linux-toradex.git/include/scsi/libfcoe.h, branch v3.14.3

libfcoe: Make fcoe_sysfs optional / fix fnic NULL exception

2013-10-11T20:25:40+00:00

fnic doesn't use any of the create/destroy/enable/disable interfaces
either from the (legacy) module paramaters or the (new) fcoe_sysfs
interfaces. When fcoe_sysfs was introduced fnic wasn't changed since
it wasn't using the interfaces. libfcoe incorrectly assumed that that
all of its users were using fcoe_sysfs and when adding and deleting
FCFs would assume the existance of a fcoe_ctlr_device. fnic was not
allocating this structure because it doesn't care about the standard
user interfaces (fnic starts on link only). If/When libfcoe tried to use
the fcoe_ctlr_device's lock for the first time a NULL pointer exception
would be triggered.

Since fnic doesn't care about sysfs or user interfaces, the solution
is to drop libfcoe's assumption that all drivers are using fcoe_sysfs.

This patch accomplishes this by changing some of the structure
relationships.

We need a way to determine when a LLD is using fcoe_sysfs or not and
we can do that by checking for the existance of the fcoe_ctlr_device.
Prior to this patch, it was assumed that the fcoe_ctlr structure was
allocated with the fcoe_ctlr_device and immediately followed it in
memory. To reach the fcoe_ctlr_device we would simply go back in memory
from the fcoe_ctlr to get the fcoe_ctlr_device.

Since fnic doesn't allocate the fcoe_ctlr_device, we cannot keep that
assumption. This patch adds a pointer from the fcoe_ctlr to the
fcoe_ctlr_device. For bnx2fc and fcoe we will continue to allocate the
two structures together, but then we'll set the ctlr->cdev pointer
to point at the fcoe_ctlr_device. fnic will not change and will continue
to allocate the fcoe_ctlr itself, and ctlr->cdev will remain NULL.

When libfcoe adds fcoe_fcf's to the fcoe_ctlr it will check if ctlr->cdev
is set and only if so will it continue to interact with fcoe_sysfs.

Signed-off-by: Robert Love 
Acked-by: Neil Horman 
Tested-by: Hiral Patel

libfcoe, fcoe: consolidate the fcoe_ctlr_get_lesb/fcoe_get_lesb

2012-12-14T18:38:55+00:00

Similarly they can be moved into libfcoe instead of being private to fcoe now.
Also add comments particularly on the term LESB to the corresponding function.

Signed-off-by: Yi Zou 
Cc: Bhanu Prakash Gollapudi 
Tested-by: Marcus Dennis 
Signed-off-by: Robert Love

libfcoe, fcoe: move fcoe_link_speed_update() to libfcoe and export it

2012-12-14T18:38:55+00:00

With the previous patch, fcoe_link_speed_update() can be moved into libfcoe and
exported to used by fcoe, bnx2fc, and etc.

Signed-off-by: Yi Zou 
Cc: Bhanu Prakash Gollapudi 
Tested-by: Marcus Dennis 
Signed-off-by: Robert Love

fcoe: add support to the get_netdev() for fcoe_interface

2012-12-14T18:38:55+00:00

Adds support to fcoe_port's newly added get_netdev fucntion pointer.

Signed-off-by: Yi Zou 
Cc: Bhanu Prakash Gollapudi 
Tested-by: Marcus Dennis 
Signed-off-by: Robert Love

fcoe: prep work to start consolidate the usage of fcoe_netdev

2012-12-14T18:38:55+00:00

Currently, in the default kernel fcoe driver, it is needed to get to the underlying
private per fcoe transport's private structure, e.g., fcoe_interface in
fcoe.ko, and returns the associated netdev. The similar logic exists in other
fcoe drivers, e.g., bnx2fc, so we add a function pointer into the common
fcoe_port struct to allow individual fcoe transport implementaion (fcoe
and bnx2fc) to get the corresponding netdev associated with a give lport.

Then a inline fcoe_get_netdev() is added as part of libfcoe for all underlying
fcoe transport drivers to use regardless of its individual fcoe transport
driver, and also allows move more common code such as fcoe_link_speed_update or
fcoe_ctlr_get_lesb to be in libfcoe, rather than specific to fcoe.

This patch is a prep work that adds aforementioned fucntion pointer, and
followed by the actual code changes to make use of it.

Signed-off-by: Yi Zou 
Cc: Bhanu Prakash Gollapudi 
Tested-by: Marcus Dennis 
Signed-off-by: Robert Love

libfcoe, fcoe, bnx2fc: Add new fcoe control interface

2012-12-14T18:38:54+00:00

This patch does a few things.

1) Makes /sys/bus/fcoe/ctlr_{create,destroy} interfaces.
   These interfaces take an  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 
Acked-by: Neil Horman

[SCSI] fcoe: Fix write errors on NPIV ports

2012-10-07T10:49:34+00:00

SCSI errors were generated while writing to LUNs
connected via NPIV ports.

Debugging this it was found that the FCoE packets
transmitted via the NPIV ports were not tagged with
correct user priority as negotiated with peer by DCB
agent. This resulted in FCoE traffic going with priority
zero(0) that did not have priority flow control (PFC)
enabled for it. The initiator after transferring data
to the target never saw any reply indicating the transfer
was complete. This resulted in error recovery (ABTS) and
SCSI command retries by the scsi-mid layer; eventually
resulting in I/O errors.

This patch fixes this issue by keeping the FCoE user
priority information in the fcoe_interface instance
that is common for both the physical port as well as
NPIV ports connected to that physical port; instead
of storing it in fcoe_port structure that has a per
port instance.

Signed-off-by: Neerav Parikh 
Acked-by: Yi Zou 
Acked-by: John Fastabend 
Tested-by: Marcus Dennis 
Signed-off-by: Robert Love 
Signed-off-by: James Bottomley

[SCSI] fcoe, bnx2fc, libfcoe: SW FCoE and bnx2fc use FCoE Syfs

2012-05-23T08:43:13+00:00

This patch has the SW FCoE driver and the bnx2fc
driver make use of the new fcoe_sysfs API added
earlier in this patch series.

After this patch a fcoe_ctlr_device is allocated with
private data in this order.

+------------------+   +------------------+
| fcoe_ctlr_device |   | fcoe_ctlr_device |
+------------------+   +------------------+
| fcoe_ctlr        |   | fcoe_ctlr        |
+------------------+   +------------------+
| fcoe_interface   |   | bnx2fc_interface |
+------------------+   +------------------+

libfcoe also takes part in this new model since it
discovers and manages fcoe_fcf instances. The memory
allocation is different for FCFs. I didn't want to
impact libfcoe's fcoe_fcf processing, so this patch
creates fcoe_fcf_device instances for each discovered
fcoe_fcf. The two are paired using a (void * priv)
member of the fcoe_ctlr_device. This allows libfcoe
to continue maintaining its list of fcoe_fcf instances
and simply attaches and detaches them from existing
or new fcoe_fcf_device instances.

Signed-off-by: Robert Love 
Tested-by: Ross Brattain 
Signed-off-by: James Bottomley

[SCSI] libfcoe: Add fcoe_sysfs

2012-05-23T08:40:09+00:00

This patch adds a 'fcoe bus' infrastructure to the kernel
that is driven by changes to libfcoe which allow LLDs to
present FIP (FCoE Initialization Protocol) discovered
entities and their attributes to user space via sysfs.

This patch adds the following APIs-

fcoe_ctlr_device_add
fcoe_ctlr_device_delete
fcoe_fcf_device_add
fcoe_fcf_device_delete

They allow the LLD to expose the FCoE ENode Controller
and any discovered FCFs (Fibre Channel Forwarders, e.g.
FCoE switches) to the user. Each of these new devices
has their own bus_type so that they are grouped together
for easy lookup from a user space application. Each
new class has an attribute_group to expose attributes
for any created instances. The attributes are-

fcoe_ctlr_device
* fcf_dev_loss_tmo
* lesb_link_fail
* lesb_vlink_fail
* lesb_miss_fka
* lesb_symb_err
* lesb_err_block
* lesb_fcs_error

fcoe_fcf_device
* fabric_name
* switch_name
* priority
* selected
* fc_map
* vfid
* mac
* fka_peroid
* fabric_state
* dev_loss_tmo

A device loss infrastructre similar to the FC Transport's
is also added by this patch. It is nice to have so that a
link flapping adapter doesn't continually advance the count
used to identify the discovered FCF. FCFs will exist in a
"Disconnected" state until either the timer expires or the
FCF is rediscovered and becomes "Connected."

This patch generates a few checkpatch.pl WARNINGS that
I'm not sure what to do about. They're macros modeled
around the FC Transport attribute building macros, which
have the same 'feature' where the caller can ommit a cast
in the argument list and no cast occurs in the code. I'm
not sure how to keep the code condensed while keeping the
macros. Any advice would be appreciated.

Signed-off-by: Robert Love 
Tested-by: Ross Brattain 
Acked-by: Greg Kroah-Hartman 
Signed-off-by: James Bottomley

[SCSI] fcoe: Allocate fcoe_ctlr with fcoe_interface, not as a member

2012-05-23T08:36:27+00:00

Currently the fcoe_ctlr associated with an interface is allocated
as a member of struct fcoe_interface. This causes problems when
attempting to use the new fcoe_sysfs APIs which allow us to allocate
the fcoe_interface as private data to the fcoe_ctlr_device instance.
The problem is that libfcoe wants to be able use pointer math to find a
fcoe_ctlr's fcoe_ctlr_device as well as finding a fcoe_ctlr_device's
assocated fcoe_ctlr. To do this we need to allocate the
fcoe_ctlr_device, with private data for the LLD. The private data
contains the fcoe_ctlr and its private data is the fcoe_interface.
This patch only allocates the fcoe_interface with the fcoe_ctlr, the
fcoe_ctlr_device will be added in a later patch, which will complete
the below diagram-

+------------------+
| fcoe_ctlr_device |
+------------------+
| fcoe_ctlr        |
+------------------+
| fcoe_interface   |
+------------------+

This prep work will allow us to go from a fcoe_ctlr_device instance
to its fcoe_ctlr as well as from a fcoe_ctlr to its fcoe_ctlr_device
once the fcoe_sysfs API is in use (later patches in this series).

Signed-off-by: Robert Love 
Tested-by: Ross Brattain 
Signed-off-by: James Bottomley