Simplify drivers by ensuring lifetime of ib_ah object. The changes
in .create_ah() go hand in hand with relevant update in .destroy_ah().

We will use this opportunity and convert .destroy_ah() to don't fail, as
it was suggested a long time ago, because there is nothing to do in case
of failure during destroy.
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Combine contiguous regions of PAGE_SIZE pages into single scatter list
entry while building the scatter table for a umem. This minimizes the
number of the entries in the scatter list and reduces the DMA mapping
overhead, particularly with the IOMMU.

Set default max_seg_size in core for IB devices to 2G and do not combine
if we exceed this limit.

Also, purge npages in struct ib_umem as we now DMA map the umem SGL with
sg_nents and npage computation is not needed. Drivers should now be using
ib_umem_num_pages(), so fix the last stragglers.

Move npages tracking to ib_umem_odp as ODP drivers still need it.
Suggested-by: NJason Gunthorpe <jgg@ziepe.ca>
Reviewed-by: NMichael J. Ruhl <michael.j.ruhl@intel.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Acked-by: NAdit Ranadive <aditr@vmware.com>
Signed-off-by: NShiraz Saleem <shiraz.saleem@intel.com>
Tested-by: NGal Pressman <galpress@amazon.com>
Tested-by: NSelvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Add netlink command that enables/disables sharing rdma device among
multiple net namespaces.

Using rdma tool,
$rdma sys set netns shared (default mode)

When rdma subsystem netns mode is set to shared mode, rdma devices
will be accessible in all net namespaces.

Using rdma tool,
$rdma sys set netns exclusive

When rdma subsystem netns mode is set to exclusive mode, devices
will be accessible in only one net namespace at any given
point of time.

If there are any net namespaces other than default init_net exists,
while executing this command, it will fail and mode cannot be changed.

To change this mode, netlink command is used instead of sysctl, because
netlink command allows to auto load a module.
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Add an interface via netlink command to query whether rdma devices are
shared among multiple net namespaces or not. When using RDMAtool, it can
be queried as,

$rdma system show netns
netns shared
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Extend ib_device_get_by_index() API to check device access for
net namespace for serving netlink commands.

Also enforce net ns check on dumpit commands which iterate over all
registered rdma devices and which don't call ib_device_get_by_index().
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Introduce an API rdma_dev_access_netns() to check whether a rdma device
can be accessed from the specified net namespace or not.
Use rdma_dev_access_netns() while opening character uverbs, umad network
device and also check while rdma cm_id binds to rdma device.
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Add module parameter to change a sharing mode of ib_core early in the
boot process. This parameter helps to those systems where modern up
to date rdma tool (iproute2) package may not be available during
kernel upgrade cycle.
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Now that sysfs compatibility layer for non init_net exists, add core port
attributes such as pkey and gid table to non init_net ns.
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Implement compatibility layer sysfs entries of ib_core so that non
init_net net namespaces can also discover rdma devices.

Each non init_net net namespace has ib_core_device created in it.
Such ib_core_device sysfs tree resembles rdma devices found in
init_net namespace.

This allows discovering rdma devices in multiple non init_net net
namespaces via sysfs entries and helpful to rdma-core userspace.
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This is a preparation patch to provide isolation of rdma device in a
network namespace.

As first step, make rdma device visible only in init net namespace.
Subsequent patch will enable rdma device visibility back in multiple net
namespaces using compat ib_core_device device/sysfs tree.

Given that the IB subsystem depends on net stack, it needs to be
initialized after netdev and since it support devices, it needs to be
initialized before the device subsystem; therefore, change initcall
sequence to fs_initcall, so that when ib_core is compiled in the kernel
image, the right init sequence is followed.
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

In order to support sysfs entries in multiple net namespaces for a rdma
device, introduce a ib_core_device whose scope is limited to hold core
device and per port sysfs related entries.

This is preparation patch so that multiple ib_core_devices in each net
namespace can be created in subsequent patch who all can share ib_device.

(a) Move sysfs specific fields to ib_core_device.
(b) Make sysfs and device life cycle related routines to work on
    ib_core_device.
(c) Introduce and use rdma_init_coredev() helper to initialize
    coredev fields.
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Following the PD conversion patch, do the same for ucontext allocations.
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Since rxe allows unregistration from other threads the rxe pointer can
become invalid any moment after ib_register_driver returns. This could
cause a user triggered use after free.

Add another driver callback to be called right after the device becomes
registered to complete any device setup required post-registration.  This
callback has enough core locking to prevent the device from becoming
unregistered.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

rxe has an open coded version of this that is not as safe as the core
version. This lets us eliminate the internal device list entirely from
rxe.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

These APIs are intended to support drivers that exist outside the usual
driver core probe()/remove() callbacks. Normally the driver core will
prevent remove() from running concurrently with probe(), once this safety
is lost drivers need more support to get the locking and lifetimes right.

ib_unregister_driver() is intended to be used during module_exit of a
driver using these APIs. It unregisters all the associated ib_devices.

ib_unregister_device_and_put() is to be used by a driver-specific removal
function (ie removal by name, removal from a netdev notifier, removal from
netlink)

ib_unregister_queued() is to be used from netdev notifier chains where
RTNL is held.

The locking is tricky here since once things become async it is possible
to race unregister with registration. This is largely solved by relying on
the registration refcount, unregistration will only ever work on something
that has a positive registration refcount - and then an unregistration
mutex serializes all competing unregistrations of the same device.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Several drivers need to find the ib_device from a given netdev. rxe needs
this at speed in an unsleepable context, so choose to implement the
translation using a RCU safe hash table.

The hash table can have a many to one mapping. This is intended to support
some future case where multiple IB drivers (ie iWarp and RoCE) connect to
the same netdevs. driver_ids will need to be different to support this.

In the process this makes the struct ib_device and ib_port_data RCU safe
by deferring their kfrees.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The associated netdev should not actually be very dynamic, so for most
drivers there is no reason for a callback like this. Provide an API to
inform the core code about the net dev affiliation and use a core
maintained data structure instead.

This allows the core code to be more aware of the ndev relationship which
will allow some new APIs based around this.

This also uses locking that makes some kind of sense, many drivers had a
confusing RCU lock, or missing locking which isn't right.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

There is no reason to have three allocations of per-port data. Combine
them together and make the lifetime for all the per-port data match the
struct ib_device.

Following patches will require more port-specific data, now there is a
good place to put it.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

We have many loops iterating over all of the end port numbers on a struct
ib_device, simplify them with a for_each helper.
Reviewed-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

There is no need to expose internals of restrack DB to IB/core.
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Move core device addition and removal from sysfs.c to device.c as device.c
is more appropriate place for device management.
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Instead of holding extra reference using get_device() that
device_unregister() releases, simplify it as below.

device_add() balances with device_del().  device_initialize() balances
with put_device(), always via ib_dealloc_device().
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The locking here started out with a single lock that covered everything
and then has lately veered into crazy town.

The fundamental problem is that several places need to iterate over a
linked list, but also need to drop their locks to avoid deadlock during
client callbacks.

xarray's restartable iteration offers a simple solution to the
problem. Once all the lists are xarrays we can drop locks in the places
that need that and rely on xarray to provide consistency and locking for
the data structure.

The resulting simplification is that each of the three lists has a
dedicated rwsem that must be held when working with the list it
covers. One data structure is no longer covered by multiple locks.

The sleeping semaphore is selected because the read side generally needs
to be held over something sleeping, and using RCU reader locking in those
cases is overkill.

In the process this simplifies the entire registration/unregistration flow
to be the expected list of setups and the reversed list of matching
teardowns, and the registration lock 'refcount' can now be revised to be
released after the ULPs are removed, providing a very sane semantic for
this feature.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Now that we have a small ID for each client we can use xarray instead of
linearly searching linked lists for client data. This will give much
faster and scalable client data lookup, and will lets us revise the
locking scheme.

Since xarray can store 'going_down' using a mark just entirely eliminate
the struct ib_client_data and directly store the client_data value in the
xarray. However this does require a special iterator as we must still
iterate over any NULL client_data values.

Also eliminate the client_data_lock in favour of internal xarray locking.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This gives each client a unique ID and will let us move client_data to use
xarray, and revise the locking scheme.

clients have to be add/removed in strict FIFO/LIFO order as they
interdepend. To support this the client_ids are assigned to increase in
FIFO order. The existing linked list is kept to support reverse iteration
until xarray can get a reverse iteration API.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NParav Pandit <parav@mellanox.com>

ida is the proper data structure to hold list of clustered small integers
and then allocate an unused integer. Get rid of the convoluted and limited
open-coded bitmap.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This really has no purpose anymore, refcount can be used to tell if the
device is still registered. Keeping it around just invites mis-use.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NParav Pandit <parav@mellanox.com>

Instead of complicated logic about when this memory is freed, always free
it during device release(). All the cache pointers start out as NULL, so
it is safe to call this before the cache is initialized.

This makes for a simpler error unwind flow, and a simpler understanding of
the lifetime of the memory allocations inside the struct ib_device.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Since this only frees memory it should be done during the release
callback. Otherwise there are possible error flows where it might not get
called if registration aborts.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Since another rename could be running in parallel it is safer to check
that the name is not changing inside the lock, where we already know the
device name will not change.

Fixes: d21943dd ("RDMA/core: Implement IB device rename function")
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NParav Pandit <parav@mellanox.com>

The PD allocations in IB/core allows us to simplify drivers and their
error flows in their .alloc_pd() paths. The changes in .alloc_pd() go hand
in had with relevant update in .dealloc_pd().

We will use this opportunity and convert .dealloc_pd() to don't fail, as
it was suggested a long time ago, failures are not happening as we have
never seen a WARN_ON print.
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Add new macros to be used in drivers while registering ops structure and
IB/core while calling allocation routines, so drivers won't need to
perform kzalloc/kfree in their paths.

The change in allocation stage allows us to initialize common fields prior
to calling to drivers (e.g. restrack).
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

When creating many MAD agents in a short period of time, receive packet
processing can be delayed long enough to cause timeouts while new agents
are being added to the atomic notifier chain with IRQs disabled.  Notifier
chain registration and unregstration is an O(n) operation. With large
numbers of MAD agents being created and destroyed simultaneously the CPUs
spend too much time with interrupts disabled.

Instead of each MAD agent registering for it's own LSM notification,
maintain a list of agents internally and register once, this registration
already existed for handling the PKeys. This list is write mostly, so a
normal spin lock is used vs a read/write lock. All MAD agents must be
checked, so a single list is used instead of breaking them down per
device.

Notifier calls are done under rcu_read_lock, so there isn't a risk of
similar packet timeouts while checking the MAD agents security settings
when notified.
Signed-off-by: NDaniel Jurgens <danielj@mellanox.com>
Reviewed-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Acked-by: NPaul Moore <paul@paul-moore.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

As preparation to hide rdma_restrack_root, refactor the code to use the
ops structure instead of a special callback which is hidden in
rdma_restrack_root.
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

In the current implementation, we have one restrack root per-device and
all users are simply providing it directly. Let's simplify the interface
and have callers provide the ib_device and internally access the
restrack_root.
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Drivers that do not provide kernel verbs support should not be used by ib
kernel clients at all.

In case a device does not implement all mandatory verbs for kverbs usage
mark it as a non kverbs provider and prevent its usage for all clients
except for uverbs.

The device is marked as a non kverbs provider using the 'kverbs_provider'
flag which should only be set by the core code.  The clients can choose
whether kverbs are requested for its usage using the 'no_kverbs_req' flag
which is currently set for uverbs only.

This patch allows drivers to remove mandatory verbs stubs and simply set
the callbacks to NULL. The IB device will be registered as a non-kverbs
provider. Note that verbs that are required for the device registration
process must be implemented.
Signed-off-by: NGal Pressman <galpress@amazon.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

All callers to ib_alloc_device() provide a larger size than struct
ib_device and rely on the fact that struct ib_device is embedded in their
driver specific structure as the first member.

Provide a safer variant of ib_alloc_device() that checks and enforces this
approach to make sure the drivers are using it right.
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

It turns out future patches need this capability quite widely now, not
just for netlink, so provide two global functions to manage the
registration lock refcount.

This also moves the point the lock becomes 1 to within
ib_register_device() so that the semantics of the public API are very sane
and clear. Calling ib_device_try_get() will fail on devices that are only
allocated but not yet registered.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Reviewed-by: NParav Pandit <parav@mellanox.com>

RDMA cgroup registration routine always returns success, so simplify
function to be void and run clang formatter over whole CONFIG_CGROUP_RDMA
art of core_priv.h.

This reduces unwinding error path for regular registration and future net
namespace change functionality for rdma device.
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

No reason to open code this loop.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>