e1000e: Fixes possible phy corrupton on 82571 designs.

Phy corruption has been observed on 2-port 82571 adapters, and is root-caused
to lack of synchronization between the 2 driver instances, which conflict
when attempting to access the phy via the single MDIC register.
A semaphore exists for this purpose, and is now used on these designs. Because
PXE &/or EFI boot code (which we cannot expect to be built with this fix) may
leave the inter-instance semaphore in an invalid initial state when the driver
first loads, this fix also includes a one-time (per driver load) fix-up of the
semaphore initial state.

Signed-off-by: dave graham <david.graham@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 79 insertions, 7 deletions

diff --git a/drivers/net/e1000e/82571.c b/drivers/net/e1000e/82571.c
index c4b3f4fe91ae..b53b40ba88a8 100644
--- a/drivers/net/e1000e/82571.c
+++ b/drivers/net/e1000e/82571.c
@@ -71,6 +71,7 @@ static s32 e1000_setup_link_82571(struct e1000_hw *hw);
 static void e1000_clear_hw_cntrs_82571(struct e1000_hw *hw);
 static bool e1000_check_mng_mode_82574(struct e1000_hw *hw);
 static s32 e1000_led_on_82574(struct e1000_hw *hw);
+static void e1000_put_hw_semaphore_82571(struct e1000_hw *hw);
 
 /**
  *  e1000_init_phy_params_82571 - Init PHY func ptrs.
@@ -212,6 +213,9 @@ static s32 e1000_init_mac_params_82571(struct e1000_adapter *adapter)
         struct e1000_hw *hw = &adapter->hw;
         struct e1000_mac_info *mac = &hw->mac;
         struct e1000_mac_operations *func = &mac->ops;
+        u32 swsm = 0;
+        u32 swsm2 = 0;
+        bool force_clear_smbi = false;
 
         /* Set media type */
         switch (adapter->pdev->device) {
@@ -276,6 +280,50 @@ static s32 e1000_init_mac_params_82571(struct e1000_adapter *adapter)
                 break;
         }
 
+        /*
+         * Ensure that the inter-port SWSM.SMBI lock bit is clear before
+         * first NVM or PHY acess. This should be done for single-port
+         * devices, and for one port only on dual-port devices so that
+         * for those devices we can still use the SMBI lock to synchronize
+         * inter-port accesses to the PHY & NVM.
+         */
+        switch (hw->mac.type) {
+        case e1000_82571:
+        case e1000_82572:
+                swsm2 = er32(SWSM2);
+
+                if (!(swsm2 & E1000_SWSM2_LOCK)) {
+                        /* Only do this for the first interface on this card */
+                        ew32(SWSM2,
+                            swsm2 | E1000_SWSM2_LOCK);
+                        force_clear_smbi = true;
+                } else
+                        force_clear_smbi = false;
+                break;
+        default:
+                force_clear_smbi = true;
+                break;
+        }
+
+        if (force_clear_smbi) {
+                /* Make sure SWSM.SMBI is clear */
+                swsm = er32(SWSM);
+                if (swsm & E1000_SWSM_SMBI) {
+                        /* This bit should not be set on a first interface, and
+                         * indicates that the bootagent or EFI code has
+                         * improperly left this bit enabled
+                         */
+                        hw_dbg(hw, "Please update your 82571 Bootagent\n");
+                }
+                ew32(SWSM, swsm & ~E1000_SWSM_SMBI);
+        }
+
+        /*
+         * Initialze device specific counter of SMBI acquisition
+         * timeouts.
+         */
+         hw->dev_spec.e82571.smb_counter = 0;
+
         return 0;
 }
 
@@ -413,11 +461,37 @@ static s32 e1000_get_phy_id_82571(struct e1000_hw *hw)
 static s32 e1000_get_hw_semaphore_82571(struct e1000_hw *hw)
 {
         u32 swsm;
-        s32 timeout = hw->nvm.word_size + 1;
+        s32 sw_timeout = hw->nvm.word_size + 1;
+        s32 fw_timeout = hw->nvm.word_size + 1;
         s32 i = 0;
 
+        /*
+         * If we have timedout 3 times on trying to acquire
+         * the inter-port SMBI semaphore, there is old code
+         * operating on the other port, and it is not
+         * releasing SMBI. Modify the number of times that
+         * we try for the semaphore to interwork with this
+         * older code.
+         */
+        if (hw->dev_spec.e82571.smb_counter > 2)
+                sw_timeout = 1;
+
+        /* Get the SW semaphore */
+        while (i < sw_timeout) {
+                swsm = er32(SWSM);
+                if (!(swsm & E1000_SWSM_SMBI))
+                        break;
+
+                udelay(50);
+                i++;
+        }
+
+        if (i == sw_timeout) {
+                hw_dbg(hw, "Driver can't access device - SMBI bit is set.\n");
+                hw->dev_spec.e82571.smb_counter++;
+        }
         /* Get the FW semaphore. */
-        for (i = 0; i < timeout; i++) {
+        for (i = 0; i < fw_timeout; i++) {
                 swsm = er32(SWSM);
                 ew32(SWSM, swsm | E1000_SWSM_SWESMBI);
 
@@ -428,9 +502,9 @@ static s32 e1000_get_hw_semaphore_82571(struct e1000_hw *hw)
                 udelay(50);
         }
 
-        if (i == timeout) {
+        if (i == fw_timeout) {
                 /* Release semaphores */
-                e1000e_put_hw_semaphore(hw);
+                e1000_put_hw_semaphore_82571(hw);
                 hw_dbg(hw, "Driver can't access the NVM\n");
                 return -E1000_ERR_NVM;
         }
@@ -449,9 +523,7 @@ static void e1000_put_hw_semaphore_82571(struct e1000_hw *hw)
         u32 swsm;
 
         swsm = er32(SWSM);
-
-        swsm &= ~E1000_SWSM_SWESMBI;
-
+        swsm &= ~(E1000_SWSM_SMBI | E1000_SWSM_SWESMBI);
         ew32(SWSM, swsm);
 }