static int mthca_tune_pci(struct mthca_dev *mdev)
 {
-       int cap;
-       u16 val;
-
        if (!tune_pci)
                return 0;
 
        /* First try to max out Read Byte Count */
-       cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_PCIX);
-       if (cap) {
-               if (pci_read_config_word(mdev->pdev, cap + PCI_X_CMD, &val)) {
-                       mthca_err(mdev, "Couldn't read PCI-X command register, "
-                                 "aborting.\n");
-                       return -ENODEV;
-               }
-               val = (val & ~PCI_X_CMD_MAX_READ) | (3 << 2);
-               if (pci_write_config_word(mdev->pdev, cap + PCI_X_CMD, val)) {
-                       mthca_err(mdev, "Couldn't write PCI-X command register, "
-                                 "aborting.\n");
+       if (pci_find_capability(mdev->pdev, PCI_CAP_ID_PCIX)) {
+               if (pcix_set_mmrbc(mdev->pdev, pcix_get_max_mmrbc(mdev->pdev))) {
+                       mthca_err(mdev, "Couldn't set PCI-X max read count, "
+                               "aborting.\n");
                        return -ENODEV;
                }
        } else if (!(mdev->mthca_flags & MTHCA_FLAG_PCIE))
                mthca_info(mdev, "No PCI-X capability, not setting RBC.\n");
 
-       cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_EXP);
-       if (cap) {
-               if (pci_read_config_word(mdev->pdev, cap + PCI_EXP_DEVCTL, &val)) {
-                       mthca_err(mdev, "Couldn't read PCI Express device control "
-                                 "register, aborting.\n");
-                       return -ENODEV;
-               }
-               val = (val & ~PCI_EXP_DEVCTL_READRQ) | (5 << 12);
-               if (pci_write_config_word(mdev->pdev, cap + PCI_EXP_DEVCTL, val)) {
-                       mthca_err(mdev, "Couldn't write PCI Express device control "
-                                 "register, aborting.\n");
+       if (pci_find_capability(mdev->pdev, PCI_CAP_ID_EXP)) {
+               if (pcie_set_readrq(mdev->pdev, 4096)) {
+                       mthca_err(mdev, "Couldn't write PCI Express read request, "
+                               "aborting.\n");
                        return -ENODEV;
                }
        } else if (mdev->mthca_flags & MTHCA_FLAG_PCIE)