[Intel-wired-lan] [PATCH net-next 1/2] e1000e: factor out systim sanitization
Jarod Wilson
jarod at redhat.com
Sat Jul 23 16:44:33 UTC 2016
This is prepatory work for an expanding list of adapter families that have
occasional ~10 hour clock jumps when being used for PTP. Factor out the
sanitization function and convert to a switch statement, rather than using
an if.
CC: Jeff Kirsher <jeffrey.t.kirsher at intel.com>
CC: intel-wired-lan at lists.osuosl.org
CC: netdev at vger.kernel.org
Signed-off-by: Jarod Wilson <jarod at redhat.com>
---
drivers/net/ethernet/intel/e1000e/netdev.c | 71 ++++++++++++++++++------------
1 file changed, 44 insertions(+), 27 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 41f32c0..955b294 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
@@ -4335,32 +4371,13 @@ 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 ((time_delta < E1000_82574_SYSTIM_EPSILON) &&
- (rem == 0))
- break;
- }
+ switch (hw->mac.type) {
+ case e1000_82574:
+ case e1000_82583:
+ systim = e1000e_sanitize_systim(hw, systim);
+ break;
+ default:
+ break;
}
return systim;
}
--
1.8.3.1
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