IB/ipath: Provide I/O bus speeds for diagnostic purposes

Modern I/O buses like PCIe and HT can be configured for multiple speeds
and widths.  When an ipath HCA seems to have lower than expected
performance, it is very useful to be able to display what the driver
thinks the bus speed is.

Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 60 insertions, 14 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_iba6120.c b/drivers/infiniband/hw/ipath/ipath_iba6120.c
index 8423fee6344b..828066e20ad7 100644
--- a/drivers/infiniband/hw/ipath/ipath_iba6120.c
+++ b/drivers/infiniband/hw/ipath/ipath_iba6120.c
@@ -626,7 +626,6 @@ static int ipath_pe_boardname(struct ipath_devdata *dd, char *name,
 			dd->ipath_f_put_tid = ipath_pe_put_tid_2;
 	}
 
-
 	/*
 	 * set here, not in ipath_init_*_funcs because we have to do
 	 * it after we can read chip registers.
@@ -879,6 +878,62 @@ static void ipath_setup_pe_cleanup(struct ipath_devdata *dd)
 	pci_disable_msi(dd->pcidev);
 }
 
+static void ipath_6120_pcie_params(struct ipath_devdata *dd)
+{
+	u16 linkstat, speed;
+	int pos;
+
+	pos = pci_find_capability(dd->pcidev, PCI_CAP_ID_EXP);
+	if (!pos) {
+		ipath_dev_err(dd, "Can't find PCI Express capability!\n");
+		goto bail;
+	}
+
+	pci_read_config_word(dd->pcidev, pos + PCI_EXP_LNKSTA,
+			     &linkstat);
+	/*
+	 * speed is bits 0-4, linkwidth is bits 4-8
+	 * no defines for them in headers
+	 */
+	speed = linkstat & 0xf;
+	linkstat >>= 4;
+	linkstat &= 0x1f;
+	dd->ipath_lbus_width = linkstat;
+
+	switch (speed) {
+	case 1:
+		dd->ipath_lbus_speed = 2500; /* Gen1, 2.5GHz */
+		break;
+	case 2:
+		dd->ipath_lbus_speed = 5000; /* Gen1, 5GHz */
+		break;
+	default: /* not defined, assume gen1 */
+		dd->ipath_lbus_speed = 2500;
+		break;
+	}
+
+	if (linkstat < 8)
+		ipath_dev_err(dd,
+			"PCIe width %u (x8 HCA), performance reduced\n",
+			linkstat);
+	else
+		ipath_cdbg(VERBOSE, "PCIe speed %u width %u (x8 HCA)\n",
+			dd->ipath_lbus_speed, linkstat);
+
+	if (speed != 1)
+		ipath_dev_err(dd,
+			"PCIe linkspeed %u is incorrect; "
+			"should be 1 (2500)!\n", speed);
+bail:
+	/* fill in string, even on errors */
+	snprintf(dd->ipath_lbus_info, sizeof(dd->ipath_lbus_info),
+		"PCIe,%uMHz,x%u\n",
+		dd->ipath_lbus_speed,
+		dd->ipath_lbus_width);
+
+	return;
+}
+
 /**
  * ipath_setup_pe_config - setup PCIe config related stuff
  * @dd: the infinipath device
@@ -936,19 +991,8 @@ static int ipath_setup_pe_config(struct ipath_devdata *dd,
 	} else
 		ipath_dev_err(dd, "Can't find MSI capability, "
 			      "can't save MSI settings for reset\n");
-	if ((pos = pci_find_capability(dd->pcidev, PCI_CAP_ID_EXP))) {
-		u16 linkstat;
-		pci_read_config_word(dd->pcidev, pos + PCI_EXP_LNKSTA,
-				     &linkstat);
-		linkstat >>= 4;
-		linkstat &= 0x1f;
-		if (linkstat != 8)
-			ipath_dev_err(dd, "PCIe width %u, "
-				      "performance reduced\n", linkstat);
-	}
-	else
-		ipath_dev_err(dd, "Can't find PCI Express "
-			      "capability!\n");
+
+	ipath_6120_pcie_params(dd);
 
 	dd->ipath_link_width_supported = IB_WIDTH_1X | IB_WIDTH_4X;
 	dd->ipath_link_speed_supported = IPATH_IB_SDR;
@@ -1206,6 +1250,8 @@ static int ipath_setup_pe_reset(struct ipath_devdata *dd)
 	ret = 0; /* failed */
 
 bail:
+	if (ret)
+		ipath_6120_pcie_params(dd);
 	return ret;
 }