[PATCH] IB uverbs: add mthca user MR support

Add support for userspace memory regions (MRs) to mthca.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 82 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/mthca/mthca_provider.c b/drivers/infiniband/hw/mthca/mthca_provider.c
index 318356c19abe..bbdfcbe6bade 100644
--- a/drivers/infiniband/hw/mthca/mthca_provider.c
+++ b/drivers/infiniband/hw/mthca/mthca_provider.c
@@ -654,6 +654,87 @@ static struct ib_mr *mthca_reg_phys_mr(struct ib_pd       *pd,
         return &mr->ibmr;
 }
 
+static struct ib_mr *mthca_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
+                                       int acc, struct ib_udata *udata)
+{
+        struct mthca_dev *dev = to_mdev(pd->device);
+        struct ib_umem_chunk *chunk;
+        struct mthca_mr *mr;
+        u64 *pages;
+        int shift, n, len;
+        int i, j, k;
+        int err = 0;
+
+        shift = ffs(region->page_size) - 1;
+
+        mr = kmalloc(sizeof *mr, GFP_KERNEL);
+        if (!mr)
+                return ERR_PTR(-ENOMEM);
+
+        n = 0;
+        list_for_each_entry(chunk, &region->chunk_list, list)
+                n += chunk->nents;
+
+        mr->mtt = mthca_alloc_mtt(dev, n);
+        if (IS_ERR(mr->mtt)) {
+                err = PTR_ERR(mr->mtt);
+                goto err;
+        }
+
+        pages = (u64 *) __get_free_page(GFP_KERNEL);
+        if (!pages) {
+                err = -ENOMEM;
+                goto err_mtt;
+        }
+
+        i = n = 0;
+
+        list_for_each_entry(chunk, &region->chunk_list, list)
+                for (j = 0; j < chunk->nmap; ++j) {
+                        len = sg_dma_len(&chunk->page_list[j]) >> shift;
+                        for (k = 0; k < len; ++k) {
+                                pages[i++] = sg_dma_address(&chunk->page_list[j]) +
+                                        region->page_size * k;
+                                /*
+                                 * Be friendly to WRITE_MTT command
+                                 * and leave two empty slots for the
+                                 * index and reserved fields of the
+                                 * mailbox.
+                                 */
+                                if (i == PAGE_SIZE / sizeof (u64) - 2) {
+                                        err = mthca_write_mtt(dev, mr->mtt,
+                                                              n, pages, i);
+                                        if (err)
+                                                goto mtt_done;
+                                        n += i;
+                                        i = 0;
+                                }
+                        }
+                }
+
+        if (i)
+                err = mthca_write_mtt(dev, mr->mtt, n, pages, i);
+mtt_done:
+        free_page((unsigned long) pages);
+        if (err)
+                goto err_mtt;
+
+        err = mthca_mr_alloc(dev, to_mpd(pd)->pd_num, shift, region->virt_base,
+                             region->length, convert_access(acc), mr);
+
+        if (err)
+                goto err_mtt;
+
+        return &mr->ibmr;
+
+err_mtt:
+        mthca_free_mtt(dev, mr->mtt);
+
+err:
+        kfree(mr);
+        return ERR_PTR(err);
+}
+
 static int mthca_dereg_mr(struct ib_mr *mr)
 {
         struct mthca_mr *mmr = to_mmr(mr);
@@ -804,6 +885,7 @@ int mthca_register_device(struct mthca_dev *dev)
         dev->ib_dev.poll_cq              = mthca_poll_cq;
         dev->ib_dev.get_dma_mr           = mthca_get_dma_mr;
         dev->ib_dev.reg_phys_mr          = mthca_reg_phys_mr;
+        dev->ib_dev.reg_user_mr          = mthca_reg_user_mr;
         dev->ib_dev.dereg_mr             = mthca_dereg_mr;
 
         if (dev->mthca_flags & MTHCA_FLAG_FMR) {