e1000e: factor out systim sanitization

[cascardo/linux.git] / drivers / net / ethernet / intel / e1000e / netdev.c

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 02f4439..7017281 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -4302,6 +4302,42 @@ void e1000e_reinit_locked(struct e1000_adapter *adapter)
        clear_bit(__E1000_RESETTING, &adapter->state);
 }
 
+/**
+ * e1000e_sanitize_systim - sanitize raw cycle counter reads
+ * @hw: pointer to the HW structure
+ * @systim: cycle_t value read, sanitized and returned
+ *
+ * Errata for 82574/82583 possible bad bits read from SYSTIMH/L:
+ * check to see that the time is incrementing at a reasonable
+ * rate and is a multiple of incvalue.
+ **/
+static cycle_t e1000e_sanitize_systim(struct e1000_hw *hw, cycle_t systim)
+{
+       u64 time_delta, rem, temp;
+       cycle_t systim_next;
+       u32 incvalue;
+       int i;
+
+       incvalue = er32(TIMINCA) & E1000_TIMINCA_INCVALUE_MASK;
+       for (i = 0; i < E1000_MAX_82574_SYSTIM_REREADS; i++) {
+               /* latch SYSTIMH on read of SYSTIML */
+               systim_next = (cycle_t)er32(SYSTIML);
+               systim_next |= (cycle_t)er32(SYSTIMH) << 32;
+
+               time_delta = systim_next - systim;
+               temp = time_delta;
+               /* VMWare users have seen incvalue of zero, don't div / 0 */
+               rem = incvalue ? do_div(temp, incvalue) : (time_delta != 0);
+
+               systim = systim_next;
+
+               if ((time_delta < E1000_82574_SYSTIM_EPSILON) && (rem == 0))
+                       break;
+       }
+
+       return systim;
+}
+
 /**
  * e1000e_cyclecounter_read - read raw cycle counter (used by time counter)
  * @cc: cyclecounter structure
@@ -4312,7 +4348,7 @@ static cycle_t e1000e_cyclecounter_read(const struct cyclecounter *cc)
                                                     cc);
        struct e1000_hw *hw = &adapter->hw;
        u32 systimel, systimeh;
-       cycle_t systim, systim_next;
+       cycle_t systim;
        /* SYSTIMH latching upon SYSTIML read does not work well.
         * This means that if SYSTIML overflows after we read it but before
         * we read SYSTIMH, the value of SYSTIMH has been incremented and we
@@ -4335,33 +4371,9 @@ static cycle_t e1000e_cyclecounter_read(const struct cyclecounter *cc)
        systim = (cycle_t)systimel;
        systim |= (cycle_t)systimeh << 32;
 
-       if ((hw->mac.type == e1000_82574) || (hw->mac.type == e1000_82583)) {
-               u64 time_delta, rem, temp;
-               u32 incvalue;
-               int i;
-
-               /* errata for 82574/82583 possible bad bits read from SYSTIMH/L
-                * check to see that the time is incrementing at a reasonable
-                * rate and is a multiple of incvalue
-                */
-               incvalue = er32(TIMINCA) & E1000_TIMINCA_INCVALUE_MASK;
-               for (i = 0; i < E1000_MAX_82574_SYSTIM_REREADS; i++) {
-                       /* latch SYSTIMH on read of SYSTIML */
-                       systim_next = (cycle_t)er32(SYSTIML);
-                       systim_next |= (cycle_t)er32(SYSTIMH) << 32;
-
-                       time_delta = systim_next - systim;
-                       temp = time_delta;
-                       /* VMWare users have seen incvalue of zero, don't div / 0 */
-                       rem = incvalue ? do_div(temp, incvalue) : (time_delta != 0);
-
-                       systim = systim_next;
+       if (adapter->flags2 & FLAG2_CHECK_SYSTIM_OVERFLOW)
+               systim = e1000e_sanitize_systim(hw, systim);
 
-                       if ((time_delta < E1000_82574_SYSTIM_EPSILON) &&
-                           (rem == 0))
-                               break;
-               }
-       }
        return systim;
 }