Re: [PATCH net-next v5 3/3] tsnep: Add TSN endpoint Ethernet MAC driver

The TSN endpoint Ethernet MAC is a FPGA based network device for
real-time communication.

It is integrated as Ethernet controller with ethtool and PTP support.
For real-time communcation TC_SETUP_QDISC_TAPRIO is supported.

Signed-off-by: Gerhard Engleder <redacted>
---
 drivers/net/ethernet/Kconfig                  |    1 +
 drivers/net/ethernet/Makefile                 |    1 +
 drivers/net/ethernet/engleder/Kconfig         |   29 +
 drivers/net/ethernet/engleder/Makefile        |    9 +
 drivers/net/ethernet/engleder/tsnep.h         |  171 +++
 drivers/net/ethernet/engleder/tsnep_ethtool.c |  288 ++++
 drivers/net/ethernet/engleder/tsnep_hw.h      |  230 +++
 drivers/net/ethernet/engleder/tsnep_main.c    | 1255 +++++++++++++++++
 drivers/net/ethernet/engleder/tsnep_ptp.c     |  221 +++
 drivers/net/ethernet/engleder/tsnep_tc.c      |  443 ++++++
 drivers/net/ethernet/engleder/tsnep_test.c    |  811 +++++++++++
 11 files changed, 3459 insertions(+)
 create mode 100644 drivers/net/ethernet/engleder/Kconfig
 create mode 100644 drivers/net/ethernet/engleder/Makefile
 create mode 100644 drivers/net/ethernet/engleder/tsnep.h
 create mode 100644 drivers/net/ethernet/engleder/tsnep_ethtool.c
 create mode 100644 drivers/net/ethernet/engleder/tsnep_hw.h
 create mode 100644 drivers/net/ethernet/engleder/tsnep_main.c
 create mode 100644 drivers/net/ethernet/engleder/tsnep_ptp.c
 create mode 100644 drivers/net/ethernet/engleder/tsnep_tc.c
 create mode 100644 drivers/net/ethernet/engleder/tsnep_test.c

diff --git a/drivers/net/ethernet/Kconfig b/drivers/net/ethernet/Kconfig
index 4601b38f532a..027cbacca1c9 100644
--- a/drivers/net/ethernet/Kconfig
+++ b/drivers/net/ethernet/Kconfig

@@ -73,6 +73,7 @@ config DNET
 source "drivers/net/ethernet/dec/Kconfig"
 source "drivers/net/ethernet/dlink/Kconfig"
 source "drivers/net/ethernet/emulex/Kconfig"
+source "drivers/net/ethernet/engleder/Kconfig"
 source "drivers/net/ethernet/ezchip/Kconfig"
 source "drivers/net/ethernet/faraday/Kconfig"
 source "drivers/net/ethernet/freescale/Kconfig"

diff --git a/drivers/net/ethernet/Makefile b/drivers/net/ethernet/Makefile
index fdd8c6c17451..33d30b619e00 100644
--- a/drivers/net/ethernet/Makefile
+++ b/drivers/net/ethernet/Makefile

@@ -36,6 +36,7 @@ obj-$(CONFIG_DNET) += dnet.o
 obj-$(CONFIG_NET_VENDOR_DEC) += dec/
 obj-$(CONFIG_NET_VENDOR_DLINK) += dlink/
 obj-$(CONFIG_NET_VENDOR_EMULEX) += emulex/
+obj-$(CONFIG_NET_VENDOR_ENGLEDER) += engleder/
 obj-$(CONFIG_NET_VENDOR_EZCHIP) += ezchip/
 obj-$(CONFIG_NET_VENDOR_FARADAY) += faraday/
 obj-$(CONFIG_NET_VENDOR_FREESCALE) += freescale/

diff --git a/drivers/net/ethernet/engleder/Kconfig b/drivers/net/ethernet/engleder/Kconfig
new file mode 100644
index 000000000000..26c2a8e0acc0
--- /dev/null
+++ b/drivers/net/ethernet/engleder/Kconfig

@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Engleder network device configuration
+#
+
+config NET_VENDOR_ENGLEDER
+	bool "Engleder devices"
+	default y
+	help
+	  If you have a network (Ethernet) card belonging to this class, say Y.
+
+	  Note that the answer to this question doesn't directly affect the
+	  kernel: saying N will just cause the configurator to skip all
+	  the questions about Engleder devices. If you say Y, you will be asked
+	  for your specific card in the following questions.
+
+if NET_VENDOR_ENGLEDER
+
+config TSNEP
+	tristate "TSN endpoint support"
+	depends on PTP_1588_CLOCK_OPTIONAL
+	select PHYLIB
+	help
+	  Support for the Engleder TSN endpoint Ethernet MAC IP Core.
+
+	  To compile this driver as a module, choose M here. The module will be
+	  called tsnep.
+
+endif # NET_VENDOR_ENGLEDER

diff --git a/drivers/net/ethernet/engleder/Makefile b/drivers/net/ethernet/engleder/Makefile
new file mode 100644
index 000000000000..fbaecbfb0944
--- /dev/null
+++ b/drivers/net/ethernet/engleder/Makefile

@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Engleder Ethernet drivers
+#
+
+obj-$(CONFIG_TSNEP) += tsnep.o
+
+tsnep-objs := tsnep_main.o tsnep_ethtool.o tsnep_ptp.o tsnep_tc.o \
+	      tsnep_test.o

diff --git a/drivers/net/ethernet/engleder/tsnep.h b/drivers/net/ethernet/engleder/tsnep.h
new file mode 100644
index 000000000000..edd6fa7dafd7
--- /dev/null
+++ b/drivers/net/ethernet/engleder/tsnep.h

@@ -0,0 +1,171 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2021 Gerhard Engleder <gerhard@engleder-embedded.com> */
+
+#ifndef _TSNEP_H
+#define _TSNEP_H
+
+#include "tsnep_hw.h"
+
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/etherdevice.h>
+#include <linux/phy.h>
+#include <linux/ethtool.h>
+#include <linux/net_tstamp.h>
+#include <linux/ptp_clock_kernel.h>
+#include <linux/miscdevice.h>
+
+#define TSNEP "tsnep"
+
+#define TSNEP_RING_SIZE 256
+#define TSNEP_RING_ENTRIES_PER_PAGE (PAGE_SIZE / TSNEP_DESC_SIZE)
+#define TSNEP_RING_PAGE_COUNT (TSNEP_RING_SIZE / TSNEP_RING_ENTRIES_PER_PAGE)
+
+#define TSNEP_QUEUES 1
+
+struct tsnep_gcl {
+	void __iomem *addr;
+
+	u64 base_time;
+	u64 cycle_time;
+	u64 cycle_time_extension;
+
+	struct tsnep_gcl_operation operation[TSNEP_GCL_COUNT];
+	int count;
+
+	u64 change_limit;
+
+	u64 start_time;
+	bool change;
+};
+
+struct tsnep_tx_entry {
+	struct tsnep_tx_desc *desc;
+	struct tsnep_tx_desc_wb *desc_wb;
+	dma_addr_t desc_dma;
+	bool owner_user_flag;
+
+	u32 properties;
+
+	struct sk_buff *skb;
+	DEFINE_DMA_UNMAP_ADDR(dma);
+	DEFINE_DMA_UNMAP_LEN(len);
+};
+
+struct tsnep_tx {
+	struct tsnep_adapter *adapter;
+	void __iomem *addr;
+
+	void *page[TSNEP_RING_PAGE_COUNT];
+	dma_addr_t page_dma[TSNEP_RING_PAGE_COUNT];
+
+	/* TX ring lock */
+	spinlock_t lock;
+	struct tsnep_tx_entry entry[TSNEP_RING_SIZE];
+	int write;
+	int read;
+	u32 owner_counter;
+	int increment_owner_counter;
+
+	u32 packets;
+	u32 bytes;
+	u32 dropped;
+};
+
+struct tsnep_rx_entry {
+	struct tsnep_rx_desc *desc;
+	struct tsnep_rx_desc_wb *desc_wb;
+	dma_addr_t desc_dma;
+
+	u32 properties;
+
+	struct sk_buff *skb;
+	DEFINE_DMA_UNMAP_ADDR(dma);
+	DEFINE_DMA_UNMAP_LEN(len);
+};
+
+struct tsnep_rx {
+	struct tsnep_adapter *adapter;
+	void __iomem *addr;
+
+	void *page[TSNEP_RING_PAGE_COUNT];
+	dma_addr_t page_dma[TSNEP_RING_PAGE_COUNT];
+
+	struct tsnep_rx_entry entry[TSNEP_RING_SIZE];
+	int read;
+	u32 owner_counter;
+	int increment_owner_counter;
+
+	u32 packets;
+	u32 bytes;
+	u32 dropped;
+	u32 multicast;
+};
+
+struct tsnep_queue {
+	struct tsnep_adapter *adapter;
+
+	struct tsnep_tx *tx;
+	struct tsnep_rx *rx;
+
+	struct napi_struct napi;
+
+	u32 irq_mask;
+};
+
+struct tsnep_adapter {
+	struct net_device *netdev;
+	u8 mac_address[ETH_ALEN];
+	struct mii_bus *mdiobus;
+	bool suppress_preamble;
+	phy_interface_t phy_mode;
+	struct phy_device *phydev;
+	int msg_enable;
+
+	struct platform_device *pdev;
+	struct device *dmadev;
+	void __iomem *addr;
+	unsigned long size;
+	int irq;
+
+	bool gate_control;
+	/* gate control lock */
+	struct mutex gate_control_lock;
+	bool gate_control_active;
+	struct tsnep_gcl gcl[2];
+	int next_gcl;
+
+	struct hwtstamp_config hwtstamp_config;
+	struct ptp_clock *ptp_clock;
+	struct ptp_clock_info ptp_clock_info;
+	/* ptp clock lock */
+	spinlock_t ptp_lock;
+
+	int num_tx_queues;
+	struct tsnep_tx tx[TSNEP_MAX_QUEUES];
+	int num_rx_queues;
+	struct tsnep_rx rx[TSNEP_MAX_QUEUES];
+
+	int num_queues;
+	struct tsnep_queue queue[TSNEP_MAX_QUEUES];
+};
+
+extern const struct ethtool_ops tsnep_ethtool_ops;
+
+int tsnep_ptp_init(struct tsnep_adapter *adapter);
+void tsnep_ptp_cleanup(struct tsnep_adapter *adapter);
+int tsnep_ptp_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd);
+
+int tsnep_tc_init(struct tsnep_adapter *adapter);
+void tsnep_tc_cleanup(struct tsnep_adapter *adapter);
+int tsnep_tc_setup(struct net_device *netdev, enum tc_setup_type type,
+		   void *type_data);
+
+int tsnep_ethtool_get_test_count(void);
+void tsnep_ethtool_get_test_strings(u8 *data);
+void tsnep_ethtool_self_test(struct net_device *netdev,
+			     struct ethtool_test *eth_test, u64 *data);
+
+void tsnep_get_system_time(struct tsnep_adapter *adapter, u64 *time);
+
+#endif /* _TSNEP_H */

diff --git a/drivers/net/ethernet/engleder/tsnep_ethtool.c b/drivers/net/ethernet/engleder/tsnep_ethtool.c
new file mode 100644
index 000000000000..f9abcaab1c7c
--- /dev/null
+++ b/drivers/net/ethernet/engleder/tsnep_ethtool.c

@@ -0,0 +1,288 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2021 Gerhard Engleder <gerhard@engleder-embedded.com> */
+
+#include "tsnep.h"
+
+static const char tsnep_stats_strings[][ETH_GSTRING_LEN] = {
+	"rx_packets",
+	"rx_bytes",
+	"rx_dropped",
+	"rx_multicast",
+	"rx_phy_errors",
+	"rx_forwarded_phy_errors",
+	"rx_invalid_frame_errors",
+	"tx_packets",
+	"tx_bytes",
+	"tx_dropped",
+};
+
+struct tsnep_stats {
+	u64 rx_packets;
+	u64 rx_bytes;
+	u64 rx_dropped;
+	u64 rx_multicast;
+	u64 rx_phy_errors;
+	u64 rx_forwarded_phy_errors;
+	u64 rx_invalid_frame_errors;
+	u64 tx_packets;
+	u64 tx_bytes;
+	u64 tx_dropped;
+};
+
+#define TSNEP_STATS_COUNT (sizeof(struct tsnep_stats) / sizeof(u64))
+
+static const char tsnep_rx_queue_stats_strings[][ETH_GSTRING_LEN] = {
+	"rx_%d_packets",
+	"rx_%d_bytes",
+	"rx_%d_dropped",
+	"rx_%d_multicast",
+	"rx_%d_no_descriptor_errors",
+	"rx_%d_buffer_too_small_errors",
+	"rx_%d_fifo_overflow_errors",
+	"rx_%d_invalid_frame_errors",
+};
+
+struct tsnep_rx_queue_stats {
+	u64 rx_packets;
+	u64 rx_bytes;
+	u64 rx_dropped;
+	u64 rx_multicast;
+	u64 rx_no_descriptor_errors;
+	u64 rx_buffer_too_small_errors;
+	u64 rx_fifo_overflow_errors;
+	u64 rx_invalid_frame_errors;
+};
+
+#define TSNEP_RX_QUEUE_STATS_COUNT (sizeof(struct tsnep_rx_queue_stats) / \
+				    sizeof(u64))
+
+static const char tsnep_tx_queue_stats_strings[][ETH_GSTRING_LEN] = {
+	"tx_%d_packets",
+	"tx_%d_bytes",
+	"tx_%d_dropped",
+};
+
+struct tsnep_tx_queue_stats {
+	u64 tx_packets;
+	u64 tx_bytes;
+	u64 tx_dropped;
+};
+
+#define TSNEP_TX_QUEUE_STATS_COUNT (sizeof(struct tsnep_tx_queue_stats) / \
+				    sizeof(u64))
+
+static void tsnep_ethtool_get_drvinfo(struct net_device *netdev,
+				      struct ethtool_drvinfo *drvinfo)
+{
+	struct tsnep_adapter *adapter = netdev_priv(netdev);
+
+	strscpy(drvinfo->driver, TSNEP, sizeof(drvinfo->driver));
+	strscpy(drvinfo->bus_info, dev_name(&adapter->pdev->dev),
+		sizeof(drvinfo->bus_info));
+}
+
+static int tsnep_ethtool_get_regs_len(struct net_device *netdev)
+{
+	struct tsnep_adapter *adapter = netdev_priv(netdev);
+	int len;
+	int num_queues;
+
+	len = TSNEP_MAC_SIZE;
+	num_queues = max(adapter->num_tx_queues, adapter->num_rx_queues);
+	len += TSNEP_QUEUE_SIZE * (num_queues - 1);
+
+	return len;
+}
+
+static void tsnep_ethtool_get_regs(struct net_device *netdev,
+				   struct ethtool_regs *regs,
+				   void *p)
+{
+	struct tsnep_adapter *adapter = netdev_priv(netdev);
+
+	regs->version = 1;
+
+	memcpy_fromio(p, adapter->addr, regs->len);
+}
+
+static u32 tsnep_ethtool_get_msglevel(struct net_device *netdev)
+{
+	struct tsnep_adapter *adapter = netdev_priv(netdev);
+
+	return adapter->msg_enable;
+}
+
+static void tsnep_ethtool_set_msglevel(struct net_device *netdev, u32 data)
+{
+	struct tsnep_adapter *adapter = netdev_priv(netdev);
+
+	adapter->msg_enable = data;
+}
+
+static void tsnep_ethtool_get_strings(struct net_device *netdev, u32 stringset,
+				      u8 *data)
+{
+	struct tsnep_adapter *adapter = netdev_priv(netdev);
+	int rx_count = adapter->num_rx_queues;
+	int tx_count = adapter->num_tx_queues;
+	int i, j;
+
+	switch (stringset) {
+	case ETH_SS_STATS:
+		memcpy(data, tsnep_stats_strings, sizeof(tsnep_stats_strings));
+		data += sizeof(tsnep_stats_strings);
+
+		for (i = 0; i < rx_count; i++) {
+			for (j = 0; j < TSNEP_RX_QUEUE_STATS_COUNT; j++) {
+				snprintf(data, ETH_GSTRING_LEN,
+					 tsnep_rx_queue_stats_strings[j], i);
+				data += ETH_GSTRING_LEN;
+			}
+		}
+
+		for (i = 0; i < tx_count; i++) {
+			for (j = 0; j < TSNEP_TX_QUEUE_STATS_COUNT; j++) {
+				snprintf(data, ETH_GSTRING_LEN,
+					 tsnep_tx_queue_stats_strings[j], i);
+				data += ETH_GSTRING_LEN;
+			}
+		}
+		break;
+	case ETH_SS_TEST:
+		tsnep_ethtool_get_test_strings(data);
+		break;
+	}
+}
+
+static void tsnep_ethtool_get_ethtool_stats(struct net_device *netdev,
+					    struct ethtool_stats *stats,
+					    u64 *data)
+{
+	struct tsnep_adapter *adapter = netdev_priv(netdev);
+	int rx_count = adapter->num_rx_queues;
+	int tx_count = adapter->num_tx_queues;
+	struct tsnep_stats tsnep_stats;
+	struct tsnep_rx_queue_stats tsnep_rx_queue_stats;
+	struct tsnep_tx_queue_stats tsnep_tx_queue_stats;
+	u32 reg;
+	int i;
+
+	memset(&tsnep_stats, 0, sizeof(tsnep_stats));
+	for (i = 0; i < adapter->num_rx_queues; i++) {
+		tsnep_stats.rx_packets += adapter->rx[i].packets;
+		tsnep_stats.rx_bytes += adapter->rx[i].bytes;
+		tsnep_stats.rx_dropped += adapter->rx[i].dropped;
+		tsnep_stats.rx_multicast += adapter->rx[i].multicast;
+	}
+	reg = ioread32(adapter->addr + ECM_STAT);
+	tsnep_stats.rx_phy_errors =
+		(reg & ECM_STAT_RX_ERR_MASK) >> ECM_STAT_RX_ERR_SHIFT;
+	tsnep_stats.rx_forwarded_phy_errors =
+		(reg & ECM_STAT_FWD_RX_ERR_MASK) >> ECM_STAT_FWD_RX_ERR_SHIFT;
+	tsnep_stats.rx_invalid_frame_errors =
+		(reg & ECM_STAT_INV_FRM_MASK) >> ECM_STAT_INV_FRM_SHIFT;
+	for (i = 0; i < adapter->num_tx_queues; i++) {
+		tsnep_stats.tx_packets += adapter->tx[i].packets;
+		tsnep_stats.tx_bytes += adapter->tx[i].bytes;
+		tsnep_stats.tx_dropped += adapter->tx[i].dropped;
+	}
+	memcpy(data, &tsnep_stats, sizeof(tsnep_stats));
+	data += TSNEP_STATS_COUNT;
+
+	for (i = 0; i < rx_count; i++) {
+		memset(&tsnep_rx_queue_stats, 0, sizeof(tsnep_rx_queue_stats));
+		tsnep_rx_queue_stats.rx_packets = adapter->rx[i].packets;
+		tsnep_rx_queue_stats.rx_bytes = adapter->rx[i].bytes;
+		tsnep_rx_queue_stats.rx_dropped = adapter->rx[i].dropped;
+		tsnep_rx_queue_stats.rx_multicast = adapter->rx[i].multicast;
+		reg = ioread32(adapter->addr + TSNEP_QUEUE(i) +
+			       TSNEP_RX_STATISTIC);
+		tsnep_rx_queue_stats.rx_no_descriptor_errors =
+			(reg & TSNEP_RX_STATISTIC_NO_DESC_MASK) >>
+			TSNEP_RX_STATISTIC_NO_DESC_SHIFT;
+		tsnep_rx_queue_stats.rx_buffer_too_small_errors =
+			(reg & TSNEP_RX_STATISTIC_BUFFER_TOO_SMALL_MASK) >>
+			TSNEP_RX_STATISTIC_BUFFER_TOO_SMALL_SHIFT;
+		tsnep_rx_queue_stats.rx_fifo_overflow_errors =
+			(reg & TSNEP_RX_STATISTIC_FIFO_OVERFLOW_MASK) >>
+			TSNEP_RX_STATISTIC_FIFO_OVERFLOW_SHIFT;
+		tsnep_rx_queue_stats.rx_invalid_frame_errors =
+			(reg & TSNEP_RX_STATISTIC_INVALID_FRAME_MASK) >>
+			TSNEP_RX_STATISTIC_INVALID_FRAME_SHIFT;
+		memcpy(data, &tsnep_rx_queue_stats,
+		       sizeof(tsnep_rx_queue_stats));
+		data += TSNEP_RX_QUEUE_STATS_COUNT;
+	}
+
+	for (i = 0; i < tx_count; i++) {
+		memset(&tsnep_tx_queue_stats, 0, sizeof(tsnep_tx_queue_stats));
+		tsnep_tx_queue_stats.tx_packets += adapter->tx[i].packets;
+		tsnep_tx_queue_stats.tx_bytes += adapter->tx[i].bytes;
+		tsnep_tx_queue_stats.tx_dropped += adapter->tx[i].dropped;
+		memcpy(data, &tsnep_tx_queue_stats,
+		       sizeof(tsnep_tx_queue_stats));
+		data += TSNEP_TX_QUEUE_STATS_COUNT;
+	}
+}
+
+static int tsnep_ethtool_get_sset_count(struct net_device *netdev, int sset)
+{
+	struct tsnep_adapter *adapter = netdev_priv(netdev);
+	int rx_count;
+	int tx_count;
+
+	switch (sset) {
+	case ETH_SS_STATS:
+		rx_count = adapter->num_rx_queues;
+		tx_count = adapter->num_tx_queues;
+		return TSNEP_STATS_COUNT +
+		       TSNEP_RX_QUEUE_STATS_COUNT * rx_count +
+		       TSNEP_TX_QUEUE_STATS_COUNT * tx_count;
+	case ETH_SS_TEST:
+		return tsnep_ethtool_get_test_count();
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int tsnep_ethtool_get_ts_info(struct net_device *dev,
+				     struct ethtool_ts_info *info)
+{
+	struct tsnep_adapter *adapter = netdev_priv(dev);
+
+	info->so_timestamping = SOF_TIMESTAMPING_TX_SOFTWARE |
+				SOF_TIMESTAMPING_RX_SOFTWARE |
+				SOF_TIMESTAMPING_SOFTWARE |
+				SOF_TIMESTAMPING_TX_HARDWARE |
+				SOF_TIMESTAMPING_RX_HARDWARE |
+				SOF_TIMESTAMPING_RAW_HARDWARE;
+
+	if (adapter->ptp_clock)
+		info->phc_index = ptp_clock_index(adapter->ptp_clock);
+	else
+		info->phc_index = -1;
+
+	info->tx_types = BIT(HWTSTAMP_TX_OFF) |
+			 BIT(HWTSTAMP_TX_ON);
+	info->rx_filters = BIT(HWTSTAMP_FILTER_NONE) |
+			   BIT(HWTSTAMP_FILTER_ALL);
+
+	return 0;
+}
+
+const struct ethtool_ops tsnep_ethtool_ops = {
+	.get_drvinfo = tsnep_ethtool_get_drvinfo,
+	.get_regs_len = tsnep_ethtool_get_regs_len,
+	.get_regs = tsnep_ethtool_get_regs,
+	.get_msglevel = tsnep_ethtool_get_msglevel,
+	.set_msglevel = tsnep_ethtool_set_msglevel,
+	.nway_reset = phy_ethtool_nway_reset,
+	.get_link = ethtool_op_get_link,
+	.self_test = tsnep_ethtool_self_test,
+	.get_strings = tsnep_ethtool_get_strings,
+	.get_ethtool_stats = tsnep_ethtool_get_ethtool_stats,
+	.get_sset_count = tsnep_ethtool_get_sset_count,
+	.get_ts_info = tsnep_ethtool_get_ts_info,
+	.get_link_ksettings = phy_ethtool_get_link_ksettings,
+	.set_link_ksettings = phy_ethtool_set_link_ksettings,
+};

diff --git a/drivers/net/ethernet/engleder/tsnep_hw.h b/drivers/net/ethernet/engleder/tsnep_hw.h
new file mode 100644
index 000000000000..71cc8577d640
--- /dev/null
+++ b/drivers/net/ethernet/engleder/tsnep_hw.h

@@ -0,0 +1,230 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2021 Gerhard Engleder <gerhard@engleder-embedded.com> */
+
+/* Hardware definition of TSNEP and EtherCAT MAC device */
+
+#ifndef _TSNEP_HW_H
+#define _TSNEP_HW_H
+
+#include <linux/types.h>
+
+/* type */
+#define ECM_TYPE 0x0000
+#define ECM_REVISION_MASK 0x000000FF
+#define ECM_REVISION_SHIFT 0
+#define ECM_VERSION_MASK 0x0000FF00
+#define ECM_VERSION_SHIFT 8
+#define ECM_QUEUE_COUNT_MASK 0x00070000
+#define ECM_QUEUE_COUNT_SHIFT 16
+#define ECM_GATE_CONTROL 0x02000000
+
+/* system time */
+#define ECM_SYSTEM_TIME_LOW 0x0008
+#define ECM_SYSTEM_TIME_HIGH 0x000C
+
+/* clock */
+#define ECM_CLOCK_RATE 0x0010
+#define ECM_CLOCK_RATE_OFFSET_MASK 0x7FFFFFFF
+#define ECM_CLOCK_RATE_OFFSET_SIGN 0x80000000
+
+/* interrupt */
+#define ECM_INT_ENABLE 0x0018
+#define ECM_INT_ACTIVE 0x001C
+#define ECM_INT_ACKNOWLEDGE 0x001C
+#define ECM_INT_LINK 0x00000020
+#define ECM_INT_TX_0 0x00000100
+#define ECM_INT_RX_0 0x00000200
+#define ECM_INT_ALL 0x7FFFFFFF
+#define ECM_INT_DISABLE 0x80000000
+
+/* reset */
+#define ECM_RESET 0x0020
+#define ECM_RESET_COMMON 0x00000001
+#define ECM_RESET_CHANNEL 0x00000100
+#define ECM_RESET_TXRX 0x00010000
+
+/* control and status */
+#define ECM_STATUS 0x0080
+#define ECM_LINK_MODE_OFF 0x01000000
+#define ECM_LINK_MODE_100 0x02000000
+#define ECM_LINK_MODE_1000 0x04000000
+#define ECM_NO_LINK 0x01000000
+#define ECM_LINK_MODE_MASK 0x06000000
+
+/* management data */
+#define ECM_MD_CONTROL 0x0084
+#define ECM_MD_STATUS 0x0084
+#define ECM_MD_PREAMBLE 0x00000001
+#define ECM_MD_READ 0x00000004
+#define ECM_MD_WRITE 0x00000002
+#define ECM_MD_ADDR_MASK 0x000000F8
+#define ECM_MD_ADDR_SHIFT 3
+#define ECM_MD_PHY_ADDR_MASK 0x00001F00
+#define ECM_MD_PHY_ADDR_SHIFT 8
+#define ECM_MD_BUSY 0x00000001
+#define ECM_MD_DATA_MASK 0xFFFF0000
+#define ECM_MD_DATA_SHIFT 16
+
+/* statistic */
+#define ECM_STAT 0x00B0
+#define ECM_STAT_RX_ERR_MASK 0x000000FF
+#define ECM_STAT_RX_ERR_SHIFT 0
+#define ECM_STAT_INV_FRM_MASK 0x0000FF00
+#define ECM_STAT_INV_FRM_SHIFT 8
+#define ECM_STAT_FWD_RX_ERR_MASK 0x00FF0000
+#define ECM_STAT_FWD_RX_ERR_SHIFT 16
+
+/* tsnep */
+#define TSNEP_MAC_SIZE 0x4000
+#define TSNEP_QUEUE_SIZE 0x1000
+#define TSNEP_QUEUE(n) ({ typeof(n) __n = (n); \
+			  (__n) == 0 ? \
+			  0 : \
+			  TSNEP_MAC_SIZE + TSNEP_QUEUE_SIZE * ((__n) - 1); })
+#define TSNEP_MAX_QUEUES 8
+#define TSNEP_MAX_FRAME_SIZE (2 * 1024) /* hardware supports actually 16k */
+#define TSNEP_DESC_SIZE 256
+#define TSNEP_DESC_OFFSET 128
+
+/* tsnep register */
+#define TSNEP_INFO 0x0100
+#define TSNEP_INFO_RX_ASSIGN 0x00010000
+#define TSNEP_INFO_TX_TIME 0x00020000
+#define TSNEP_CONTROL 0x0108
+#define TSNEP_CONTROL_TX_RESET 0x00000001
+#define TSNEP_CONTROL_TX_ENABLE 0x00000002
+#define TSNEP_CONTROL_TX_DMA_ERROR 0x00000010
+#define TSNEP_CONTROL_TX_DESC_ERROR 0x00000020
+#define TSNEP_CONTROL_RX_RESET 0x00000100
+#define TSNEP_CONTROL_RX_ENABLE 0x00000200
+#define TSNEP_CONTROL_RX_DISABLE 0x00000400
+#define TSNEP_CONTROL_RX_DMA_ERROR 0x00001000
+#define TSNEP_CONTROL_RX_DESC_ERROR 0x00002000
+#define TSNEP_TX_DESC_ADDR_LOW 0x0140
+#define TSNEP_TX_DESC_ADDR_HIGH 0x0144
+#define TSNEP_RX_DESC_ADDR_LOW 0x0180
+#define TSNEP_RX_DESC_ADDR_HIGH 0x0184
+#define TSNEP_RESET_OWNER_COUNTER 0x01
+#define TSNEP_RX_STATISTIC 0x0190
+#define TSNEP_RX_STATISTIC_NO_DESC_MASK 0x000000FF
+#define TSNEP_RX_STATISTIC_NO_DESC_SHIFT 0
+#define TSNEP_RX_STATISTIC_BUFFER_TOO_SMALL_MASK 0x0000FF00
+#define TSNEP_RX_STATISTIC_BUFFER_TOO_SMALL_SHIFT 8
+#define TSNEP_RX_STATISTIC_FIFO_OVERFLOW_MASK 0x00FF0000
+#define TSNEP_RX_STATISTIC_FIFO_OVERFLOW_SHIFT 16
+#define TSNEP_RX_STATISTIC_INVALID_FRAME_MASK 0xFF000000
+#define TSNEP_RX_STATISTIC_INVALID_FRAME_SHIFT 24
+#define TSNEP_RX_STATISTIC_NO_DESC 0x0190
+#define TSNEP_RX_STATISTIC_BUFFER_TOO_SMALL 0x0191
+#define TSNEP_RX_STATISTIC_FIFO_OVERFLOW 0x0192
+#define TSNEP_RX_STATISTIC_INVALID_FRAME 0x0193
+#define TSNEP_RX_ASSIGN 0x01A0
+#define TSNEP_RX_ASSIGN_ETHER_TYPE_ACTIVE 0x00000001
+#define TSNEP_RX_ASSIGN_ETHER_TYPE_MASK 0xFFFF0000
+#define TSNEP_RX_ASSIGN_ETHER_TYPE_SHIFT 16
+#define TSNEP_MAC_ADDRESS_LOW 0x0800
+#define TSNEP_MAC_ADDRESS_HIGH 0x0804
+#define TSNEP_RX_FILTER 0x0806
+#define TSNEP_RX_FILTER_ACCEPT_ALL_MULTICASTS 0x0001
+#define TSNEP_RX_FILTER_ACCEPT_ALL_UNICASTS 0x0002
+#define TSNEP_GC 0x0808
+#define TSNEP_GC_ENABLE_A 0x00000002
+#define TSNEP_GC_ENABLE_B 0x00000004
+#define TSNEP_GC_DISABLE 0x00000008
+#define TSNEP_GC_ENABLE_TIMEOUT 0x00000010
+#define TSNEP_GC_ACTIVE_A 0x00000002
+#define TSNEP_GC_ACTIVE_B 0x00000004
+#define TSNEP_GC_CHANGE_AB 0x00000008
+#define TSNEP_GC_TIMEOUT_ACTIVE 0x00000010
+#define TSNEP_GC_TIMEOUT_SIGNAL 0x00000020
+#define TSNEP_GC_LIST_ERROR 0x00000080
+#define TSNEP_GC_OPEN 0x00FF0000
+#define TSNEP_GC_OPEN_SHIFT 16
+#define TSNEP_GC_NEXT_OPEN 0xFF000000
+#define TSNEP_GC_NEXT_OPEN_SHIFT 24
+#define TSNEP_GC_TIMEOUT 131072
+#define TSNEP_GC_TIME 0x080C
+#define TSNEP_GC_CHANGE 0x0810
+#define TSNEP_GCL_A 0x2000
+#define TSNEP_GCL_B 0x2800
+#define TSNEP_GCL_SIZE SZ_2K
+
+/* tsnep gate control list operation */
+struct tsnep_gcl_operation {
+	u32 properties;
+	u32 interval;
+};
+
+#define TSNEP_GCL_COUNT (TSNEP_GCL_SIZE / sizeof(struct tsnep_gcl_operation))
+#define TSNEP_GCL_MASK 0x000000FF
+#define TSNEP_GCL_INSERT 0x20000000
+#define TSNEP_GCL_CHANGE 0x40000000
+#define TSNEP_GCL_LAST 0x80000000
+#define TSNEP_GCL_MIN_INTERVAL 32
+
+/* tsnep TX/RX descriptor */
+#define TSNEP_DESC_SIZE 256
+#define TSNEP_DESC_SIZE_DATA_AFTER 2048
+#define TSNEP_DESC_OFFSET 128
+#define TSNEP_DESC_OWNER_COUNTER_MASK 0xC0000000
+#define TSNEP_DESC_OWNER_COUNTER_SHIFT 30
+#define TSNEP_DESC_LENGTH_MASK 0x00003FFF
+#define TSNEP_DESC_INTERRUPT_FLAG 0x00040000
+#define TSNEP_DESC_EXTENDED_WRITEBACK_FLAG 0x00080000
+#define TSNEP_DESC_NO_LINK_FLAG 0x01000000
+
+/* tsnep TX descriptor */
+struct tsnep_tx_desc {
+	__le32 properties;
+	__le32 more_properties;
+	__le32 reserved[2];
+	__le64 next;
+	__le64 tx;
+};
+
+#define TSNEP_TX_DESC_OWNER_MASK 0xE0000000
+#define TSNEP_TX_DESC_OWNER_USER_FLAG 0x20000000
+#define TSNEP_TX_DESC_LAST_FRAGMENT_FLAG 0x00010000
+#define TSNEP_TX_DESC_DATA_AFTER_DESC_FLAG 0x00020000
+
+/* tsnep TX descriptor writeback */
+struct tsnep_tx_desc_wb {
+	__le32 properties;
+	__le32 reserved1[3];
+	__le64 timestamp;
+	__le32 dma_delay;
+	__le32 reserved2;
+};
+
+#define TSNEP_TX_DESC_UNDERRUN_ERROR_FLAG 0x00010000
+#define TSNEP_TX_DESC_DMA_DELAY_FIRST_DATA_MASK 0x0000FFFC
+#define TSNEP_TX_DESC_DMA_DELAY_FIRST_DATA_SHIFT 2
+#define TSNEP_TX_DESC_DMA_DELAY_LAST_DATA_MASK 0xFFFC0000
+#define TSNEP_TX_DESC_DMA_DELAY_LAST_DATA_SHIFT 18
+#define TSNEP_TX_DESC_DMA_DELAY_NS 64
+
+/* tsnep RX descriptor */
+struct tsnep_rx_desc {
+	__le32 properties;
+	__le32 reserved[3];
+	__le64 next;
+	__le64 rx;
+};
+
+#define TSNEP_RX_DESC_BUFFER_SIZE_MASK 0x00003FFC
+
+/* tsnep RX descriptor writeback */
+struct tsnep_rx_desc_wb {
+	__le32 properties;
+	__le32 reserved[7];
+};
+
+/* tsnep RX inline meta */
+struct tsnep_rx_inline {
+	__le64 reserved;
+	__le64 timestamp;
+};
+
+#define TSNEP_RX_INLINE_METADATA_SIZE (sizeof(struct tsnep_rx_inline))
+
+#endif /* _TSNEP_HW_H */

diff --git a/drivers/net/ethernet/engleder/tsnep_main.c b/drivers/net/ethernet/engleder/tsnep_main.c
new file mode 100644
index 000000000000..86d488821a65
--- /dev/null
+++ b/drivers/net/ethernet/engleder/tsnep_main.c

@@ -0,0 +1,1255 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2021 Gerhard Engleder <gerhard@engleder-embedded.com> */
+
+/* TSN endpoint Ethernet MAC driver
+ *
+ * The TSN endpoint Ethernet MAC is a FPGA based network device for real-time
+ * communication. It is designed for endpoints within TSN (Time Sensitive
+ * Networking) networks; e.g., for PLCs in the industrial automation case.
+ *
+ * It supports multiple TX/RX queue pairs. The first TX/RX queue pair is used
+ * by the driver.
+ *
+ * More information can be found here:
+ * - www.embedded-experts.at/tsn
+ * - www.engleder-embedded.com
+ */
+
+#include "tsnep.h"
+#include "tsnep_hw.h"
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_net.h>
+#include <linux/of_mdio.h>
+#include <linux/interrupt.h>
+#include <linux/etherdevice.h>
+#include <linux/phy.h>
+#include <linux/iopoll.h>
+
+#define RX_SKB_LENGTH (round_up(TSNEP_RX_INLINE_METADATA_SIZE + ETH_HLEN + \
+				TSNEP_MAX_FRAME_SIZE + ETH_FCS_LEN, 4))
+#define RX_SKB_RESERVE ((16 - TSNEP_RX_INLINE_METADATA_SIZE) + NET_IP_ALIGN)
+#define RX_SKB_ALLOC_LENGTH (RX_SKB_RESERVE + RX_SKB_LENGTH)
+
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+#define DMA_ADDR_HIGH(dma_addr) ((u32)(((dma_addr) >> 32) & 0xFFFFFFFF))
+#else
+#define DMA_ADDR_HIGH(dma_addr) ((u32)(0))
+#endif
+#define DMA_ADDR_LOW(dma_addr) ((u32)((dma_addr) & 0xFFFFFFFF))
+
+static void tsnep_enable_irq(struct tsnep_adapter *adapter, u32 mask)
+{
+	iowrite32(mask, adapter->addr + ECM_INT_ENABLE);
+}
+
+static void tsnep_disable_irq(struct tsnep_adapter *adapter, u32 mask)
+{
+	mask |= ECM_INT_DISABLE;
+	iowrite32(mask, adapter->addr + ECM_INT_ENABLE);
+}
+
+static irqreturn_t tsnep_irq(int irq, void *arg)
+{
+	struct tsnep_adapter *adapter = arg;
+	u32 active = ioread32(adapter->addr + ECM_INT_ACTIVE);
+
+	/* acknowledge interrupt */
+	if (active != 0)
+		iowrite32(active, adapter->addr + ECM_INT_ACKNOWLEDGE);
+
+	/* handle link interrupt */
+	if ((active & ECM_INT_LINK) != 0) {
+		if (adapter->netdev->phydev)
+			phy_mac_interrupt(adapter->netdev->phydev);
+	}
+
+	/* handle TX/RX queue 0 interrupt */
+	if ((active & adapter->queue[0].irq_mask) != 0) {
+		if (adapter->netdev) {
+			tsnep_disable_irq(adapter, adapter->queue[0].irq_mask);
+			napi_schedule(&adapter->queue[0].napi);
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int tsnep_mdiobus_read(struct mii_bus *bus, int addr, int regnum)
+{
+	struct tsnep_adapter *adapter = bus->priv;
+	u32 md;
+	int retval;
+
+	if (regnum & MII_ADDR_C45)
+		return -EOPNOTSUPP;
+
+	md = ECM_MD_READ;
+	if (!adapter->suppress_preamble)
+		md |= ECM_MD_PREAMBLE;
+	md |= (regnum << ECM_MD_ADDR_SHIFT) & ECM_MD_ADDR_MASK;
+	md |= (addr << ECM_MD_PHY_ADDR_SHIFT) & ECM_MD_PHY_ADDR_MASK;
+	iowrite32(md, adapter->addr + ECM_MD_CONTROL);
+	retval = readl_poll_timeout_atomic(adapter->addr + ECM_MD_STATUS, md,
+					   !(md & ECM_MD_BUSY), 16, 1000);
+	if (retval != 0)
+		return retval;
+
+	return (md & ECM_MD_DATA_MASK) >> ECM_MD_DATA_SHIFT;
+}
+
+static int tsnep_mdiobus_write(struct mii_bus *bus, int addr, int regnum,
+			       u16 val)
+{
+	struct tsnep_adapter *adapter = bus->priv;
+	u32 md;
+	int retval;
+
+	if (regnum & MII_ADDR_C45)
+		return -EOPNOTSUPP;
+
+	md = ECM_MD_WRITE;
+	if (!adapter->suppress_preamble)
+		md |= ECM_MD_PREAMBLE;
+	md |= (regnum << ECM_MD_ADDR_SHIFT) & ECM_MD_ADDR_MASK;
+	md |= (addr << ECM_MD_PHY_ADDR_SHIFT) & ECM_MD_PHY_ADDR_MASK;
+	md |= ((u32)val << ECM_MD_DATA_SHIFT) & ECM_MD_DATA_MASK;
+	iowrite32(md, adapter->addr + ECM_MD_CONTROL);
+	retval = readl_poll_timeout_atomic(adapter->addr + ECM_MD_STATUS, md,
+					   !(md & ECM_MD_BUSY), 16, 1000);
+	if (retval != 0)
+		return retval;
+
+	return 0;
+}
+
+static void tsnep_phy_link_status_change(struct net_device *netdev)
+{
+	struct tsnep_adapter *adapter = netdev_priv(netdev);
+	struct phy_device *phydev = netdev->phydev;
+	u32 mode;
+
+	if (phydev->link) {
+		switch (phydev->speed) {
+		case SPEED_100:
+			mode = ECM_LINK_MODE_100;
+			break;
+		case SPEED_1000:
+			mode = ECM_LINK_MODE_1000;
+			break;
+		default:
+			mode = ECM_LINK_MODE_OFF;
+			break;
+		}
+		iowrite32(mode, adapter->addr + ECM_STATUS);
+	}
+
+	phy_print_status(netdev->phydev);
+}
+
+static int tsnep_phy_open(struct tsnep_adapter *adapter)
+{
+	struct phy_device *phydev;
+	struct ethtool_eee ethtool_eee;
+	int retval;
+
+	retval = phy_connect_direct(adapter->netdev, adapter->phydev,
+				    tsnep_phy_link_status_change,
+				    adapter->phy_mode);
+	if (retval)
+		return retval;
+	phydev = adapter->netdev->phydev;
+
+	/* MAC supports only 100Mbps|1000Mbps full duplex
+	 * SPE (Single Pair Ethernet) is also an option but not implemented yet
+	 */
+	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_10baseT_Half_BIT);
+	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_10baseT_Full_BIT);
+	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_100baseT_Half_BIT);
+	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_1000baseT_Half_BIT);
+
+	/* disable EEE autoneg, EEE not supported by TSNEP */
+	memset(&ethtool_eee, 0, sizeof(ethtool_eee));
+	phy_ethtool_set_eee(adapter->phydev, &ethtool_eee);
+
+	adapter->phydev->irq = PHY_MAC_INTERRUPT;
+	phy_start(adapter->phydev);
+
+	return 0;
+}
+
+static void tsnep_phy_close(struct tsnep_adapter *adapter)
+{
+	phy_stop(adapter->netdev->phydev);
+	phy_disconnect(adapter->netdev->phydev);
+	adapter->netdev->phydev = NULL;
+}
+
+static void tsnep_tx_ring_cleanup(struct tsnep_tx *tx)
+{
+	struct device *dmadev = tx->adapter->dmadev;
+	int i;
+
+	memset(tx->entry, 0, sizeof(tx->entry));
+
+	for (i = 0; i < TSNEP_RING_PAGE_COUNT; i++) {
+		if (tx->page[i]) {
+			dma_free_coherent(dmadev, PAGE_SIZE, tx->page[i],
+					  tx->page_dma[i]);
+			tx->page[i] = NULL;
+			tx->page_dma[i] = 0;
+		}
+	}
+}
+
+static int tsnep_tx_ring_init(struct tsnep_tx *tx)
+{
+	struct device *dmadev = tx->adapter->dmadev;
+	struct tsnep_tx_entry *entry;
+	struct tsnep_tx_entry *next_entry;
+	int i, j;
+	int retval;
+
+	for (i = 0; i < TSNEP_RING_PAGE_COUNT; i++) {
+		tx->page[i] =
+			dma_alloc_coherent(dmadev, PAGE_SIZE, &tx->page_dma[i],
+					   GFP_KERNEL);
+		if (!tx->page[i]) {
+			retval = -ENOMEM;
+			goto alloc_failed;
+		}
+		for (j = 0; j < TSNEP_RING_ENTRIES_PER_PAGE; j++) {
+			entry = &tx->entry[TSNEP_RING_ENTRIES_PER_PAGE * i + j];
+			entry->desc_wb = (struct tsnep_tx_desc_wb *)
+				(((u8 *)tx->page[i]) + TSNEP_DESC_SIZE * j);
+			entry->desc = (struct tsnep_tx_desc *)
+				(((u8 *)entry->desc_wb) + TSNEP_DESC_OFFSET);
+			entry->desc_dma = tx->page_dma[i] + TSNEP_DESC_SIZE * j;
+		}
+	}
+	for (i = 0; i < TSNEP_RING_SIZE; i++) {
+		entry = &tx->entry[i];
+		next_entry = &tx->entry[(i + 1) % TSNEP_RING_SIZE];
+		entry->desc->next = __cpu_to_le64(next_entry->desc_dma);
+	}
+
+	return 0;
+
+alloc_failed:
+	tsnep_tx_ring_cleanup(tx);
+	return retval;
+}
+
+static void tsnep_tx_activate(struct tsnep_tx *tx, int index, bool last)
+{
+	struct tsnep_tx_entry *entry = &tx->entry[index];
+
+	entry->properties = 0;
+	if (entry->skb) {
+		entry->properties =
+			skb_pagelen(entry->skb) & TSNEP_DESC_LENGTH_MASK;
+		entry->properties |= TSNEP_DESC_INTERRUPT_FLAG;
+		if (skb_shinfo(entry->skb)->tx_flags & SKBTX_IN_PROGRESS)
+			entry->properties |= TSNEP_DESC_EXTENDED_WRITEBACK_FLAG;
+
+		/* toggle user flag to prevent false acknowledge
+		 *
+		 * Only the first fragment is acknowledged. For all other
+		 * fragments no acknowledge is done and the last written owner
+		 * counter stays in the writeback descriptor. Therefore, it is
+		 * possible that the last written owner counter is identical to
+		 * the new incremented owner counter and a false acknowledge is
+		 * detected before the real acknowledge has been done by
+		 * hardware.
+		 *
+		 * The user flag is used to prevent this situation. The user
+		 * flag is copied to the writeback descriptor by the hardware
+		 * and is used as additional acknowledge data. By toggeling the
+		 * user flag only for the first fragment (which is
+		 * acknowledged), it is guaranteed that the last acknowledge
+		 * done for this descriptor has used a different user flag and
+		 * cannot be detected as false acknowledge.
+		 */
+		entry->owner_user_flag = !entry->owner_user_flag;
+	}
+	if (last)
+		entry->properties |= TSNEP_TX_DESC_LAST_FRAGMENT_FLAG;
+	if (index == tx->increment_owner_counter) {
+		tx->owner_counter++;
+		if (tx->owner_counter == 4)
+			tx->owner_counter = 1;
+		tx->increment_owner_counter--;
+		if (tx->increment_owner_counter < 0)
+			tx->increment_owner_counter = TSNEP_RING_SIZE - 1;
+	}
+	entry->properties |=
+		(tx->owner_counter << TSNEP_DESC_OWNER_COUNTER_SHIFT) &
+		TSNEP_DESC_OWNER_COUNTER_MASK;
+	if (entry->owner_user_flag)
+		entry->properties |= TSNEP_TX_DESC_OWNER_USER_FLAG;
+	entry->desc->more_properties =
+		__cpu_to_le32(entry->len & TSNEP_DESC_LENGTH_MASK);
+
+	dma_wmb();
+
+	entry->desc->properties = __cpu_to_le32(entry->properties);
+}
+
+static int tsnep_tx_desc_available(struct tsnep_tx *tx)
+{
+	if (tx->read <= tx->write)
+		return TSNEP_RING_SIZE - tx->write + tx->read - 1;
+	else
+		return tx->read - tx->write - 1;
+}
+
+static int tsnep_tx_map(struct sk_buff *skb, struct tsnep_tx *tx, int count)
+{
+	struct device *dmadev = tx->adapter->dmadev;
+	struct tsnep_tx_entry *entry;
+	unsigned int len;
+	dma_addr_t dma;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		entry = &tx->entry[(tx->write + i) % TSNEP_RING_SIZE];
+
+		if (i == 0) {
+			len = skb_headlen(skb);
+			dma = dma_map_single(dmadev, skb->data, len,
+					     DMA_TO_DEVICE);
+		} else {
+			len = skb_frag_size(&skb_shinfo(skb)->frags[i - 1]);
+			dma = skb_frag_dma_map(dmadev,
+					       &skb_shinfo(skb)->frags[i - 1],
+					       0, len, DMA_TO_DEVICE);
+		}
+		if (dma_mapping_error(dmadev, dma))
+			return -ENOMEM;
+
+		dma_unmap_len_set(entry, len, len);
+		dma_unmap_addr_set(entry, dma, dma);
+
+		entry->desc->tx = __cpu_to_le64(dma);
+	}
+
+	return 0;
+}
+
+static void tsnep_tx_unmap(struct tsnep_tx *tx, int count)
+{
+	struct device *dmadev = tx->adapter->dmadev;
+	struct tsnep_tx_entry *entry;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		entry = &tx->entry[(tx->read + i) % TSNEP_RING_SIZE];
+
+		if (dma_unmap_len(entry, len)) {
+			if (i == 0)
+				dma_unmap_single(dmadev,
+						 dma_unmap_addr(entry, dma),
+						 dma_unmap_len(entry, len),
+						 DMA_TO_DEVICE);
+			else
+				dma_unmap_page(dmadev,
+					       dma_unmap_addr(entry, dma),
+					       dma_unmap_len(entry, len),
+					       DMA_TO_DEVICE);
+			dma_unmap_len_set(entry, len, 0);
+		}
+	}
+}
+
+static netdev_tx_t tsnep_xmit_frame_ring(struct sk_buff *skb,
+					 struct tsnep_tx *tx)
+{
+	unsigned long flags;
+	int count = 1;
+	struct tsnep_tx_entry *entry;
+	int i;
+	int retval;
+
+	if (skb_shinfo(skb)->nr_frags > 0)
+		count += skb_shinfo(skb)->nr_frags;
+
+	spin_lock_irqsave(&tx->lock, flags);
+
+	if (tsnep_tx_desc_available(tx) < count) {
+		/* ring full, shall not happen because queue is stopped if full
+		 * below
+		 */
+		netif_stop_queue(tx->adapter->netdev);
+
+		spin_unlock_irqrestore(&tx->lock, flags);
+
+		return NETDEV_TX_BUSY;
+	}
+
+	entry = &tx->entry[tx->write];
+	entry->skb = skb;
+
+	retval = tsnep_tx_map(skb, tx, count);
+	if (retval != 0) {
+		tsnep_tx_unmap(tx, count);
+		dev_kfree_skb_any(entry->skb);
+		entry->skb = NULL;
+
+		tx->dropped++;
+
+		spin_unlock_irqrestore(&tx->lock, flags);
+
+		netdev_err(tx->adapter->netdev, "TX DMA map failed\n");
+
+		return NETDEV_TX_OK;
+	}
+
+	if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)
+		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
+
+	for (i = 0; i < count; i++)
+		tsnep_tx_activate(tx, (tx->write + i) % TSNEP_RING_SIZE,
+				  i == (count - 1));
+	skb_tx_timestamp(skb);
+
+	/* entry->properties shall be valid before write pointer is
+	 * incrememted
+	 */
+	wmb();