Introduce helper rdma_cap_iw_cm() to help us check if the port of an
IB device support IWARP Communication Manager.
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Introduce helper rdma_cap_ib_cm() to help us check if the port of an
IB device support Infiniband Communication Manager.
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Introduce helper rdma_cap_ib_smi() to help us check if the port of an
IB device support Infiniband Subnet Management Interface.
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Introduce helper rdma_cap_ib_mad() to help us check if the port of an
IB device support Infiniband Management Datagrams.
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Use raw management helpers to reform rest part in IB-core cma.
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Reform cma_acquire_dev() with management helpers, introduce
cma_validate_port() to make the code more clean.
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Use raw management helpers to reform mcast related part in IB-core cma.
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Use raw management helpers to reform route related part in IB-core cma.
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Use raw management helpers to reform cm related part in IB-core cma/ucm.

Few checks focus on the device cm type rather than the port capability,
directly pass port 1 works currently, but can't support mixing cm type
device in future.
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Use raw management helpers to reform IB-core verbs
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Use raw management helpers to reform IB-ulp ipoib.
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Use raw management helpers to reform IB-core multicast.
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Use raw management helpers to reform IB-core sa_query.
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Use raw management helpers to reform IB-core cm.
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Use raw management helpers to reform IB-core mad/agent/user_mad.
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Add new callback query_protocol() and implement for each HW.

Mapping List:
		node-type	link-layer	transport	protocol
nes		RNIC		ETH		IWARP		IWARP
amso1100	RNIC		ETH		IWARP		IWARP
cxgb3   	RNIC		ETH		IWARP		IWARP
cxgb4   	RNIC		ETH		IWARP		IWARP
usnic   	USNIC_UDP	ETH		USNIC_UDP	USNIC_UDP
ocrdma  	IB_CA		ETH		IB		IBOE
mlx4    	IB_CA		IB/ETH		IB		IB/IBOE
mlx5    	IB_CA		IB		IB		IB
ehca    	IB_CA		IB		IB		IB
ipath   	IB_CA		IB		IB		IB
mthca   	IB_CA		IB		IB		IB
qib     	IB_CA		IB		IB		IB
Signed-off-by: NMichael Wang <yun.wang@profitbricks.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Tested-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NSean Hefty <sean.hefty@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NDoug Ledford <dledford@redhat.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

These KERN_<LEVEL> uses are unnecessary with pr_<level> and cause
bad logging output so remove them.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Commit d4988623 ("IB/qib: use arch_phys_wc_add()")
adjusted mtrr inititialization to use the new interface.

Unfortunately, the new interface returns a signed
value and the patch tested the unsigned wc_cookie.

Fix the issue by changing the type of wc_cookie to int.  For
the success case the ret left at zero to avoid
a warning from the caller.  For failure wc_cookie
is used as the ret.
Signed-off-by: NMike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

The string iwpm_ulib_name is recorded in a nlmsg as a netlink attribute.
Without this fix parsing of the nlmsg by the userspace port mapper service fails
because of unknown attribute length, causing the port mapper service not to
register the client, which has sent the nlmsg.
Signed-off-by: NTatyana Nikolova <tatyana.e.nikolova@intel.com>
Cc: <stable@vger.kernel.org> #v3.16
Reviewed-By: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

For listening endpoints bound to the wildcard address, we need to pass
the wildcard address mapping to iwpm_get_remote_info() instead of the
mapped address of the new child connection.

Without this fix, and with iwarp port mapping enabled, each iw_cxgb4
connection that is spawned from a listening endpoint bound to the wildcard
address, will generate an annoying dmesg entry about failing to find
the remote address mapping info, and the connection state displayed in
debugfs under /sys/kernel/debug/iw_cxgb4/<pci-slot-no>/eps  will not have
the peer's address/port mapping info.  The connection still works though.

Fixes: 5b6b8fe6 ("RDMA/cxgb4: Report the actual address of the remote connecting peer")
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Reviewed-by: NTatyana Nikolova <Tatyana.E.Nikolova@intel.com>
Reviewed-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Using an element of a struct as the address for the memcpy of the whole
struct may introduce a buffer overflow and does not help readability either
simply pass the real thing as first argument to memcpy.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NNicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

See also patch "IPoIB/cm: Add connected mode support for devices
without SRQs" (commit ID 68e995a2). Detected by smatch.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Cc: Pradeep Satyanarayana <pradeeps@linux.vnet.ibm.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Remove these log messages in favor of per-endpoint counters as well as
device-global counters that can be inspected via debugfs.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Addresses the following kernel logs seen during boot of sparc systems:

Kernel unaligned access at TPC[103bce50] cm_find_listen+0x34/0xf8 [ib_cm]
Kernel unaligned access at TPC[103bce50] cm_find_listen+0x34/0xf8 [ib_cm]
Kernel unaligned access at TPC[103bce50] cm_find_listen+0x34/0xf8 [ib_cm]
Kernel unaligned access at TPC[103bce50] cm_find_listen+0x34/0xf8 [ib_cm]
Kernel unaligned access at TPC[103bce50] cm_find_listen+0x34/0xf8 [ib_cm]
Signed-off-by: NDavid Ahern <david.ahern@oracle.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Signed-off-by: NHonggang Li <honli@redhat.com>
Acked-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

This driver already makes use of ioremap_wc() on PIO buffers,
so convert it to use arch_phys_wc_add().

The qib driver uses a mmap() special case for when PAT is
not used, this behaviour used to be determined with a
module parameter but since we have been asked to just
remove that module parameter this checks for the WC cookie,
if not set we can assume PAT was used. If its set we do
what we used to do for the mmap for when MTRR was enabled.

The removal of the module parameter is OK given that Andy
notes that even if users of module parameter are still around
it will not prevent loading of the module on recent kernels.

Cc: Doug Ledford <dledford@redhat.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: Dennis Dalessandro <dennis.dalessandro@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Stefan Bader <stefan.bader@canonical.com>
Cc: konrad.wilk@oracle.com
Cc: ville.syrjala@linux.intel.com
Cc: david.vrabel@citrix.com
Cc: jbeulich@suse.com
Cc: Roger Pau Monné <roger.pau@citrix.com>
Cc: infinipath@intel.com
Cc: linux-rdma@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: xen-devel@lists.xensource.com
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

There is no good reason not to, we eventually delete it as well.

Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Mike Marciniszyn <infinipath@intel.com>
Cc: Roland Dreier <roland@kernel.org>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: linux-rdma@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

While unmapping an ODP writable page, the dirty bit of the page is set. In
order to do so, the head of the compound page is found.
Currently, the compound head is found even on non-writable pages, where it is
never used, leading to unnecessary cpu barrier that impacts performance.

This patch moves the search for the compound head to be done only when needed.
Signed-off-by: NGuy Shapiro <guysh@mellanox.com>
Acked-by: NShachar Raindel <raindel@mellanox.com>
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Currently, while mapping or unmapping pages for ODP, the umem mutex is locked
and unlocked once for each page. Such lock/unlock operation take few tens to
hundreds of nsecs. This makes a significant impact when mapping or unmapping few
MBs of memory.

To avoid this, the mutex should be locked only once per operation, and not per
page.
Signed-off-by: NGuy Shapiro <guysh@mellanox.com>
Acked-by: NShachar Raindel <raindel@mellanox.com>
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Get the actual (non-mapped) ip/tcp address of the connecting peer from
the port mapper

Also setup the passive side endpoint to correctly display the actual
and mapped addresses for the new connection.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Get the actual (non-mapped) ip/tcp address of the connecting peer from
the port mapper and report the address info to the user space application
at the time of connection establishment
Signed-off-by: NTatyana Nikolova <tatyana.e.nikolova@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

RDMA/core: Enable the iWarp Port Mapper to provide the actual address of the connecting peer to its clients

Add functionality to enable the port mapper on the passive side to provide to its
clients the actual (non-mapped) ip/tcp address information of the connecting peer

1) Adding remote_info_cb() to process the address info of the connecting peer
   The address info is provided by the user space port mapper service when
   the connection is initiated by the peer
2) Adding a hash list to store the remote address info
3) Adding functionality to add/remove the remote address info
   After the info has been provided to the port mapper client,
   it is removed from the hash list
Signed-off-by: NTatyana Nikolova <tatyana.e.nikolova@intel.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Currently the iw_cxgb4 implementation requires the qp and cq qid densities
to match as well as the qp and cq id ranges.  So fail a device open if
the device configuration doesn't meet the requirements.

The reason for these restictions has to do with the fact that IQ qid X
has a UGTS register in the same bar2 page as EQ qid X.  Thus both qids
need to be allocated to the same user process for security reasons.
The logic that does this (the qpid allocator in iw_cxgb4/resource.c)
handles this but requires the above restrictions.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

For T5, we must not use the kdb/kgts registers, in order avoid db drops
under extreme loads.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

- get_dma_mr() was using ~0UL which is should be ~0ULL.  This causes the
DMA MR to get setup incorrectly in hardware.

- wr_log_show() needed a 64b divide function div64_u64() instead of
  doing
division directly.

- fixed warnings about recasting a pointer to a u64
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Cleanup macros and register defines for consistency
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

When accepting a new IPv4 connect to an IPv6 socket, the CMA tries to
canonize the address family to IPv4, but does not properly process
the listening sockaddr to get the listening port, and does not properly
set the address family of the canonized sockaddr.

Fixes: e51060f0 ("IB: IP address based RDMA connection manager")

Cc: <stable@vger.kernel.org>
Reported-By: NYotam Kenneth <yotamke@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: NHaggai Eran <haggaie@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Currently, iflink of the parent interface was always accessed, even
when interface didn't have a parent and hence we crashed there.

Handle the interface types properly: for a child interface, return
the ifindex of the parent, for parent interface, return its ifindex.

For child devices, make sure to set the parent pointer prior to
invoking register_netdevice(), this allows the new ndo to be called
by the stack immediately after the child device is registered.

Fixes: 5aa7add8 ('infiniband/ipoib: implement ndo_get_iflink')
Reported-by: NHonggang Li <honli@redhat.com>
Signed-off-by: NErez Shitrit <erezsh@mellanox.com>
Signed-off-by: NHonggang Li <honli@redhat.com>
Reviewed-By: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>+
Acked-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

set_filter_wr is requesting __GFP_NOFAIL allocation although it can return
ENOMEM without any problems obviously (t4_l2t_set_switching does that
already).  So the non-failing requirement is too strong without any
obvious reason.  Drop __GFP_NOFAIL and reorganize the code to have the
failure paths easier.

The same applies to _c4iw_write_mem_dma_aligned which uses __GFP_NOFAIL
and then checks the return value and returns -ENOMEM on failure.  This
doesn't make any sense what so ever.  Either the allocation cannot fail or
it can.

del_filter_wr seems to be safe as well because the filter entry is not
marked as pending and the return value is propagated up the stack up to
c4iw_destroy_listen.
Signed-off-by: NMichal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Hariprasad S <hariprasad@chelsio.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In some rare cases, IO operations may be not aligned to page
boundaries. This prevents iser from performing fast memory
registration. In order to overcome that iser uses a bounce
buffer to carry the transaction. We basically allocate a buffer
in the size of the transaction and perform a copy.

The buffer allocation using kmalloc is too restrictive since it
requires higher order (atomic) allocations for large transactions
(which may result in memory exhaustion fairly fast for some workloads).
We rewrite the bounce buffer code path to allocate scattered pages
and perform a copy between the transaction sg and the bounce sg.
Reported-by: NAlex Lyakas <alex@zadarastorage.com>
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>