ixgbe: Refactor MSI-X allocation mechanism

Our current MSI-X allocation mechanism does not support new hardware
at all.  It also isn't getting the actual number of supported MSI-X vectors
from the device.

This patch allows the number of MSI-X vectors to be specific to a device,
plus it gets the number of MSI-X vectors available from PCIe configuration
space.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/net/ixgbe/ixgbe_82598.c b/drivers/net/ixgbe/ixgbe_82598.c
index dffe7f062c8..7fb4b86f869 100644
--- a/drivers/net/ixgbe/ixgbe_82598.c
+++ b/drivers/net/ixgbe/ixgbe_82598.c
@@ -50,6 +50,27 @@ static s32 ixgbe_read_i2c_eeprom_82598(struct ixgbe_hw *hw, u8 byte_offset,
                                        u8 *eeprom_data);
 
 /**
+ *  ixgbe_get_pcie_msix_count_82598 - Gets MSI-X vector count
+ *  @hw: pointer to hardware structure
+ *
+ *  Read PCIe configuration space, and get the MSI-X vector count from
+ *  the capabilities table.
+ **/
+u16 ixgbe_get_pcie_msix_count_82598(struct ixgbe_hw *hw)
+{
+        struct ixgbe_adapter *adapter = hw->back;
+        u16 msix_count;
+        pci_read_config_word(adapter->pdev, IXGBE_PCIE_MSIX_82598_CAPS,
+                             &msix_count);
+        msix_count &= IXGBE_PCIE_MSIX_TBL_SZ_MASK;
+
+        /* MSI-X count is zero-based in HW, so increment to give proper value */
+        msix_count++;
+
+        return msix_count;
+}
+
+/**
  */
 static s32 ixgbe_get_invariants_82598(struct ixgbe_hw *hw)
 {
@@ -106,6 +127,7 @@ static s32 ixgbe_get_invariants_82598(struct ixgbe_hw *hw)
         mac->num_rar_entries = IXGBE_82598_RAR_ENTRIES;
         mac->max_rx_queues = IXGBE_82598_MAX_RX_QUEUES;
         mac->max_tx_queues = IXGBE_82598_MAX_TX_QUEUES;
+        mac->max_msix_vectors = ixgbe_get_pcie_msix_count_82598(hw);
 
 out:
         return ret_val;