diff options
| -rw-r--r-- | drivers/net/ethernet/intel/e1000e/ich8lan.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c index 56c4935b2578..ad9d8f2dd868 100644 --- a/drivers/net/ethernet/intel/e1000e/ich8lan.c +++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c @@ -839,6 +839,94 @@ release: } /** + * e1000_platform_pm_pch_lpt - Set platform power management values + * @hw: pointer to the HW structure + * @link: bool indicating link status + * + * Set the Latency Tolerance Reporting (LTR) values for the "PCIe-like" + * GbE MAC in the Lynx Point PCH based on Rx buffer size and link speed + * when link is up (which must not exceed the maximum latency supported + * by the platform), otherwise specify there is no LTR requirement. + * Unlike true-PCIe devices which set the LTR maximum snoop/no-snoop + * latencies in the LTR Extended Capability Structure in the PCIe Extended + * Capability register set, on this device LTR is set by writing the + * equivalent snoop/no-snoop latencies in the LTRV register in the MAC and + * set the SEND bit to send an Intel On-chip System Fabric sideband (IOSF-SB) + * message to the PMC. + **/ +static s32 e1000_platform_pm_pch_lpt(struct e1000_hw *hw, bool link) +{ + u32 reg = link << (E1000_LTRV_REQ_SHIFT + E1000_LTRV_NOSNOOP_SHIFT) | + link << E1000_LTRV_REQ_SHIFT | E1000_LTRV_SEND; + u16 lat_enc = 0; /* latency encoded */ + + if (link) { + u16 speed, duplex, scale = 0; + u16 max_snoop, max_nosnoop; + u16 max_ltr_enc; /* max LTR latency encoded */ + s64 lat_ns; /* latency (ns) */ + s64 value; + u32 rxa; + + if (!hw->adapter->max_frame_size) { + e_dbg("max_frame_size not set.\n"); + return -E1000_ERR_CONFIG; + } + + hw->mac.ops.get_link_up_info(hw, &speed, &duplex); + if (!speed) { + e_dbg("Speed not set.\n"); + return -E1000_ERR_CONFIG; + } + + /* Rx Packet Buffer Allocation size (KB) */ + rxa = er32(PBA) & E1000_PBA_RXA_MASK; + + /* Determine the maximum latency tolerated by the device. + * + * Per the PCIe spec, the tolerated latencies are encoded as + * a 3-bit encoded scale (only 0-5 are valid) multiplied by + * a 10-bit value (0-1023) to provide a range from 1 ns to + * 2^25*(2^10-1) ns. The scale is encoded as 0=2^0ns, + * 1=2^5ns, 2=2^10ns,...5=2^25ns. + */ + lat_ns = ((s64)rxa * 1024 - + (2 * (s64)hw->adapter->max_frame_size)) * 8 * 1000; + if (lat_ns < 0) + lat_ns = 0; + else + do_div(lat_ns, speed); + + value = lat_ns; + while (value > PCI_LTR_VALUE_MASK) { + scale++; + value = DIV_ROUND_UP(value, (1 << 5)); + } + if (scale > E1000_LTRV_SCALE_MAX) { + e_dbg("Invalid LTR latency scale %d\n", scale); + return -E1000_ERR_CONFIG; + } + lat_enc = (u16)((scale << PCI_LTR_SCALE_SHIFT) | value); + + /* Determine the maximum latency tolerated by the platform */ + pci_read_config_word(hw->adapter->pdev, E1000_PCI_LTR_CAP_LPT, + &max_snoop); + pci_read_config_word(hw->adapter->pdev, + E1000_PCI_LTR_CAP_LPT + 2, &max_nosnoop); + max_ltr_enc = max_t(u16, max_snoop, max_nosnoop); + + if (lat_enc > max_ltr_enc) + lat_enc = max_ltr_enc; + } + + /* Set Snoop and No-Snoop latencies the same */ + reg |= lat_enc | (lat_enc << E1000_LTRV_NOSNOOP_SHIFT); + ew32(LTRV, reg); + + return 0; +} + +/** * e1000_check_for_copper_link_ich8lan - Check for link (Copper) * @hw: pointer to the HW structure * @@ -911,6 +999,15 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) return ret_val; } + if (hw->mac.type == e1000_pch_lpt) { + /* Set platform power management values for + * Latency Tolerance Reporting (LTR) + */ + ret_val = e1000_platform_pm_pch_lpt(hw, link); + if (ret_val) + return ret_val; + } + /* Clear link partner's EEE ability */ hw->dev_spec.ich8lan.eee_lp_ability = 0; |