From 1d1f19cfce7687b557cebdc41bf8a5eeba8a9882 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Sat, 10 Feb 2007 23:17:26 +0200 Subject: [PATCH] IB/mthca: Give reserved MTTs a separate cache line MTTs are allocated in non-cache-coherent memory, so we must give reserved MTTs their own cache line, to prevent both device and CPU from writing into the same cache line at the same time. Signed-off-by: Michael S. Tsirkin Signed-off-by: Roland Dreier --- drivers/infiniband/hw/mthca/mthca_main.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/infiniband/hw/mthca/mthca_main.c b/drivers/infiniband/hw/mthca/mthca_main.c index 44bc6cc734abf..9a9dd32885a08 100644 --- a/drivers/infiniband/hw/mthca/mthca_main.c +++ b/drivers/infiniband/hw/mthca/mthca_main.c @@ -464,6 +464,10 @@ static int mthca_init_icm(struct mthca_dev *mdev, goto err_unmap_aux; } + /* CPU writes to non-reserved MTTs, while HCA might DMA to reserved mtts */ + mdev->limits.reserved_mtts = ALIGN(mdev->limits.reserved_mtts * MTHCA_MTT_SEG_SIZE, + dma_get_cache_alignment()) / MTHCA_MTT_SEG_SIZE; + mdev->mr_table.mtt_table = mthca_alloc_icm_table(mdev, init_hca->mtt_base, MTHCA_MTT_SEG_SIZE, mdev->limits.num_mtt_segs,