libsas
link_power_management_policy
lpfc
+ megaraid
scsi_transport_srp/figures
--- /dev/null
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
+Notes on Management Module
+==========================
+
+Overview
+--------
+
+Different classes of controllers from LSI Logic accept and respond to the
+user applications in a similar way. They understand the same firmware control
+commands. Furthermore, the applications also can treat different classes of
+the controllers uniformly. Hence it is logical to have a single module that
+interfaces with the applications on one side and all the low level drivers
+on the other.
+
+The advantages, though obvious, are listed for completeness:
+
+ i. Avoid duplicate code from the low level drivers.
+ ii. Unburden the low level drivers from having to export the
+ character node device and related handling.
+ iii. Implement any policy mechanisms in one place.
+ iv. Applications have to interface with only module instead of
+ multiple low level drivers.
+
+Currently this module (called Common Management Module) is used only to issue
+ioctl commands. But this module is envisioned to handle all user space level
+interactions. So any 'proc', 'sysfs' implementations will be localized in this
+common module.
+
+Credits
+-------
+
+::
+
+ "Shared code in a third module, a "library module", is an acceptable
+ solution. modprobe automatically loads dependent modules, so users
+ running "modprobe driver1" or "modprobe driver2" would automatically
+ load the shared library module."
+
+- Jeff Garzik (jgarzik@pobox.com), 02.25.2004 LKML
+
+::
+
+ "As Jeff hinted, if your userspace<->driver API is consistent between
+ your new MPT-based RAID controllers and your existing megaraid driver,
+ then perhaps you need a single small helper module (lsiioctl or some
+ better name), loaded by both mptraid and megaraid automatically, which
+ handles registering the /dev/megaraid node dynamically. In this case,
+ both mptraid and megaraid would register with lsiioctl for each
+ adapter discovered, and lsiioctl would essentially be a switch,
+ redirecting userspace tool ioctls to the appropriate driver."
+
+- Matt Domsch, (Matt_Domsch@dell.com), 02.25.2004 LKML
+
+Design
+------
+
+The Common Management Module is implemented in megaraid_mm.[ch] files. This
+module acts as a registry for low level hba drivers. The low level drivers
+(currently only megaraid) register each controller with the common module.
+
+The applications interface with the common module via the character device
+node exported by the module.
+
+The lower level drivers now understand only a new improved ioctl packet called
+uioc_t. The management module converts the older ioctl packets from the older
+applications into uioc_t. After driver handles the uioc_t, the common module
+will convert that back into the old format before returning to applications.
+
+As new applications evolve and replace the old ones, the old packet format
+will be retired.
+
+Common module dedicates one uioc_t packet to each controller registered. This
+can easily be more than one. But since megaraid is the only low level driver
+today, and it can handle only one ioctl, there is no reason to have more. But
+as new controller classes get added, this will be tuned appropriately.
+++ /dev/null
- Notes on Management Module
- ~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-Overview:
---------
-
-Different classes of controllers from LSI Logic accept and respond to the
-user applications in a similar way. They understand the same firmware control
-commands. Furthermore, the applications also can treat different classes of
-the controllers uniformly. Hence it is logical to have a single module that
-interfaces with the applications on one side and all the low level drivers
-on the other.
-
-The advantages, though obvious, are listed for completeness:
-
- i. Avoid duplicate code from the low level drivers.
- ii. Unburden the low level drivers from having to export the
- character node device and related handling.
- iii. Implement any policy mechanisms in one place.
- iv. Applications have to interface with only module instead of
- multiple low level drivers.
-
-Currently this module (called Common Management Module) is used only to issue
-ioctl commands. But this module is envisioned to handle all user space level
-interactions. So any 'proc', 'sysfs' implementations will be localized in this
-common module.
-
-Credits:
--------
-
-"Shared code in a third module, a "library module", is an acceptable
-solution. modprobe automatically loads dependent modules, so users
-running "modprobe driver1" or "modprobe driver2" would automatically
-load the shared library module."
-
- - Jeff Garzik (jgarzik@pobox.com), 02.25.2004 LKML
-
-"As Jeff hinted, if your userspace<->driver API is consistent between
-your new MPT-based RAID controllers and your existing megaraid driver,
-then perhaps you need a single small helper module (lsiioctl or some
-better name), loaded by both mptraid and megaraid automatically, which
-handles registering the /dev/megaraid node dynamically. In this case,
-both mptraid and megaraid would register with lsiioctl for each
-adapter discovered, and lsiioctl would essentially be a switch,
-redirecting userspace tool ioctls to the appropriate driver."
-
- - Matt Domsch, (Matt_Domsch@dell.com), 02.25.2004 LKML
-
-Design:
-------
-
-The Common Management Module is implemented in megaraid_mm.[ch] files. This
-module acts as a registry for low level hba drivers. The low level drivers
-(currently only megaraid) register each controller with the common module.
-
-The applications interface with the common module via the character device
-node exported by the module.
-
-The lower level drivers now understand only a new improved ioctl packet called
-uioc_t. The management module converts the older ioctl packets from the older
-applications into uioc_t. After driver handles the uioc_t, the common module
-will convert that back into the old format before returning to applications.
-
-As new applications evolve and replace the old ones, the old packet format
-will be retired.
-
-Common module dedicates one uioc_t packet to each controller registered. This
-can easily be more than one. But since megaraid is the only low level driver
-today, and it can handle only one ioctl, there is no reason to have more. But
-as new controller classes get added, this will be tuned appropriately.
L: linux-scsi@vger.kernel.org
W: http://www.avagotech.com/support/
S: Maintained
-F: Documentation/scsi/megaraid.txt
+F: Documentation/scsi/megaraid.rst
F: drivers/scsi/megaraid.*
F: drivers/scsi/megaraid/
projects / linux.git / commitdiff