[net 2/6] e1000e: factor out systim sanitization
From: Jeff Kirsher <hidden>
Date: 2016-08-16 20:40:17
Subsystem:
intel ethernet drivers, networking drivers, the rest · Maintainers:
Tony Nguyen, Przemek Kitszel, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Jarod Wilson <redacted> 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 using a feature (bug) flag, per suggestion from Jesse Brandeburg. Littering functional code with device-specific checks is much messier than simply checking a flag, and having device-specific init set flags as needed. There are probably a number of other cases in the e1000e code that could/should be converted similarly. Suggested-by: Jesse Brandeburg <redacted> Signed-off-by: Jarod Wilson <redacted> Tested-by: Aaron Brown <redacted> Signed-off-by: Jeff Kirsher <redacted> --- drivers/net/ethernet/intel/e1000e/82571.c | 6 ++- drivers/net/ethernet/intel/e1000e/e1000.h | 1 + drivers/net/ethernet/intel/e1000e/netdev.c | 66 ++++++++++++++++++------------ 3 files changed, 44 insertions(+), 29 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000e/82571.c b/drivers/net/ethernet/intel/e1000e/82571.c
index 7fd4d54..6b03c85 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 ef96cd1..879cca4 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/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 02f4439..7017281 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; }
--
2.7.4