From 831ec0b4226cec7ea34f5c4c9810e78aeb2069bf Mon Sep 17 00:00:00 2001 From: Carolyn Wyborny Date: Fri, 11 Mar 2011 20:43:54 -0800 Subject: igb: Add DMA Coalescing feature to driver This patch add DMA Coalescing which is a power-saving feature that coalesces DMA writes in order to stay in a low-power state as much as possible. Feature is disabled by default. Signed-off-by: Carolyn Wyborny Tested-by: Jeff Pieper Signed-off-by: Jeff Kirsher --- drivers/net/igb/e1000_defines.h | 29 ++++++++++++++++++++- drivers/net/igb/e1000_regs.h | 9 +++++++ drivers/net/igb/igb.h | 6 +++++ drivers/net/igb/igb_ethtool.c | 6 +++++ drivers/net/igb/igb_main.c | 57 +++++++++++++++++++++++++++++++++++++++++ 5 files changed, 106 insertions(+), 1 deletion(-) diff --git a/drivers/net/igb/e1000_defines.h b/drivers/net/igb/e1000_defines.h index 97969ad8afef..9bb192825893 100644 --- a/drivers/net/igb/e1000_defines.h +++ b/drivers/net/igb/e1000_defines.h @@ -287,7 +287,34 @@ #define E1000_TCTL_COLD 0x003ff000 /* collision distance */ #define E1000_TCTL_RTLC 0x01000000 /* Re-transmit on late collision */ -/* Transmit Arbitration Count */ +/* DMA Coalescing register fields */ +#define E1000_DMACR_DMACWT_MASK 0x00003FFF /* DMA Coalescing + * Watchdog Timer */ +#define E1000_DMACR_DMACTHR_MASK 0x00FF0000 /* DMA Coalescing Receive + * Threshold */ +#define E1000_DMACR_DMACTHR_SHIFT 16 +#define E1000_DMACR_DMAC_LX_MASK 0x30000000 /* Lx when no PCIe + * transactions */ +#define E1000_DMACR_DMAC_LX_SHIFT 28 +#define E1000_DMACR_DMAC_EN 0x80000000 /* Enable DMA Coalescing */ + +#define E1000_DMCTXTH_DMCTTHR_MASK 0x00000FFF /* DMA Coalescing Transmit + * Threshold */ + +#define E1000_DMCTLX_TTLX_MASK 0x00000FFF /* Time to LX request */ + +#define E1000_DMCRTRH_UTRESH_MASK 0x0007FFFF /* Receive Traffic Rate + * Threshold */ +#define E1000_DMCRTRH_LRPRCW 0x80000000 /* Rcv packet rate in + * current window */ + +#define E1000_DMCCNT_CCOUNT_MASK 0x01FFFFFF /* DMA Coal Rcv Traffic + * Current Cnt */ + +#define E1000_FCRTC_RTH_COAL_MASK 0x0003FFF0 /* Flow ctrl Rcv Threshold + * High val */ +#define E1000_FCRTC_RTH_COAL_SHIFT 4 +#define E1000_PCIEMISC_LX_DECISION 0x00000080 /* Lx power decision */ /* SerDes Control */ #define E1000_SCTL_DISABLE_SERDES_LOOPBACK 0x0400 diff --git a/drivers/net/igb/e1000_regs.h b/drivers/net/igb/e1000_regs.h index b2f8e593da87..ad77ed510d7c 100644 --- a/drivers/net/igb/e1000_regs.h +++ b/drivers/net/igb/e1000_regs.h @@ -106,6 +106,15 @@ #define E1000_RQDPC(_n) (0x0C030 + ((_n) * 0x40)) +/* DMA Coalescing registers */ +#define E1000_DMACR 0x02508 /* Control Register */ +#define E1000_DMCTXTH 0x03550 /* Transmit Threshold */ +#define E1000_DMCTLX 0x02514 /* Time to Lx Request */ +#define E1000_DMCRTRH 0x05DD0 /* Receive Packet Rate Threshold */ +#define E1000_DMCCNT 0x05DD4 /* Current Rx Count */ +#define E1000_FCRTC 0x02170 /* Flow Control Rx high watermark */ +#define E1000_PCIEMISC 0x05BB8 /* PCIE misc config register */ + /* TX Rate Limit Registers */ #define E1000_RTTDQSEL 0x3604 /* Tx Desc Plane Queue Select - WO */ #define E1000_RTTBCNRC 0x36B0 /* Tx BCN Rate-Scheduler Config - WO */ diff --git a/drivers/net/igb/igb.h b/drivers/net/igb/igb.h index bbc5ebfe254a..1c687e298d5e 100644 --- a/drivers/net/igb/igb.h +++ b/drivers/net/igb/igb.h @@ -333,6 +333,12 @@ struct igb_adapter { #define IGB_FLAG_DCA_ENABLED (1 << 1) #define IGB_FLAG_QUAD_PORT_A (1 << 2) #define IGB_FLAG_QUEUE_PAIRS (1 << 3) +#define IGB_FLAG_DMAC (1 << 4) + +/* DMA Coalescing defines */ +#define IGB_MIN_TXPBSIZE 20408 +#define IGB_TX_BUF_4096 4096 +#define IGB_DMCTLX_DCFLUSH_DIS 0x80000000 /* Disable DMA Coal Flush */ #define IGB_82576_TSYNC_SHIFT 19 #define IGB_82580_TSYNC_SHIFT 24 diff --git a/drivers/net/igb/igb_ethtool.c b/drivers/net/igb/igb_ethtool.c index df15a915bbea..d976733bbcc2 100644 --- a/drivers/net/igb/igb_ethtool.c +++ b/drivers/net/igb/igb_ethtool.c @@ -2009,6 +2009,12 @@ static int igb_set_coalesce(struct net_device *netdev, if ((adapter->flags & IGB_FLAG_QUEUE_PAIRS) && ec->tx_coalesce_usecs) return -EINVAL; + /* If ITR is disabled, disable DMAC */ + if (ec->rx_coalesce_usecs == 0) { + if (adapter->flags & IGB_FLAG_DMAC) + adapter->flags &= ~IGB_FLAG_DMAC; + } + /* convert to rate of irq's per second */ if (ec->rx_coalesce_usecs && ec->rx_coalesce_usecs <= 3) adapter->rx_itr_setting = ec->rx_coalesce_usecs; diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c index 8c6af11d93a6..49476f773825 100644 --- a/drivers/net/igb/igb_main.c +++ b/drivers/net/igb/igb_main.c @@ -1674,7 +1674,58 @@ void igb_reset(struct igb_adapter *adapter) if (hw->mac.ops.init_hw(hw)) dev_err(&pdev->dev, "Hardware Error\n"); + if (hw->mac.type > e1000_82580) { + if (adapter->flags & IGB_FLAG_DMAC) { + u32 reg; + /* + * DMA Coalescing high water mark needs to be higher + * than * the * Rx threshold. The Rx threshold is + * currently * pba - 6, so we * should use a high water + * mark of pba * - 4. */ + hwm = (pba - 4) << 10; + + reg = (((pba-6) << E1000_DMACR_DMACTHR_SHIFT) + & E1000_DMACR_DMACTHR_MASK); + + /* transition to L0x or L1 if available..*/ + reg |= (E1000_DMACR_DMAC_EN | E1000_DMACR_DMAC_LX_MASK); + + /* watchdog timer= +-1000 usec in 32usec intervals */ + reg |= (1000 >> 5); + wr32(E1000_DMACR, reg); + + /* no lower threshold to disable coalescing(smart fifb) + * -UTRESH=0*/ + wr32(E1000_DMCRTRH, 0); + + /* set hwm to PBA - 2 * max frame size */ + wr32(E1000_FCRTC, hwm); + + /* + * This sets the time to wait before requesting tran- + * sition to * low power state to number of usecs needed + * to receive 1 512 * byte frame at gigabit line rate + */ + reg = rd32(E1000_DMCTLX); + reg |= IGB_DMCTLX_DCFLUSH_DIS; + + /* Delay 255 usec before entering Lx state. */ + reg |= 0xFF; + wr32(E1000_DMCTLX, reg); + + /* free space in Tx packet buffer to wake from DMAC */ + wr32(E1000_DMCTXTH, + (IGB_MIN_TXPBSIZE - + (IGB_TX_BUF_4096 + adapter->max_frame_size)) + >> 6); + + /* make low power state decision controlled by DMAC */ + reg = rd32(E1000_PCIEMISC); + reg |= E1000_PCIEMISC_LX_DECISION; + wr32(E1000_PCIEMISC, reg); + } /* end if IGB_FLAG_DMAC set */ + } if (hw->mac.type == e1000_82580) { u32 reg = rd32(E1000_PCIEMISC); wr32(E1000_PCIEMISC, @@ -2157,6 +2208,9 @@ static void __devinit igb_probe_vfs(struct igb_adapter * adapter) random_ether_addr(mac_addr); igb_set_vf_mac(adapter, i, mac_addr); } + /* DMA Coalescing is not supported in IOV mode. */ + if (adapter->flags & IGB_FLAG_DMAC) + adapter->flags &= ~IGB_FLAG_DMAC; } #endif /* CONFIG_PCI_IOV */ } @@ -2331,6 +2385,9 @@ static int __devinit igb_sw_init(struct igb_adapter *adapter) /* Explicitly disable IRQ since the NIC can be in any state. */ igb_irq_disable(adapter); + if (hw->mac.type == e1000_i350) + adapter->flags &= ~IGB_FLAG_DMAC; + set_bit(__IGB_DOWN, &adapter->state); return 0; } -- cgit v1.2.3-59-g8ed1b