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  1. 21 9月, 2018 2 次提交
  3. 18 9月, 2018 1 次提交
    • J
      IB/rxe: Revise the ib_wr_opcode enum · 9a59739b
      由 Jason Gunthorpe 提交于 
      This enum has become part of the uABI, as both RXE and the
ib_uverbs_post_send() command expect userspace to supply values from this
enum. So it should be properly placed in include/uapi/rdma.

In userspace this enum is called 'enum ibv_wr_opcode' as part of
libibverbs.h. That enum defines different values for IB_WR_LOCAL_INV,
IB_WR_SEND_WITH_INV, and IB_WR_LSO. These were introduced (incorrectly, it
turns out) into libiberbs in 2015.

The kernel has changed its mind on the numbering for several of the IB_WC
values over the years, but has remained stable on IB_WR_LOCAL_INV and
below.

Based on this we can conclude that there is no real user space user of the
values beyond IB_WR_ATOMIC_FETCH_AND_ADD, as they have never worked via
rdma-core. This is confirmed by inspection, only rxe uses the kernel enum
and implements the latter operations. rxe has clearly never worked with
these attributes from userspace. Other drivers that support these opcodes
implement the functionality without calling out to the kernel.

To make IB_WR_SEND_WITH_INV and related work for RXE in userspace we
choose to renumber the IB_WR enum in the kernel to match the uABI that
userspace has bee using since before Soft RoCE was merged. This is an
overall simpler configuration for the whole software stack, and obviously
can't break anything existing.
Reported-by: NSeth Howell <seth.howell@intel.com>
Tested-by: NSeth Howell <seth.howell@intel.com>
Fixes: 8700e3e7 ("Soft RoCE driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
      9a59739b
  5. 14 9月, 2018 1 次提交
  7. 13 9月, 2018 2 次提交
  9. 11 9月, 2018 6 次提交
  11. 07 9月, 2018 1 次提交
  13. 06 9月, 2018 5 次提交
  15. 23 8月, 2018 1 次提交
    • M
      mm, oom: distinguish blockable mode for mmu notifiers · 93065ac7
      由 Michal Hocko 提交于 
      There are several blockable mmu notifiers which might sleep in
mmu_notifier_invalidate_range_start and that is a problem for the
oom_reaper because it needs to guarantee a forward progress so it cannot
depend on any sleepable locks.

Currently we simply back off and mark an oom victim with blockable mmu
notifiers as done after a short sleep.  That can result in selecting a new
oom victim prematurely because the previous one still hasn't torn its
memory down yet.

We can do much better though.  Even if mmu notifiers use sleepable locks
there is no reason to automatically assume those locks are held.  Moreover
majority of notifiers only care about a portion of the address space and
there is absolutely zero reason to fail when we are unmapping an unrelated
range.  Many notifiers do really block and wait for HW which is harder to
handle and we have to bail out though.

This patch handles the low hanging fruit.
__mmu_notifier_invalidate_range_start gets a blockable flag and callbacks
are not allowed to sleep if the flag is set to false.  This is achieved by
using trylock instead of the sleepable lock for most callbacks and
continue as long as we do not block down the call chain.

I think we can improve that even further because there is a common pattern
to do a range lookup first and then do something about that.  The first
part can be done without a sleeping lock in most cases AFAICS.

The oom_reaper end then simply retries if there is at least one notifier
which couldn't make any progress in !blockable mode.  A retry loop is
already implemented to wait for the mmap_sem and this is basically the
same thing.

The simplest way for driver developers to test this code path is to wrap
userspace code which uses these notifiers into a memcg and set the hard
limit to hit the oom.  This can be done e.g.  after the test faults in all
the mmu notifier managed memory and set the hard limit to something really
small.  Then we are looking for a proper process tear down.

[akpm@linux-foundation.org: coding style fixes]
[akpm@linux-foundation.org: minor code simplification]
Link: http://lkml.kernel.org/r/20180716115058.5559-1-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Acked-by: Christian König <christian.koenig@amd.com> # AMD notifiers
Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx and umem_odp
Reported-by: NDavid Rientjes <rientjes@google.com>
Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Dennis Dalessandro <dennis.dalessandro@intel.com>
Cc: Sudeep Dutt <sudeep.dutt@intel.com>
Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      93065ac7
  17. 18 8月, 2018 1 次提交
  19. 17 8月, 2018 1 次提交
  21. 13 8月, 2018 3 次提交
    • J
      IB/uverbs: Remove struct uverbs_root_spec and all supporting code · 51d0a2b4
      由 Jason Gunthorpe 提交于 
      Everything now uses the uverbs_uapi data structure.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
      51d0a2b4
    • J
      IB/uverbs: Use uverbs_api to unmarshal ioctl commands · 3a863577
      由 Jason Gunthorpe 提交于 
      Convert the ioctl method syscall path to use the uverbs_api data
structures. The new uapi structure includes all the same information, just
in a different and more optimal way.

 - Use attr_bkey instead of 2 level radix trees for everything related to
   attributes. This includes the attribute storage, presence, and
   detection of missing mandatory attributes.
 - Avoid iterating over all attribute storage at finish, instead use
   find_first_bit with the attr_bkey to locate only those attrs that need
   cleanup.
 - Organize things to always run, and always rely on, cleanup. This
   avoids a bunch of tricky error unwind cases.
 - Locate the method using the radix tree, and locate the attributes
   using a very efficient incremental radix tree lookup
 - Use the precomputed destroy_bkey to handle uobject destruction
 - Use the precomputed allocation sizes and precomputed 'need_stack'
   to avoid maths in the fast path. This is optimal if userspace
   does not pass (many) unsupported attributes.

Overall this results in much better codegen for the attribute accessors,
everything is now stored in bitmaps or linear arrays indexed by attr_bkey.
The compiler can compute attr_bkey values at compile time for all method
attributes, meaning things like uverbs_attr_is_valid() now compile into
single instruction bit tests.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
      3a863577
    • J
      IB/uverbs: Add a simple allocator to uverbs_attr_bundle · 461bb2ee
      由 Jason Gunthorpe 提交于 
      This is similar in spirit to devm, it keeps track of any allocations
linked to this method call and ensures they are all freed when the method
exits. Further, if there is space in the internal/onstack buffer then the
allocator will hand out that memory and avoid an expensive call to
kalloc/kfree in the syscall path.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
      461bb2ee
  23. 11 8月, 2018 5 次提交
    • J
      IB/uverbs: Remove the ib_uverbs_attr pointer from each attr · 6a1f444f
      由 Jason Gunthorpe 提交于 
      Memory in the bundle is valuable, do not waste it holding an 8 byte
pointer for the rare case of writing to a PTR_OUT. We can compute the
pointer by storing a small 1 byte array offset and the base address of the
uattr memory in the bundle private memory.

This also means we can access the kernel's copy of the ib_uverbs_attr, so
drop the copy of flags as well.

Since the uattr base should be private bundle information this also
de-inlines the already too big uverbs_copy_to inline and moves
create_udata into uverbs_ioctl.c so they can see the private struct
definition.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
      6a1f444f
    • J
      IB/uverbs: Provide implementation private memory for the uverbs_attr_bundle · 4b3dd2bb
      由 Jason Gunthorpe 提交于 
      This already existed as the anonymous 'ctx' structure, but this was not
really a useful form. Hoist this struct into bundle_priv and rework the
internal things to use it instead.

Move a bunch of the processing internal state into the priv and reduce the
excessive use of function arguments.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
      4b3dd2bb
    • J
      IB/uverbs: Use uverbs_api to manage the object type inside the uobject · 6b0d08f4
      由 Jason Gunthorpe 提交于 
      Currently the struct uverbs_obj_type stored in the ib_uobject is part of
the .rodata segment of the module that defines the object. This is a
problem if drivers define new uapi objects as we will be left with a
dangling pointer after device disassociation.

Switch the uverbs_obj_type for struct uverbs_api_object, which is
allocated memory that is part of the uverbs_api and is guaranteed to
always exist. Further this moves the 'type_class' into this memory which
means access to the IDR/FD function pointers is also guaranteed. Drivers
cannot define new types.

This makes it safe to continue to use all uobjects, including driver
defined ones, after disassociation.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
      6b0d08f4
    • J
      IB/uverbs: Build the specs into a radix tree at runtime · 9ed3e5f4
      由 Jason Gunthorpe 提交于 
      This radix tree datastructure is intended to replace the 'hash' structure
used today for parsing ioctl methods during system calls. This first
commit introduces the structure and builds it from the existing .rodata
descriptions.

The so-called hash arrangement is actually a 5 level open coded radix tree.
This new version uses a 3 level radix tree built using the radix tree
library.

Overall this is much less code and much easier to build as the radix tree
API allows for dynamic modification during the building. There is a small
memory penalty to pay for this, but since the radix tree is allocated on
a per device basis, a few kb of RAM seems immaterial considering the
gained simplicity.

The radix tree is similar to the existing tree, but also has a 'attr_bkey'
concept, which is a small value'd index for each method attribute. This is
used to simplify and improve performance of everything in the next
patches.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Reviewed-by: NMichael J. Ruhl <michael.j.ruhl@intel.com>
      9ed3e5f4
    • J
      IB/uverbs: Have the core code create the uverbs_root_spec · 7d96c9b1
      由 Jason Gunthorpe 提交于 
      There is no reason for drivers to do this, the core code should take of
everything. The drivers will provide their information from rodata to
describe their modifications to the core's base uapi specification.

The core uses this to build up the runtime uapi for each device.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NMichael J. Ruhl <michael.j.ruhl@intel.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
      7d96c9b1
  25. 03 8月, 2018 1 次提交
    • J
      RDMA/netdev: Use priv_destructor for netdev cleanup · 9f49a5b5
      由 Jason Gunthorpe 提交于 
      Now that the unregister_netdev flow for IPoIB no longer relies on external
code we can now introduce the use of priv_destructor and
needs_free_netdev.

The rdma_netdev flow is switched to use the netdev common priv_destructor
instead of the special free_rdma_netdev and the IPOIB ULP adjusted:
 - priv_destructor needs to switch to point to the ULP's destructor
   which will then call the rdma_ndev's in the right order
 - We need to be careful around the error unwind of register_netdev
   as it sometimes calls priv_destructor on failure
 - ULPs need to use ndo_init/uninit to ensure proper ordering
   of failures around register_netdev

Switching to priv_destructor is a necessary pre-requisite to using
the rtnl new_link mechanism.

The VNIC user for rdma_netdev should also be revised, but that is left for
another patch.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NDenis Drozdov <denisd@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
      9f49a5b5
  27. 02 8月, 2018 7 次提交
    • J
      IB/uverbs: Allow all DESTROY commands to succeed after disassociate · 0f50d88a
      由 Jason Gunthorpe 提交于 
      The disassociate function was broken by design because it failed all
commands. This prevents userspace from calling destroy on a uobject after
it has detected a device fatal error and thus reclaiming the resources in
userspace is prevented.

This fix is now straightforward, when anything destroys a uobject that is
not the user the object remains on the IDR with a NULL context and object
pointer. All lookup locking modes other than DESTROY will fail. When the
user ultimately calls the destroy function it is simply dropped from the
IDR while any related information is returned.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
      0f50d88a
    • J
      IB/uverbs: Do not pass struct ib_device to the ioctl methods · e83f0ecd
      由 Jason Gunthorpe 提交于 
      This does the same as the patch before, except for ioctl. The rules are
the same, but for the ioctl methods the core code handles setting up the
uobject.

- Retrieve the ib_dev from the uobject->context->device. This is
  safe under ioctl as the core has already done rdma_alloc_begin_uobject
  and so CREATE calls are entirely protected by the rwsem.
- Retrieve the ib_dev from uobject->object
- Call ib_uverbs_get_ucontext()
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
      e83f0ecd
    • J
      IB/uverbs: Do not pass struct ib_device to the write based methods · bbd51e88
      由 Jason Gunthorpe 提交于 
      This is a step to get rid of the global check for disassociation. In this
model, the ib_dev is not proven to be valid by the core code and cannot be
provided to the method. Instead, every method decides if it is able to
run after disassociation and obtains the ib_dev using one of three
different approaches:

- Call srcu_dereference on the udevice's ib_dev. As before, this means
  the method cannot be called after disassociation begins.
  (eg alloc ucontext)
- Retrieve the ib_dev from the ucontext, via ib_uverbs_get_ucontext()
- Retrieve the ib_dev from the uobject->object after checking
  under SRCU if disassociation has started (eg uobj_get)

Largely, the code is all ready for this, the main work is to provide a
ib_dev after calling uobj_alloc(). The few other places simply use
ib_uverbs_get_ucontext() to get the ib_dev.

This flexibility will let the next patches allow destroy to operate
after disassociation.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
      bbd51e88
    • J
      IB/uverbs: Allow RDMA_REMOVE_DESTROY to work concurrently with disassociate · 7452a3c7
      由 Jason Gunthorpe 提交于 
      After all the recent structural changes this is now straightfoward, hoist
the hw_destroy_rwsem up out of rdma_destroy_explicit and wrap it around
the uobject write lock as well as the destroy.

This is necessary as obtaining a write lock concurrently with
uverbs_destroy_ufile_hw() will cause malfunction.

After this change none of the destroy callbacks require the
disassociate_srcu lock to be correct.

This requires introducing a new lookup mode, UVERBS_LOOKUP_DESTROY as the
IOCTL interface needs to hold an unlocked kref until all command
verification is completed.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
      7452a3c7
    • J
      IB/uverbs: Convert 'bool exclusive' into an enum · 9867f5c6
      由 Jason Gunthorpe 提交于 
      This is more readable, and future patches will need a 3rd lookup type.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
      9867f5c6
    • J
      IB/uverbs: Consolidate uobject destruction · 87ad80ab
      由 Jason Gunthorpe 提交于 
      There are several flows that can destroy a uobject and each one is
minimized and sprinkled throughout the code base, making it difficult to
understand and very hard to modify the destroy path.

Consolidate all of these into uverbs_destroy_uobject() and call it in all
cases where a uobject has to be destroyed.

This makes one change to the lifecycle, during any abort (eg when
alloc_commit is not called) we always call out to alloc_abort, even if
remove_commit needs to be called to delete a HW object.

This also renames RDMA_REMOVE_DURING_CLEANUP to RDMA_REMOVE_ABORT to
clarify its actual usage and revises some of the comments to reflect what
the life cycle is for the type implementation.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
      87ad80ab
    • J
      IB/uverbs: Make the write path destroy methods use the same flow as ioctl · 32ed5c00
      由 Jason Gunthorpe 提交于 
      The ridiculous dance with uobj_remove_commit() is not needed, the write
path can follow the same flow as ioctl - lock and destroy the HW object
then use the data left over in the uobject to form the response to
userspace.

Two helpers are introduced to make this flow straightforward for the
caller.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
      32ed5c00
  29. 31 7月, 2018 3 次提交