IB/mlx4_ib: Add support for user MR re-registration
This enables the user to change the protection domain, access flags
and translation (address and length) of the MR.
Use basic mlx4_core helper functions to get, update and set MPT and
MTT objects according to the required modifications.
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/hw/mlx4/mr.c b/drivers/infiniband/hw/mlx4/mr.c
index cb2a872..9b0e80e 100644
--- a/drivers/infiniband/hw/mlx4/mr.c
+++ b/drivers/infiniband/hw/mlx4/mr.c
@@ -144,8 +144,10 @@
if (!mr)
return ERR_PTR(-ENOMEM);
+ /* Force registering the memory as writable. */
+ /* Used for memory re-registeration. HCA protects the access */
mr->umem = ib_umem_get(pd->uobject->context, start, length,
- access_flags, 0);
+ access_flags | IB_ACCESS_LOCAL_WRITE, 0);
if (IS_ERR(mr->umem)) {
err = PTR_ERR(mr->umem);
goto err_free;
@@ -183,6 +185,90 @@
return ERR_PTR(err);
}
+int mlx4_ib_rereg_user_mr(struct ib_mr *mr, int flags,
+ u64 start, u64 length, u64 virt_addr,
+ int mr_access_flags, struct ib_pd *pd,
+ struct ib_udata *udata)
+{
+ struct mlx4_ib_dev *dev = to_mdev(mr->device);
+ struct mlx4_ib_mr *mmr = to_mmr(mr);
+ struct mlx4_mpt_entry *mpt_entry;
+ struct mlx4_mpt_entry **pmpt_entry = &mpt_entry;
+ int err;
+
+ /* Since we synchronize this call and mlx4_ib_dereg_mr via uverbs,
+ * we assume that the calls can't run concurrently. Otherwise, a
+ * race exists.
+ */
+ err = mlx4_mr_hw_get_mpt(dev->dev, &mmr->mmr, &pmpt_entry);
+
+ if (err)
+ return err;
+
+ if (flags & IB_MR_REREG_PD) {
+ err = mlx4_mr_hw_change_pd(dev->dev, *pmpt_entry,
+ to_mpd(pd)->pdn);
+
+ if (err)
+ goto release_mpt_entry;
+ }
+
+ if (flags & IB_MR_REREG_ACCESS) {
+ err = mlx4_mr_hw_change_access(dev->dev, *pmpt_entry,
+ convert_access(mr_access_flags));
+
+ if (err)
+ goto release_mpt_entry;
+ }
+
+ if (flags & IB_MR_REREG_TRANS) {
+ int shift;
+ int err;
+ int n;
+
+ mlx4_mr_rereg_mem_cleanup(dev->dev, &mmr->mmr);
+ ib_umem_release(mmr->umem);
+ mmr->umem = ib_umem_get(mr->uobject->context, start, length,
+ mr_access_flags |
+ IB_ACCESS_LOCAL_WRITE,
+ 0);
+ if (IS_ERR(mmr->umem)) {
+ err = PTR_ERR(mmr->umem);
+ mmr->umem = NULL;
+ goto release_mpt_entry;
+ }
+ n = ib_umem_page_count(mmr->umem);
+ shift = ilog2(mmr->umem->page_size);
+
+ mmr->mmr.iova = virt_addr;
+ mmr->mmr.size = length;
+ err = mlx4_mr_rereg_mem_write(dev->dev, &mmr->mmr,
+ virt_addr, length, n, shift,
+ *pmpt_entry);
+ if (err) {
+ ib_umem_release(mmr->umem);
+ goto release_mpt_entry;
+ }
+
+ err = mlx4_ib_umem_write_mtt(dev, &mmr->mmr.mtt, mmr->umem);
+ if (err) {
+ mlx4_mr_rereg_mem_cleanup(dev->dev, &mmr->mmr);
+ ib_umem_release(mmr->umem);
+ goto release_mpt_entry;
+ }
+ }
+
+ /* If we couldn't transfer the MR to the HCA, just remember to
+ * return a failure. But dereg_mr will free the resources.
+ */
+ err = mlx4_mr_hw_write_mpt(dev->dev, &mmr->mmr, pmpt_entry);
+
+release_mpt_entry:
+ mlx4_mr_hw_put_mpt(dev->dev, pmpt_entry);
+
+ return err;
+}
+
int mlx4_ib_dereg_mr(struct ib_mr *ibmr)
{
struct mlx4_ib_mr *mr = to_mmr(ibmr);