugFS node to display Port Database
  qla2xxx: Use IOCB interface to submit non-critical MBX.
  qla2xxx: Add async new target notification
  qla2xxx: Export DIF stats via debugfs
  qla2xxx: Improve T10-DIF/PI handling in driver.
  qla2xxx: Allow relogin to proceed if remote login did not finish
  qla2xxx: Fix sess_lock & hardware_lock lock order problem.
  qla2xxx: Fix inadequate lock protection for ABTS.
  qla2xxx: Fix request queue corruption.
  qla2xxx: Fix memory leak for abts processing
  qla2xxx: Allow vref count to timeout on vport delete.
  tcmu: Convert cmd_time_out into backend device attribute
  tcmu: make cmd timeout configurable
  tcmu: add helper to check if dev was configured
  target: fix race during implicit transition work flushes
  target: allow userspace to set state to transitioning
  target: fix ALUA transition timeout handling
  ...

Pull device-dax fixes from Dan Williams:
 "The device-dax driver was not being careful to handle falling back to
  smaller fault-granularity sizes.

  The driver already fails fault attempts that are smaller than the
  device's alignment, but it also needs to handle the cases where a
  larger page mapping could be established. For simplicity of the
  immediate fix the implementation just signals VM_FAULT_FALLBACK until
  fault-size == device-alignment.

  One fix is for -stable to address pmd-to-pte fallback from the
  original implementation, another fix is for the new (introduced in
  4.11-rc1) pud-to-pmd regression, and a typo fix comes along for the
  ride.

  These have received a build success notification from the kbuild
  robot"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  device-dax: fix debug output typo
  device-dax: fix pud fault fallback handling
  device-dax: fix pmd/pte fault fallback handling

Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
signed-off-by: Giridhar Malavali <giridhar.malavali@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Current driver wait for FW to be in the ready state before
processing in-coming commands. For Arbitrated Loop or
Point-to- Point (not switch), FW Ready state can take a while.
FW will transition to ready state after all Nports have been
logged in. In the mean time, certain initiators have completed
the login and starts IO. Driver needs to start processing all
queues if FW is already started.
Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

For target mode, when new scsi command arrive, driver first performs
a look up of the SCSI Host. The current look up method is based on
the ALPA portion of the NPort ID. For Cisco switch, the ALPA can
not be used as the index. Instead, the new search method is based
on the full value of the Nport_ID via btree lib.
Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Giridhar Malavali <giridhar.malavali@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

The Mailbox interface is currently over subscribed. We like
to reserve the Mailbox interface for the chip managment and
link initialization. Any non essential Mailbox command will
be routed through the IOCB interface. The IOCB interface is
able to absorb more commands.

Following commands are being routed through IOCB interface

- Get ID List (007Ch)
- Get Port DB (0064h)
- Get Link Priv Stats (006Dh)
Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: Anil Gurumurthy <anil.gurumurthy@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Add routines to support T10 DIF tag.
Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Anil Gurumurthy <anil.gurumurthy@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

If the remote port have started the login process, then the
PLOGI and PRLI should be back to back. Driver will allow
the remote port to complete the process. For the case where
the remote port decide to back off from sending PRLI, this
local port sets an expiration timer for the PRLI. Once the
expiration time passes, the relogin retry logic is allowed
to go through and perform login with the remote port.
Signed-off-by: Quinn Tran <quinn.tran@qlogic.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

The main lock that needs to be held for CMD or TMR submission
to upper layer is the sess_lock. The sess_lock is used to
serialize cmd submission and session deletion. The addition
of hardware_lock being held is not necessary. This patch removes
hardware_lock dependency from CMD/TMR submission.

Use hardware_lock only for error response in this case.

Path1
       CPU0                    CPU1
       ----                    ----
  lock(&(&ha->tgt.sess_lock)->rlock);
                               lock(&(&ha->hardware_lock)->rlock);
                               lock(&(&ha->tgt.sess_lock)->rlock);
  lock(&(&ha->hardware_lock)->rlock);

Path2/deadlock
*** DEADLOCK ***
Call Trace:
dump_stack+0x85/0xc2
print_circular_bug+0x1e3/0x250
__lock_acquire+0x1425/0x1620
lock_acquire+0xbf/0x210
_raw_spin_lock_irqsave+0x53/0x70
qlt_sess_work_fn+0x21d/0x480 [qla2xxx]
process_one_work+0x1f4/0x6e0

Cc: <stable@vger.kernel.org>
Cc: Bart Van Assche <Bart.VanAssche@sandisk.com>
Reported-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Normally, ABTS is sent to Target Core as Task MGMT command.
In the case of error, qla2xxx needs to send response, hardware_lock
is required to prevent request queue corruption.

Cc: <stable@vger.kernel.org>
Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

When FW notify driver or driver detects low FW resource,
driver tries to send out Busy SCSI Status to tell Initiator
side to back off. During the send process, the lock was not held.

Cc: <stable@vger.kernel.org>
Signed-off-by: Quinn Tran <quinn.tran@qlogic.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Cc: <stable@vger.kernel.org>
Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Cc: <stable@vger.kernel.org>
Signed-off-by: Joe Carnuccio <joe.carnuccio@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>