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>

1 files changed, 98 insertions, 28 deletions

diff --git a/drivers/ntb/ntb_hw.c b/drivers/ntb/ntb_hw.c
index 7567452250df..6f1c92182f35 100644
--- 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;