IB/mthca: Merge MR and FMR space on 64-bit systems

For Tavor, we currently reserve separate MPT and MTT space for FMRs to
avoid abusing the vmalloc space on 32 bit kernels. No such problem
exists on 64 bit kernels so let's not do it there.

This way we have a shared pool for MR and FMR resources, used on
demand. This will also make it possible to write MTTs for regular
regions directly from driver.

Signed-off-by: Michael S. Tsirkin <[e-mail]>
Signed-off-by: Roland Dreier <[e-mail]>

drivers/infiniband/hw/mthca/mthca_mr.c

···
 int mthca_init_mr_table(struct mthca_dev *dev)
 {
 	unsigned long addr;
-	int err, i;
+	int mpts, mtts, err, i;
 
 	err = mthca_alloc_init(&dev->mr_table.mpt_alloc,
 			       dev->limits.num_mpts,
···
 			err = -EINVAL;
 			goto err_fmr_mpt;
 		}
+		mpts = mtts = 1 << i;
+	} else {
+		mpts = dev->limits.num_mtt_segs;
+		mtts = dev->limits.num_mpts;
+	}
+
+	if (!mthca_is_memfree(dev) &&
+	    (dev->mthca_flags & MTHCA_FLAG_FMR)) {
 
 		addr = pci_resource_start(dev->pdev, 4) +
 			((pci_resource_len(dev->pdev, 4) - 1) &
 			 dev->mr_table.mpt_base);
 
 		dev->mr_table.tavor_fmr.mpt_base =
-			ioremap(addr, (1 << i) * sizeof(struct mthca_mpt_entry));
+			ioremap(addr, mpts * sizeof(struct mthca_mpt_entry));
 
 		if (!dev->mr_table.tavor_fmr.mpt_base) {
 			mthca_warn(dev, "MPT ioremap for FMR failed.\n");
···
 			 dev->mr_table.mtt_base);
 
 		dev->mr_table.tavor_fmr.mtt_base =
-			ioremap(addr, (1 << i) * MTHCA_MTT_SEG_SIZE);
+			ioremap(addr, mtts * MTHCA_MTT_SEG_SIZE);
 		if (!dev->mr_table.tavor_fmr.mtt_base) {
 			mthca_warn(dev, "MTT ioremap for FMR failed.\n");
 			err = -ENOMEM;
 			goto err_fmr_mtt;
 		}
+	}
 
-		err = mthca_buddy_init(&dev->mr_table.tavor_fmr.mtt_buddy, i);
+	if (dev->limits.fmr_reserved_mtts) {
+		err = mthca_buddy_init(&dev->mr_table.tavor_fmr.mtt_buddy, fls(mtts - 1));
 		if (err)
 			goto err_fmr_mtt_buddy;
 
 		/* Prevent regular MRs from using FMR keys */
-		err = mthca_buddy_alloc(&dev->mr_table.mtt_buddy, i);
+		err = mthca_buddy_alloc(&dev->mr_table.mtt_buddy, fls(mtts - 1));
 		if (err)
 			goto err_reserve_fmr;
 

drivers/infiniband/hw/mthca/mthca_profile.c

···
 	 * out of the MR pool. They don't use additional memory, but
 	 * we assign them as part of the HCA profile anyway.
 	 */
-	if (mthca_is_memfree(dev))
+	if (mthca_is_memfree(dev) || BITS_PER_LONG == 64)
 		dev->limits.fmr_reserved_mtts = 0;
 	else
 		dev->limits.fmr_reserved_mtts = request->fmr_reserved_mtts;