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path: root/drivers/infiniband/hw/qib/qib_qp.c (follow)
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2013-02-14IB/qib: Fix QP locate/remove raceMike Marciniszyn1-2/+3
remove_qp() can execute concurrently with a qib_lookup_qpn() on another CPU, which in of itself, is ok, given the RCU locking. The issue is that remove_qp() NULLs out the qp->next field so that a qib_lookup_qpn() might fail to find a qp if it occurs after the one that is being deleted. This is a momentary issue and subsequent qib_lookup_qpn() calls would find the qp's since the search restarts from the bucket head. At scale, the issue might causes dropped packets and unnecessary retransmissions. The fix just deletes the qp->next NULL assignment to prevent the remove_qp() from hiding qp's from qib_lookup_qpn(). Reviewed-by: Dean Luick <dean.luick@intel.com> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-02-05IB/qib: Fix for broken sparse warning fixMike Marciniszyn1-8/+3
Commit 1fb9fed6d489 ("IB/qib: Fix QP RCU sparse warning") broke QP hash list deletion in qp_remove() badly. This patch restores the former for loop behavior, while still fixing the sparse warnings. Cc: <stable@vger.kernel.org> Reviewed-by: Gary Leshner <gary.s.leshner@intel.com> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-07-17IB/qib: Fix QP RCU sparse warningsMike Marciniszyn1-11/+24
Commit af061a644a0e ("IB/qib: Use RCU for qpn lookup") introduced sparse warnings. This patch corrects those issues. Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-07-08IB/qib: Avoid returning EBUSY from MR deregisterMike Marciniszyn1-15/+6
A timing issue can occur where qib_mr_dereg can return -EBUSY if the MR use count is not zero. This can occur if the MR is de-registered while RDMA read response packets are being progressed from the SDMA ring. The suspicion is that the peer sent an RDMA read request, which has already been copied across to the peer. The peer sees the completion of his request and then communicates to the responder that the MR is not needed any longer. The responder tries to de-register the MR, catching some responses remaining in the SDMA ring holding the MR use count. The code now uses a get/put paradigm to track MR use counts and coordinates with the MR de-registration process using a completion when the count has reached zero. A timeout on the delay is in place to catch other EBUSY issues. The reference count protocol is as follows: - The return to the user counts as 1 - A reference from the lk_table or the qib_ibdev counts as 1. - Transient I/O operations increase/decrease as necessary A lot of code duplication has been folded into the new routines init_qib_mregion() and deinit_qib_mregion(). Additionally, explicit initialization of fields to zero is now handled by kzalloc(). Also, duplicated code 'while.*num_sge' that decrements reference counts have been consolidated in qib_put_ss(). Reviewed-by: Ramkrishna Vepa <ramkrishna.vepa@intel.com> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-05-14IB/qib: Add cache line awareness to qib_qp and qib_devdata structuresMike Marciniszyn1-0/+7
This patch reorganizes the QP and devdata files to be more cache line aware. qib_qp fields in particular are split into read-mostly, send, and receive fields. qib_devdata fields are split into read-mostly and read/write fields Testing has show that bidirectional tests improve by as much as 100% with this patch. Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2011-10-21IB/qib: Precompute timeout jiffies to optimize latencyMike Marciniszyn1-1/+8
A new field is added to qib_qp called timeout_jiffies. It is initialized upon create and modify. The field is now used instead of a computation based on qp->timeout. Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2011-10-21IB/qib: Use RCU for qpn lookupMike Marciniszyn1-29/+48
The heavy weight spinlock in qib_lookup_qpn() is replaced with RCU. The hash list itself is now accessed via jhash functions instead of mod. The changes should benefit multiple receive contexts in different processors by not contending for the lock just to read the hash structures. The patch also adds a lookaside_qp (pointer) and a lookaside_qpn in the context. The interrupt handler will test the current packet's qpn against lookaside_qpn if the lookaside_qp pointer is non-NULL. The pointer is NULL'ed when the interrupt handler exits. Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2011-10-21IB/qib: Decode path MTU optimizationMike Marciniszyn1-1/+3
Store both the encoded and decoded MTU in the QP structure as a minor optimization for UC/RC receive routines. Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2011-01-10IB/qib: Change QPN incrementMike Marciniszyn1-1/+1
Changing from +1 to +2 allows for better QP distribution across receive contexts. Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2011-01-10IB/qib: Change receive queue/QPN selectionMike Marciniszyn1-16/+10
The basic idea is that on SusieQ, the difficult part of mapping QPN to context is handled by the mapping registers so the generic QPN allocation doesn't need to worry about chip specifics. For Monty and Linda, there is no mapping table so the qpt->mask (same as dd->qpn_mask), is used to see if the QPN to context falls within [zero..dd->n_krcv_queues). Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2011-01-10IB/qib: Clear WAIT_SEND flags when setting QP to error stateMike Marciniszyn1-0/+4
If these flags are set when the QP is transitioned to the error state, it will wait until the flags are cleared, which may never happen if the error transition is due to a link going down. Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2010-08-03IB/qib: Fix race between qib_error_qp() and receive packet processingRalph Campbell1-1/+1
When transitioning a QP to the error state, in progress RWQEs need to be marked complete. This also involves releasing the reference count to the memory regions referenced in the SGEs. The locking in the receive packet processing wasn't sufficient to prevent qib_error_qp() from modifying the r_sge state at the same time, thus leading to kernel panics. Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2010-05-23IB/qib: Add new qib driver for QLogic PCIe InfiniBand adaptersRalph Campbell1-0/+1255
Add a low-level IB driver for QLogic PCIe adapters. Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>