<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/include/rdma, branch v4.3-rc1</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma</title>
<updated>2015-09-09T15:33:31+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-09-09T15:33:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=26d2177e977c912863ac04f6c1a967e793ca3a56'/>
<id>26d2177e977c912863ac04f6c1a967e793ca3a56</id>
<content type='text'>
Pull inifiniband/rdma updates from Doug Ledford:
 "This is a fairly sizeable set of changes.  I've put them through a
  decent amount of testing prior to sending the pull request due to
  that.

  There are still a few fixups that I know are coming, but I wanted to
  go ahead and get the big, sizable chunk into your hands sooner rather
  than waiting for those last few fixups.

  Of note is the fact that this creates what is intended to be a
  temporary area in the drivers/staging tree specifically for some
  cleanups and additions that are coming for the RDMA stack.  We
  deprecated two drivers (ipath and amso1100) and are waiting to hear
  back if we can deprecate another one (ehca).  We also put Intel's new
  hfi1 driver into this area because it needs to be refactored and a
  transfer library created out of the factored out code, and then it and
  the qib driver and the soft-roce driver should all be modified to use
  that library.

  I expect drivers/staging/rdma to be around for three or four kernel
  releases and then to go away as all of the work is completed and final
  deletions of deprecated drivers are done.

  Summary of changes for 4.3:

   - Create drivers/staging/rdma
   - Move amso1100 driver to staging/rdma and schedule for deletion
   - Move ipath driver to staging/rdma and schedule for deletion
   - Add hfi1 driver to staging/rdma and set TODO for move to regular
     tree
   - Initial support for namespaces to be used on RDMA devices
   - Add RoCE GID table handling to the RDMA core caching code
   - Infrastructure to support handling of devices with differing read
     and write scatter gather capabilities
   - Various iSER updates
   - Kill off unsafe usage of global mr registrations
   - Update SRP driver
   - Misc  mlx4 driver updates
   - Support for the mr_alloc verb
   - Support for a netlink interface between kernel and user space cache
     daemon to speed path record queries and route resolution
   - Ininitial support for safe hot removal of verbs devices"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (136 commits)
  IB/ipoib: Suppress warning for send only join failures
  IB/ipoib: Clean up send-only multicast joins
  IB/srp: Fix possible protection fault
  IB/core: Move SM class defines from ib_mad.h to ib_smi.h
  IB/core: Remove unnecessary defines from ib_mad.h
  IB/hfi1: Add PSM2 user space header to header_install
  IB/hfi1: Add CSRs for CONFIG_SDMA_VERBOSITY
  mlx5: Fix incorrect wc pkey_index assignment for GSI messages
  IB/mlx5: avoid destroying a NULL mr in reg_user_mr error flow
  IB/uverbs: reject invalid or unknown opcodes
  IB/cxgb4: Fix if statement in pick_local_ip6adddrs
  IB/sa: Fix rdma netlink message flags
  IB/ucma: HW Device hot-removal support
  IB/mlx4_ib: Disassociate support
  IB/uverbs: Enable device removal when there are active user space applications
  IB/uverbs: Explicitly pass ib_dev to uverbs commands
  IB/uverbs: Fix race between ib_uverbs_open and remove_one
  IB/uverbs: Fix reference counting usage of event files
  IB/core: Make ib_dealloc_pd return void
  IB/srp: Create an insecure all physical rkey only if needed
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull inifiniband/rdma updates from Doug Ledford:
 "This is a fairly sizeable set of changes.  I've put them through a
  decent amount of testing prior to sending the pull request due to
  that.

  There are still a few fixups that I know are coming, but I wanted to
  go ahead and get the big, sizable chunk into your hands sooner rather
  than waiting for those last few fixups.

  Of note is the fact that this creates what is intended to be a
  temporary area in the drivers/staging tree specifically for some
  cleanups and additions that are coming for the RDMA stack.  We
  deprecated two drivers (ipath and amso1100) and are waiting to hear
  back if we can deprecate another one (ehca).  We also put Intel's new
  hfi1 driver into this area because it needs to be refactored and a
  transfer library created out of the factored out code, and then it and
  the qib driver and the soft-roce driver should all be modified to use
  that library.

  I expect drivers/staging/rdma to be around for three or four kernel
  releases and then to go away as all of the work is completed and final
  deletions of deprecated drivers are done.

  Summary of changes for 4.3:

   - Create drivers/staging/rdma
   - Move amso1100 driver to staging/rdma and schedule for deletion
   - Move ipath driver to staging/rdma and schedule for deletion
   - Add hfi1 driver to staging/rdma and set TODO for move to regular
     tree
   - Initial support for namespaces to be used on RDMA devices
   - Add RoCE GID table handling to the RDMA core caching code
   - Infrastructure to support handling of devices with differing read
     and write scatter gather capabilities
   - Various iSER updates
   - Kill off unsafe usage of global mr registrations
   - Update SRP driver
   - Misc  mlx4 driver updates
   - Support for the mr_alloc verb
   - Support for a netlink interface between kernel and user space cache
     daemon to speed path record queries and route resolution
   - Ininitial support for safe hot removal of verbs devices"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (136 commits)
  IB/ipoib: Suppress warning for send only join failures
  IB/ipoib: Clean up send-only multicast joins
  IB/srp: Fix possible protection fault
  IB/core: Move SM class defines from ib_mad.h to ib_smi.h
  IB/core: Remove unnecessary defines from ib_mad.h
  IB/hfi1: Add PSM2 user space header to header_install
  IB/hfi1: Add CSRs for CONFIG_SDMA_VERBOSITY
  mlx5: Fix incorrect wc pkey_index assignment for GSI messages
  IB/mlx5: avoid destroying a NULL mr in reg_user_mr error flow
  IB/uverbs: reject invalid or unknown opcodes
  IB/cxgb4: Fix if statement in pick_local_ip6adddrs
  IB/sa: Fix rdma netlink message flags
  IB/ucma: HW Device hot-removal support
  IB/mlx4_ib: Disassociate support
  IB/uverbs: Enable device removal when there are active user space applications
  IB/uverbs: Explicitly pass ib_dev to uverbs commands
  IB/uverbs: Fix race between ib_uverbs_open and remove_one
  IB/uverbs: Fix reference counting usage of event files
  IB/core: Make ib_dealloc_pd return void
  IB/srp: Create an insecure all physical rkey only if needed
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>IB/core: Move SM class defines from ib_mad.h to ib_smi.h</title>
<updated>2015-09-03T19:50:32+00:00</updated>
<author>
<name>Ira Weiny</name>
<email>ira.weiny@intel.com</email>
</author>
<published>2015-09-03T18:16:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0629cb06cdf8f1a403ce71bce5b83380ae898e1a'/>
<id>0629cb06cdf8f1a403ce71bce5b83380ae898e1a</id>
<content type='text'>
When the hfi1 driver was added these definitions were moved from the qib driver
to ib_mad.h to be used by both qib and hfi1.  They should have been moved to
ib_smi.h instead.

Fixes: d4ab347005fb ("IB/core: Add core header changes needed for OPA")
Reviewed-by: Hal Rosenstock &lt;hal@mellanox.com&gt;
Signed-off-by: Ira Weiny &lt;ira.weiny@intel.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When the hfi1 driver was added these definitions were moved from the qib driver
to ib_mad.h to be used by both qib and hfi1.  They should have been moved to
ib_smi.h instead.

Fixes: d4ab347005fb ("IB/core: Add core header changes needed for OPA")
Reviewed-by: Hal Rosenstock &lt;hal@mellanox.com&gt;
Signed-off-by: Ira Weiny &lt;ira.weiny@intel.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>IB/core: Remove unnecessary defines from ib_mad.h</title>
<updated>2015-09-03T19:49:37+00:00</updated>
<author>
<name>Ira Weiny</name>
<email>ira.weiny@intel.com</email>
</author>
<published>2015-09-02T22:45:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ce755c9b01e09ee4907cf79bd0f57fa5cf65c4c3'/>
<id>ce755c9b01e09ee4907cf79bd0f57fa5cf65c4c3</id>
<content type='text'>
Remove the unused IB_NOTICE_REPRESS_* defines.

When the hfi1 driver was added these definitions were moved from the qib driver
to ib_mad.h.  They should have been removed instead.

Fixes: d4ab347005fb ("IB/core: Add core header changes needed for OPA")
Signed-off-by: Ira Weiny &lt;ira.weiny@intel.com&gt;
Reviewed-by: Hal Rosenstock &lt;hal@mellanox.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove the unused IB_NOTICE_REPRESS_* defines.

When the hfi1 driver was added these definitions were moved from the qib driver
to ib_mad.h.  They should have been removed instead.

Fixes: d4ab347005fb ("IB/core: Add core header changes needed for OPA")
Signed-off-by: Ira Weiny &lt;ira.weiny@intel.com&gt;
Reviewed-by: Hal Rosenstock &lt;hal@mellanox.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>IB/uverbs: Enable device removal when there are active user space applications</title>
<updated>2015-08-30T22:12:40+00:00</updated>
<author>
<name>Yishai Hadas</name>
<email>yishaih@mellanox.com</email>
</author>
<published>2015-08-13T15:32:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=036b10635739ffd030246eedde3d67f724800177'/>
<id>036b10635739ffd030246eedde3d67f724800177</id>
<content type='text'>
Enables the uverbs_remove_one to succeed despite the fact that there are
running IB applications working with the given ib device.  This
functionality enables a HW device to be unbind/reset despite the fact that
there are running user space applications using it.

It exposes a new IB kernel API named 'disassociate_ucontext' which lets
a driver detaching its HW resources from a given user context without
crashing/terminating the application. In case a driver implemented the
above API and registered with ib_uverb there will be no dependency between its
device to its uverbs_device. Upon calling remove_one of ib_uverbs the call
should return after disassociating the open HW resources without waiting to
clients disconnecting. In case driver didn't implement this API there will be no
change to current behaviour and uverbs_remove_one will return only when last
client has disconnected and reference count on uverbs device became 0.

In case the lower driver device was removed any application will
continue working over some zombie HCA, further calls will ended with an
immediate error.

Signed-off-by: Yishai Hadas &lt;yishaih@mellanox.com&gt;
Signed-off-by: Shachar Raindel &lt;raindel@mellanox.com&gt;
Reviewed-by: Jason Gunthorpe &lt;jgunthorpe@obsidianresearch.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Enables the uverbs_remove_one to succeed despite the fact that there are
running IB applications working with the given ib device.  This
functionality enables a HW device to be unbind/reset despite the fact that
there are running user space applications using it.

It exposes a new IB kernel API named 'disassociate_ucontext' which lets
a driver detaching its HW resources from a given user context without
crashing/terminating the application. In case a driver implemented the
above API and registered with ib_uverb there will be no dependency between its
device to its uverbs_device. Upon calling remove_one of ib_uverbs the call
should return after disassociating the open HW resources without waiting to
clients disconnecting. In case driver didn't implement this API there will be no
change to current behaviour and uverbs_remove_one will return only when last
client has disconnected and reference count on uverbs device became 0.

In case the lower driver device was removed any application will
continue working over some zombie HCA, further calls will ended with an
immediate error.

Signed-off-by: Yishai Hadas &lt;yishaih@mellanox.com&gt;
Signed-off-by: Shachar Raindel &lt;raindel@mellanox.com&gt;
Reviewed-by: Jason Gunthorpe &lt;jgunthorpe@obsidianresearch.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>IB/core: Make ib_dealloc_pd return void</title>
<updated>2015-08-30T22:12:39+00:00</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgunthorpe@obsidianresearch.com</email>
</author>
<published>2015-08-05T20:34:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7dd78647a2c2c224e376fc72797d411a3a0bb047'/>
<id>7dd78647a2c2c224e376fc72797d411a3a0bb047</id>
<content type='text'>
The majority of callers never check the return value, and even if they
did, they can't do anything about a failure.

All possible failure cases represent a bug in the caller, so just
WARN_ON inside the function instead.

This fixes a few random errors:
 net/rd/iw.c infinite loops while it fails. (racing with EBUSY?)

This also lays the ground work to get rid of error return from the
drivers. Most drivers do not error, the few that do are broken since
it cannot be handled.

Since uverbs can legitimately make use of EBUSY, open code the
check.

Signed-off-by: Jason Gunthorpe &lt;jgunthorpe@obsidianresearch.com&gt;
Reviewed-by: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The majority of callers never check the return value, and even if they
did, they can't do anything about a failure.

All possible failure cases represent a bug in the caller, so just
WARN_ON inside the function instead.

This fixes a few random errors:
 net/rd/iw.c infinite loops while it fails. (racing with EBUSY?)

This also lays the ground work to get rid of error return from the
drivers. Most drivers do not error, the few that do are broken since
it cannot be handled.

Since uverbs can legitimately make use of EBUSY, open code the
check.

Signed-off-by: Jason Gunthorpe &lt;jgunthorpe@obsidianresearch.com&gt;
Reviewed-by: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>IB/mad: Remove ib_get_dma_mr calls</title>
<updated>2015-08-30T22:12:33+00:00</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgunthorpe@obsidianresearch.com</email>
</author>
<published>2015-07-30T23:22:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4be90bc60df47f6268b594c4fb6c90f0ff2f519f'/>
<id>4be90bc60df47f6268b594c4fb6c90f0ff2f519f</id>
<content type='text'>
The pd now has a local_dma_lkey member which completely replaces
ib_get_dma_mr, use it instead.

Signed-off-by: Jason Gunthorpe &lt;jgunthorpe@obsidianresearch.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The pd now has a local_dma_lkey member which completely replaces
ib_get_dma_mr, use it instead.

Signed-off-by: Jason Gunthorpe &lt;jgunthorpe@obsidianresearch.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>IB/core: Guarantee that a local_dma_lkey is available</title>
<updated>2015-08-30T22:12:33+00:00</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgunthorpe@obsidianresearch.com</email>
</author>
<published>2015-08-05T20:14:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=96249d70dd70496084c7ec1465ec449cd032955a'/>
<id>96249d70dd70496084c7ec1465ec449cd032955a</id>
<content type='text'>
Every single ULP requires a local_dma_lkey to do anything with
a QP, so let us ensure one exists for every PD created.

If the driver can supply a global local_dma_lkey then use that, otherwise
ask the driver to create a local use all physical memory MR associated
with the new PD.

Signed-off-by: Jason Gunthorpe &lt;jgunthorpe@obsidianresearch.com&gt;
Reviewed-by: Sagi Grimberg &lt;sagig@dev.mellanox.co.il&gt;
Acked-by: Christoph Hellwig &lt;hch@infradead.org&gt;
Reviewed-by: Steve Wise &lt;swise@opengridcomputing.com&gt;
Reviewed-by: Ira Weiny &lt;ira.weiny@intel.com&gt;
Tested-by: Ira Weiny &lt;ira.weiny@intel.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Every single ULP requires a local_dma_lkey to do anything with
a QP, so let us ensure one exists for every PD created.

If the driver can supply a global local_dma_lkey then use that, otherwise
ask the driver to create a local use all physical memory MR associated
with the new PD.

Signed-off-by: Jason Gunthorpe &lt;jgunthorpe@obsidianresearch.com&gt;
Reviewed-by: Sagi Grimberg &lt;sagig@dev.mellanox.co.il&gt;
Acked-by: Christoph Hellwig &lt;hch@infradead.org&gt;
Reviewed-by: Steve Wise &lt;swise@opengridcomputing.com&gt;
Reviewed-by: Ira Weiny &lt;ira.weiny@intel.com&gt;
Tested-by: Ira Weiny &lt;ira.weiny@intel.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>IB/core: Add rdma netlink helper functions</title>
<updated>2015-08-30T22:12:25+00:00</updated>
<author>
<name>Kaike Wan</name>
<email>kaike.wan@intel.com</email>
</author>
<published>2015-08-14T12:52:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bc10ed7d3d19ff61427007b4d7bf98d3e57bb333'/>
<id>bc10ed7d3d19ff61427007b4d7bf98d3e57bb333</id>
<content type='text'>
This patch adds a function to check if listeners for a netlink multicast
group are present. It also adds a function to receive netlink response
messages.

Signed-off-by: Kaike Wan &lt;kaike.wan@intel.com&gt;
Signed-off-by: John Fleck &lt;john.fleck@intel.com&gt;
Signed-off-by: Ira Weiny &lt;ira.weiny@intel.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch adds a function to check if listeners for a netlink multicast
group are present. It also adds a function to receive netlink response
messages.

Signed-off-by: Kaike Wan &lt;kaike.wan@intel.com&gt;
Signed-off-by: John Fleck &lt;john.fleck@intel.com&gt;
Signed-off-by: Ira Weiny &lt;ira.weiny@intel.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>IB/mlx4: Implement ib_device callbacks</title>
<updated>2015-08-30T22:12:20+00:00</updated>
<author>
<name>Moni Shoua</name>
<email>monis@mellanox.com</email>
</author>
<published>2015-07-30T15:33:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e26be1bfef81a2314a075f54dd8930cf5e8656df'/>
<id>e26be1bfef81a2314a075f54dd8930cf5e8656df</id>
<content type='text'>
get_netdev: get the net_device on the physical port of the IB transport port. In
port aggregation mode it is required to return the netdev of the active port.

modify_gid: note for a change in the RoCE gid cache. Handle this by writing to
the harsware GID table. It is possible that indexes in cahce and hardware tables
won't match so a translation is required when modifying a QP or creating an
address handle.

Signed-off-by: Moni Shoua &lt;monis@mellanox.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
get_netdev: get the net_device on the physical port of the IB transport port. In
port aggregation mode it is required to return the netdev of the active port.

modify_gid: note for a change in the RoCE gid cache. Handle this by writing to
the harsware GID table. It is possible that indexes in cahce and hardware tables
won't match so a translation is required when modifying a QP or creating an
address handle.

Signed-off-by: Moni Shoua &lt;monis@mellanox.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>IB/core: Add RoCE GID table management</title>
<updated>2015-08-30T22:08:50+00:00</updated>
<author>
<name>Matan Barak</name>
<email>matanb@mellanox.com</email>
</author>
<published>2015-07-30T15:33:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=03db3a2d81e6e84f3ed3cb9e087cae17d762642b'/>
<id>03db3a2d81e6e84f3ed3cb9e087cae17d762642b</id>
<content type='text'>
RoCE GIDs are based on IP addresses configured on Ethernet net-devices
which relate to the RDMA (RoCE) device port.

Currently, each of the low-level drivers that support RoCE (ocrdma,
mlx4) manages its own RoCE port GID table. As there's nothing which is
essentially vendor specific, we generalize that, and enhance the RDMA
core GID cache to do this job.

In order to populate the GID table, we listen for events:

(a) netdev up/down/change_addr events - if a netdev is built onto
    our RoCE device, we need to add/delete its IPs. This involves
    adding all GIDs related to this ndev, add default GIDs, etc.

(b) inet events - add new GIDs (according to the IP addresses)
    to the table.

For programming the port RoCE GID table, providers must implement
the add_gid and del_gid callbacks.

RoCE GID management requires us to state the associated net_device
alongside the GID. This information is necessary in order to manage
the GID table. For example, when a net_device is removed, its
associated GIDs need to be removed as well.

RoCE mandates generating a default GID for each port, based on the
related net-device's IPv6 link local. In contrast to the GID based on
the regular IPv6 link-local (as we generate GID per IP address),
the default GID is also available when the net device is down (in
order to support loopback).

Locking is done as follows:
The patch modify the GID table code both for new RoCE drivers
implementing the add_gid/del_gid callbacks and for current RoCE and
IB drivers that do not. The flows for updating the table are
different, so the locking requirements are too.

While updating RoCE GID table, protection against multiple writers is
achieved via mutex_lock(&amp;table-&gt;lock). Since writing to a table
requires us to find an entry (possible a free entry) in the table and
then modify it, this mutex protects both the find_gid and write_gid
ensuring the atomicity of the action.
Each entry in the GID cache is protected by rwlock. In RoCE, writing
(usually results from netdev notifier) involves invoking the vendor's
add_gid and del_gid callbacks, which could sleep.
Therefore, an invalid flag is added for each entry. Updates for RoCE are
done via a workqueue, thus sleeping is permitted.

In IB, updates are done in write_lock_irq(&amp;device-&gt;cache.lock), thus
write_gid isn't allowed to sleep and add_gid/del_gid are not called.

When passing net-device into/out-of the GID cache, the device
is always passed held (dev_hold).

The code uses a single work item for updating all RDMA devices,
following a netdev or inet notifier.

The patch moves the cache from being a client (which was incorrect,
as the cache is part of the IB infrastructure) to being explicitly
initialized/freed when a device is registered/removed.

Signed-off-by: Matan Barak &lt;matanb@mellanox.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
RoCE GIDs are based on IP addresses configured on Ethernet net-devices
which relate to the RDMA (RoCE) device port.

Currently, each of the low-level drivers that support RoCE (ocrdma,
mlx4) manages its own RoCE port GID table. As there's nothing which is
essentially vendor specific, we generalize that, and enhance the RDMA
core GID cache to do this job.

In order to populate the GID table, we listen for events:

(a) netdev up/down/change_addr events - if a netdev is built onto
    our RoCE device, we need to add/delete its IPs. This involves
    adding all GIDs related to this ndev, add default GIDs, etc.

(b) inet events - add new GIDs (according to the IP addresses)
    to the table.

For programming the port RoCE GID table, providers must implement
the add_gid and del_gid callbacks.

RoCE GID management requires us to state the associated net_device
alongside the GID. This information is necessary in order to manage
the GID table. For example, when a net_device is removed, its
associated GIDs need to be removed as well.

RoCE mandates generating a default GID for each port, based on the
related net-device's IPv6 link local. In contrast to the GID based on
the regular IPv6 link-local (as we generate GID per IP address),
the default GID is also available when the net device is down (in
order to support loopback).

Locking is done as follows:
The patch modify the GID table code both for new RoCE drivers
implementing the add_gid/del_gid callbacks and for current RoCE and
IB drivers that do not. The flows for updating the table are
different, so the locking requirements are too.

While updating RoCE GID table, protection against multiple writers is
achieved via mutex_lock(&amp;table-&gt;lock). Since writing to a table
requires us to find an entry (possible a free entry) in the table and
then modify it, this mutex protects both the find_gid and write_gid
ensuring the atomicity of the action.
Each entry in the GID cache is protected by rwlock. In RoCE, writing
(usually results from netdev notifier) involves invoking the vendor's
add_gid and del_gid callbacks, which could sleep.
Therefore, an invalid flag is added for each entry. Updates for RoCE are
done via a workqueue, thus sleeping is permitted.

In IB, updates are done in write_lock_irq(&amp;device-&gt;cache.lock), thus
write_gid isn't allowed to sleep and add_gid/del_gid are not called.

When passing net-device into/out-of the GID cache, the device
is always passed held (dev_hold).

The code uses a single work item for updating all RDMA devices,
following a netdev or inet notifier.

The patch moves the cache from being a client (which was incorrect,
as the cache is part of the IB infrastructure) to being explicitly
initialized/freed when a device is registered/removed.

Signed-off-by: Matan Barak &lt;matanb@mellanox.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</pre>
</div>
</content>
</entry>
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