RFC3270 mandates that iSCSI PDUs are padded to the closest integer
number of four byte words.  Fix the iser code to support that on both
the TX/RX flows.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.co.il>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

The code that prepares the SG associated with SCSI command for FMR was
buggy for systems with DMA addresses that don't fit in unsigned long,
e.g under the 32-bit based XenServer dom0 sizeof(dma_addr_t) is 8.

Fix that by casting to unsigned long long a masking constant used by
the code. This resolves a crash in iser_sg_to_page_vec on this system.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.co.il>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Fix a bug introduced in 69cce1d1 ("net: Abstract dst->neighbour
accesses behind helpers.") where we might dereference skb_dst(skb)
even if it is NULL, which causes:

    [  240.944030] BUG: unable to handle kernel NULL pointer dereference at 0000000000000040
    [  240.948007] IP: [<ffffffffa0366ce9>] ipoib_start_xmit+0x39/0x280 [ib_ipoib]
    [...]
    [  240.948007] Call Trace:
    [  240.948007]  <IRQ>
    [  240.948007]  [<ffffffff812cd5e0>] dev_hard_start_xmit+0x2a0/0x590
    [  240.948007]  [<ffffffff8131f680>] ? arp_create+0x70/0x200
    [  240.948007]  [<ffffffff812e8e1f>] sch_direct_xmit+0xef/0x1c0

Addresses: https://bugzilla.kernel.org/show_bug.cgi?id=41212Signed-off-by: NBernd Schubert <bernd.schubert@itwm.fraunhofer.de>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: NArun Sharma <asharma@fb.com>
Reviewed-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch renames the following iscsi_proto.h structures to avoid
namespace issues with drivers/target/iscsi/iscsi_target_core.h:

*) struct iscsi_cmd -> struct iscsi_scsi_req
*) struct iscsi_cmd_rsp -> struct iscsi_scsi_rsp
*) struct iscsi_login -> struct iscsi_login_req

This patch includes useful ISCSI_FLAG_LOGIN_[CURRENT,NEXT]_STAGE*,
and ISCSI_FLAG_SNACK_TYPE_* definitions used by iscsi_target_mod, and
fixes the incorrect definition of struct iscsi_snack to following
RFC-3720 Section 10.16. SNACK Request.

Also, this patch updates libiscsi, iSER, be2iscsi, and bn2xi to
use the updated structure definitions in a handful of locations.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NNicholas A. Bellinger <nab@linux-iscsi.org>

dst_{get,set}_neighbour()
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SCSI scanning of a channel:id:lun triplet in Linux works as follows
(function scsi_scan_target() in drivers/scsi/scsi_scan.c):

- If lun == SCAN_WILD_CARD, send a REPORT LUNS command to the target
  and process the result.

- If lun != SCAN_WILD_CARD, send an INQUIRY command to the LUN
  corresponding to the specified channel:id:lun triplet to verify
  whether the LUN exists.

So a SCSI driver must either take the channel and target id values in
account in its quecommand() function or it should declare that it only
supports one channel and one target id.

Currently the ib_srp driver does neither.  As a result scanning the
SCSI bus via e.g. rescan-scsi-bus.sh causes many duplicate SCSI
devices to be created. For each 0:0:L device, several duplicates are
created with the same LUN number and with (C:I) != (0:0). Fix this by
declaring that the ib_srp driver only supports one channel and one
target id.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Cc: <stable@kernel.org>
Acked-by: NDavid Dillow <dillowda@ornl.gov>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

* remove interrupt.g inclusion from netdevice.h -- not needed
* fixup fallout, add interrupt.h and hardirq.h back where needed.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The RDMA CM currently infers the QP type from the port space selected
by the user.  In the future (eg with RDMA_PS_IB or XRC), there may not
be a 1-1 correspondence between port space and QP type.  For netlink
export of RDMA CM state, we want to export the QP type to userspace,
so it is cleaner to explicitly associate a QP type to an ID.

Modify rdma_create_id() to allow the user to specify the QP type, and
use it to make our selections of datagram versus connected mode.
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Fix

    drivers/infiniband/ulp/srp/ib_srp.c: In function 'srp_handle_recv':
    drivers/infiniband/ulp/srp/ib_srp.c:1150: warning: cast to pointer from integer of different size
    drivers/infiniband/ulp/srp/ib_srp.c: In function 'srp_send_completion':
    drivers/infiniband/ulp/srp/ib_srp.c:1234: warning: cast to pointer from integer of different size

by adding an intermediate cast to uintptr_t.
Signed-off-by: NRoland Dreier <roland@purestorage.com>
Acked-by: NDavid Dillow <dillowda@ornl.gov>

Signed-off-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Now that we can get larger SG lists, we can take advantage of HCAs that
allow us to use larger FMR sizes. In many cases, we can use up to 512
entries, so start there and work our way down.
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>

This allows us to guarantee the ability to submit up to 8 MB requests
based on the current value of SCSI_MAX_SG_CHAIN_SEGMENTS. While FMR will
usually condense the requests into 8 SG entries, it is imperative that
the target support external tables in case the FMR mapping fails or is
not supported.

We add a safety valve to allow targets without the needed support to
reap the benefits of the large tables, but fail in a manner that lets
the user know that the data didn't make it to the device. The user must
add "allow_ext_sg=1" to the target parameters to indicate that the
target has the needed support.

If indirect_sg_entries is not specified in the modules options, then
the sg_tablesize for the target will default to cmd_sg_entries unless
overridden by the target options.
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>

Instead of forcing all of the S/G entries to fit in one FMR, and falling
back to indirect descriptors if that fails, allow the use of as many
FMRs as needed to map the request. This lays the groundwork for allowing
indirect descriptor tables that are larger than can fit in the command
IU, but should marginally improve performance now by reducing the number
of indirect descriptors needed.

We increase the minimum page size for the FMR pool to 4K, as larger
pages help increase the coverage of each FMR, and it is rare that the
kernel would send down a request with scattered 512 byte fragments.

This patch also move some of the target initialization code afte the
parsing of options, to keep it together with the new code that needs to
allocate memory based on the options given.
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>

Different configurations of target software allow differing max sizes of
the command IU. Allowing this to be changed per-target allows all
targets on an initiator to get an optimal setting.

We deprecate srp_sg_tablesize and replace it with cmd_sg_entries in
preparation for allowing more indirect descriptors than can fit in the
IU.
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>

This is to clean up prior to further changes.
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>

It is unclear exactly how this code works around Mellanox SRP targets,
or if the problem is on the target side or in the HCA itself. In an
abundance of caution, we should always enable the workaround.
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>

This pactch has iser export the address and port
of the endpoint.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
is used to configure any non-standard kernel with a much larger scope than
only small devices.

This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes
references to the option throughout the kernel.  A new CONFIG_EMBEDDED
option is added that automatically selects CONFIG_EXPERT when enabled and
can be used in the future to isolate options that should only be
considered for embedded systems (RISC architectures, SLOB, etc).

Calling the option "EXPERT" more accurately represents its intention: only
expert users who understand the impact of the configuration changes they
are making should enable it.
Reviewed-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NDavid Woodhouse <david.woodhouse@intel.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Cc: Greg KH <gregkh@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* ib_wq is added, which is used as the common workqueue for infiniband
  instead of the system workqueue.  All system workqueue usages
  including flush_scheduled_work() callers are converted to use and
  flush ib_wq.

* cancel_delayed_work() + flush_scheduled_work() converted to
  cancel_delayed_work_sync().

* qib_wq is removed and ib_wq is used instead.

This is to prepare for deprecation of flush_scheduled_work().
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Merge the two tests in srp_queuecommand() of whether information unit
allocation succeeded into one.  An intended side effect of this change
is that we fix the warning:

    drivers/infiniband/ulp/srp/ib_srp.c: In function 'srp_queuecommand':
    drivers/infiniband/ulp/srp/ib_srp.c:1116: warning: 'req' may be used uninitialized in this function

(seen with CONFIG_CC_OPTIMIZE_FOR_SIZE=y at least with gcc 4.4.4)
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Acked-by: NDavid Dillow <dillowda@ornl.gov>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Signed-off-by: NOr Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

As a first step in moving from LRO to GRO, revert commit af40da89
("IPoIB: add LRO support").  Also eliminate the ethtool set_flags
callback which isn't needed anymore.  Finally, we need to include
<linux/sched.h> directly to get the declaration of restart_syscall()
(which used to be included implicitly through <linux/inet_lro.h>).

Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vladimir Sokolovsky <vlad@mellanox.co.il>
Signed-off-by: NOr Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Put the variables accessed together in the hot-path into common
cachelines, and separate them by RW vs RO to avoid false dirtying.
We keep a local copy of the lkey and rkey in the target to avoid
traversing pointers (and associated cache lines) to find them.
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>

We don't need protection against the SCSI stack, so use our own lock to
allow parallel progress on separate CPUs.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
[ broken out and small cleanups by David Dillow ]
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>

We only need the lock to cover list and credit manipulations, so push
those into srp_remove_req() and update the call chains.

We reorder the request removal and command completion in
srp_process_rsp() to avoid the SCSI mid-layer sending another command
before we've released our request and added any credits returned by the
target. This prevents us from returning HOST_BUSY unneccesarily.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
[ broken out, small cleanups, and modified to avoid potential extraneous
  HOST_BUSY returns by David Dillow ]
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>

We only need locks to protect our lists and number of credits available.
By pre-consuming the credit for the request, we can reduce our lock
coverage to just those areas. If we don't actually send the request,
we'll need to put the credit back into the pool.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
[ broken out and small cleanups by David Dillow ]
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>

We use req->scmnd != NULL to indicate an active request, so there's no
need to keep a separate list for them. We can afford the array iteration
during error handling, and dropping it gives us one less item that needs
lock protection.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
[ broken out and small cleanups by David Dillow ]
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>

Only one CPU at a time will own an RX IU, so using the address of the IU
as the work request cookie allows us to avoid taking a lock. We can
similarly prepare the TX path for lockless posting by moving the free TX
IUs to a list. This also removes the requirement that the queue sizes be
a power of 2.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
[ broken out, small cleanups, and modified to avoid needing an extra field
  in the IU by David Dillow]
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>

Signed-off-by: NBart Van Assche <bvanassche@acm.org>
[ broken out and small cleanups by David Dillow ]
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>

We can only have one task management comment outstanding, so move the
completion and status to the target port. This allows us to handle
resets of a LUN without a corresponding request having been sent.
Meanwhile, we don't need to play games with host_scribble, just use it
as the pointer it is.

This fixes a crash when we issue a bus reset using sg_reset.

Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=13893Reported-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>

Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.

The patch below presents a simple SCSI host lock push-down as an
equivalent transformation.  No locking or other behavior should change
with this patch.  All existing bugs and locking orders are preserved.

Additionally, add one parameter to queuecommand,
	struct Scsi_Host *
and remove one parameter from queuecommand,
	void (*done)(struct scsi_cmnd *)

Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.

Minimal code disturbance was attempted with this change.  Most drivers
needed only two one-line modifications for their host lock push-down.
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>
Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the new {max,min}3 macros to save some cycles and bytes on the stack.
This patch substitutes trivial nested macros with their counterpart.
Signed-off-by: NHagen Paul Pfeifer <hagen@jauu.net>
Cc: Joe Perches <joe@perches.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

srp_send_tsk_mgmt() was missing the proper DMA sync calls before posting
the buffer to the device.
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Use the list_first_entry() macro in ib_srp instead of open-coding the equivalent,
which makes the source code slightly more descriptive.  The list_first_entry()
macro itself was introduced in kernel 2.6.22.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

As proposed by the SRP (draft) standard, ib_srp reserves one ring
element for SRP_TSK_MGMT requests. This patch makes sure that the SCSI
mid-layer never tries to queue more than (SRP request limit) - 1 SCSI
commands to ib_srp. This improves performance for targets whose request
limit is less than or equal to SRP_NORMAL_REQ_SQ_SIZE by reducing the
number of BUSY responses reported by ib_srp to the SCSI mid-layer.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Signed-off-by: NDavid Dillow <dillowda@ornl.gov>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Use the net device's dev_id field to encode the port number of the pci
device.  This can be used to to associate a net device with the pci
device's port. The encoding is: dev_id = port - 1.
Signed-off-by: NEli Cohen <eli@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>