4 files changed, 46 insertions, 30 deletions

diff --git a/drivers/net/ethernet/intel/e1000e/82571.c b/drivers/net/ethernet/intel/e1000e/82571.c
index 7fd4d54599e4..6b03c8553e59 100644
--- a/drivers/net/ethernet/intel/e1000e/82571.c
+++ b/drivers/net/ethernet/intel/e1000e/82571.c
@@ -2032,7 +2032,8 @@ const struct e1000_info e1000_82574_info = {
                                   | FLAG2_DISABLE_ASPM_L0S
                                   | FLAG2_DISABLE_ASPM_L1
                                   | FLAG2_NO_DISABLE_RX
-                                  | FLAG2_DMA_BURST,
+                                  | FLAG2_DMA_BURST
+                                  | FLAG2_CHECK_SYSTIM_OVERFLOW,
         .pba                    = 32,
         .max_hw_frame_size      = DEFAULT_JUMBO,
         .get_variants           = e1000_get_variants_82571,
@@ -2053,7 +2054,8 @@ const struct e1000_info e1000_82583_info = {
                                   | FLAG_HAS_CTRLEXT_ON_LOAD,
         .flags2                 = FLAG2_DISABLE_ASPM_L0S
                                   | FLAG2_DISABLE_ASPM_L1
-                                  | FLAG2_NO_DISABLE_RX,
+                                  | FLAG2_NO_DISABLE_RX
+                                  | FLAG2_CHECK_SYSTIM_OVERFLOW,
         .pba                    = 32,
         .max_hw_frame_size      = DEFAULT_JUMBO,
         .get_variants           = e1000_get_variants_82571,
diff --git a/drivers/net/ethernet/intel/e1000e/e1000.h b/drivers/net/ethernet/intel/e1000e/e1000.h
index ef96cd11d6d2..879cca47b021 100644
--- a/drivers/net/ethernet/intel/e1000e/e1000.h
+++ b/drivers/net/ethernet/intel/e1000e/e1000.h
@@ -452,6 +452,7 @@ s32 e1000e_get_base_timinca(struct e1000_adapter *adapter, u32 *timinca);
 #define FLAG2_PCIM2PCI_ARBITER_WA         BIT(11)
 #define FLAG2_DFLT_CRC_STRIPPING          BIT(12)
 #define FLAG2_CHECK_RX_HWTSTAMP           BIT(13)
+#define FLAG2_CHECK_SYSTIM_OVERFLOW       BIT(14)
 
 #define E1000_RX_DESC_PS(R, i)      \
         (&(((union e1000_rx_desc_packet_split *)((R).desc))[i]))
diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c
index 3e11322d8d58..f3aaca743ea3 100644
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
@@ -5885,7 +5885,8 @@ const struct e1000_info e1000_pch_lpt_info = {
                                   | FLAG_HAS_JUMBO_FRAMES
                                   | FLAG_APME_IN_WUC,
         .flags2                 = FLAG2_HAS_PHY_STATS
-                                  | FLAG2_HAS_EEE,
+                                  | FLAG2_HAS_EEE
+                                  | FLAG2_CHECK_SYSTIM_OVERFLOW,
         .pba                    = 26,
         .max_hw_frame_size      = 9022,
         .get_variants           = e1000_get_variants_ich8lan,
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 02f443958f31..7017281ba2dc 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -4303,6 +4303,42 @@ void e1000e_reinit_locked(struct e1000_adapter *adapter)
 }
 
 /**
+ * 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;
 }