ntb: conslidate reading of PPD to move platform detection earlier

To simplify some of the platform detection code. Move the platform detection
to a function to be called earlier.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

diff --git a/drivers/ntb/ntb_hw.c b/drivers/ntb/ntb_hw.c
index 7567452..6f1c921 100644 (file)
--- a/drivers/ntb/ntb_hw.c
+++ b/drivers/ntb/ntb_hw.c
@@ -702,24 +702,8 @@ static void bwd_link_poll(struct work_struct *work)
 
 static int ntb_xeon_setup(struct ntb_device *ndev)
 {
-       int rc;
-       u8 val;
-
-       ndev->hw_type = SNB_HW;
-
-       rc = pci_read_config_byte(ndev->pdev, NTB_PPD_OFFSET, &val);
-       if (rc)
-               return rc;
-
-       if (val & SNB_PPD_DEV_TYPE)
-               ndev->dev_type = NTB_DEV_USD;
-       else
-               ndev->dev_type = NTB_DEV_DSD;
-
-       switch (val & SNB_PPD_CONN_TYPE) {
+       switch (ndev->conn_type) {
        case NTB_CONN_B2B:
-               dev_info(&ndev->pdev->dev, "Conn Type = B2B\n");
-               ndev->conn_type = NTB_CONN_B2B;
                ndev->reg_ofs.ldb = ndev->reg_base + SNB_PDOORBELL_OFFSET;
                ndev->reg_ofs.ldb_mask = ndev->reg_base + SNB_PDBMSK_OFFSET;
                ndev->reg_ofs.spad_read = ndev->reg_base + SNB_SPAD_OFFSET;
@@ -835,9 +819,6 @@ static int ntb_xeon_setup(struct ntb_device *ndev)
                }
                break;
        case NTB_CONN_RP:
-               dev_info(&ndev->pdev->dev, "Conn Type = RP\n");
-               ndev->conn_type = NTB_CONN_RP;
-
                if (xeon_errata_workaround) {
                        dev_err(&ndev->pdev->dev,
                                "NTB-RP disabled due to hardware errata.  To disregard this warning and potentially lock-up the system, add the parameter 'xeon_errata_workaround=0'.\n");
@@ -867,8 +848,6 @@ static int ntb_xeon_setup(struct ntb_device *ndev)
                ndev->limits.max_mw = SNB_MAX_MW;
                break;
        case NTB_CONN_TRANSPARENT:
-               dev_info(&ndev->pdev->dev, "Conn Type = TRANSPARENT\n");
-               ndev->conn_type = NTB_CONN_TRANSPARENT;
                /* Scratch pads need to have exclusive access from the primary
                 * or secondary side.  Halve the num spads so that each side can
                 * have an equal amount.
@@ -890,10 +869,10 @@ static int ntb_xeon_setup(struct ntb_device *ndev)
                ndev->limits.max_mw = SNB_MAX_MW;
                break;
        default:
-               /* Most likely caused by the remote NTB-RP device not being
-                * configured
+               /*
+                * we should never hit this. the detect function should've
+                * take cared of everything.
                 */
-               dev_err(&ndev->pdev->dev, "Unknown PPD %x\n", val);
                return -EINVAL;
        }
 
@@ -977,9 +956,6 @@ static int ntb_device_setup(struct ntb_device *ndev)
        if (rc)
                return rc;
 
-       dev_info(&ndev->pdev->dev, "Device Type = %s\n",
-                ndev->dev_type == NTB_DEV_USD ? "USD/DSP" : "DSD/USP");
-
        if (ndev->conn_type == NTB_CONN_B2B)
                /* Enable Bus Master and Memory Space on the secondary side */
                writew(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER,
@@ -1519,6 +1495,96 @@ static void ntb_hw_link_down(struct ntb_device *ndev)
        writel(ntb_cntl, ndev->reg_ofs.lnk_cntl);
 }
 
+static int ntb_xeon_detect(struct ntb_device *ndev)
+{
+       int rc;
+       u8 ppd;
+
+       ndev->hw_type = SNB_HW;
+
+       rc = pci_read_config_byte(ndev->pdev, NTB_PPD_OFFSET, &ppd);
+       if (rc)
+               return -EIO;
+
+       if (ppd & SNB_PPD_DEV_TYPE)
+               ndev->dev_type = NTB_DEV_USD;
+       else
+               ndev->dev_type = NTB_DEV_DSD;
+
+       switch (ppd & SNB_PPD_CONN_TYPE) {
+       case NTB_CONN_B2B:
+               dev_info(&ndev->pdev->dev, "Conn Type = B2B\n");
+               ndev->conn_type = NTB_CONN_B2B;
+               break;
+       case NTB_CONN_RP:
+               dev_info(&ndev->pdev->dev, "Conn Type = RP\n");
+               ndev->conn_type = NTB_CONN_RP;
+               break;
+       case NTB_CONN_TRANSPARENT:
+               dev_info(&ndev->pdev->dev, "Conn Type = TRANSPARENT\n");
+               ndev->conn_type = NTB_CONN_TRANSPARENT;
+               /*
+                * This mode is default to USD/DSP. HW does not report
+                * properly in transparent mode as it has no knowledge of
+                * NTB. We will just force correct here.
+                */
+               ndev->dev_type = NTB_DEV_USD;
+               break;
+       default:
+               dev_err(&ndev->pdev->dev, "Unknown PPD %x\n", ppd);
+               return -ENODEV;
+       }
+
+       return 0;
+}
+
+static int ntb_atom_detect(struct ntb_device *ndev)
+{
+       int rc;
+       u32 ppd;
+
+       ndev->hw_type = BWD_HW;
+
+       rc = pci_read_config_dword(ndev->pdev, NTB_PPD_OFFSET, &ppd);
+       if (rc)
+               return rc;
+
+       switch ((ppd & BWD_PPD_CONN_TYPE) >> 8) {
+       case NTB_CONN_B2B:
+               dev_info(&ndev->pdev->dev, "Conn Type = B2B\n");
+               ndev->conn_type = NTB_CONN_B2B;
+               break;
+       case NTB_CONN_RP:
+       default:
+               dev_err(&ndev->pdev->dev, "Unsupported NTB configuration\n");
+               return -EINVAL;
+       }
+
+       if (ppd & BWD_PPD_DEV_TYPE)
+               ndev->dev_type = NTB_DEV_DSD;
+       else
+               ndev->dev_type = NTB_DEV_USD;
+
+       return 0;
+}
+
+static int ntb_device_detect(struct ntb_device *ndev)
+{
+       int rc;
+
+       if (is_ntb_xeon(ndev))
+               rc = ntb_xeon_detect(ndev);
+       else if (is_ntb_atom(ndev))
+               rc = ntb_atom_detect(ndev);
+       else
+               rc = -ENODEV;
+
+       dev_info(&ndev->pdev->dev, "Device Type = %s\n",
+                ndev->dev_type == NTB_DEV_USD ? "USD/DSP" : "DSD/USP");
+
+       return 0;
+}
+
 static int ntb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
        struct ntb_device *ndev;
@@ -1539,6 +1605,10 @@ static int ntb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
        pci_set_master(ndev->pdev);
 
+       rc = ntb_device_detect(ndev);
+       if (rc)
+               goto err;
+
        rc = pci_request_selected_regions(pdev, NTB_BAR_MASK, KBUILD_MODNAME);
        if (rc)
                goto err1;