kernel_optimize_test/Documentation/ABI
Robert Love 6a891b071b libfcoe, fcoe, bnx2fc: Add new fcoe control interface
This patch does a few things.

1) Makes /sys/bus/fcoe/ctlr_{create,destroy} interfaces.
   These interfaces take an <ifname> and will either
   create an FCoE Controller or destroy an FCoE
   Controller depending on which file is written to.

   The new FCoE Controller will start in a DISABLED
   state and will not do discovery or login until it
   is ENABLED. This pause will allow us to configure
   the FCoE Controller before enabling it.

2) Makes the 'mode' attribute of a fcoe_ctlr_device
   writale. This allows the user to configure the mode
   in which the FCoE Controller will start in when it
   is ENABLED.

   Possible modes are 'Fabric', or 'VN2VN'.

   The default mode for a fcoe_ctlr{,_device} is 'Fabric'.
   Drivers must implement the set_fcoe_ctlr_mode routine
   to support this feature.

   libfcoe offers an exported routine to set a FCoE
   Controller's mode. The mode can only be changed
   when the FCoE Controller is DISABLED.

   This patch also removes the get_fcoe_ctlr_mode pointer
   in the fcoe_sysfs function template, the code in
   fcoe_ctlr.c to get the mode and the assignment of
   the fcoe_sysfs function pointer to the fcoe_ctlr.c
   implementation (in fcoe and bnx2fc). fcoe_sysfs can
   return that value for the mode without consulting the
   LLD.

3) Make a 'enabled' attribute of a fcoe_ctlr_device. On a
   read, fcoe_sysfs will return the attribute's value. On
   a write, fcoe_sysfs will call the LLD (if there is a
   callback) to notifiy that the enalbed state has changed.

This patch maintains the old FCoE control interfaces as
module parameters, but it adds comments pointing out that
the old interfaces are deprecated.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
2012-12-14 10:38:54 -08:00
..
obsolete oom: remove deprecated oom_adj 2012-10-09 16:22:24 +09:00
removed netfilter: remove ip_queue support 2012-05-08 20:25:42 +02:00
stable - Small fixes and optimizations. 2012-07-30 09:32:39 -07:00
testing libfcoe, fcoe, bnx2fc: Add new fcoe control interface 2012-12-14 10:38:54 -08:00
README

This directory attempts to document the ABI between the Linux kernel and
userspace, and the relative stability of these interfaces.  Due to the
everchanging nature of Linux, and the differing maturity levels, these
interfaces should be used by userspace programs in different ways.

We have four different levels of ABI stability, as shown by the four
different subdirectories in this location.  Interfaces may change levels
of stability according to the rules described below.

The different levels of stability are:

  stable/
	This directory documents the interfaces that the developer has
	defined to be stable.  Userspace programs are free to use these
	interfaces with no restrictions, and backward compatibility for
	them will be guaranteed for at least 2 years.  Most interfaces
	(like syscalls) are expected to never change and always be
	available.

  testing/
	This directory documents interfaces that are felt to be stable,
	as the main development of this interface has been completed.
	The interface can be changed to add new features, but the
	current interface will not break by doing this, unless grave
	errors or security problems are found in them.  Userspace
	programs can start to rely on these interfaces, but they must be
	aware of changes that can occur before these interfaces move to
	be marked stable.  Programs that use these interfaces are
	strongly encouraged to add their name to the description of
	these interfaces, so that the kernel developers can easily
	notify them if any changes occur (see the description of the
	layout of the files below for details on how to do this.)

  obsolete/
  	This directory documents interfaces that are still remaining in
	the kernel, but are marked to be removed at some later point in
	time.  The description of the interface will document the reason
	why it is obsolete and when it can be expected to be removed.
	The file Documentation/feature-removal-schedule.txt may describe
	some of these interfaces, giving a schedule for when they will
	be removed.

  removed/
	This directory contains a list of the old interfaces that have
	been removed from the kernel.

Every file in these directories will contain the following information:

What:		Short description of the interface
Date:		Date created
KernelVersion:	Kernel version this feature first showed up in.
Contact:	Primary contact for this interface (may be a mailing list)
Description:	Long description of the interface and how to use it.
Users:		All users of this interface who wish to be notified when
		it changes.  This is very important for interfaces in
		the "testing" stage, so that kernel developers can work
		with userspace developers to ensure that things do not
		break in ways that are unacceptable.  It is also
		important to get feedback for these interfaces to make
		sure they are working in a proper way and do not need to
		be changed further.


How things move between levels:

Interfaces in stable may move to obsolete, as long as the proper
notification is given.

Interfaces may be removed from obsolete and the kernel as long as the
documented amount of time has gone by.

Interfaces in the testing state can move to the stable state when the
developers feel they are finished.  They cannot be removed from the
kernel tree without going through the obsolete state first.

It's up to the developer to place their interfaces in the category they
wish for it to start out in.