clearing up netdev-typo
-H

On Sun, Jun 12, 2016 at 12:22:16AM +0200, Henrik Austad wrote:
> This adds support for loading the igb.ko module with tsn
> capabilities. This requires a 2-step approach. First enabling TSN in
> .config, then load the module with use_tsn=1.
> 
> Once enabled and loaded, the controller will be placed in "Qav-mode"
> which is when the credit-based shaper is available, 3 of the queues are
> removed from regular traffic, max payload is set to 1522 octets (no
> jumboframes allowed).
> 
> It dumps the registers of interest before and after, so this clutters
> kern.log a bit. In time this will be reduced / tied to the debug-param
> for the module.
> 
> Note: currently this driver is *not* stable, it is still a work in
> progress.
> 
> Cc: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
> Cc: intel-wired-...@lists.osuosl.org
> Cc: "David S. Miller" <da...@davemloft.net>
> Signed-off-by: Henrik Austad <haus...@cisco.com>
> ---
>  drivers/net/ethernet/intel/Kconfig        |  18 ++
>  drivers/net/ethernet/intel/igb/Makefile   |   2 +-
>  drivers/net/ethernet/intel/igb/igb.h      |  19 ++
>  drivers/net/ethernet/intel/igb/igb_main.c |  10 +-
>  drivers/net/ethernet/intel/igb/igb_tsn.c  | 396 
> ++++++++++++++++++++++++++++++
>  5 files changed, 443 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/net/ethernet/intel/igb/igb_tsn.c
> 
> diff --git a/drivers/net/ethernet/intel/Kconfig 
> b/drivers/net/ethernet/intel/Kconfig
> index 714bd10..8e620a9 100644
> --- a/drivers/net/ethernet/intel/Kconfig
> +++ b/drivers/net/ethernet/intel/Kconfig
> @@ -99,6 +99,24 @@ config IGB
>         To compile this driver as a module, choose M here. The module
>         will be called igb.
>  
> +config IGB_TSN
> +       tristate "TSN Support for Intel(R) 82575/82576 i210 Network 
> Controller"
> +       depends on IGB && TSN
> +     ---help---
> +       This driver supports TSN (AVB) on Intel I210 network controllers.
> +
> +       When enabled, it will allow the module to be loaded with
> +       "use_tsn" which will initialize the controller to A/V-mode
> +       instead of legacy-mode. This will take 3 of the tx-queues and
> +       place them in 802.1Q QoS mode and enable the credit-based
> +       shaper for 2 of the queues.
> +
> +       If built with this option, but not loaded with use_tsn, the
> +       only difference is a slightly larger module, no extra
> +       code paths are called.
> +
> +       If unsure, say No
> +
>  config IGB_HWMON
>       bool "Intel(R) PCI-Express Gigabit adapters HWMON support"
>       default y
> diff --git a/drivers/net/ethernet/intel/igb/Makefile 
> b/drivers/net/ethernet/intel/igb/Makefile
> index 5bcb2de..1a9b776 100644
> --- a/drivers/net/ethernet/intel/igb/Makefile
> +++ b/drivers/net/ethernet/intel/igb/Makefile
> @@ -33,4 +33,4 @@ obj-$(CONFIG_IGB) += igb.o
>  
>  igb-objs := igb_main.o igb_ethtool.o e1000_82575.o \
>           e1000_mac.o e1000_nvm.o e1000_phy.o e1000_mbx.o \
> -         e1000_i210.o igb_ptp.o igb_hwmon.o
> +         e1000_i210.o igb_ptp.o igb_hwmon.o igb_tsn.o
> diff --git a/drivers/net/ethernet/intel/igb/igb.h 
> b/drivers/net/ethernet/intel/igb/igb.h
> index b9609af..708f705 100644
> --- a/drivers/net/ethernet/intel/igb/igb.h
> +++ b/drivers/net/ethernet/intel/igb/igb.h
> @@ -356,6 +356,7 @@ struct hwmon_buff {
>  #define IGB_RETA_SIZE        128
>  
>  /* board specific private data structure */
> +
>  struct igb_adapter {
>       unsigned long active_vlans[BITS_TO_LONGS(VLAN_N_VID)];
>  
> @@ -472,6 +473,13 @@ struct igb_adapter {
>       int copper_tries;
>       struct e1000_info ei;
>       u16 eee_advert;
> +
> +#if IS_ENABLED(CONFIG_IGB_TSN)
> +     /* Reserved BW for class A and B */
> +     u16 sra_idleslope_res;
> +     u16 srb_idleslope_res;
> +     u8 tsn_ready:1;
> +#endif       /* IGB_TSN */
>  };
>  
>  #define IGB_FLAG_HAS_MSI             BIT(0)
> @@ -552,6 +560,17 @@ void igb_ptp_rx_pktstamp(struct igb_q_vector *q_vector, 
> unsigned char *va,
>                        struct sk_buff *skb);
>  int igb_ptp_set_ts_config(struct net_device *netdev, struct ifreq *ifr);
>  int igb_ptp_get_ts_config(struct net_device *netdev, struct ifreq *ifr);
> +/* This should be the only place where we add ifdeffery
> + * to include tsn-stuff or not. Everything else is located in igb_tsn.c
> + */
> +#if IS_ENABLED(CONFIG_IGB_TSN)
> +void igb_tsn_init(struct igb_adapter *adapter);
> +int igb_tsn_capable(struct net_device *netdev);
> +int igb_tsn_link_configure(struct net_device *netdev, enum sr_class sr_class,
> +                        u16 framesize, u16 vid);
> +#else
> +static inline void igb_tsn_init(struct igb_adapter *adapter) { }
> +#endif       /* CONFIG_IGB_TSN */
>  void igb_set_flag_queue_pairs(struct igb_adapter *, const u32);
>  #ifdef CONFIG_IGB_HWMON
>  void igb_sysfs_exit(struct igb_adapter *adapter);
> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c 
> b/drivers/net/ethernet/intel/igb/igb_main.c
> index ef3d642..4d8789f 100644
> --- a/drivers/net/ethernet/intel/igb/igb_main.c
> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -2142,6 +2142,10 @@ static const struct net_device_ops igb_netdev_ops = {
>  #ifdef CONFIG_NET_POLL_CONTROLLER
>       .ndo_poll_controller    = igb_netpoll,
>  #endif
> +#if IS_ENABLED(CONFIG_IGB_TSN)
> +     .ndo_tsn_capable        = igb_tsn_capable,
> +     .ndo_tsn_link_configure = igb_tsn_link_configure,
> +#endif       /* CONFIG_IGB_TSN */
>       .ndo_fix_features       = igb_fix_features,
>       .ndo_set_features       = igb_set_features,
>       .ndo_fdb_add            = igb_ndo_fdb_add,
> @@ -2665,6 +2669,8 @@ static int igb_probe(struct pci_dev *pdev, const struct 
> pci_device_id *ent)
>       /* do hw tstamp init after resetting */
>       igb_ptp_init(adapter);
>  
> +     igb_tsn_init(adapter);
> +
>       dev_info(&pdev->dev, "Intel(R) Gigabit Ethernet Network Connection\n");
>       /* print bus type/speed/width info, not applicable to i354 */
>       if (hw->mac.type != e1000_i354) {
> @@ -5323,8 +5329,10 @@ static netdev_tx_t igb_xmit_frame(struct sk_buff *skb,
>       /* The minimum packet size with TCTL.PSP set is 17 so pad the skb
>        * in order to meet this minimum size requirement.
>        */
> -     if (skb_put_padto(skb, 17))
> +     if (skb_put_padto(skb, 17)) {
> +             pr_err("%s: skb_put_padto FAILED. skb->len < 17\n", __func__);
>               return NETDEV_TX_OK;
> +     }
>  
>       return igb_xmit_frame_ring(skb, igb_tx_queue_mapping(adapter, skb));
>  }
> diff --git a/drivers/net/ethernet/intel/igb/igb_tsn.c 
> b/drivers/net/ethernet/intel/igb/igb_tsn.c
> new file mode 100644
> index 0000000..641f4f2
> --- /dev/null
> +++ b/drivers/net/ethernet/intel/igb/igb_tsn.c
> @@ -0,0 +1,396 @@
> +/*
> + * Copyright(c) 2015-2016 Henrik Austad <haus...@cisco.com>
> + *                        Cisco Systems, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + */
> +
> +/* FIXME: This should probably be handled by some Makefile-magic */
> +
> +#if IS_ENABLED(CONFIG_IGB_TSN)
> +#include "igb.h"
> +#include <linux/module.h>
> +
> +/* NOTE: keep the defines not present in e1000_regs.h to avoid
> + * cluttering too many files. Once we are pretty stable, these will move
> + * into it's proper home. Until then, make merge a bit easier by
> + * avoiding it
> + */
> +
> +/* Qav regs */
> +#define E1000_IRPBS   0x02404 /* Rx Packet Buffer Size - RW */
> +#define E1000_ITPBS   0x03404 /* Tx buffer size assignment */
> +#define E1000_TQAVCTRL   0x03570 /* Tx Qav Control */
> +#define E1000_DTXMXPKTSZ 0x0355C /* DMA TX Maximum Packet Size */
> +
> +/* Qav defines. */
> +#define E1000_TQAVCH_ZERO_CREDIT       0x80000000
> +#define E1000_LINK_RATE                     0x7735
> +
> +/* queue mode, 0=strict, 1=SR mode */
> +#define E1000_TQAVCC_QUEUEMODE         0x80000000
> +/* Transmit mode, 0=legacy, 1=QAV */
> +#define E1000_TQAVCTRL_TXMODE          0x00000001
> +/* report DMA time of tx packets */
> +#define E1000_TQAVCTRL_1588_STAT_EN    0x00000004
> +/* data fetch arbitration */
> +#define E1000_TQAVCTRL_DATA_FETCH_ARB  0x00000010
> +/* data tx arbitration */
> +#define E1000_TQAVCTRL_DATA_TRAN_ARB   0x00000100
> +/* data launch time valid */
> +#define E1000_TQAVCTRL_DATA_TRAN_TIM   0x00000200
> +/* stall SP to guarantee SR */
> +#define E1000_TQAVCTRL_SP_WAIT_SR      0x00000400
> +
> +/* ... and associated shift value */
> +#define E1000_TQAVCTRL_FETCH_TM_SHIFT  (16)
> +
> +/* QAV Tx mode control registers where _n can be 0 or 1. */
> +#define E1000_TQAVCC(_idx)                   (0x03004 + 0x40 * (_idx))
> +
> +/* Tx Qav High Credit - See 7.2.7.6 for calculations
> + * intel 8.12.18
> + */
> +#define E1000_TQAVHC(_idx)                   (0x0300C + 0x40 * (_idx))
> +
> +/* Queues priority masks where _n and _p can be 0-3. */
> +
> +#define MAX_FRAME_SIZE 1522
> +#define MIN_FRAME_SIZE   64
> +
> +static int use_tsn = -1;
> +static int debug_tsn = -1;
> +module_param(use_tsn, int, 0);
> +module_param(debug_tsn, int, 0);
> +MODULE_PARM_DESC(use_tsn, "use_tsn (0=off, 1=enabled)");
> +MODULE_PARM_DESC(debug_tsn, "debug_tsn (0=off, 1=enabled)");
> +
> +/* For a full list of the registers dumped here, see sec 8.1.3 in the
> + * i210 controller datasheet.
> + */
> +static inline void _tsn_dump_regs(struct igb_adapter *adapter)
> +{
> +     u32 val = 0;
> +     struct device *dev;
> +     struct e1000_hw *hw = &adapter->hw;
> +
> +     /* do not dump regs if we're not debugging driver */
> +     if (debug_tsn != 1)
> +             return;
> +
> +     dev = &adapter->pdev->dev;
> +     dev_info(dev, "num_tx_queues=%d, num_rx_queues=%d\n",
> +              adapter->num_tx_queues, adapter->num_rx_queues);
> +
> +     /* 0x0008 - E1000_STATUS Device status register */
> +     val = rd32(E1000_STATUS);
> +     dev_info(&adapter->pdev->dev, "\n");
> +     dev_info(dev, "Status: FullDuplex=%s, LinkUp=%s, speed=%0x01x\n",
> +              val & 0x1 ? "FD" : "HD",
> +              val & 0x2 ? "LU" : "LD",
> +              val & 0xc0 >> 6);
> +
> +     /* E1000_VET vlan ether type */
> +     val = rd32(E1000_VET);
> +     dev_info(dev, "VLAN ether type: VET.VET=0x%04x, VET.VET_EXT=0x%04x\n",
> +              val & 0xffff, (val >> 16) & 0xffff);
> +
> +     /* E1000_RXPBS (RXPBSIZE) Rx Packet Buffer Size */
> +     val = rd32(E1000_RXPBS);
> +     dev_info(dev, "Rx Packet buffer: RXPBSIZE=%dkB, Bmc2ospbsize=%dkB, 
> cfg_ts_en=%s\n",
> +              val & 0x1f,
> +              (val >> 6) & 0x1f,
> +              (val & (1 << 31)) ? "cfg_ts_en" : "cfg_ts_dis");
> +
> +     /* Transmit stuff */
> +     /* E1000_TXPBS (TXPBSIZE) Tx Packet Buffer Size - RW */
> +     val = rd32(E1000_TXPBS);
> +     dev_info(dev, "Tx Packet buffer: Txpb0size=%dkB, Txpb1size=%dkB, 
> Txpb2size=%dkB, Txpb3size=%dkB, os2Bmcpbsize=%dkB\n",
> +              val & 0x3f, (val >> 6) & 0x3f, (val >> 12) & 0x3f,
> +              (val >> 18) & 0x3f, (val >> 24) & 0x3f);
> +
> +     /* E1000_TCTL (TCTL) Tx control - RW*/
> +     val = rd32(E1000_TCTL);
> +     dev_info(dev, "Tx control reg: TxEnable=%s, CT=0x%X\n",
> +              val & 2 ? "EN" : "DIS", (val >> 3) & 0x3F);
> +
> +     /* TQAVHC     : Transmit Qav High credits 0x300C + 0x40*n - RW */
> +     val = rd32(E1000_TQAVHC(0));
> +     dev_info(dev, "E1000_TQAVHC0: %0x08x\n", val);
> +     val = rd32(E1000_TQAVHC(1));
> +     dev_info(dev, "E1000_TQAVHC1: %0x08x\n", val);
> +
> +     /* TQAVCC[0-1]: Transmit Qav 0x3004 + 0x40*n  - RW */
> +     val = rd32(E1000_TQAVCC(0));
> +     dev_info(dev, "E1000_TQAVCC0: idleSlope=%02x, QueueMode=%s\n",
> +              val % 0xff,
> +              val > 31 ? "Stream reservation" : "Strict priority");
> +     val = rd32(E1000_TQAVCC(1));
> +     dev_info(dev, "E1000_TQAVCC1: idleSlope=%02x, QueueMode=%s\n",
> +              val % 0xff,
> +              val > 31 ? "Stream reservation" : "Strict priority");
> +
> +     /* TQAVCTRL   : Transmit Qav control - RW */
> +     val = rd32(E1000_TQAVCTRL);
> +     dev_info(dev, "E1000_TQAVCTRL: 
> TransmitMode=%s,1588_STAT_EN=%s,DataFetchARB=%s,DataTranARB=%s,DataTranTIM=%s,SP_WAIT_SR=%s,FetchTimDelta=%dns
>  (0x%04x)\n",
> +              (val & 0x0001) ? "Qav" : "Legacy",
> +              (val & 0x0004) ? "En" : "Dis",
> +              (val & 0x0010) ? "Most Empty" : "Round Robin",
> +              (val & 0x0100) ? "Credit Shaper" : "Strict priority",
> +              (val & 0x0200) ? "Valid" : "N/A",
> +              (val & 0x0400) ? "Wait" : "nowait",
> +              (val >> 16) * 32, (val >> 16));
> +}
> +
> +/* Place the NIC in Qav-mode.
> + *
> + * This will result in a _single_ queue for normal BE traffic, the rest
> + * will be grabbed by the Qav-machinery and kept for strict priority
> + * transmission.
> + *
> + * I210 Datasheet Sec 7.2.7.7 gives a lot of information.
> + */
> +void igb_tsn_init(struct igb_adapter *adapter)
> +{
> +     struct e1000_hw *hw = &adapter->hw;
> +     u32 val;
> +
> +     if (use_tsn != 1) {
> +             adapter->tsn_ready = 0;
> +             dev_info(&adapter->pdev->dev, "%s got use_tsn > 0 (%d)\n",
> +                      __func__, use_tsn);
> +             return;
> +     }
> +
> +     if (debug_tsn < 0 || debug_tsn > 1)
> +             debug_tsn = 0;
> +
> +     if (!adapter->pdev) {
> +             adapter->tsn_ready = 0;
> +             return;
> +     }
> +
> +     switch (adapter->pdev->device) {
> +     case 0x1533:   /* E1000_DEV_ID_I210_COPPER */
> +     case 0x1536:   /* E1000_DEV_ID_I210_FIBER */
> +     case 0x1537:   /* E1000_DEV_ID_I210_SERDES: */
> +     case 0x1538:   /* E1000_DEV_ID_I210_SGMII: */
> +     case 0x157b:   /* E1000_DEV_ID_I210_COPPER_FLASHLESS: */
> +     case 0x157c:   /* E1000_DEV_ID_I210_SERDES_FLASHLESS: */
> +             break;
> +     default:
> +             /* not a known IGB-TSN capable device */
> +             adapter->tsn_ready = 0;
> +             return;
> +     }
> +     _tsn_dump_regs(adapter);
> +
> +     /* Set Tx packet buffer size assignment, see 7.2.7.7 in i210
> +      * PB0: 8kB
> +      * PB1: 8kB
> +      * PB2: 4kB
> +      * PB3: 4kB
> +      * os2bmcsize: 2kB
> +      * sumTx: 26kB
> +      *
> +      * Rxpbsize: 0x20 (32kB)
> +      * bmc2ossize: 0x02
> +      * sumRx: 34kB
> +      *
> +      * See 8.3.1 && 8.3.2
> +      */
> +     val = (0x02 << 24 | 0x04 << 18 | 0x04 << 12 | 0x08 << 6 | 0x08);
> +     wr32(E1000_ITPBS, val);
> +     wr32(E1000_IRPBS, (0x02 << 6 | 0x20));
> +
> +     /* DMA Tx maximum packet size, the largest frame DMA should transport
> +      * do not allow frames larger than 1522 + preample. Reg expects
> +      * size in 64B increments. 802.1BA 6.3
> +      * Round up to 1536 to handle 64B increments
> +      *
> +      * Initial value: 0x98 (152 => 9728 bytes)
> +      */
> +     wr32(E1000_DTXMXPKTSZ, 1536 >> 6);
> +
> +     /* Place card in Qav-mode, use tx-queue 0,1 for Qav
> +      * (Credit-based shaper), 2,3 for standard priority (and
> +      * best-effort) traffic.
> +      *
> +      * i210 8.12.19 and 8.12.21
> +      *
> +      * - Fetch: most empty and time based (not round-robin)
> +      * - Transmit: Credit based shaper for SR queues
> +      * - Data launch time valid (in Qav mode)
> +      * - Wait for SR queues to ensure that launch time is always valid.
> +      * - Set ~10us wait-time-delta, 32ns granularity
> +      *
> +      * Do *not* enable Tx for shaper (E1000_TQAVCTRL_DATA_TRAN_ARB)
> +      * yet as we do not have data to Tx
> +      */
> +     val = E1000_TQAVCTRL_TXMODE           |
> +             E1000_TQAVCTRL_DATA_FETCH_ARB |
> +             E1000_TQAVCTRL_DATA_TRAN_TIM  |
> +             E1000_TQAVCTRL_SP_WAIT_SR     |
> +             320 << E1000_TQAVCTRL_FETCH_TM_SHIFT;
> +
> +     wr32(E1000_TQAVCTRL, val);
> +
> +     /* For now, only set CreditBased shaper for A and B, not set
> +      * idleSlope as we have not yet gotten any streams.
> +      * 8.12.19
> +      */
> +     wr32(E1000_TQAVCC(0), E1000_TQAVCC_QUEUEMODE);
> +     wr32(E1000_TQAVCC(1), E1000_TQAVCC_QUEUEMODE);
> +
> +     wr32(E1000_TQAVHC(0), E1000_TQAVCH_ZERO_CREDIT);
> +     wr32(E1000_TQAVHC(1), E1000_TQAVCH_ZERO_CREDIT);
> +
> +     /* reset Tx Descriptor tail and head for the queues */
> +     wr32(E1000_TDT(0), 0);
> +     wr32(E1000_TDT(1), 0);
> +     wr32(E1000_TDH(0), 0);
> +     wr32(E1000_TDH(1), 0);
> +
> +     _tsn_dump_regs(adapter);
> +     dev_info(&adapter->pdev->dev, "\n");
> +
> +     adapter->sra_idleslope_res = 0;
> +     adapter->srb_idleslope_res = 0;
> +     adapter->tsn_ready = 1;
> +
> +     dev_info(&adapter->pdev->dev, "%s: setup done\n", __func__);
> +}
> +
> +int igb_tsn_capable(struct net_device *netdev)
> +{
> +     struct igb_adapter *adapter;
> +
> +     if (!netdev)
> +             return -EINVAL;
> +     adapter = netdev_priv(netdev);
> +     if (use_tsn == 1)
> +             return adapter->tsn_ready == 1;
> +     return 0;
> +}
> +
> +/* igb_tsn_link_configure - configure NIC to handle a new stream
> + *
> + * @netdev: pointer to NIC device
> + * @class: the class for the stream used to find the correct queue.
> + * @framesize: size of each frame, *including* headers (not preamble)
> + * @vid: VLAN ID
> + *
> + * NOTE: the sr_class only instructs the driver which queue to use, not
> + * what priority the network expects for a given class. This is
> + * something userspace must find out and then let the tsn-driver set in
> + * the frame before xmit.
> + *
> + * FIXME: remove bw-req from a stream that goes away.
> + */
> +int igb_tsn_link_configure(struct net_device *netdev, enum sr_class class,
> +                        u16 framesize, u16 vid)
> +{
> +     /* FIXME: push into adapter-storage */
> +     static int class_a_size;
> +     static int class_b_size;
> +     int err;
> +     u32 idle_slope_a = 0;
> +     u32 idle_slope_b = 0;
> +     u32 new_is = 0;
> +     u32 hicred_a = 0;
> +     u32 hicred_b = 0;
> +     u32 tqavctrl;
> +
> +     struct igb_adapter *adapter;
> +     struct e1000_hw *hw;
> +
> +     if (!netdev)
> +             return -EINVAL;
> +     adapter  = netdev_priv(netdev);
> +     hw = &adapter->hw;
> +
> +     if (!igb_tsn_capable(netdev)) {
> +             pr_err("%s:  NIC not capable\n", __func__);
> +             return -EINVAL;
> +     }
> +
> +     if (framesize > MAX_FRAME_SIZE || framesize < MIN_FRAME_SIZE) {
> +             pr_err("%s: framesize (%u) must be [%d,%d]\n", __func__,
> +                    framesize, MIN_FRAME_SIZE, MAX_FRAME_SIZE);
> +             return -EINVAL;
> +     }
> +
> +     /* TODO: is this the correct place/way? Is it required? */
> +     rtnl_lock();
> +     pr_info("%s: adding VLAN %u to HW filter on device %s\n",
> +             __func__, vid, netdev->name);
> +     err = vlan_vid_add(netdev, htons(ETH_P_8021Q), vid);
> +     if (err != 0)
> +             pr_err("%s: error adding vlan %u, res=%d\n",
> +                    __func__, vid, err);
> +     rtnl_unlock();
> +
> +     /* Grab current values of idle_slope */
> +     idle_slope_a = rd32(E1000_TQAVHC(0)) & ~E1000_TQAVCH_ZERO_CREDIT;
> +     idle_slope_b = rd32(E1000_TQAVHC(1)) & ~E1000_TQAVCH_ZERO_CREDIT;
> +
> +     /* Calculate new idle slope and add to appropriate idle_slope
> +      * idle_slope = BW * linkrate * 2 (0r 0.2 for 100Mbit)
> +      * BW: % of total bandwidth
> +      */
> +     new_is = framesize * E1000_LINK_RATE * 16 / 1000000;
> +
> +     switch (class) {
> +     case SR_CLASS_A:
> +             new_is *= 2; /* A is 8kHz, B is 4kHz */
> +             idle_slope_a += new_is;
> +             class_a_size  = framesize;
> +             break;
> +     case SR_CLASS_B:
> +             idle_slope_b += new_is;
> +             class_b_size  = framesize;
> +             break;
> +     default:
> +             pr_err("%s: unhandled SR-class (%d)\n", __func__, class);
> +             return -EINVAL;
> +     }
> +
> +     /* HiCred: cred obtained while waiting for current frame &&
> +      * higher-class frames to finish xmit.
> +      *
> +      * Covered in detail in 7.2.7.6 in i210 datasheet
> +      * For class A: only worst-case framesize that just started;
> +      *              i.e. 1522 * idleSlope / linkrate;
> +      * For class B: (worst-case framesize + burstSize(A))*idleSlope
> +      *
> +      * See 802.1Q Annex L, eq L.10 for hicred_a and L.41 for
> +      * hicred_b
> +      */
> +     if (class == SR_CLASS_A) {
> +             hicred_a = E1000_TQAVCH_ZERO_CREDIT + idle_slope_a * 
> MAX_FRAME_SIZE / E1000_LINK_RATE;
> +             wr32(E1000_TQAVCC(0), E1000_TQAVCC_QUEUEMODE | idle_slope_a);
> +             wr32(E1000_TQAVHC(0), hicred_a);
> +     } else {
> +             hicred_b = E1000_TQAVCH_ZERO_CREDIT | idle_slope_b * 
> (MAX_FRAME_SIZE + class_a_size) / (E1000_LINK_RATE - idle_slope_a);
> +             wr32(E1000_TQAVCC(1), E1000_TQAVCC_QUEUEMODE | idle_slope_b);
> +             wr32(E1000_TQAVHC(1), hicred_b);
> +     }
> +
> +     /* Enable Tx for shaper now that we have data */
> +     tqavctrl = rd32(E1000_TQAVCTRL);
> +     if (!(tqavctrl & E1000_TQAVCTRL_DATA_TRAN_ARB)) {
> +             tqavctrl |= E1000_TQAVCTRL_DATA_TRAN_ARB;
> +             wr32(E1000_TQAVCTRL, tqavctrl);
> +     }
> +     _tsn_dump_regs(netdev_priv(netdev));
> +     return 0;
> +}
> +
> +#endif       /* #if IS_ENABLED(CONFIG_IGB_TSN) */
> -- 
> 2.7.4
> 

-- 
Henrik Austad
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