[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>

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) {