The implementation assumes that any RMPP request that requires a
response uses DS RMPP.  Based on the RMPP start-up scenarios defined
by the spec, this should be a valid assumption.  That is, there is no
start-up scenario defined where an RMPP request is followed by a
non-RMPP response.  By having this assumption we avoid any API
changes.

In order for a node that supports DS RMPP to communicate with one that
does not, RMPP responses assume a new window size of 1 if a DS ACK has
not been received.  (By DS ACK, I'm referring to the turn-around ACK
after the final ACK of the request.)  This is a slight spec deviation,
but is necessary to allow communication with nodes that do not
generate the DS ACK.  It also handles the case when a response is sent
after the request state has been discarded.
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

This patch converts the combination of list_del(A) and list_add(A, B) to
list_move(A, B) under drivers/.
Acked-by: NCorey Minyard <minyard@mvista.com>
Cc: Ben Collins <bcollins@debian.org>
Acked-by: NRoland Dreier <rolandd@cisco.com>
Cc: Alasdair Kergon <dm-devel@redhat.com>
Cc: Gerd Knorr <kraxel@bytesex.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frank Pavlic <fpavlic@de.ibm.com>
Acked-by: NMatthew Wilcox <matthew@wil.cx>
Cc: Andrew Vasquez <linux-driver@qlogic.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Signed-off-by: NAkinobu Mita <mita@miraclelinux.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix race condition during destruction calls to avoid possibility of
accessing object after it has been freed.  Instead of waking up a wait
queue directly, which is susceptible to a race where the object is
freed between the reference count going to 0 and the wake_up(), use a
completion to wait in the function doing the freeing.
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add RMPP support for additional management classes that support it.
Also, validate RMPP is consistent with management class specified.
Signed-off-by: NHal Rosenstock <halr@voltaire.com>
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Received responses are currently matched against sent requests based
on TID only.  According to the spec, responses should match based on
the combination of TID, management class, and requester LID/GID.

Without the additional qualification, an agent that is responding to
two requests, both of which have the same TID, can match RMPP ACKs
with the incorrect transaction.  This problem can occur on the SM node
when responding to SA queries.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add support for sending and receiving large RMPP transfers.  The old
code supports transfers only as large as a single contiguous kernel
memory allocation.  This patch uses linked list of memory buffers when
sending and receiving data to avoid needing contiguous pages for
larger transfers.

  Receive side: copy the arriving MADs in chunks instead of coalescing
  to one large buffer in kernel space.

  Send side: split a multipacket MAD buffer to a list of segments,
  (multipacket_list) and send these using a gather list of size 2.
  Also, save pointer to last sent segment, and retrieve requested
  segments by walking list starting at last sent segment. Finally,
  save pointer to last-acked segment.  When retrying, retrieve
  segments for resending relative to this pointer.  When updating last
  ack, start at this pointer.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Change alloc_response_msg() in mad_rmpp.c to return the struct
it allocates directly (or an error code a la ERR_PTR), rather than
returning a status and passing the struct back in a pointer param.
This simplifies the code and gets rid of warnings like

    drivers/infiniband/core/mad_rmpp.c: In function nack_recv:
    drivers/infiniband/core/mad_rmpp.c:192: warning: msg may be used uninitialized in this function

with newer versions of gcc.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

The MAD layer was violating the DMA API by touching data buffers used
for sends after the DMA mapping was done.  This causes problems on
non-cache-coherent architectures, because the device doing DMA won't
see updates to the payload buffers that exist only in the CPU cache.

Fix this by having all MAD consumers use ib_create_send_mad() to
allocate their send buffers, and moving the DMA mapping into the MAD
layer so it can be done just before calling send (and after any
modifications of the send buffer by the MAD layer).

Tested on a non-cache-coherent PowerPC 440SPe system.
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Based on simplification idea from Sean Hefty <sean.hefty@intel.com>
Signed-off-by: NHal Rosenstock <halr@voltaire.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Clean up code by using enums instead of hard-coded magic numbers.
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

- Fix payload length of middle RMPP sent segments. Middle payload
  lengths should be 0 on the send side.

  (This is perhaps a compliance and should not be an interop issue as
  middle payload lengths are supposed to be ignored on receive).

- Fix length in first segment of multipacket sends

  (This is a compliance issue but does not affect at least OpenIB to
  OpenIB RMPP transfers).
Signed-off-by: NHal Rosenstock <halr@voltaire.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add handling for ABORT / STOP RMPP MADs.
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Fix sparse warnings.  Use __be* where appropriate.
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add RMPP implementation.
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NHal Rosenstock <halr@voltaire.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>