[MTHCA] Give reserved MTTs a separate cache line (mlnx: 2959)

(Linux, 13/02/07, Michael S. Tsirkin, commit: 1d1f19cfce7687b557cebdc41bf8a5eeba8a9882)

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.

git-svn-id: svn://openib.tc.cornell.edu/gen1@1509 ad392aa1-c5ef-ae45-8dd8-e69d62a5ef86

diff --git a/trunk/hw/mthca/kernel/mthca_main.c b/trunk/hw/mthca/kernel/mthca_main.c
index f6c5264547c7aad1b8b11360f955f79027465c3b..16a0641f7db7ff9a27757199cb0fc6f57cd4151f 100644 (file)
--- a/trunk/hw/mthca/kernel/mthca_main.c
+++ b/trunk/hw/mthca/kernel/mthca_main.c
@@ -440,6 +440,10 @@ static int  mthca_init_icm(struct mthca_dev *mdev,
                goto err_unmap_aux;\r
        }\r
 \r
+       /* CPU writes to non-reserved MTTs, while HCA might DMA to reserved mtts */\r
+       mdev->limits.reserved_mtts = ALIGN(mdev->limits.reserved_mtts * MTHCA_MTT_SEG_SIZE,\r
+                                                        dma_get_cache_alignment()) / MTHCA_MTT_SEG_SIZE;\r
+       \r
        mdev->mr_table.mtt_table = mthca_alloc_icm_table(mdev, init_hca->mtt_base,\r
                                                         MTHCA_MTT_SEG_SIZE,\r
                                                         mdev->limits.num_mtt_segs,\r