igb: Enable reading of wake up packet

Currently, in igb_resume(), igb driver ignores the Wake Up Status (WUS)
and Wake Up Packet Memory (WUPM) registers. This patch enables the igb
driver to read the WUPM if the controller was woken by a wake up packet
that is not more than 128 bytes long (maximum WUPM size), then pass it
up the kernel network stack.

Signed-off-by: Kim Tatt Chuah <kim.tatt.chuah@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 35 insertions, 1 deletions

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 53e66c87abaf..1cf74aa4ebd9 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -7985,6 +7985,36 @@ static int __igb_shutdown(struct pci_dev *pdev, bool *enable_wake,
         return 0;
 }
 
+static void igb_deliver_wake_packet(struct net_device *netdev)
+{
+        struct igb_adapter *adapter = netdev_priv(netdev);
+        struct e1000_hw *hw = &adapter->hw;
+        struct sk_buff *skb;
+        u32 wupl;
+
+        wupl = rd32(E1000_WUPL) & E1000_WUPL_MASK;
+
+        /* WUPM stores only the first 128 bytes of the wake packet.
+         * Read the packet only if we have the whole thing.
+         */
+        if ((wupl == 0) || (wupl > E1000_WUPM_BYTES))
+                return;
+
+        skb = netdev_alloc_skb_ip_align(netdev, E1000_WUPM_BYTES);
+        if (!skb)
+                return;
+
+        skb_put(skb, wupl);
+
+        /* Ensure reads are 32-bit aligned */
+        wupl = roundup(wupl, 4);
+
+        memcpy_fromio(skb->data, hw->hw_addr + E1000_WUPM_REG(0), wupl);
+
+        skb->protocol = eth_type_trans(skb, netdev);
+        netif_rx(skb);
+}
+
 #ifdef CONFIG_PM
 #ifdef CONFIG_PM_SLEEP
 static int igb_suspend(struct device *dev)
@@ -8014,7 +8044,7 @@ static int igb_resume(struct device *dev)
         struct net_device *netdev = pci_get_drvdata(pdev);
         struct igb_adapter *adapter = netdev_priv(netdev);
         struct e1000_hw *hw = &adapter->hw;
-        u32 err;
+        u32 err, val;
 
         pci_set_power_state(pdev, PCI_D0);
         pci_restore_state(pdev);
@@ -8045,6 +8075,10 @@ static int igb_resume(struct device *dev)
          */
         igb_get_hw_control(adapter);
 
+        val = rd32(E1000_WUS);
+        if (val & WAKE_PKT_WUS)
+                igb_deliver_wake_packet(netdev);
+
         wr32(E1000_WUS, ~0);
 
         rtnl_lock();