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: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This is my libata compatible low level driver for the Marvell SATA
family. Currently it successfully runs in PIO mode on a 6081 chip.
EDMA support is in the works and should be done shortly. Review,
testing (especially on other flavors of Marvell), comments welcome.
Signed-off-by: Brett Russ <russb@emc.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
The idea behind a RAID class is to provide a uniform interface to all
RAID subsystems (both hardware and software) in the kernel.
To do that, I've made this class a transport class that's entirely
subsystem independent (although the matching routines have to match per
subsystem, as you'll see looking at the code). I put it in the scsi
subdirectory purely because I needed somewhere to play with it, but it's
not a scsi specific module.
I used a fusion raid card as the test bed for this; with that kind of
card, this is the type of class output you get:
jejb@titanic> ls -l /sys/class/raid_devices/20\:0\:0\:0/
total 0
lrwxrwxrwx 1 root root 0 Aug 16 17:21 component-0 -> ../../../devices/pci0000:80/0000:80:04.0/host20/target20:1:0/20:1:0:0/
lrwxrwxrwx 1 root root 0 Aug 16 17:21 component-1 -> ../../../devices/pci0000:80/0000:80:04.0/host20/target20:1:1/20:1:1:0/
lrwxrwxrwx 1 root root 0 Aug 16 17:21 device -> ../../../devices/pci0000:80/0000:80:04.0/host20/target20:0:0/20:0:0:0/
-r--r--r-- 1 root root 16384 Aug 16 17:21 level
-r--r--r-- 1 root root 16384 Aug 16 17:21 resync
-r--r--r-- 1 root root 16384 Aug 16 17:21 state
So it's really simple: for a SCSI device representing a hardware raid,
it shows the raid level, the array state, the resync % complete (if the
state is resyncing) and the underlying components of the RAID (these are
exposed in fusion on the virtual channel 1).
As you can see, this type of information can be exported by almost
anything, including software raid.
The more difficult trick, of course, is going to be getting it to
perform configuration type actions with writable attributes.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This patch adds a device driver for scsi media changer devices.
Signed-off-by: Gerd Knorr <kraxel@bytesex.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
From: Christoph Hellwig <hch@lst.de>
Both drivers are marked broken and haven't compiled since very early
2.5.x. And they're for IDE hardware so they shouldn't have been
written to the SCSI layer at all.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Bagalkote, Sreenivas