mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 02:09:42 +00:00
![Randy Dunlap](/assets/img/avatar_default.png)
Modify URLs to use https instead of http. Remove ancient URLs that don't work. Change "scsi" in text to "SCSI". Change "cdrom" in text to "CD-ROM". Drop the reference to "autoclean" for modules since I can't find it in any current documentation. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20230518212749.18266-3-rdunlap@infradead.org Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: linux-scsi@vger.kernel.org Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
44 lines
2.2 KiB
ReStructuredText
44 lines
2.2 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0
|
|
|
|
============================
|
|
SCSI subsystem documentation
|
|
============================
|
|
|
|
The Linux Documentation Project (LDP) maintains a document describing
|
|
the SCSI subsystem in the Linux kernel (lk) 2.4 series. See:
|
|
https://www.tldp.org/HOWTO/SCSI-2.4-HOWTO . The LDP has single
|
|
and multiple page HTML renderings as well as postscript and pdf.
|
|
|
|
Notes on using modules in the SCSI subsystem
|
|
============================================
|
|
The SCSI support in the Linux kernel can be modularized in a number of
|
|
different ways depending upon the needs of the end user. To understand
|
|
your options, we should first define a few terms.
|
|
|
|
The scsi-core (also known as the "mid level") contains the core of SCSI
|
|
support. Without it you can do nothing with any of the other SCSI drivers.
|
|
The SCSI core support can be a module (scsi_mod.o), or it can be built into
|
|
the kernel. If the core is a module, it must be the first SCSI module
|
|
loaded, and if you unload the modules, it will have to be the last one
|
|
unloaded. In practice the modprobe and rmmod commands
|
|
will enforce the correct ordering of loading and unloading modules in
|
|
the SCSI subsystem.
|
|
|
|
The individual upper and lower level drivers can be loaded in any order
|
|
once the SCSI core is present in the kernel (either compiled in or loaded
|
|
as a module). The disk driver (sd_mod.o), CD-ROM driver (sr_mod.o),
|
|
tape driver [1]_ (st.o) and SCSI generics driver (sg.o) represent the upper
|
|
level drivers to support the various assorted devices which can be
|
|
controlled. You can for example load the tape driver to use the tape drive,
|
|
and then unload it once you have no further need for the driver (and release
|
|
the associated memory).
|
|
|
|
The lower level drivers are the ones that support the individual cards that
|
|
are supported for the hardware platform that you are running under. Those
|
|
individual cards are often called Host Bus Adapters (HBAs). For example the
|
|
aic7xxx.o driver is used to control all recent SCSI controller cards from
|
|
Adaptec. Almost all lower level drivers can be built either as modules or
|
|
built into the kernel.
|
|
|
|
.. [1] There is a variant of the st driver for controlling OnStream tape
|
|
devices. Its module name is osst.o .
|