Replace the session lock with two locks, a forward lock and
a backwards lock named frwd_lock and back_lock respectively.

The forward lock protects resources that change while sending a
request to the target, such as cmdsn, queued_cmdsn, and allocating
task from the commands' pool with kfifo_out.

The backward lock protects resources that change while processing
a response or in error path, such as cmdsn_exp, cmdsn_max, and
returning tasks to the commands' pool with kfifo_in.

Under a steady state fast-path situation, that is when one
or more processes/threads submit IO to an iscsi device and
a single kernel upcall (e.g softirq) is dealing with processing
of responses without errors, this patch eliminates the contention
between the queuecommand()/request response/scsi_done() flows
associated with iscsi sessions.

Between the forward and the backward locks exists a strict locking
hierarchy. The mutual exclusion zone protected by the forward lock can
enclose the mutual exclusion zone protected by the backward lock but not
vice versa.

For example, in iscsi_conn_teardown or in iscsi_xmit_data when there is
a failure and __iscsi_put_task is called, the backward lock is taken while
the forward lock is still taken. On the other hand, if in the RX path a nop
is to be sent, for example in iscsi_handle_reject or __iscsi_complete_pdu
than the forward lock is released and the backward lock is taken for the
duration of iscsi_send_nopout, later the backward lock is released and the
forward lock is retaken.

libiscsi_tcp uses two kernel fifos the r2t pool and the r2t queue.

The insertion and deletion from these queues didn't corespond to the
assumption taken by the new forward/backwards session locking paradigm.

That is, in iscsi_tcp_clenup_task which belongs to the RX (backwards)
path, r2t is taken out from r2t queue and inserted to the r2t pool.
In iscsi_tcp_get_curr_r2t which belong to the TX (forward) path, r2t
is also inserted to the r2t pool and another r2t is pulled from r2t
queue.

Only in iscsi_tcp_r2t_rsp which is called in the RX path but can requeue
to the TX path, r2t is taken from the r2t pool and inserted to the r2t
queue.

In order to cope with this situation, two spin locks were added,
pool2queue and queue2pool. The former protects extracting from the
r2t pool and inserting to the r2t queue, and the later protects the
extracing from the r2t queue and inserting to the r2t pool.
Signed-off-by: NShlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
[minor fix up to apply cleanly and compile fix]
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NNilesh Javali <nilesh.javali@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Issue:
While booting with kdump kernel, driver receive IOCB interrupts
for which it is not ready which results in processing them
before init_firmware during driver probe

Fix:
Two steps solution
1. Make driver ready to process the interrupt before interupts
   handlers is registered.
2. Stop driver processing iocb interrupts if not generated as per
   firmware protocol i.e R2H bit set
Signed-off-by: NTej Parkash <tej.parkash@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NNilesh Javali <nilesh.javali@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Added support for Diagnostics MBOX command via BSG Vendor HST_VENDOR
interface.  This command provides various tests for validating hardware
functionality.
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Added support to display and update additional network parameters
through iscsiadm.
Signed-off-by: NHarish Zunjarrao <harish.zunjarrao@qlogic.com>
Signed-off-by: NAdheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

While loopback diagnostic is in progress, disable the ACB which resets
all the active connections to target. Disable ACB would filter out all
the DHCP multicast and broadcast packets which otherwise cause the
diagnostic test to take longer time to complete or failures in some
other cases.
Signed-off-by: NNilesh Javali <nilesh.javali@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Added print statements for following AENs:
1. MBOX_ASTS_INITIALIZATION_FAILED
2. MBOX_ASTS_SYSTEM_WARNING_EVENT
3. MBOX_ASTS_DCBX_CONF_CHANGE
4. MBOX_ASTS_IPV6_DEFAULT_ROUTER_CHANGED
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Issue:
Request queue count holds the information about free space in request queue
which has to be manipulated based on request in and out pointer.
But in driver response path, this count was incremented unconditionally,
which could move req_in pointer beyond req_out pointer.
This scenario leads fw hang during IO.

Solution:
Request queue count manipulation has to be done in IO path only, keeping
req_in and req_out pointer two IOCB count away
Signed-off-by: NTej Parkash <tej.parkash@qlogic.com>
Signed-off-by: NShyam Sundar <shyam.sundar@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Move "Incorrect function ID" print message in case INTX interrupt
from DEBUG2 to DEBUG7. This will avoid floods of this message if
DEBUG2 is enabled.
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Quiesce all different activities performed by driver upon the link events
while loopback diagnostics is in progress.
Signed-off-by: NNilesh Javali <nilesh.javali@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NNilesh Javali <nilesh.javali@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

The spurious interrupt messages are seen when interrupt lines are
shared between different adapters or modules. Example, interrupt
lines are shared between qlcnic and qla4xxx and USB modules, then the
console is flooded with flurry of spurious interrupt messages
which are expected in such scenario.

Hence put these messages under debug level 2 for INTx interrupt mode.
Signed-off-by: NNilesh Javali <nilesh.javali@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Issue:
Mailbox command timed out after switching from polling mode to interrupt mode.

Events:-
 1. Mailbox interrupts are disabled
 2. FW generates AEN and at same time driver enables Mailbox Interrupt
 3. Driver issues new mailbox to Firmware

In above case driver will not get AEN interrupts generated by FW in step #2 as
FW generated this AEN when interrupts are disabled. During the same time
driver enabled the mailbox interrupt, so driver will not poll for interrupt.
Driver will never process AENs generated in step #2 and issues new mailbox to
FW, but now FW is not able to post mailbox completion as AENs generated before
are not processed by driver.

Fix:
Enable Mailbox / AEN interrupts before initializing FW in case of ISP83XX.
This will make sure we process all Mailbox and AENs in interrupt mode.
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Handle IDC Request Notify AEN and post IDC Acknowledgement
while participating in Loopback IDC.
Signed-off-by: NNilesh Javali <nilesh.javali@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

For ISP82xx mixed interrupt mode is not supported.
Hence prevent MSI/MSI-x from falling back to INTx mode.
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NPoornima Vonti <poornima.vonti@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

The current code would incorrectly return a DID_OK for a
CHECK CONDITION with Recovered error sense key causing incorrect
completion of a command when there is a dropped frame.
Signed-off-by: NLalit Chandivade <lalit.chandivade@qlogic.com>
Signed-off-by: NTej Parkash <tej.parkash@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Defined error codes for ping completion status.

This patch take care of Mike Christie's commets
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Added ping support for network connection diagnostics.
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Added support to post kernel host event to application using
netlink interface.
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

For 4032, context reset was the same as chip reset, and any firmware
issue was recovered by performing a chip reset.
For 82xx, the iSCSI firmware runs along with FCoE and the NIC
firmware contexts, and an error encountered doesnot essentially mean
that a chip reset is necessary.

Perform Chip resets only in the following cases:
1. Mailbox system error.
2. Mailbox command timeout.
3. fw_heartbeat_counter counter stops incrementing.

For all other cases, only perform a context reset.
1. Command Completion with an invalid srb.
2. Other mailbox failures.
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NShyam Sunder <shyam.sunder@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Add scsi_transport_iscsi hooks in qla4xxx to support
iSCSI session management using iscsiadm.

This patch is based on discussion here
http://groups.google.com/group/open-iscsi/browse_thread/thread/e89fd888baf656a0#

Now users can use iscsiadm to do target discovery and do login/logout to
individual targets using the qla4xxx iSCSI class interface.

This patch leaves some dead code, but to make it easier to review
we are leaving and in the next patch we will remove that old code.

V2 - NOTE: Added code to avoid waiting for AEN during login/logout
in the driver, instead added a kernel to user event
to notify iscsid about login status. Because of this
iscsid will not get blocked.
Signed-off-by: NManish Rangankar <manish.rangankar@qlogic.com>
Signed-off-by: NLalit Chandivade <lalit.chandivade@qlogic.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Complete the cmd if sense length is zero. For cases where sense
data spans across multiple iocb's by FW, we need to hold on to the
I/O (ha->status_srb != NULL) till we have processed them all and
copied the sense data from internal buffer to scsi_cmd sense buffer.
Signed-off-by: NPrasanna Mumbai <prasanna.mumbai@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <jbottomley@parallels.com>

- Added MBOX_ASTS_DUPLICATE_IP AEN handling.
- Update MBOX_AEN_REG_COUNT to 8 so that driver will save status
  of all mbox registers in aen_q
Signed-off-by: NPrasanna Mumbai <prasanna.mumbai@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <jbottomley@parallels.com>

remove ha flag AF_HBA_GOING_AWAY and added flag AF_HA_REMOVAL
to mark the other ISP-4xxx port to indicate that the driver is
being removed, so that the other port will not re-initialize
while in the process of removing the ha due to driver unload
or hba hotplug.
Signed-off-by: NKaren Higgins <karen.higgins@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Driver has capability to add device dynamically and present
them to OS, driver no longer need to wait for DDBs to come
online during driver initialization.
Driver still issues a relogin for DDBs that are not online,
but no longer wait for DDB to come online.
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NKaren Higgins <karen.higgins@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Signed-off-by: NJustin P. Mattock <justinmattock@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NRavi Anand <ravi.anand@qlogic.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Prior to firmware state change from ACQUIRING to READY, an
0x8029 AEN is received. Added code to check previous state
being ACQUIRING in order to update the ip address in the driver.
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NPrasanna Mumbai <prasanna.mumbai@qlogic.com>
Signed-off-by: NRavi Anand <ravi.anand@qlogic.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

IRQF_SHARED flag should not be set when calling request_irq for MSI since
this interrupt mechanism cannot be shared like standard INTx
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NShyam Sundar <shyam.sundar@qlogic.com>
Signed-off-by: NRavi Anand <ravi.anand@qlogic.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

IRQF_DISABLE flag is deprecated and this flag is a NOOP in kernel.
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NRavi Anand <ravi.anand@qlogic.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>