1. 09 May, 2007 3 commits
    • Roland Dreier's avatar
      IB/mlx4: Add a driver Mellanox ConnectX InfiniBand adapters · 225c7b1f
      Roland Dreier authored
      Add an InfiniBand driver for Mellanox ConnectX adapters.  Because
      these adapters can also be used as ethernet NICs and Fibre Channel 
      HBAs, the driver is split into two modules: 
       
        mlx4_core: Handles low-level things like device initialization and 
          processing firmware commands.  Also controls resource allocation 
          so that the InfiniBand, ethernet and FC functions can share a 
          device without stepping on each other. 
       
        mlx4_ib: Handles InfiniBand-specific things; plugs into the 
          InfiniBand midlayer. 
      Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
      225c7b1f
    • Roland Dreier's avatar
      IB: Put rlimit accounting struct in struct ib_umem · 1bf66a30
      Roland Dreier authored
      When memory pinned with ib_umem_get() is released, ib_umem_release()
      needs to subtract the amount of memory being unpinned from
      mm->locked_vm.  However, ib_umem_release() may be called with
      mm->mmap_sem already held for writing if the memory is being released
      as part of an munmap() call, so it is sometimes necessary to defer
      this accounting into a workqueue.
      
      However, the work struct used to defer this accounting is dynamically
      allocated before it is queued, so there is the possibility of failing
      that allocation.  If the allocation fails, then ib_umem_release has no
      choice except to bail out and leave the process with a permanently
      elevated locked_vm.
      
      Fix this by allocating the structure to defer accounting as part of
      the original struct ib_umem, so there's no possibility of failing a
      later allocation if creating the struct ib_umem and pinning memory
      succeeds.
      Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
      1bf66a30
    • Roland Dreier's avatar
      IB/uverbs: Export ib_umem_get()/ib_umem_release() to modules · f7c6a7b5
      Roland Dreier authored
      Export ib_umem_get()/ib_umem_release() and put low-level drivers in
      control of when to call ib_umem_get() to pin and DMA map userspace,
      rather than always calling it in ib_uverbs_reg_mr() before calling the
      low-level driver's reg_user_mr method.
      
      Also move these functions to be in the ib_core module instead of
      ib_uverbs, so that driver modules using them do not depend on
      ib_uverbs.
      
      This has a number of advantages:
       - It is better design from the standpoint of making generic code a
         library that can be used or overridden by device-specific code as
         the details of specific devices dictate.
       - Drivers that do not need to pin userspace memory regions do not
         need to take the performance hit of calling ib_mem_get().  For
         example, although I have not tried to implement it in this patch,
         the ipath driver should be able to avoid pinning memory and just
         use copy_{to,from}_user() to access userspace memory regions.
       - Buffers that need special mapping treatment can be identified by
         the low-level driver.  For example, it may be possible to solve
         some Altix-specific memory ordering issues with mthca CQs in
         userspace by mapping CQ buffers with extra flags.
       - Drivers that need to pin and DMA map userspace memory for things
         other than memory regions can use ib_umem_get() directly, instead
         of hacks using extra parameters to their reg_phys_mr method.  For
         example, the mlx4 driver that is pending being merged needs to pin
         and DMA map QP and CQ buffers, but it does not need to create a
         memory key for these buffers.  So the cleanest solution is for mlx4
         to call ib_umem_get() in the create_qp and create_cq methods.
      Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
      f7c6a7b5
  2. 08 May, 2007 37 commits