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| author | Roland Dreier <rolandd@cisco.com> | 2005-10-30 13:07:03 -0800 |
|---|---|---|
| committer | Roland Dreier <rolandd@cisco.com> | 2005-10-31 07:10:32 -0800 |
| commit | e5b251a24a9cd34a7ef98e361eb94e7ab122a554 (patch) | |
| tree | c29760bafd7107252389712965ad7e4ed0791a82 /drivers/infiniband | |
| parent | 7162a3e0db34e914a8bc5bf74bbae0b386310cf8 (diff) | |
| download | blackbird-op-linux-e5b251a24a9cd34a7ef98e361eb94e7ab122a554.tar.gz blackbird-op-linux-e5b251a24a9cd34a7ef98e361eb94e7ab122a554.zip | |
[IB] mthca: Avoid SRQ free WQE list corruption
Fix wqe_to_link() to use a structure field that we know is definitely
always unused for receive work requests, so that it really avoids the
free list corruption bug that the comment claims it does.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/hw/mthca/mthca_srq.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/infiniband/hw/mthca/mthca_srq.c b/drivers/infiniband/hw/mthca/mthca_srq.c index 64f70aa1b3c0..292f55be8cbd 100644 --- a/drivers/infiniband/hw/mthca/mthca_srq.c +++ b/drivers/infiniband/hw/mthca/mthca_srq.c @@ -75,15 +75,16 @@ static void *get_wqe(struct mthca_srq *srq, int n) /* * Return a pointer to the location within a WQE that we're using as a - * link when the WQE is in the free list. We use an offset of 4 - * because in the Tavor case, posting a WQE may overwrite the first - * four bytes of the previous WQE. The offset avoids corrupting our - * free list if the WQE has already completed and been put on the free - * list when we post the next WQE. + * link when the WQE is in the free list. We use the imm field + * because in the Tavor case, posting a WQE may overwrite the next + * segment of the previous WQE, but a receive WQE will never touch the + * imm field. This avoids corrupting our free list if the previous + * WQE has already completed and been put on the free list when we + * post the next WQE. */ static inline int *wqe_to_link(void *wqe) { - return (int *) (wqe + 4); + return (int *) (wqe + offsetof(struct mthca_next_seg, imm)); } static void mthca_tavor_init_srq_context(struct mthca_dev *dev, |
