diff options
Diffstat (limited to 'drivers/net/ethernet/intel/igc/igc_i225.c')
| -rw-r--r-- | drivers/net/ethernet/intel/igc/igc_i225.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/drivers/net/ethernet/intel/igc/igc_i225.c b/drivers/net/ethernet/intel/igc/igc_i225.c index 3a4e982edb67..8b67d9b49a83 100644 --- a/drivers/net/ethernet/intel/igc/igc_i225.c +++ b/drivers/net/ethernet/intel/igc/igc_i225.c @@ -544,3 +544,103 @@ s32 igc_set_eee_i225(struct igc_hw *hw, bool adv2p5G, bool adv1G, return IGC_SUCCESS; } + +/* igc_set_ltr_i225 - Set Latency Tolerance Reporting thresholds + * @hw: pointer to the HW structure + * @link: bool indicating link status + * + * Set the LTR thresholds based on the link speed (Mbps), EEE, and DMAC + * settings, otherwise specify that there is no LTR requirement. + */ +s32 igc_set_ltr_i225(struct igc_hw *hw, bool link) +{ + u32 tw_system, ltrc, ltrv, ltr_min, ltr_max, scale_min, scale_max; + u16 speed, duplex; + s32 size; + + /* If we do not have link, LTR thresholds are zero. */ + if (link) { + hw->mac.ops.get_speed_and_duplex(hw, &speed, &duplex); + + /* Check if using copper interface with EEE enabled or if the + * link speed is 10 Mbps. + */ + if (hw->dev_spec._base.eee_enable && + speed != SPEED_10) { + /* EEE enabled, so send LTRMAX threshold. */ + ltrc = rd32(IGC_LTRC) | + IGC_LTRC_EEEMS_EN; + wr32(IGC_LTRC, ltrc); + + /* Calculate tw_system (nsec). */ + if (speed == SPEED_100) { + tw_system = ((rd32(IGC_EEE_SU) & + IGC_TW_SYSTEM_100_MASK) >> + IGC_TW_SYSTEM_100_SHIFT) * 500; + } else { + tw_system = (rd32(IGC_EEE_SU) & + IGC_TW_SYSTEM_1000_MASK) * 500; + } + } else { + tw_system = 0; + } + + /* Get the Rx packet buffer size. */ + size = rd32(IGC_RXPBS) & + IGC_RXPBS_SIZE_I225_MASK; + + /* Calculations vary based on DMAC settings. */ + if (rd32(IGC_DMACR) & IGC_DMACR_DMAC_EN) { + size -= (rd32(IGC_DMACR) & + IGC_DMACR_DMACTHR_MASK) >> + IGC_DMACR_DMACTHR_SHIFT; + /* Convert size to bits. */ + size *= 1024 * 8; + } else { + /* Convert size to bytes, subtract the MTU, and then + * convert the size to bits. + */ + size *= 1024; + size *= 8; + } + + if (size < 0) { + hw_dbg("Invalid effective Rx buffer size %d\n", + size); + return -IGC_ERR_CONFIG; + } + + /* Calculate the thresholds. Since speed is in Mbps, simplify + * the calculation by multiplying size/speed by 1000 for result + * to be in nsec before dividing by the scale in nsec. Set the + * scale such that the LTR threshold fits in the register. + */ + ltr_min = (1000 * size) / speed; + ltr_max = ltr_min + tw_system; + scale_min = (ltr_min / 1024) < 1024 ? IGC_LTRMINV_SCALE_1024 : + IGC_LTRMINV_SCALE_32768; + scale_max = (ltr_max / 1024) < 1024 ? IGC_LTRMAXV_SCALE_1024 : + IGC_LTRMAXV_SCALE_32768; + ltr_min /= scale_min == IGC_LTRMINV_SCALE_1024 ? 1024 : 32768; + ltr_min -= 1; + ltr_max /= scale_max == IGC_LTRMAXV_SCALE_1024 ? 1024 : 32768; + ltr_max -= 1; + + /* Only write the LTR thresholds if they differ from before. */ + ltrv = rd32(IGC_LTRMINV); + if (ltr_min != (ltrv & IGC_LTRMINV_LTRV_MASK)) { + ltrv = IGC_LTRMINV_LSNP_REQ | ltr_min | + (scale_min << IGC_LTRMINV_SCALE_SHIFT); + wr32(IGC_LTRMINV, ltrv); + } + + ltrv = rd32(IGC_LTRMAXV); + if (ltr_max != (ltrv & IGC_LTRMAXV_LTRV_MASK)) { + ltrv = IGC_LTRMAXV_LSNP_REQ | ltr_max | + (scale_min << IGC_LTRMAXV_SCALE_SHIFT); + wr32(IGC_LTRMAXV, ltrv); + } + } + + return IGC_SUCCESS; +} |