[TSN RFC v2 4/9] Adding TSN-driver to Intel I210 controller

From: henrik
Date: Fri Dec 16 2016 - 13:00:41 EST

From: Henrik Austad <henrik@xxxxxxxxx>

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 if it is loaded with debug_tsn=1.

Regardless of number of online CPUs, it will enable *all* for Tx-queues as
2 is required for Qav traffic. This has not been tested extensively, so
there may be some instabilities in this.

Improved SR(A|B) accounting:
Use the idleslope-bins to keep track of how much time is reserved for
each class. This can then be used to strip the vlan-tag on the NIC when
the last stream goes (and also allow for reconfiguration of PCP when the
NIC is not sending TSN traffic).

Note: currently this driver is *not* stable, it is still a work in
progress, some points to keep tabs on:
- Set hicred to unlim (for testing this is ok and we avoid some nasty
calculations)
- once we configure it for TSN, enable credit shaping, do not wait for
first link to be configured (nobody else should use these queues after
being configured).
- enable all Tx-/Rx-queues in TSN-mode regardless of num_online_cpus()
- Add 802.1Qav Prio-bit in adapter->flags
Cc: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Cc: Jesse Brandeburg <jesse.brandeburg@xxxxxxxxx>
Cc: intel-wired-lan@xxxxxxxxxxxxxxxx
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Signed-off-by: Henrik Austad <haustad@xxxxxxxxx>
---
drivers/net/ethernet/intel/Kconfig | 18 ++
drivers/net/ethernet/intel/igb/Makefile | 2 +-
drivers/net/ethernet/intel/igb/igb.h | 26 ++
drivers/net/ethernet/intel/igb/igb_main.c | 39 ++-
drivers/net/ethernet/intel/igb/igb_tsn.c | 468 ++++++++++++++++++++++++++++++
5 files changed, 550 insertions(+), 3 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 c0e1743..d4382b4 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 d11093d..474a5b4 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -394,6 +394,7 @@ struct igb_nfc_filter {
};

/* board specific private data structure */
+
struct igb_adapter {
unsigned long active_vlans[BITS_TO_LONGS(VLAN_N_VID)];

@@ -519,6 +520,17 @@ struct igb_adapter {
/* lock for RX network flow classification filter */
spinlock_t nfc_lock;
bool etype_bitmap[MAX_ETYPE_FILTER];
+
+#if IS_ENABLED(CONFIG_IGB_TSN)
+ /* Reserved BW for class A and B */
+ s32 sra_idleslope_res;
+ s32 srb_idleslope_res;
+ u8 pcp_hi;
+ u8 pcp_lo;
+ u8 tsn_ready:1;
+ u8 tsn_vlan_added:1;
+ u8 res:6;
+#endif /* IGB_TSN */
};

/* flags controlling PTP/1588 function */
@@ -540,6 +552,7 @@ struct igb_adapter {
#define IGB_FLAG_HAS_MSIX BIT(13)
#define IGB_FLAG_EEE BIT(14)
#define IGB_FLAG_VLAN_PROMISC BIT(15)
+#define IGB_FLAG_QAV_PRIO BIT(16)

/* Media Auto Sense */
#define IGB_MAS_ENABLE_0 0X0001
@@ -603,6 +616,19 @@ 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, u8 add_link, u8 pcp_hi, u8 pcp_lo);
+u16 igb_tsn_select_queue(struct net_device *netdev, struct sk_buff *skb,
+ void *accel_priv, select_queue_fallback_t fallback);
+#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 9affd7c..0283864 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -256,6 +256,12 @@ static int debug = -1;
module_param(debug, int, 0);
MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");

+static int use_tsn = 0;
+#if IS_ENABLED(CONFIG_IGB_TSN)
+MODULE_PARM_DESC(use_tsn, "use_tsn (0=off, 1=enabled)");
+module_param(use_tsn, int, 0);
+#endif
+
struct igb_reg_info {
u32 ofs;
char *name;
@@ -675,6 +681,9 @@ static int __init igb_init_module(void)
{
int ret;

+ if (use_tsn != 1)
+ use_tsn = 0;
+
pr_info("%s - version %s\n",
igb_driver_string, igb_driver_version);
pr_info("%s\n", igb_copyright);
@@ -2161,6 +2170,11 @@ 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,
+ .ndo_select_queue = igb_tsn_select_queue,
+#endif /* CONFIG_IGB_TSN */
.ndo_fix_features = igb_fix_features,
.ndo_set_features = igb_set_features,
.ndo_fdb_add = igb_ndo_fdb_add,
@@ -2682,6 +2696,9 @@ static int igb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
/* do hw tstamp init after resetting */
igb_ptp_init(adapter);

+ if (use_tsn)
+ 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) {
@@ -3009,6 +3026,21 @@ static void igb_init_queue_configuration(struct igb_adapter *adapter)

adapter->rss_queues = min_t(u32, max_rss_queues, num_online_cpus());

+#if IS_ENABLED(CONFIG_IGB_TSN)
+ /* For I210: If we are using TSN, we don't want to use num_online_cpus(),
+ * as we need 4 Tx-queues.
+ *
+ * Rx is another matter, but in time we probably want to assign
+ * Rx-0 to class A, Rx-1 to B, -2 to PTP/MSRP control etc and -3
+ * to all other traffic.
+ */
+ if (use_tsn && hw->mac.type == e1000_i210) {
+ adapter->rss_queues = max_rss_queues;
+ pr_info("igb_init_queue_configuration: rss_queues=%u\n",
+ adapter->rss_queues);
+ }
+#endif /* IGB_TSN */
+
igb_set_flag_queue_pairs(adapter, max_rss_queues);
}

@@ -3397,7 +3429,8 @@ void igb_configure_tx_ring(struct igb_adapter *adapter,
txdctl |= IGB_TX_PTHRESH;
txdctl |= IGB_TX_HTHRESH << 8;
txdctl |= IGB_TX_WTHRESH << 16;
-
+ if (ring->flags & IGB_FLAG_QAV_PRIO)
+ txdctl |= E1000_TXDCTL_PRIORITY;
txdctl |= E1000_TXDCTL_QUEUE_ENABLE;
wr32(E1000_TXDCTL(reg_idx), txdctl);
}
@@ -5345,8 +5378,10 @@ 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..dd5d9ed
--- /dev/null
+++ b/drivers/net/ethernet/intel/igb/igb_tsn.c
@@ -0,0 +1,468 @@
+/*
+ * Copyright(c) 2015-2016 Henrik Austad <haustad@xxxxxxxxx>
+ * 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_UNLIM_CREDIT 0xFFFFFFFF
+#define E1000_TQAVCH_ZERO_CREDIT 0x80000000
+#define E1000_LINK_RATE 0x7735
+
+/* 0:15 idleSlope
+ * 16:29 reserved
+ * 30 reserved
+ * 31 queue mode, 0=strict, 1=SR mode
+ */
+#define E1000_TQAVCC_QUEUEMODE 0x80000000
+#define E1000_TQAVCC_IDLE_SLOPE_MASK 0x0000ffff
+
+/* 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 debug_tsn = -1;
+module_param(debug_tsn, int, 0);
+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 (netdev=%d, real=%d), num_rx_queues=%d (netdev=%d, real=%d)\n",
+ adapter->num_tx_queues, adapter->netdev->num_tx_queues, adapter->netdev->real_num_tx_queues,
+ adapter->num_rx_queues, adapter->netdev->num_rx_queues, adapter->netdev->real_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=0x%x\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=0x%02x, QueueMode=%s\n",
+ val % 0xff,
+ val > 31 ? "Stream reservation" : "Strict priority");
+ val = rd32(E1000_TQAVCC(1));
+ dev_info(dev, "E1000_TQAVCC1: idleSlope=0x%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 txpbsize;
+ u32 tqavctrl;
+
+ 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);
+
+ if (adapter->num_tx_queues != 4) {
+ pr_err("IGB_TSN: ERROR, not enough TX-queues available, need 4, got %d\n",
+ adapter->num_tx_queues);
+ return;
+ }
+
+ /* setup the Transmit Descriptor Control (see 8.12.15)
+ *
+ * Set a flag for priority-queue and call igb_configure_tx_ring() in igb_main.c
+ */
+ adapter->tx_ring[0]->flags |= IGB_FLAG_QAV_PRIO;
+ adapter->tx_ring[1]->flags |= IGB_FLAG_QAV_PRIO;
+ igb_configure_tx_ring(adapter, adapter->tx_ring[0]);
+ igb_configure_tx_ring(adapter, adapter->tx_ring[1]);
+
+ /* Set Tx packet buffer size assignment, see 7.2.7.7 in i210
+ * PB0: 8kB (default 20 kB)
+ * PB1: 8kB (default 0 pkB)
+ * PB2: 4kB (default 0 kB)
+ * PB3: 4kB (default 0 kB)
+ *
+ * os2bmcsize: 2kB (default 4 kB)
+
+ * UPDATE: set os2bmcpbsize to 0, then we can drop setting RX
+ * packet buffer
+ *
+ * sumTx: 24kB (26kB)
+ *
+ * Rxpbsize: 0x20 (32kB default 34kB
+ * bmc2ossize: 0x02 (default 0x02)
+ * sumRx: 34kB
+ *
+ * Total 60kB (see 4.5.9)
+ *
+ * See 8.3.1 && 8.3.2 for fields
+ */
+ txpbsize = (0 << 30 | 0x00 << 24 | 0x04 << 18 | 0x04 << 12 | 0x08 << 6 | 0x08);
+ wr32(E1000_ITPBS, txpbsize);
+
+ /* Since we dropped os2bmcsize, we do not have to change the
+ * default here after all */
+ /* 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);
+
+ /* For now, only set CreditBased shaper for A and B, do not set
+ * idleSlope as we have not yet gotten any streams. Set HiCredit
+ * to be unlimitied (this violates the 75% 'default' boundary
+ *
+ * 8.12.19
+ */
+ wr32(E1000_TQAVCC(0), E1000_TQAVCC_QUEUEMODE);
+ wr32(E1000_TQAVCC(1), E1000_TQAVCC_QUEUEMODE);
+ wr32(E1000_TQAVHC(0), E1000_TQAVCH_UNLIM_CREDIT);
+ wr32(E1000_TQAVHC(1), E1000_TQAVCH_UNLIM_CREDIT);
+
+ /* 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) is off (we do not want
+ * time-triggered launch)
+ * - Wait for SR queues to ensure that launch time is always valid.
+ * - Set ~10us wait-time-delta, 32ns granularity
+ */
+ tqavctrl = E1000_TQAVCTRL_TXMODE | \
+ E1000_TQAVCTRL_DATA_FETCH_ARB | \
+ E1000_TQAVCTRL_DATA_TRAN_ARB | \
+ E1000_TQAVCTRL_SP_WAIT_SR | \
+ 320 << E1000_TQAVCTRL_FETCH_TM_SHIFT;
+ wr32(E1000_TQAVCTRL, tqavctrl);
+
+ /* 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;
+ adapter->tsn_vlan_added = 0;
+
+ 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);
+ return adapter->tsn_ready == 1;
+}
+
+/* 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, u8 add_link, u8 pcp_hi, u8 pcp_lo)
+{
+ s32 idle_slope = 0;
+ s32 frames_pr_ms;
+ s32 new_is = 0;
+ u32 tqavcc;
+ int err;
+
+ 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;
+ }
+
+ /*
+ * FIXME: This should disable EEE and (possibly) enable it when
+ * removing the last link.
+ *
+ * FIXME: This is only done the first time and have the
+ * potentional of never being reset as we do not count the
+ * number of configured links.
+ *
+ * This means that if all links goes away and the network
+ * reconfigures the domain to use different PCPs, we will drop
+ * that.
+ *
+ * FIXME: this update is racy
+ */
+ if (add_link && !adapter->tsn_vlan_added) {
+ 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();
+ adapter->pcp_hi = pcp_hi & 0x7;
+ adapter->pcp_lo = pcp_lo & 0x7;
+ adapter->tsn_vlan_added = 1;
+ }
+
+ /* we currently drop hicred (we have set this to unlim to ease calculation) */
+ /* Grab current values of idle_slope
+ */
+ switch(class) {
+ case SR_CLASS_A:
+ tqavcc = rd32(E1000_TQAVCC(0));
+ frames_pr_ms = 8;
+ break;
+ case SR_CLASS_B:
+ tqavcc = rd32(E1000_TQAVCC(1));
+ frames_pr_ms = 4;
+ break;
+ default:
+ pr_err("igb_tsn: unknown traffic-class, aborting configuration\n");
+ return -EINVAL;
+ }
+ idle_slope = tqavcc & E1000_TQAVCC_IDLE_SLOPE_MASK;
+
+ /* Calculate new idle slope and add to appropriate idle_slope
+ * idle_slope = BW * linkrate * 2 (0r 0.2 for 100Mbit)
+ * BW: % of total bandwidth
+ *
+ * E1000_LINK_RATE: 0x7735
+ * LINE_SPEED: 1e9
+ */
+ new_is = (s32)framesize * frames_pr_ms * E1000_LINK_RATE * 2 * 8;
+ if (new_is % 1000000)
+ new_is += 1000000;
+ new_is /= 1000000;
+
+ pr_info("Framesize=%u,E1000_LINK_RATE=%u,class=%s,new_is=%s%d,current_is=%u\n",
+ framesize,E1000_LINK_RATE,
+ (class == SR_CLASS_A ? "A" : "B"),
+ (add_link ? "+" : "-"),
+ new_is, idle_slope);
+ if (!add_link)
+ new_is *= -1;
+ idle_slope += new_is;
+
+ tqavcc &= ~E1000_TQAVCC_IDLE_SLOPE_MASK;
+ tqavcc |= idle_slope & E1000_TQAVCC_IDLE_SLOPE_MASK;
+ if (class == SR_CLASS_A) {
+ wr32(E1000_TQAVCC(0), tqavcc);
+ adapter->sra_idleslope_res += (s16)new_is;
+ } else {
+ wr32(E1000_TQAVCC(1), tqavcc);
+ adapter->srb_idleslope_res += (s16)new_is;
+ }
+
+ if (adapter->sra_idleslope_res == 0 && adapter->srb_idleslope_res == 0) {
+ /* removing last stream going through NIC, drop vlan and
+ * make it possible to change PCP */
+ rtnl_lock();
+ vlan_vid_del(netdev, htons(ETH_P_8021Q), vid);
+ adapter->tsn_vlan_added = 0;
+ rtnl_unlock();
+ }
+ _tsn_dump_regs(netdev_priv(netdev));
+ pr_info("igb_tsn_link_configure: done setting up TSN, idle_slope: %u,for frame: %u\n",
+ idle_slope, new_is);
+
+ return 0;
+}
+
+u16 igb_tsn_select_queue(struct net_device *netdev, struct sk_buff *skb,
+ void *accel_priv, select_queue_fallback_t fallback)
+{
+ struct igb_adapter *adapter = netdev_priv(netdev);
+ if (!adapter)
+ return fallback(netdev, skb);
+
+ /* we only return the special queue(s) for tsn-traffic, and gPTP
+ * otherwise we pick the last queue
+ */
+ if (igb_tsn_capable(netdev)) {
+ switch (vlan_get_protocol(skb)) {
+ case htons(ETH_P_TSN):
+ if (skb->priority == adapter->pcp_hi)
+ return 0;
+ if (skb->priority == adapter->pcp_lo)
+ return 1;
+ pr_err("igb_tsn select queu: unknown PCP:%u, expected either hi=%u or lo=%u\n",
+ skb->priority, adapter->pcp_hi, adapter->pcp_lo);
+ break;
+ case htons(ETH_P_1588):
+ /* PTP should be sent via tx-queue 2 */
+ return 2;
+ default:
+ /* rest via 3 */
+ return 3;
+ }
+ }
+ return fallback(netdev, skb);
+}
+#endif /* #if IS_ENABLED(CONFIG_IGB_TSN) */
--
2.7.4