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

Fix following sparse warnings:-
 drivers/scsi/qla4xxx/ql4_os.c:2109:33: warning: cast truncates bits from constant value (ffff7fff becomes 7fff)
 drivers/scsi/qla4xxx/ql4_os.c:2306:33: warning: cast truncates bits from constant value (ffff7fff becomes 7fff)
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>

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>

Removing unused code as FW does not need any value in mbox-5.
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 unloading driver MBOX 0x31 fail as DDB logout (MBOX 0x56)
operation is not completed.

Fix:
Wait for DDB Logout completion before MBOX 0x31
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:
Driver holds rom-lock for too long during reset recovery.

During adapter reset testing, it was found that the driver
holds the rom-lock for too long, because of which other
drivers fail to acquire the rom-lock, leading to reset
failures.
The primary cause is, in the bootstrap code, while
holding the rom-lock, the driver checks if the peg is
halted, causing a 2 second contention.

Fix:
When a reset recovery starts, the driver deduces the cause, and
sets appropriate flags in watchdog & recover_adapter routines.
This flag should be used to determine if bootstrap is invoked
from probe or reset context, reducing the rom-lock footprint of
the drivers.
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:
minidump data collection fails as driver reports data mismatch

Fix:
When the driver encounters a new entry type that it cannot process,
it should just skip the entry and adjust the total buffer size by
subtracting the skipped bytes from it. This is to ensure that there
is no data mismatch because of the new entries.
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>

Issue:
Pending IO wait does not complete after triggering Graceful reset,
causing ack timeout and call traces.

Fix:
1. Reducing the IO command wait timeout before triggering reset,
   as logically also timeout should be less than reset timeout (10sec).
2. Moving the abort IO after chip reset, because only after
   chip reset, driver owns the IO otherwise it is with firmware and can
   still revert back with response.
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>

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>

Issue:
Mailbox command 0x102 (IDC Time Extend) failure seen while applying
changes to iface using iscsiadm

Fix:
Added fix to extend IDC timeout only for ISP84xx when IDC ACK
needs to be posted and disable ACB mailbox command completion
is in intermediate state.
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:
qla4xxx Unable to clear DDB indices when logout fails due to
failure of connection close mbox command.

Root cause:
If login to session fail, iscsiadm make call to destroy_session.
qla4xxx driver does not free ddb index map before free_ddb()

Fix:
Clear DDB Index map before free_ddb in "destroy_session"
in case of connection close mailbox command failure with 4005h.
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>

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>

If waiting for signals was interrupted then the device was put to
FAILED state. Use msleep instead of msleep_interruptible to handle
this correctly.
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>

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>

Removed AF_83XX_NO_FWDUMP flag and directly checking IDC_CTRL bit1
while taking minidump, to check for graceful reset.
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>

Issue:

For ISP8xxx, adapter initialization is not retried if
qla4xxx_initialize_adapter fails.

Fix:

If qla4xxx_initialize_adapter fails, first check if failure is due to IRQs not
attached in order to skip retrial, then free the IRQs and then retry
initializing the adapter.
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>

This patch fixed several typo in printk from various
part of kernel source.
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

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

Recreate the chap data list during the get chap operation in
qla4xxx_get_chap_list().
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: 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>

The statistics include MAC, TCP/IP & iSCSI statistics.
Signed-off-by: NLalit Chandivade <lalit.chandivade@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>

We should cap the size of memcpy() because it comes from the network
and can't be trusted.

Fixes: 26ffd7b4 ('[SCSI] qla4xxx: Add support to set CHAP entries')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NAdheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
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>

Add support to get local CHAP - index, username and password,
sysfs params of iscsi session corresponding to flash target entry.
Signed-off-by: NAdheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Provide support to add/update the CHAP entries in adapter's flash
using iscsi tools, like Open-iSCSI.
Signed-off-by: NAdheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

To write a CHAP entry in adapter's flash calculate the offset based
on the type of adapter.
Signed-off-by: NAdheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

If any flash target entry is using CHAP authentication then set
CHAP username and password sysfs params for the corresponding
iscsi sessions.
Signed-off-by: NAdheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Support setting of CHAP_OUT_IDX param for the target entry in flash.
Setting of valid local CHAP index with enable CHAP AUTH for that
flash target entry and disabling CHAP AUTH will invalidate the CHAP
index for the flash target entry.
Signed-off-by: NAdheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

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