[net-next v5 04/17] i40e: Populate and check pci bus speed and width

Jeff Kirsher
2014-01-04T05:56:53Z

From: Catherine Sullivan <catherine.sullivan@intel.com>

Call i40e_set_pci_config_data from probe, then check that
we are in a 8GT/s x8 PCIe slot and send a warning if we are not.

Change-Id: I62815c574cee50d2787c50bbe956dde7a7a75a11
CC: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
drivers/net/ethernet/intel/i40e/i40e_common.c | 44 ++++++++++++++++++++++++
drivers/net/ethernet/intel/i40e/i40e_main.c | 23 +++++++++++++
drivers/net/ethernet/intel/i40e/i40e_prototype.h | 1 +
3 files changed, 68 insertions(+)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_common.c b/drivers/net/ethernet/intel/i40e/i40e_common.c
index 8b6d56a..a69959e 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_common.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_common.c
@@ -2029,3 +2029,47 @@ i40e_status i40e_set_filter_control(struct i40e_hw *hw,

return 0;
}
+/**
+ * i40e_set_pci_config_data - store PCI bus info
+ * @hw: pointer to hardware structure
+ * @link_status: the link status word from PCI config space
+ *
+ * Stores the PCI bus info (speed, width, type) within the i40e_hw structure
+ **/
+void i40e_set_pci_config_data(struct i40e_hw *hw, u16 link_status)
+{
+ hw->bus.type = i40e_bus_type_pci_express;
+
+ switch (link_status & PCI_EXP_LNKSTA_NLW) {
+ case PCI_EXP_LNKSTA_NLW_X1:
+ hw->bus.width = i40e_bus_width_pcie_x1;
+ break;
+ case PCI_EXP_LNKSTA_NLW_X2:
+ hw->bus.width = i40e_bus_width_pcie_x2;
+ break;
+ case PCI_EXP_LNKSTA_NLW_X4:
+ hw->bus.width = i40e_bus_width_pcie_x4;
+ break;
+ case PCI_EXP_LNKSTA_NLW_X8:
+ hw->bus.width = i40e_bus_width_pcie_x8;
+ break;
+ default:
+ hw->bus.width = i40e_bus_width_unknown;
+ break;
+ }
+
+ switch (link_status & PCI_EXP_LNKSTA_CLS) {
+ case PCI_EXP_LNKSTA_CLS_2_5GB:
+ hw->bus.speed = i40e_bus_speed_2500;
+ break;
+ case PCI_EXP_LNKSTA_CLS_5_0GB:
+ hw->bus.speed = i40e_bus_speed_5000;
+ break;
+ case PCI_EXP_LNKSTA_CLS_8_0GB:
+ hw->bus.speed = i40e_bus_speed_8000;
+ break;
+ default:
+ hw->bus.speed = i40e_bus_speed_unknown;
+ break;
+ }
+}
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index f14b31c..22a2c0e 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -7369,6 +7369,7 @@ static int i40e_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
struct i40e_pf *pf;
struct i40e_hw *hw;
static u16 pfs_found;
+ u16 link_status;
int err = 0;
u32 len;

@@ -7603,6 +7604,28 @@ static int i40e_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
mod_timer(&pf->service_timer,
round_jiffies(jiffies + pf->service_timer_period));

+ /* Get the negotiated link width and speed from PCI config space */
+ pcie_capability_read_word(pf->pdev, PCI_EXP_LNKSTA, &link_status);
+
+ i40e_set_pci_config_data(hw, link_status);
+
+ dev_info(&pdev->dev, "PCI Express: %s %s\n",
+ (hw->bus.speed == i40e_bus_speed_8000 ? "Speed 8.0GT/s" :
+ hw->bus.speed == i40e_bus_speed_5000 ? "Speed 5.0GT/s" :
+ hw->bus.speed == i40e_bus_speed_2500 ? "Speed 2.5GT/s" :
+ "Unknown"),
+ (hw->bus.width == i40e_bus_width_pcie_x8 ? "Width x8" :
+ hw->bus.width == i40e_bus_width_pcie_x4 ? "Width x4" :
+ hw->bus.width == i40e_bus_width_pcie_x2 ? "Width x2" :
+ hw->bus.width == i40e_bus_width_pcie_x1 ? "Width x1" :
+ "Unknown"));
+
+ if (hw->bus.width < i40e_bus_width_pcie_x8 ||
+ hw->bus.speed < i40e_bus_speed_8000) {
+ dev_warn(&pdev->dev, "PCI-Express bandwidth available for this device may be insufficient for optimal performance.\n");
+ dev_warn(&pdev->dev, "Please move the device to a different PCI-e link with more lanes and/or higher transfer rate.\n");
+ }
+
return 0;

/* Unwind what we've done if something failed in the setup */
diff --git a/drivers/net/ethernet/intel/i40e/i40e_prototype.h b/drivers/net/ethernet/intel/i40e/i40e_prototype.h
index 2fc9ce5..db7bf93 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_prototype.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_prototype.h
@@ -215,6 +215,7 @@ i40e_status i40e_read_nvm_buffer(struct i40e_hw *hw, u16 offset,
u16 *words, u16 *data);
i40e_status i40e_validate_nvm_checksum(struct i40e_hw *hw,
u16 *checksum);
+void i40e_set_pci_config_data(struct i40e_hw *hw, u16 link_status);

/* prototype for functions used for SW locks */

--
1.8.3.1