firewire: Add function to get speed from opaque struct fw_request

Sometimes it's useful to know the FireWire speed of the request that has
just come in to a fw_address_handler callback. As struct fw_request is
opaque we can't peek inside to get the speed out of the struct fw_packet
that's just inside. For example, the SBP-2 spec says:

"The speed at which the block write request to the MANAGEMENT_AGENT
register is received shall determine the speed used by the target for
all subsequent requests to read the initiator’s configuration ROM, fetch
ORB’s from initiator memory or store status at the initiator’s
status_FIFO. Command block ORB’s separately specify the speed for
requests addressed to the data buffer or page table."

[ ANSI T10/1155D Revision 4 page 53/54 ]

Signed-off-by: Chris Boot <bootc@bootc.net>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
firewire: Move fw_card kref functions into linux/firewire.h

When writing a firewire driver that doesn't deal with struct fw_device
objects (e.g. it only publishes FireWire units and doesn't subscribe to
them), you likely need to keep referenced to struct fw_card objects so
that you can send messages to other nodes. This patch moves
fw_card_put(), fw_card_get() and fw_card_release() into the public
include/linux/firewire.h header instead of drivers/firewire/core.h, and
adds EXPORT_SYMBOL_GPL(fw_card_release).

The firewire-sbp-target module requires these so it can keep a reference
to the fw_card object in order that it can fetch ORBs to execute and
read/write related data and status information.

Signed-off-by: Chris Boot <bootc@bootc.net>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
sbp-target: Initial merge of firewire/ieee-1394 target mode support

The FireWire SBP-2 Target is a driver for using an IEEE-1394 connection
as a SCSI transport. This module uses the SCSI Target framework to
expose LUNs to other machines attached to a FireWire bus, in effect
acting as a FireWire hard disk similar to FireWire Target Disk mode
on many Apple computers.

This commit contains the squashed pull from Chris Boot's SBP-2-Target:

      https://github.com/bootc/Linux-SBP-2-Target.git patch-v3

firewire-sbp-target: Add sbp_base.h header
firewire-sbp-target: Add sbp_configfs.c
firewire-sbp-target: Add sbp_fabric.{c,h}
firewire-sbp-target: Add sbp_management_agent.{c,h}
firewire-sbp-target: Add sbp_login.{c,h}
firewire-sbp-target: Add sbp_target_agent.{c,h}
firewire-sbp-target: Add sbp_scsi_cmnd.{c,h}
firewire-sbp-target: Add to target Kconfig and Makefile

Also add bootc's entry to the MAINTAINERS file.  Great work Chris !!

Signed-off-by: Chris Boot <bootc@bootc.net>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
arm: remove ability to select CONFIG_MCA

It isn't clear to me why this ever existed, as I've never heard
of an ARM board with an MCA bus.  Regardless, the MCA bus support
is going away, so remove the ability to select it from ARM.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
serial: delete the MCA specific 8250 support.

The support for CONFIG_MCA is being removed, since the 20
year old hardware simply isn't capable of meeting today's
software demands on CPU and memory resources.

This commit removes the MCA specific 8250 UART code.

Cc: Alan Cox <alan@linux.intel.com>
Cc: linux-serial@vger.kernel.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
scsi: delete the MCA specific drivers and driver code

The support for CONFIG_MCA is being removed, since the 20
year old hardware simply isn't capable of meeting today's
software demands on CPU and memory resources.

This commit removes the MCA specific SCSI drivers, and the
MCA specific portions of code in dual role ISA/MCA drivers.
Also, the MCA specific SCSI documentation is removed.

Cc: James Bottomley <JBottomley@parallels.com>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
MCA: delete all remaining traces of microchannel bus support.

Hardware with MCA bus is limited to 386 and 486 class machines
that are now 20+ years old and typically with less than 32MB
of memory.  A quick search on the internet, and you see that
even the MCA hobbyist/enthusiast community has lost interest
in the early 2000 era and never really even moved ahead from
the 2.4 kernels to the 2.6 series.

This deletes anything remaining related to CONFIG_MCA from core
kernel code and from the x86 architecture.  There is no point in
carrying this any further into the future.

One complication to watch for is inadvertently scooping up
stuff relating to machine check, since there is overlap in
the TLA name space (e.g. arch/x86/boot/mca.c).

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: James Bottomley <JBottomley@Parallels.com>
Cc: x86@kernel.org
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
md: using GFP_NOIO to allocate bio for flush request

A flush request is usually issued in transaction commit code path, so
using GFP_KERNEL to allocate memory for flush request bio falls into
the classic deadlock issue.

This is suitable for any -stable kernel to which it applies as it
avoids a possible deadlock.

Cc: stable@vger.kernel.org
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
md: allow a reshape operation to be reversed.

Currently a reshape operation always progresses from the start
of the array to the end unless the number of devices is being
reduced, in which case it progressed in the opposite direction.

To reverse a partial reshape which changes the number of devices
you can stop the array and re-assemble with the raid-disks numbers
reversed and it will undo.

However for a reshape that does not change the number of devices
it is not possible to reverse the reshape in the middle - you have to
wait until it completes.

So add a 'reshape_direction' attribute with is either 'forwards' or
'backwards' and can be explicitly set when delta_disks is zero.

This will become more important when we allow the data_offset to
change in a reshape.  Then the explicit statement of what direction is
being used will be more useful.

This can be enabled in raid5 trivially as it already supports
reverse reshape and just needs to use a different trigger to request it.

Signed-off-by: NeilBrown <neilb@suse.de>
md: add possibility to change data-offset for devices.

When reshaping we can avoid costly intermediate backup by
changing the 'start' address of the array on the device
(if there is enough room).

So as a first step, allow such a change to be requested
through sysfs, and recorded in v1.x metadata.

(As we didn't previous check that all 'pad' fields were zero,
 we need a new FEATURE flag for this.
 A (belatedly) check that all remaining 'pad' fields are
 zero to avoid a repeat of this)

The new data offset must be requested separately for each device.
This allows each to have a different change in the data offset.
This is not likely to be used often but as data_offset can be
set per-device, new_data_offset should be too.

This patch also removes the 'acknowledged' arg to rdev_set_badblocks as
it is never used and never will be.  At the same time we add a new
arg ('in_new') which is currently always zero but will be used more
soon.

When a reshape finishes we will need to update the data_offset
and rdev->sectors.  So provide an exported function to do that.

Signed-off-by: NeilBrown <neilb@suse.de>
md/raid5:  Use correct data_offset for all IO.

As there can now be two different data_offsets - an 'old' and
a 'new' - we need to carefully choose between them.

Signed-off-by: NeilBrown <neilb@suse.de>
md/raid5: allow for change in data_offset while managing a reshape.

The important issue here is incorporating the different in data_offset
into calculations concerning when we might need to over-write data
that is still thought to be valid.

To this end we find the minimum offset difference across all devices
and add that where appropriate.

Signed-off-by: NeilBrown <neilb@suse.de>
md/raid10: collect some geometry fields into a dedicated structure.

We will shortly be adding reshape support for RAID10 which will
require it having 2 concurrent geometries (before and after).
To make that easier, collect most geometry fields into 'struct geom'
and access them from there.  Then we will more easily be able to add
a second set of fields.

Note that 'copies' is not in this struct and so cannot be changed.
There is little need to change this number and doing so is a lot
more difficult as it requires reallocating more things.
So leave it out for now.

Signed-off-by: NeilBrown <neilb@suse.de>
md: teach sync_page_io about new_data_offset.

Some code in raid1 and raid10 use sync_page_io to
read/write pages when responding to read errors.
As we will shortly support changing data_offset for
raid10, this function must understand new_data_offset.

So add that understanding.

Signed-off-by: NeilBrown <neilb@suse.de>
md: use resync_max_sectors for reshape as well as resync.

Some resync type operations need to act on the address space of the
device, others on the address space of the array.

This only affects RAID10, so it sets resync_max_sectors to the array
size (it defaults to the device size), and that is currently used for
resync only.  However reshape of a RAID10 must be done against the
array size, not device size, so change code to use resync_max_sectors
for both the resync and the reshape cases.
This does not affect RAID5 or RAID1, just RAID10.

Signed-off-by: NeilBrown <neilb@suse.de>
md/raid10: Introduce 'prev' geometry to support reshape.

When RAID10 supports reshape it will need a 'previous' and a 'current'
geometry, so introduce that here.
Use the 'prev' geometry when before the reshape_position, and the
current 'geo' when beyond it.  At other times, use both as
appropriate.

For now, both are identical (And reshape_position is never set).

When we use the 'prev' geometry, we must use the old data_offset.
When we use the current (And a reshape is happening) we must use
the new_data_offset.

Signed-off-by: NeilBrown <neilb@suse.de>
md/raid10: split out interpretation of layout to separate function.

We will soon be interpreting the layout (and chunksize etc) from
multiple places to support reshape.  So split it out into separate
function.

Signed-off-by: NeilBrown <neilb@suse.de>
md/raid10: add reshape support

A 'near' or 'offset' lay RAID10 array can be reshaped to a different
'near' or 'offset' layout, a different chunk size, and a different
number of devices.
However the number of copies cannot change.

Unlike RAID5/6, we do not support having user-space backup data that
is being relocated during a 'critical section'.  Rather, the
data_offset of each device must change so that when writing any block
to a new location, it will not over-write any data that is still
'live'.

This means that RAID10 reshape is not supportable on v0.90 metadata.

The different between the old data_offset and the new_offset must be
at least the larger of the chunksize multiplied by offset copies of
each of the old and new layout. (for 'near' mode, offset_copies == 1).

A larger difference of around 64M seems useful for in-place reshapes
as more data can be moved between metadata updates.
Very large differences (e.g. 512M) seem to slow the process down due
to lots of long seeks (on oldish consumer graded devices at least).

Metadata needs to be updated whenever the place we are about to write
to is considered - by the current metadata - to still contain data in
the old layout.

[unbalanced locking fix from Dan Carpenter <dan.carpenter@oracle.com>]

Signed-off-by: NeilBrown <neilb@suse.de>
crypto: wait for a full jiffy in do_xor_speed

In the existing do_xor_speed(), there is no guarantee that we actually
run do_2() for a full jiffy. We get the current jiffy, then run do_2()
until the next jiffy.

Instead, let's get the current jiffy, then wait until the next jiffy
to start our test.

Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
crypto: disable preemption while benchmarking RAID5 xor checksumming

With CONFIG_PREEMPT=y, we need to disable preemption while benchmarking
RAID5 xor checksumming to ensure we're actually measuring what we think
we're measuring.

Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>