sas_rphy_delete does two things: it removes the sas_rphy from the transport
layer and frees the sas_rphy.  This can be broken down into two functions,
sas_rphy_remove and sas_rphy_free; sas_rphy_remove is of interest to
sas_discover_root_expander because it calls functions that require
sas_rphy_add as a prerequisite and can fail (namely sas_discover_expander).
In that case, sas_discover_root_expander needs to be able to undo the effects
of sas_rphy_add yet leave the job of freeing the sas_rphy to the caller of
sas_discover_root_expander.

This patch also removes some unnecessary code from sas_discover_end_dev
to eliminate an unnecessary cycle of sas_notify_lldd_gone/found for SAS
devices, thus eliminating a sas_rphy_remove call (and fixing a race condition
where a SCSI target scan can come in between the gone and found call).
It also moves the sas_rphy_free calls into sas_discover_domain and
sas_ex_discover_end_dev to complement the sas_rphy_allocation via
sas_get_port_device.

This patch does not change the semantics of sas_rphy_delete.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

fix typos and bump version number
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Acked-by: NAlexis Bruemmer <alexisb@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Allowing the phy reset controls to be world-triggerable does not seem like
a terribly good idea because SAS devices can be disrupted (and ATA devices
are really disrupted) by a phy reset.  By default only root should be able
to do things like that.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Magic number cleanup.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch lets a user arbitrarily enable or disable a phy via sysfs.
Potential applications include shutting down a phy to replace one
lane of wide port, and (more importantly) providing a method for the
libata SATL to control the phy.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

According to SPEC, the minimum_linkrate and maximum_linkrate should be
settable by the user.  This patch introduces a callback that allows the
sas class to pass these settings on to the driver.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This flag denotes local attachment of the phy.  There are two problems
with it:

1) It's actually redundant ... you can get the same information simply
by seeing whether a host is the phys parent
2) we condition a lot of phy parameters on it on the false assumption
that we can only control local phys.  I'm wiring up phy resets in the
aic94xx now, and it will be able to reset non-local phys as well.

I fixed 2) by moving the local check into the reset and stats function
of the mptsas, since that seems to be the only HBA that can't
(currently) control non-local phys.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Using the port_id for the channel is completely unnecessary since the
host_id/target_id are constructed to be globally unique.  Also move
the mptsas driver on to virtual channel 1 for its raid devices.
Acked-by: N"Moore, Eric" <Eric.Moore@lsil.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch adds the ability to add a backlink to a particular port.  The
idea is to represent properly ports on expanders that are used
specifically for linking to the parent device in the topology.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Some SAS HBAs don't want to go to the trouble of tracking port numbers,
so they'd simply like to say "add this port and give it a number".
This is especially beneficial from the hotplug point of view, since
tracking ports and the available number space can be a real pain.

The current implementation uses an incrementing number per expander to
add the port on.  However, since there can never be more ports than
there are phys, a later implementation will try to be more intelligent
about this.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

this patch introduces a port object, separates out ports and phys,
with ports becoming the primary objects of the tree.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This is a hold over from the end device/expander conversion.  Apparently
the rphy list pointer is never initialised, so list_del() on the
uninitialised pointer can panic the system
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Use ARRAY_SIZE macro instead of sizeof(x)/sizeof(x[0]) and remove
duplicates of the macro.
Signed-off-by: NTobias Klauser <tklauser@nuerscht.ch>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

A couple write attributes in sas transport layer have a small
bug that prevents them from being written to.  Those
attributes are the link_reset and write_reset.  This is due
the store field being set to NULL.
Signed-off-by: NEric Moore <Eric.Moore@lsil.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

the user_scan() callback currently has the potential to identify the
wrong device in the presence of expanders.  This is because it finds
the first device with a matching target_id, which might be an
expander.  Fix this by making it look specifically for end devices.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Any end device that can't support any of the scanning protocols
shouldn't be scanned, so set its id to -1 to prevent
scsi_scan_target() being called for it.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

necessary to make the domain class use the internal structures
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Fix puts so that release functions will be called.
Signed-off-by: NMike Anderson <andmike@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This allows the removal of the contained flag and also does a bit of
class renaming (sas_rphy->sas_device).
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch makes expanders appear as labelled objects with properties in
the SAS tree.

I've also modified the phy code to make expander phys appear labelled by
host number, expander number and phy index.

So, for my current config, you see something like this in sysfs:

/sys/class/scsi_host/host1/device/phy-1:4/expander-1:0/phy-1-0:12/rphy-1:0-12/target1:0:1

And the expander properties are:

jejb@sparkweed> cd /sys/class/sas_expander/expander-1\:0/
jejb@sparkweed> for f in *; do echo -n $f ": "; cat $f; done
component_id : 29024
component_revision_id : 4
component_vendor_id : VITESSE
device : cat: device: Is a directory
level : 0
product_id : VSC7160 Eval Brd
product_rev : 4
uevent : cat: uevent: Permission denied
vendor_id : VITESSE
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Begin introducing the concept of sas remote devices that have an rphy
embedded.  The first one (this) is a simple end device.  All that an
end device really does is have port mode page parameters contained.
The next and more complex piece will be expander remote devices.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

aic94xx doesn't have a use for the bay or enclosure identifiers.
Also, I think it's not going to need a get_linkerrors(), so wire up
all of these exported properties as conditional on the underlying
function support.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

I don't think these exist in silicon yet, but the aic94xx driver has a
register setting for them.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Change the core SCSI code to use kzalloc rather than kmalloc+memset
where possible.
Signed-off-by: NJes Sorensen <jes@sgi.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch displays the port identifier on
the folder attribute; located in the middle digit.

/sys/class/sas_rphy/rphy-%x:%x:%x

The port identifier is basically the unique identifier
for each sas domain.
Signed-off-by: NEric Moore <Eric.Moore@lsil.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

We will be mapping the RAID volumes in mptsas to a reserved
channel that
is one larger than the anticapated number of ports on the direct
attached host
adapter.
Signed-off-by: NEric Moore <Eric.Moore@lsil.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

When James Smart fixed the issue of the userspace scan atributes
crashing the system with the FC transport class he added a patch to
let the transport class check if the parent is valid for a given
transport class.

When adding support for the integrated raid of fusion sas devices
we ran into a problem with that, as it didn't allow adding virtual
raid volumes without the transport class knowing about it.

So this patch adds a user_scan attribute instead, that takes over from
scsi_scan_host_selected if the transport class sets it and thus lets
the transport class control the user-initiated scanning.  As this
plugs the hole about user-initiated scanning the target_parent hook
goes away and we rely on callers of the scanning routines to do
something sensible.

For SAS this meant I had to switch from a spinlock to a mutex to
synchronize the topology linked lists, in FC they were completely
unsynchronized which seems wrong.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

We need to iterate over all children when removing and expander, else
stale objects will be around after host removal.  This fixes the oops
Eric Moore saw when removing and reloading mptsas.

Also don't try the scsi_remove_target call unless operating on an end
device.  The current unconditional call is harmless but confusing.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

We need to clear the backpointer on rphy removal, else we'll run into
problems with host removal after a device has been hot unplugged.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Fix more include file problems that surfaced since I submitted the previous
fix-missing-includes.patch.  This should now allow not to include sched.h
from module.h, which is done by a followup patch.
Signed-off-by: NTim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Add a flag to mark a PHY as attached to the HBA as opposed to beeing on
an expander.  This is needed because various features are only supported
on those.  This is a crude hack, the proper fix would be to use
different classes for host-attached vs expander phys.  I'm looking into
that.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

For now supporting the ->get_linkerrors method is mandatory.  I'll
probably be beaten to implement the .show_foo variables and different
types of attributes soon..
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Brown paperbag bug:  sas_rphy_delete was ordered completely
wrong.  Fix it up to be the same order as sas_phy_delete or
fc_rport_terminate and fix rphy objects that leaked after module
removal.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The SAS transport class contains common code to deal with SAS HBAs, an
aproximated representation of SAS topologies in the driver model,
and various sysfs attributes to expose these topologies and managment
interfaces to userspace.

In addition to the basic SCSI core objects this transport class introduces
two additional intermediate objects:  The SAS PHY as represented by struct
sas_phy defines an "outgoing" PHY on a SAS HBA or Expander, and the SAS
remote PHY represented by struct sas_rphy defines an "incoming" PHY on a
SAS Expander or end device.  Note that this is purely a software concept, the
underlying hardware for a PHY and a remote PHY is the exactly the same.

There is no concept of a SAS port in this code, users can see what PHYs
form a wide port based on the port_identifier attribute, which is the same
for all PHYs in a port.

This submission doesn't handle hot-plug addition or removal of SAS devices
and thus doesn't do scanning in a workqueue yet, that will be added in
phase2 after this submission.  In a third phase I will add additional
managment infrastructure.

I think this submission is ready for 2.6.14, but additional comments are
of course very welcome.

I'd like to thanks James Smart a lot for his very useful input on the
design.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>