diff options
| -rw-r--r-- | drivers/net/ethernet/intel/i40e/i40e.h | 2 | ||||
| -rw-r--r-- | drivers/net/ethernet/intel/i40e/i40e_ptp.c | 41 |
2 files changed, 28 insertions, 15 deletions
diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h index 70d369e9139c..1d59ab6ca90f 100644 --- a/drivers/net/ethernet/intel/i40e/i40e.h +++ b/drivers/net/ethernet/intel/i40e/i40e.h @@ -586,7 +586,7 @@ struct i40e_pf { unsigned long ptp_tx_start; struct hwtstamp_config tstamp_config; struct mutex tmreg_lock; /* Used to protect the SYSTIME registers. */ - u64 ptp_base_adj; + u32 ptp_adj_mult; u32 tx_hwtstamp_timeouts; u32 tx_hwtstamp_skipped; u32 rx_hwtstamp_cleared; diff --git a/drivers/net/ethernet/intel/i40e/i40e_ptp.c b/drivers/net/ethernet/intel/i40e/i40e_ptp.c index 43d7c44d6d9f..aa3daec2049d 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_ptp.c +++ b/drivers/net/ethernet/intel/i40e/i40e_ptp.c @@ -16,9 +16,9 @@ * At 1Gb link, the period is multiplied by 20. (32ns) * 1588 functionality is not supported at 100Mbps. */ -#define I40E_PTP_40GB_INCVAL 0x0199999999ULL -#define I40E_PTP_10GB_INCVAL 0x0333333333ULL -#define I40E_PTP_1GB_INCVAL 0x2000000000ULL +#define I40E_PTP_40GB_INCVAL 0x0199999999ULL +#define I40E_PTP_10GB_INCVAL_MULT 2 +#define I40E_PTP_1GB_INCVAL_MULT 20 #define I40E_PRTTSYN_CTL1_TSYNTYPE_V1 BIT(I40E_PRTTSYN_CTL1_TSYNTYPE_SHIFT) #define I40E_PRTTSYN_CTL1_TSYNTYPE_V2 (2 << \ @@ -106,17 +106,24 @@ static int i40e_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb) ppb = -ppb; } - smp_mb(); /* Force any pending update before accessing. */ - adj = READ_ONCE(pf->ptp_base_adj); - - freq = adj; + freq = I40E_PTP_40GB_INCVAL; freq *= ppb; diff = div_u64(freq, 1000000000ULL); if (neg_adj) - adj -= diff; + adj = I40E_PTP_40GB_INCVAL - diff; else - adj += diff; + adj = I40E_PTP_40GB_INCVAL + diff; + + /* At some link speeds, the base incval is so large that directly + * multiplying by ppb would result in arithmetic overflow even when + * using a u64. Avoid this by instead calculating the new incval + * always in terms of the 40GbE clock rate and then multiplying by the + * link speed factor afterwards. This does result in slightly lower + * precision at lower link speeds, but it is fairly minor. + */ + smp_mb(); /* Force any pending update before accessing. */ + adj *= READ_ONCE(pf->ptp_adj_mult); wr32(hw, I40E_PRTTSYN_INC_L, adj & 0xFFFFFFFF); wr32(hw, I40E_PRTTSYN_INC_H, adj >> 32); @@ -438,6 +445,7 @@ void i40e_ptp_set_increment(struct i40e_pf *pf) struct i40e_link_status *hw_link_info; struct i40e_hw *hw = &pf->hw; u64 incval; + u32 mult; hw_link_info = &hw->phy.link_info; @@ -445,10 +453,10 @@ void i40e_ptp_set_increment(struct i40e_pf *pf) switch (hw_link_info->link_speed) { case I40E_LINK_SPEED_10GB: - incval = I40E_PTP_10GB_INCVAL; + mult = I40E_PTP_10GB_INCVAL_MULT; break; case I40E_LINK_SPEED_1GB: - incval = I40E_PTP_1GB_INCVAL; + mult = I40E_PTP_1GB_INCVAL_MULT; break; case I40E_LINK_SPEED_100MB: { @@ -459,15 +467,20 @@ void i40e_ptp_set_increment(struct i40e_pf *pf) "1588 functionality is not supported at 100 Mbps. Stopping the PHC.\n"); warn_once++; } - incval = 0; + mult = 0; break; } case I40E_LINK_SPEED_40GB: default: - incval = I40E_PTP_40GB_INCVAL; + mult = 1; break; } + /* The increment value is calculated by taking the base 40GbE incvalue + * and multiplying it by a factor based on the link speed. + */ + incval = I40E_PTP_40GB_INCVAL * mult; + /* Write the new increment value into the increment register. The * hardware will not update the clock until both registers have been * written. @@ -476,7 +489,7 @@ void i40e_ptp_set_increment(struct i40e_pf *pf) wr32(hw, I40E_PRTTSYN_INC_H, incval >> 32); /* Update the base adjustement value. */ - WRITE_ONCE(pf->ptp_base_adj, incval); + WRITE_ONCE(pf->ptp_adj_mult, mult); smp_mb(); /* Force the above update. */ } |