Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

6 files changed, 1788 insertions, 0 deletions

diff --git a/drivers/net/ethernet/arc/Kconfig b/drivers/net/ethernet/arc/Kconfig
new file mode 100644
index 000000000..0d400a7d8
--- /dev/null
+++ b/drivers/net/ethernet/arc/Kconfig
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# ARC EMAC network device configuration
+#
+
+config NET_VENDOR_ARC
+	bool "ARC 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 ARC cards. If you say Y, you will be asked for
+	  your specific card in the following questions.
+
+if NET_VENDOR_ARC
+
+config ARC_EMAC_CORE
+	tristate
+	depends on ARC || ARCH_ROCKCHIP || COMPILE_TEST
+	select MII
+	select PHYLIB
+	select CRC32
+
+config EMAC_ROCKCHIP
+	tristate "Rockchip EMAC support"
+	select ARC_EMAC_CORE
+	depends on OF_IRQ && REGULATOR
+	depends on ARCH_ROCKCHIP || COMPILE_TEST
+	help
+	  Support for Rockchip RK3036/RK3066/RK3188 EMAC ethernet controllers.
+	  This selects Rockchip SoC glue layer support for the
+	  emac device driver. This driver is used for RK3036/RK3066/RK3188
+	  EMAC ethernet controller.
+
+endif # NET_VENDOR_ARC
diff --git a/drivers/net/ethernet/arc/Makefile b/drivers/net/ethernet/arc/Makefile
new file mode 100644
index 000000000..23586eefe
--- /dev/null
+++ b/drivers/net/ethernet/arc/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the ARC network device drivers.
+#
+
+arc_emac-objs := emac_main.o emac_mdio.o
+obj-$(CONFIG_ARC_EMAC_CORE) += arc_emac.o
+obj-$(CONFIG_EMAC_ROCKCHIP) += emac_rockchip.o
diff --git a/drivers/net/ethernet/arc/emac.h b/drivers/net/ethernet/arc/emac.h
new file mode 100644
index 000000000..0e244f0e2
--- /dev/null
+++ b/drivers/net/ethernet/arc/emac.h
@@ -0,0 +1,225 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com)
+ *
+ * Registers and bits definitions of ARC EMAC
+ */
+
+#ifndef ARC_EMAC_H
+#define ARC_EMAC_H
+
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/netdevice.h>
+#include <linux/phy.h>
+#include <linux/clk.h>
+
+/* STATUS and ENABLE Register bit masks */
+#define TXINT_MASK	(1 << 0)	/* Transmit interrupt */
+#define RXINT_MASK	(1 << 1)	/* Receive interrupt */
+#define ERR_MASK	(1 << 2)	/* Error interrupt */
+#define TXCH_MASK	(1 << 3)	/* Transmit chaining error interrupt */
+#define MSER_MASK	(1 << 4)	/* Missed packet counter error */
+#define RXCR_MASK	(1 << 8)	/* RXCRCERR counter rolled over  */
+#define RXFR_MASK	(1 << 9)	/* RXFRAMEERR counter rolled over */
+#define RXFL_MASK	(1 << 10)	/* RXOFLOWERR counter rolled over */
+#define MDIO_MASK	(1 << 12)	/* MDIO complete interrupt */
+#define TXPL_MASK	(1 << 31)	/* Force polling of BD by EMAC */
+
+/* CONTROL Register bit masks */
+#define EN_MASK		(1 << 0)	/* VMAC enable */
+#define TXRN_MASK	(1 << 3)	/* TX enable */
+#define RXRN_MASK	(1 << 4)	/* RX enable */
+#define DSBC_MASK	(1 << 8)	/* Disable receive broadcast */
+#define ENFL_MASK	(1 << 10)	/* Enable Full-duplex */
+#define PROM_MASK	(1 << 11)	/* Promiscuous mode */
+
+/* Buffer descriptor INFO bit masks */
+#define OWN_MASK	(1 << 31)	/* 0-CPU or 1-EMAC owns buffer */
+#define FIRST_MASK	(1 << 16)	/* First buffer in chain */
+#define LAST_MASK	(1 << 17)	/* Last buffer in chain */
+#define LEN_MASK	0x000007FF	/* last 11 bits */
+#define CRLS		(1 << 21)
+#define DEFR		(1 << 22)
+#define DROP		(1 << 23)
+#define RTRY		(1 << 24)
+#define LTCL		(1 << 28)
+#define UFLO		(1 << 29)
+
+#define FOR_EMAC	OWN_MASK
+#define FOR_CPU		0
+
+/* ARC EMAC register set combines entries for MAC and MDIO */
+enum {
+	R_ID = 0,
+	R_STATUS,
+	R_ENABLE,
+	R_CTRL,
+	R_POLLRATE,
+	R_RXERR,
+	R_MISS,
+	R_TX_RING,
+	R_RX_RING,
+	R_ADDRL,
+	R_ADDRH,
+	R_LAFL,
+	R_LAFH,
+	R_MDIO,
+};
+
+#define TX_TIMEOUT		(400 * HZ / 1000) /* Transmission timeout */
+
+#define ARC_EMAC_NAPI_WEIGHT	40		/* Workload for NAPI */
+
+#define EMAC_BUFFER_SIZE	1536		/* EMAC buffer size */
+
+/**
+ * struct arc_emac_bd - EMAC buffer descriptor (BD).
+ *
+ * @info:	Contains status information on the buffer itself.
+ * @data:	32-bit byte addressable pointer to the packet data.
+ */
+struct arc_emac_bd {
+	__le32 info;
+	dma_addr_t data;
+};
+
+/* Number of Rx/Tx BD's */
+#define RX_BD_NUM	128
+#define TX_BD_NUM	128
+
+#define RX_RING_SZ	(RX_BD_NUM * sizeof(struct arc_emac_bd))
+#define TX_RING_SZ	(TX_BD_NUM * sizeof(struct arc_emac_bd))
+
+/**
+ * struct buffer_state - Stores Rx/Tx buffer state.
+ * @sk_buff:	Pointer to socket buffer.
+ * @addr:	Start address of DMA-mapped memory region.
+ * @len:	Length of DMA-mapped memory region.
+ */
+struct buffer_state {
+	struct sk_buff *skb;
+	DEFINE_DMA_UNMAP_ADDR(addr);
+	DEFINE_DMA_UNMAP_LEN(len);
+};
+
+struct arc_emac_mdio_bus_data {
+	struct gpio_desc *reset_gpio;
+	int msec;
+};
+
+/**
+ * struct arc_emac_priv - Storage of EMAC's private information.
+ * @dev:	Pointer to the current device.
+ * @phy_dev:	Pointer to attached PHY device.
+ * @bus:	Pointer to the current MII bus.
+ * @regs:	Base address of EMAC memory-mapped control registers.
+ * @napi:	Structure for NAPI.
+ * @rxbd:	Pointer to Rx BD ring.
+ * @txbd:	Pointer to Tx BD ring.
+ * @rxbd_dma:	DMA handle for Rx BD ring.
+ * @txbd_dma:	DMA handle for Tx BD ring.
+ * @rx_buff:	Storage for Rx buffers states.
+ * @tx_buff:	Storage for Tx buffers states.
+ * @txbd_curr:	Index of Tx BD to use on the next "ndo_start_xmit".
+ * @txbd_dirty:	Index of Tx BD to free on the next Tx interrupt.
+ * @last_rx_bd:	Index of the last Rx BD we've got from EMAC.
+ * @link:	PHY's last seen link state.
+ * @duplex:	PHY's last set duplex mode.
+ * @speed:	PHY's last set speed.
+ */
+struct arc_emac_priv {
+	const char *drv_name;
+	void (*set_mac_speed)(void *priv, unsigned int speed);
+
+	/* Devices */
+	struct device *dev;
+	struct mii_bus *bus;
+	struct arc_emac_mdio_bus_data bus_data;
+
+	void __iomem *regs;
+	struct clk *clk;
+
+	struct napi_struct napi;
+
+	struct arc_emac_bd *rxbd;
+	struct arc_emac_bd *txbd;
+
+	dma_addr_t rxbd_dma;
+	dma_addr_t txbd_dma;
+
+	struct buffer_state rx_buff[RX_BD_NUM];
+	struct buffer_state tx_buff[TX_BD_NUM];
+	unsigned int txbd_curr;
+	unsigned int txbd_dirty;
+
+	unsigned int last_rx_bd;
+
+	unsigned int link;
+	unsigned int duplex;
+	unsigned int speed;
+
+	unsigned int rx_missed_errors;
+};
+
+/**
+ * arc_reg_set - Sets EMAC register with provided value.
+ * @priv:	Pointer to ARC EMAC private data structure.
+ * @reg:	Register offset from base address.
+ * @value:	Value to set in register.
+ */
+static inline void arc_reg_set(struct arc_emac_priv *priv, int reg, int value)
+{
+	iowrite32(value, priv->regs + reg * sizeof(int));
+}
+
+/**
+ * arc_reg_get - Gets value of specified EMAC register.
+ * @priv:	Pointer to ARC EMAC private data structure.
+ * @reg:	Register offset from base address.
+ *
+ * returns:	Value of requested register.
+ */
+static inline unsigned int arc_reg_get(struct arc_emac_priv *priv, int reg)
+{
+	return ioread32(priv->regs + reg * sizeof(int));
+}
+
+/**
+ * arc_reg_or - Applies mask to specified EMAC register - ("reg" | "mask").
+ * @priv:	Pointer to ARC EMAC private data structure.
+ * @reg:	Register offset from base address.
+ * @mask:	Mask to apply to specified register.
+ *
+ * This function reads initial register value, then applies provided mask
+ * to it and then writes register back.
+ */
+static inline void arc_reg_or(struct arc_emac_priv *priv, int reg, int mask)
+{
+	unsigned int value = arc_reg_get(priv, reg);
+
+	arc_reg_set(priv, reg, value | mask);
+}
+
+/**
+ * arc_reg_clr - Applies mask to specified EMAC register - ("reg" & ~"mask").
+ * @priv:	Pointer to ARC EMAC private data structure.
+ * @reg:	Register offset from base address.
+ * @mask:	Mask to apply to specified register.
+ *
+ * This function reads initial register value, then applies provided mask
+ * to it and then writes register back.
+ */
+static inline void arc_reg_clr(struct arc_emac_priv *priv, int reg, int mask)
+{
+	unsigned int value = arc_reg_get(priv, reg);
+
+	arc_reg_set(priv, reg, value & ~mask);
+}
+
+int arc_mdio_probe(struct arc_emac_priv *priv);
+int arc_mdio_remove(struct arc_emac_priv *priv);
+int arc_emac_probe(struct net_device *ndev, int interface);
+void arc_emac_remove(struct net_device *ndev);
+
+#endif /* ARC_EMAC_H */
diff --git a/drivers/net/ethernet/arc/emac_main.c b/drivers/net/ethernet/arc/emac_main.c
new file mode 100644
index 000000000..dde4046cb
--- /dev/null
+++ b/drivers/net/ethernet/arc/emac_main.c
@@ -0,0 +1,1043 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com)
+ *
+ * Driver for the ARC EMAC 10100 (hardware revision 5)
+ *
+ * Contributors:
+ *		Amit Bhor
+ *		Sameer Dhavale
+ *		Vineet Gupta
+ */
+
+#include <linux/crc32.h>
+#include <linux/etherdevice.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_mdio.h>
+#include <linux/of_net.h>
+
+#include "emac.h"
+
+static void arc_emac_restart(struct net_device *ndev);
+
+/**
+ * arc_emac_tx_avail - Return the number of available slots in the tx ring.
+ * @priv: Pointer to ARC EMAC private data structure.
+ *
+ * returns: the number of slots available for transmission in tx the ring.
+ */
+static inline int arc_emac_tx_avail(struct arc_emac_priv *priv)
+{
+	return (priv->txbd_dirty + TX_BD_NUM - priv->txbd_curr - 1) % TX_BD_NUM;
+}
+
+/**
+ * arc_emac_adjust_link - Adjust the PHY link duplex.
+ * @ndev:	Pointer to the net_device structure.
+ *
+ * This function is called to change the duplex setting after auto negotiation
+ * is done by the PHY.
+ */
+static void arc_emac_adjust_link(struct net_device *ndev)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+	struct phy_device *phy_dev = ndev->phydev;
+	unsigned int reg, state_changed = 0;
+
+	if (priv->link != phy_dev->link) {
+		priv->link = phy_dev->link;
+		state_changed = 1;
+	}
+
+	if (priv->speed != phy_dev->speed) {
+		priv->speed = phy_dev->speed;
+		state_changed = 1;
+		if (priv->set_mac_speed)
+			priv->set_mac_speed(priv, priv->speed);
+	}
+
+	if (priv->duplex != phy_dev->duplex) {
+		reg = arc_reg_get(priv, R_CTRL);
+
+		if (phy_dev->duplex == DUPLEX_FULL)
+			reg |= ENFL_MASK;
+		else
+			reg &= ~ENFL_MASK;
+
+		arc_reg_set(priv, R_CTRL, reg);
+		priv->duplex = phy_dev->duplex;
+		state_changed = 1;
+	}
+
+	if (state_changed)
+		phy_print_status(phy_dev);
+}
+
+/**
+ * arc_emac_get_drvinfo - Get EMAC driver information.
+ * @ndev:	Pointer to net_device structure.
+ * @info:	Pointer to ethtool_drvinfo structure.
+ *
+ * This implements ethtool command for getting the driver information.
+ * Issue "ethtool -i ethX" under linux prompt to execute this function.
+ */
+static void arc_emac_get_drvinfo(struct net_device *ndev,
+				 struct ethtool_drvinfo *info)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+
+	strscpy(info->driver, priv->drv_name, sizeof(info->driver));
+}
+
+static const struct ethtool_ops arc_emac_ethtool_ops = {
+	.get_drvinfo	= arc_emac_get_drvinfo,
+	.get_link	= ethtool_op_get_link,
+	.get_link_ksettings = phy_ethtool_get_link_ksettings,
+	.set_link_ksettings = phy_ethtool_set_link_ksettings,
+};
+
+#define FIRST_OR_LAST_MASK	(FIRST_MASK | LAST_MASK)
+
+/**
+ * arc_emac_tx_clean - clears processed by EMAC Tx BDs.
+ * @ndev:	Pointer to the network device.
+ */
+static void arc_emac_tx_clean(struct net_device *ndev)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+	struct net_device_stats *stats = &ndev->stats;
+	struct device *dev = ndev->dev.parent;
+	unsigned int i;
+
+	for (i = 0; i < TX_BD_NUM; i++) {
+		unsigned int *txbd_dirty = &priv->txbd_dirty;
+		struct arc_emac_bd *txbd = &priv->txbd[*txbd_dirty];
+		struct buffer_state *tx_buff = &priv->tx_buff[*txbd_dirty];
+		struct sk_buff *skb = tx_buff->skb;
+		unsigned int info = le32_to_cpu(txbd->info);
+
+		if ((info & FOR_EMAC) || !txbd->data || !skb)
+			break;
+
+		if (unlikely(info & (DROP | DEFR | LTCL | UFLO))) {
+			stats->tx_errors++;
+			stats->tx_dropped++;
+
+			if (info & DEFR)
+				stats->tx_carrier_errors++;
+
+			if (info & LTCL)
+				stats->collisions++;
+
+			if (info & UFLO)
+				stats->tx_fifo_errors++;
+		} else if (likely(info & FIRST_OR_LAST_MASK)) {
+			stats->tx_packets++;
+			stats->tx_bytes += skb->len;
+		}
+
+		dma_unmap_single(dev, dma_unmap_addr(tx_buff, addr),
+				 dma_unmap_len(tx_buff, len), DMA_TO_DEVICE);
+
+		/* return the sk_buff to system */
+		dev_consume_skb_irq(skb);
+
+		txbd->data = 0;
+		txbd->info = 0;
+		tx_buff->skb = NULL;
+
+		*txbd_dirty = (*txbd_dirty + 1) % TX_BD_NUM;
+	}
+
+	/* Ensure that txbd_dirty is visible to tx() before checking
+	 * for queue stopped.
+	 */
+	smp_mb();
+
+	if (netif_queue_stopped(ndev) && arc_emac_tx_avail(priv))
+		netif_wake_queue(ndev);
+}
+
+/**
+ * arc_emac_rx - processing of Rx packets.
+ * @ndev:	Pointer to the network device.
+ * @budget:	How many BDs to process on 1 call.
+ *
+ * returns:	Number of processed BDs
+ *
+ * Iterate through Rx BDs and deliver received packages to upper layer.
+ */
+static int arc_emac_rx(struct net_device *ndev, int budget)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+	struct device *dev = ndev->dev.parent;
+	unsigned int work_done;
+
+	for (work_done = 0; work_done < budget; work_done++) {
+		unsigned int *last_rx_bd = &priv->last_rx_bd;
+		struct net_device_stats *stats = &ndev->stats;
+		struct buffer_state *rx_buff = &priv->rx_buff[*last_rx_bd];
+		struct arc_emac_bd *rxbd = &priv->rxbd[*last_rx_bd];
+		unsigned int pktlen, info = le32_to_cpu(rxbd->info);
+		struct sk_buff *skb;
+		dma_addr_t addr;
+
+		if (unlikely((info & OWN_MASK) == FOR_EMAC))
+			break;
+
+		/* Make a note that we saw a packet at this BD.
+		 * So next time, driver starts from this + 1
+		 */
+		*last_rx_bd = (*last_rx_bd + 1) % RX_BD_NUM;
+
+		if (unlikely((info & FIRST_OR_LAST_MASK) !=
+			     FIRST_OR_LAST_MASK)) {
+			/* We pre-allocate buffers of MTU size so incoming
+			 * packets won't be split/chained.
+			 */
+			if (net_ratelimit())
+				netdev_err(ndev, "incomplete packet received\n");
+
+			/* Return ownership to EMAC */
+			rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
+			stats->rx_errors++;
+			stats->rx_length_errors++;
+			continue;
+		}
+
+		/* Prepare the BD for next cycle. netif_receive_skb()
+		 * only if new skb was allocated and mapped to avoid holes
+		 * in the RX fifo.
+		 */
+		skb = netdev_alloc_skb_ip_align(ndev, EMAC_BUFFER_SIZE);
+		if (unlikely(!skb)) {
+			if (net_ratelimit())
+				netdev_err(ndev, "cannot allocate skb\n");
+			/* Return ownership to EMAC */
+			rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
+			stats->rx_errors++;
+			stats->rx_dropped++;
+			continue;
+		}
+
+		addr = dma_map_single(dev, (void *)skb->data,
+				      EMAC_BUFFER_SIZE, DMA_FROM_DEVICE);
+		if (dma_mapping_error(dev, addr)) {
+			if (net_ratelimit())
+				netdev_err(ndev, "cannot map dma buffer\n");
+			dev_kfree_skb(skb);
+			/* Return ownership to EMAC */
+			rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
+			stats->rx_errors++;
+			stats->rx_dropped++;
+			continue;
+		}
+
+		/* unmap previosly mapped skb */
+		dma_unmap_single(dev, dma_unmap_addr(rx_buff, addr),
+				 dma_unmap_len(rx_buff, len), DMA_FROM_DEVICE);
+
+		pktlen = info & LEN_MASK;
+		stats->rx_packets++;
+		stats->rx_bytes += pktlen;
+		skb_put(rx_buff->skb, pktlen);
+		rx_buff->skb->dev = ndev;
+		rx_buff->skb->protocol = eth_type_trans(rx_buff->skb, ndev);
+
+		netif_receive_skb(rx_buff->skb);
+
+		rx_buff->skb = skb;
+		dma_unmap_addr_set(rx_buff, addr, addr);
+		dma_unmap_len_set(rx_buff, len, EMAC_BUFFER_SIZE);
+
+		rxbd->data = cpu_to_le32(addr);
+
+		/* Make sure pointer to data buffer is set */
+		wmb();
+
+		/* Return ownership to EMAC */
+		rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
+	}
+
+	return work_done;
+}
+
+/**
+ * arc_emac_rx_miss_handle - handle R_MISS register
+ * @ndev:	Pointer to the net_device structure.
+ */
+static void arc_emac_rx_miss_handle(struct net_device *ndev)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+	struct net_device_stats *stats = &ndev->stats;
+	unsigned int miss;
+
+	miss = arc_reg_get(priv, R_MISS);
+	if (miss) {
+		stats->rx_errors += miss;
+		stats->rx_missed_errors += miss;
+		priv->rx_missed_errors += miss;
+	}
+}
+
+/**
+ * arc_emac_rx_stall_check - check RX stall
+ * @ndev:	Pointer to the net_device structure.
+ * @budget:	How many BDs requested to process on 1 call.
+ * @work_done:	How many BDs processed
+ *
+ * Under certain conditions EMAC stop reception of incoming packets and
+ * continuously increment R_MISS register instead of saving data into
+ * provided buffer. This function detect that condition and restart
+ * EMAC.
+ */
+static void arc_emac_rx_stall_check(struct net_device *ndev,
+				    int budget, unsigned int work_done)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+	struct arc_emac_bd *rxbd;
+
+	if (work_done)
+		priv->rx_missed_errors = 0;
+
+	if (priv->rx_missed_errors && budget) {
+		rxbd = &priv->rxbd[priv->last_rx_bd];
+		if (le32_to_cpu(rxbd->info) & FOR_EMAC) {
+			arc_emac_restart(ndev);
+			priv->rx_missed_errors = 0;
+		}
+	}
+}
+
+/**
+ * arc_emac_poll - NAPI poll handler.
+ * @napi:	Pointer to napi_struct structure.
+ * @budget:	How many BDs to process on 1 call.
+ *
+ * returns:	Number of processed BDs
+ */
+static int arc_emac_poll(struct napi_struct *napi, int budget)
+{
+	struct net_device *ndev = napi->dev;
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+	unsigned int work_done;
+
+	arc_emac_tx_clean(ndev);
+	arc_emac_rx_miss_handle(ndev);
+
+	work_done = arc_emac_rx(ndev, budget);
+	if (work_done < budget) {
+		napi_complete_done(napi, work_done);
+		arc_reg_or(priv, R_ENABLE, RXINT_MASK | TXINT_MASK);
+	}
+
+	arc_emac_rx_stall_check(ndev, budget, work_done);
+
+	return work_done;
+}
+
+/**
+ * arc_emac_intr - Global interrupt handler for EMAC.
+ * @irq:		irq number.
+ * @dev_instance:	device instance.
+ *
+ * returns: IRQ_HANDLED for all cases.
+ *
+ * ARC EMAC has only 1 interrupt line, and depending on bits raised in
+ * STATUS register we may tell what is a reason for interrupt to fire.
+ */
+static irqreturn_t arc_emac_intr(int irq, void *dev_instance)
+{
+	struct net_device *ndev = dev_instance;
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+	struct net_device_stats *stats = &ndev->stats;
+	unsigned int status;
+
+	status = arc_reg_get(priv, R_STATUS);
+	status &= ~MDIO_MASK;
+
+	/* Reset all flags except "MDIO complete" */
+	arc_reg_set(priv, R_STATUS, status);
+
+	if (status & (RXINT_MASK | TXINT_MASK)) {
+		if (likely(napi_schedule_prep(&priv->napi))) {
+			arc_reg_clr(priv, R_ENABLE, RXINT_MASK | TXINT_MASK);
+			__napi_schedule(&priv->napi);
+		}
+	}
+
+	if (status & ERR_MASK) {
+		/* MSER/RXCR/RXFR/RXFL interrupt fires on corresponding
+		 * 8-bit error counter overrun.
+		 */
+
+		if (status & MSER_MASK) {
+			stats->rx_missed_errors += 0x100;
+			stats->rx_errors += 0x100;
+			priv->rx_missed_errors += 0x100;
+			napi_schedule(&priv->napi);
+		}
+
+		if (status & RXCR_MASK) {
+			stats->rx_crc_errors += 0x100;
+			stats->rx_errors += 0x100;
+		}
+
+		if (status & RXFR_MASK) {
+			stats->rx_frame_errors += 0x100;
+			stats->rx_errors += 0x100;
+		}
+
+		if (status & RXFL_MASK) {
+			stats->rx_over_errors += 0x100;
+			stats->rx_errors += 0x100;
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_NET_POLL_CONTROLLER
+static void arc_emac_poll_controller(struct net_device *dev)
+{
+	disable_irq(dev->irq);
+	arc_emac_intr(dev->irq, dev);
+	enable_irq(dev->irq);
+}
+#endif
+
+/**
+ * arc_emac_open - Open the network device.
+ * @ndev:	Pointer to the network device.
+ *
+ * returns: 0, on success or non-zero error value on failure.
+ *
+ * This function sets the MAC address, requests and enables an IRQ
+ * for the EMAC device and starts the Tx queue.
+ * It also connects to the phy device.
+ */
+static int arc_emac_open(struct net_device *ndev)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+	struct phy_device *phy_dev = ndev->phydev;
+	struct device *dev = ndev->dev.parent;
+	int i;
+
+	phy_dev->autoneg = AUTONEG_ENABLE;
+	phy_dev->speed = 0;
+	phy_dev->duplex = 0;
+	linkmode_and(phy_dev->advertising, phy_dev->advertising,
+		     phy_dev->supported);
+
+	priv->last_rx_bd = 0;
+
+	/* Allocate and set buffers for Rx BD's */
+	for (i = 0; i < RX_BD_NUM; i++) {
+		dma_addr_t addr;
+		unsigned int *last_rx_bd = &priv->last_rx_bd;
+		struct arc_emac_bd *rxbd = &priv->rxbd[*last_rx_bd];
+		struct buffer_state *rx_buff = &priv->rx_buff[*last_rx_bd];
+
+		rx_buff->skb = netdev_alloc_skb_ip_align(ndev,
+							 EMAC_BUFFER_SIZE);
+		if (unlikely(!rx_buff->skb))
+			return -ENOMEM;
+
+		addr = dma_map_single(dev, (void *)rx_buff->skb->data,
+				      EMAC_BUFFER_SIZE, DMA_FROM_DEVICE);
+		if (dma_mapping_error(dev, addr)) {
+			netdev_err(ndev, "cannot dma map\n");
+			dev_kfree_skb(rx_buff->skb);
+			return -ENOMEM;
+		}
+		dma_unmap_addr_set(rx_buff, addr, addr);
+		dma_unmap_len_set(rx_buff, len, EMAC_BUFFER_SIZE);
+
+		rxbd->data = cpu_to_le32(addr);
+
+		/* Make sure pointer to data buffer is set */
+		wmb();
+
+		/* Return ownership to EMAC */
+		rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
+
+		*last_rx_bd = (*last_rx_bd + 1) % RX_BD_NUM;
+	}
+
+	priv->txbd_curr = 0;
+	priv->txbd_dirty = 0;
+
+	/* Clean Tx BD's */
+	memset(priv->txbd, 0, TX_RING_SZ);
+
+	/* Initialize logical address filter */
+	arc_reg_set(priv, R_LAFL, 0);
+	arc_reg_set(priv, R_LAFH, 0);
+
+	/* Set BD ring pointers for device side */
+	arc_reg_set(priv, R_RX_RING, (unsigned int)priv->rxbd_dma);
+	arc_reg_set(priv, R_TX_RING, (unsigned int)priv->txbd_dma);
+
+	/* Enable interrupts */
+	arc_reg_set(priv, R_ENABLE, RXINT_MASK | TXINT_MASK | ERR_MASK);
+
+	/* Set CONTROL */
+	arc_reg_set(priv, R_CTRL,
+		    (RX_BD_NUM << 24) |	/* RX BD table length */
+		    (TX_BD_NUM << 16) |	/* TX BD table length */
+		    TXRN_MASK | RXRN_MASK);
+
+	napi_enable(&priv->napi);
+
+	/* Enable EMAC */
+	arc_reg_or(priv, R_CTRL, EN_MASK);
+
+	phy_start(ndev->phydev);
+
+	netif_start_queue(ndev);
+
+	return 0;
+}
+
+/**
+ * arc_emac_set_rx_mode - Change the receive filtering mode.
+ * @ndev:	Pointer to the network device.
+ *
+ * This function enables/disables promiscuous or all-multicast mode
+ * and updates the multicast filtering list of the network device.
+ */
+static void arc_emac_set_rx_mode(struct net_device *ndev)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+
+	if (ndev->flags & IFF_PROMISC) {
+		arc_reg_or(priv, R_CTRL, PROM_MASK);
+	} else {
+		arc_reg_clr(priv, R_CTRL, PROM_MASK);
+
+		if (ndev->flags & IFF_ALLMULTI) {
+			arc_reg_set(priv, R_LAFL, ~0);
+			arc_reg_set(priv, R_LAFH, ~0);
+		} else if (ndev->flags & IFF_MULTICAST) {
+			struct netdev_hw_addr *ha;
+			unsigned int filter[2] = { 0, 0 };
+			int bit;
+
+			netdev_for_each_mc_addr(ha, ndev) {
+				bit = ether_crc_le(ETH_ALEN, ha->addr) >> 26;
+				filter[bit >> 5] |= 1 << (bit & 31);
+			}
+
+			arc_reg_set(priv, R_LAFL, filter[0]);
+			arc_reg_set(priv, R_LAFH, filter[1]);
+		} else {
+			arc_reg_set(priv, R_LAFL, 0);
+			arc_reg_set(priv, R_LAFH, 0);
+		}
+	}
+}
+
+/**
+ * arc_free_tx_queue - free skb from tx queue
+ * @ndev:	Pointer to the network device.
+ *
+ * This function must be called while EMAC disable
+ */
+static void arc_free_tx_queue(struct net_device *ndev)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+	struct device *dev = ndev->dev.parent;
+	unsigned int i;
+
+	for (i = 0; i < TX_BD_NUM; i++) {
+		struct arc_emac_bd *txbd = &priv->txbd[i];
+		struct buffer_state *tx_buff = &priv->tx_buff[i];
+
+		if (tx_buff->skb) {
+			dma_unmap_single(dev,
+					 dma_unmap_addr(tx_buff, addr),
+					 dma_unmap_len(tx_buff, len),
+					 DMA_TO_DEVICE);
+
+			/* return the sk_buff to system */
+			dev_kfree_skb_irq(tx_buff->skb);
+		}
+
+		txbd->info = 0;
+		txbd->data = 0;
+		tx_buff->skb = NULL;
+	}
+}
+
+/**
+ * arc_free_rx_queue - free skb from rx queue
+ * @ndev:	Pointer to the network device.
+ *
+ * This function must be called while EMAC disable
+ */
+static void arc_free_rx_queue(struct net_device *ndev)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+	struct device *dev = ndev->dev.parent;
+	unsigned int i;
+
+	for (i = 0; i < RX_BD_NUM; i++) {
+		struct arc_emac_bd *rxbd = &priv->rxbd[i];
+		struct buffer_state *rx_buff = &priv->rx_buff[i];
+
+		if (rx_buff->skb) {
+			dma_unmap_single(dev,
+					 dma_unmap_addr(rx_buff, addr),
+					 dma_unmap_len(rx_buff, len),
+					 DMA_FROM_DEVICE);
+
+			/* return the sk_buff to system */
+			dev_kfree_skb_irq(rx_buff->skb);
+		}
+
+		rxbd->info = 0;
+		rxbd->data = 0;
+		rx_buff->skb = NULL;
+	}
+}
+
+/**
+ * arc_emac_stop - Close the network device.
+ * @ndev:	Pointer to the network device.
+ *
+ * This function stops the Tx queue, disables interrupts and frees the IRQ for
+ * the EMAC device.
+ * It also disconnects the PHY device associated with the EMAC device.
+ */
+static int arc_emac_stop(struct net_device *ndev)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+
+	napi_disable(&priv->napi);
+	netif_stop_queue(ndev);
+
+	phy_stop(ndev->phydev);
+
+	/* Disable interrupts */
+	arc_reg_clr(priv, R_ENABLE, RXINT_MASK | TXINT_MASK | ERR_MASK);
+
+	/* Disable EMAC */
+	arc_reg_clr(priv, R_CTRL, EN_MASK);
+
+	/* Return the sk_buff to system */
+	arc_free_tx_queue(ndev);
+	arc_free_rx_queue(ndev);
+
+	return 0;
+}
+
+/**
+ * arc_emac_stats - Get system network statistics.
+ * @ndev:	Pointer to net_device structure.
+ *
+ * Returns the address of the device statistics structure.
+ * Statistics are updated in interrupt handler.
+ */
+static struct net_device_stats *arc_emac_stats(struct net_device *ndev)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+	struct net_device_stats *stats = &ndev->stats;
+	unsigned long miss, rxerr;
+	u8 rxcrc, rxfram, rxoflow;
+
+	rxerr = arc_reg_get(priv, R_RXERR);
+	miss = arc_reg_get(priv, R_MISS);
+
+	rxcrc = rxerr;
+	rxfram = rxerr >> 8;
+	rxoflow = rxerr >> 16;
+
+	stats->rx_errors += miss;
+	stats->rx_errors += rxcrc + rxfram + rxoflow;
+
+	stats->rx_over_errors += rxoflow;
+	stats->rx_frame_errors += rxfram;
+	stats->rx_crc_errors += rxcrc;
+	stats->rx_missed_errors += miss;
+
+	return stats;
+}
+
+/**
+ * arc_emac_tx - Starts the data transmission.
+ * @skb:	sk_buff pointer that contains data to be Transmitted.
+ * @ndev:	Pointer to net_device structure.
+ *
+ * returns: NETDEV_TX_OK, on success
+ *		NETDEV_TX_BUSY, if any of the descriptors are not free.
+ *
+ * This function is invoked from upper layers to initiate transmission.
+ */
+static netdev_tx_t arc_emac_tx(struct sk_buff *skb, struct net_device *ndev)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+	unsigned int len, *txbd_curr = &priv->txbd_curr;
+	struct net_device_stats *stats = &ndev->stats;
+	__le32 *info = &priv->txbd[*txbd_curr].info;
+	struct device *dev = ndev->dev.parent;
+	dma_addr_t addr;
+
+	if (skb_padto(skb, ETH_ZLEN))
+		return NETDEV_TX_OK;
+
+	len = max_t(unsigned int, ETH_ZLEN, skb->len);
+
+	if (unlikely(!arc_emac_tx_avail(priv))) {
+		netif_stop_queue(ndev);
+		netdev_err(ndev, "BUG! Tx Ring full when queue awake!\n");
+		return NETDEV_TX_BUSY;
+	}
+
+	addr = dma_map_single(dev, (void *)skb->data, len, DMA_TO_DEVICE);
+
+	if (unlikely(dma_mapping_error(dev, addr))) {
+		stats->tx_dropped++;
+		stats->tx_errors++;
+		dev_kfree_skb_any(skb);
+		return NETDEV_TX_OK;
+	}
+	dma_unmap_addr_set(&priv->tx_buff[*txbd_curr], addr, addr);
+	dma_unmap_len_set(&priv->tx_buff[*txbd_curr], len, len);
+
+	priv->txbd[*txbd_curr].data = cpu_to_le32(addr);
+
+	/* Make sure pointer to data buffer is set */
+	wmb();
+
+	skb_tx_timestamp(skb);
+
+	*info = cpu_to_le32(FOR_EMAC | FIRST_OR_LAST_MASK | len);
+
+	/* Make sure info word is set */
+	wmb();
+
+	priv->tx_buff[*txbd_curr].skb = skb;
+
+	/* Increment index to point to the next BD */
+	*txbd_curr = (*txbd_curr + 1) % TX_BD_NUM;
+
+	/* Ensure that tx_clean() sees the new txbd_curr before
+	 * checking the queue status. This prevents an unneeded wake
+	 * of the queue in tx_clean().
+	 */
+	smp_mb();
+
+	if (!arc_emac_tx_avail(priv)) {
+		netif_stop_queue(ndev);
+		/* Refresh tx_dirty */
+		smp_mb();
+		if (arc_emac_tx_avail(priv))
+			netif_start_queue(ndev);
+	}
+
+	arc_reg_set(priv, R_STATUS, TXPL_MASK);
+
+	return NETDEV_TX_OK;
+}
+
+static void arc_emac_set_address_internal(struct net_device *ndev)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+	unsigned int addr_low, addr_hi;
+
+	addr_low = le32_to_cpu(*(__le32 *)&ndev->dev_addr[0]);
+	addr_hi = le16_to_cpu(*(__le16 *)&ndev->dev_addr[4]);
+
+	arc_reg_set(priv, R_ADDRL, addr_low);
+	arc_reg_set(priv, R_ADDRH, addr_hi);
+}
+
+/**
+ * arc_emac_set_address - Set the MAC address for this device.
+ * @ndev:	Pointer to net_device structure.
+ * @p:		6 byte Address to be written as MAC address.
+ *
+ * This function copies the HW address from the sockaddr structure to the
+ * net_device structure and updates the address in HW.
+ *
+ * returns:	-EBUSY if the net device is busy or 0 if the address is set
+ *		successfully.
+ */
+static int arc_emac_set_address(struct net_device *ndev, void *p)
+{
+	struct sockaddr *addr = p;
+
+	if (netif_running(ndev))
+		return -EBUSY;
+
+	if (!is_valid_ether_addr(addr->sa_data))
+		return -EADDRNOTAVAIL;
+
+	eth_hw_addr_set(ndev, addr->sa_data);
+
+	arc_emac_set_address_internal(ndev);
+
+	return 0;
+}
+
+/**
+ * arc_emac_restart - Restart EMAC
+ * @ndev:	Pointer to net_device structure.
+ *
+ * This function do hardware reset of EMAC in order to restore
+ * network packets reception.
+ */
+static void arc_emac_restart(struct net_device *ndev)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+	struct net_device_stats *stats = &ndev->stats;
+	int i;
+
+	if (net_ratelimit())
+		netdev_warn(ndev, "restarting stalled EMAC\n");
+
+	netif_stop_queue(ndev);
+
+	/* Disable interrupts */
+	arc_reg_clr(priv, R_ENABLE, RXINT_MASK | TXINT_MASK | ERR_MASK);
+
+	/* Disable EMAC */
+	arc_reg_clr(priv, R_CTRL, EN_MASK);
+
+	/* Return the sk_buff to system */
+	arc_free_tx_queue(ndev);
+
+	/* Clean Tx BD's */
+	priv->txbd_curr = 0;
+	priv->txbd_dirty = 0;
+	memset(priv->txbd, 0, TX_RING_SZ);
+
+	for (i = 0; i < RX_BD_NUM; i++) {
+		struct arc_emac_bd *rxbd = &priv->rxbd[i];
+		unsigned int info = le32_to_cpu(rxbd->info);
+
+		if (!(info & FOR_EMAC)) {
+			stats->rx_errors++;
+			stats->rx_dropped++;
+		}
+		/* Return ownership to EMAC */
+		rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
+	}
+	priv->last_rx_bd = 0;
+
+	/* Make sure info is visible to EMAC before enable */
+	wmb();
+
+	/* Enable interrupts */
+	arc_reg_set(priv, R_ENABLE, RXINT_MASK | TXINT_MASK | ERR_MASK);
+
+	/* Enable EMAC */
+	arc_reg_or(priv, R_CTRL, EN_MASK);
+
+	netif_start_queue(ndev);
+}
+
+static const struct net_device_ops arc_emac_netdev_ops = {
+	.ndo_open		= arc_emac_open,
+	.ndo_stop		= arc_emac_stop,
+	.ndo_start_xmit		= arc_emac_tx,
+	.ndo_set_mac_address	= arc_emac_set_address,
+	.ndo_get_stats		= arc_emac_stats,
+	.ndo_set_rx_mode	= arc_emac_set_rx_mode,
+	.ndo_eth_ioctl		= phy_do_ioctl_running,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	.ndo_poll_controller	= arc_emac_poll_controller,
+#endif
+};
+
+int arc_emac_probe(struct net_device *ndev, int interface)
+{
+	struct device *dev = ndev->dev.parent;
+	struct resource res_regs;
+	struct device_node *phy_node;
+	struct phy_device *phydev = NULL;
+	struct arc_emac_priv *priv;
+	unsigned int id, clock_frequency, irq;
+	int err;
+
+	/* Get PHY from device tree */
+	phy_node = of_parse_phandle(dev->of_node, "phy", 0);
+	if (!phy_node) {
+		dev_err(dev, "failed to retrieve phy description from device tree\n");
+		return -ENODEV;
+	}
+
+	/* Get EMAC registers base address from device tree */
+	err = of_address_to_resource(dev->of_node, 0, &res_regs);
+	if (err) {
+		dev_err(dev, "failed to retrieve registers base from device tree\n");
+		err = -ENODEV;
+		goto out_put_node;
+	}
+
+	/* Get IRQ from device tree */
+	irq = irq_of_parse_and_map(dev->of_node, 0);
+	if (!irq) {
+		dev_err(dev, "failed to retrieve <irq> value from device tree\n");
+		err = -ENODEV;
+		goto out_put_node;
+	}
+
+	ndev->netdev_ops = &arc_emac_netdev_ops;
+	ndev->ethtool_ops = &arc_emac_ethtool_ops;
+	ndev->watchdog_timeo = TX_TIMEOUT;
+
+	priv = netdev_priv(ndev);
+	priv->dev = dev;
+
+	priv->regs = devm_ioremap_resource(dev, &res_regs);
+	if (IS_ERR(priv->regs)) {
+		err = PTR_ERR(priv->regs);
+		goto out_put_node;
+	}
+
+	dev_dbg(dev, "Registers base address is 0x%p\n", priv->regs);
+
+	if (priv->clk) {
+		err = clk_prepare_enable(priv->clk);
+		if (err) {
+			dev_err(dev, "failed to enable clock\n");
+			goto out_put_node;
+		}
+
+		clock_frequency = clk_get_rate(priv->clk);
+	} else {
+		/* Get CPU clock frequency from device tree */
+		if (of_property_read_u32(dev->of_node, "clock-frequency",
+					 &clock_frequency)) {
+			dev_err(dev, "failed to retrieve <clock-frequency> from device tree\n");
+			err = -EINVAL;
+			goto out_put_node;
+		}
+	}
+
+	id = arc_reg_get(priv, R_ID);
+
+	/* Check for EMAC revision 5 or 7, magic number */
+	if (!(id == 0x0005fd02 || id == 0x0007fd02)) {
+		dev_err(dev, "ARC EMAC not detected, id=0x%x\n", id);
+		err = -ENODEV;
+		goto out_clken;
+	}
+	dev_info(dev, "ARC EMAC detected with id: 0x%x\n", id);
+
+	/* Set poll rate so that it polls every 1 ms */
+	arc_reg_set(priv, R_POLLRATE, clock_frequency / 1000000);
+
+	/*
+	 * Put the device into a known quiescent state before requesting
+	 * the IRQ. Clear only EMAC interrupt status bits here; leave the
+	 * MDIO completion bit alone and avoid writing TXPL_MASK, which is
+	 * used to force TX polling rather than acknowledge interrupts.
+	 */
+	arc_reg_set(priv, R_ENABLE, 0);
+	arc_reg_set(priv, R_STATUS, RXINT_MASK | TXINT_MASK | ERR_MASK |
+		    TXCH_MASK | MSER_MASK | RXCR_MASK |
+		    RXFR_MASK | RXFL_MASK);
+
+	ndev->irq = irq;
+	dev_info(dev, "IRQ is %d\n", ndev->irq);
+
+	/* Register interrupt handler for device */
+	err = devm_request_irq(dev, ndev->irq, arc_emac_intr, 0,
+			       ndev->name, ndev);
+	if (err) {
+		dev_err(dev, "could not allocate IRQ\n");
+		goto out_clken;
+	}
+
+	/* Get MAC address from device tree */
+	err = of_get_ethdev_address(dev->of_node, ndev);
+	if (err)
+		eth_hw_addr_random(ndev);
+
+	arc_emac_set_address_internal(ndev);
+	dev_info(dev, "MAC address is now %pM\n", ndev->dev_addr);
+
+	/* Do 1 allocation instead of 2 separate ones for Rx and Tx BD rings */
+	priv->rxbd = dmam_alloc_coherent(dev, RX_RING_SZ + TX_RING_SZ,
+					 &priv->rxbd_dma, GFP_KERNEL);
+
+	if (!priv->rxbd) {
+		dev_err(dev, "failed to allocate data buffers\n");
+		err = -ENOMEM;
+		goto out_clken;
+	}
+
+	priv->txbd = priv->rxbd + RX_BD_NUM;
+
+	priv->txbd_dma = priv->rxbd_dma + RX_RING_SZ;
+	dev_dbg(dev, "EMAC Device addr: Rx Ring [0x%x], Tx Ring[%x]\n",
+		(unsigned int)priv->rxbd_dma, (unsigned int)priv->txbd_dma);
+
+	err = arc_mdio_probe(priv);
+	if (err) {
+		dev_err(dev, "failed to probe MII bus\n");
+		goto out_clken;
+	}
+
+	phydev = of_phy_connect(ndev, phy_node, arc_emac_adjust_link, 0,
+				interface);
+	if (!phydev) {
+		dev_err(dev, "of_phy_connect() failed\n");
+		err = -ENODEV;
+		goto out_mdio;
+	}
+
+	dev_info(dev, "connected to %s phy with id 0x%x\n",
+		 phydev->drv->name, phydev->phy_id);
+
+	netif_napi_add_weight(ndev, &priv->napi, arc_emac_poll,
+			      ARC_EMAC_NAPI_WEIGHT);
+
+	err = register_netdev(ndev);
+	if (err) {
+		dev_err(dev, "failed to register network device\n");
+		goto out_netif_api;
+	}
+
+	of_node_put(phy_node);
+	return 0;
+
+out_netif_api:
+	netif_napi_del(&priv->napi);
+	phy_disconnect(phydev);
+out_mdio:
+	arc_mdio_remove(priv);
+out_clken:
+	if (priv->clk)
+		clk_disable_unprepare(priv->clk);
+out_put_node:
+	of_node_put(phy_node);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(arc_emac_probe);
+
+void arc_emac_remove(struct net_device *ndev)
+{
+	struct arc_emac_priv *priv = netdev_priv(ndev);
+
+	phy_disconnect(ndev->phydev);
+	arc_mdio_remove(priv);
+	unregister_netdev(ndev);
+	netif_napi_del(&priv->napi);
+
+	if (!IS_ERR(priv->clk))
+		clk_disable_unprepare(priv->clk);
+}
+EXPORT_SYMBOL_GPL(arc_emac_remove);
+
+MODULE_AUTHOR("Alexey Brodkin <abrodkin@synopsys.com>");
+MODULE_DESCRIPTION("ARC EMAC driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/net/ethernet/arc/emac_mdio.c b/drivers/net/ethernet/arc/emac_mdio.c
new file mode 100644
index 000000000..078b1a72c
--- /dev/null
+++ b/drivers/net/ethernet/arc/emac_mdio.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com)
+ *
+ * MDIO implementation for ARC EMAC
+ */
+
+#include <linux/delay.h>
+#include <linux/of_mdio.h>
+#include <linux/platform_device.h>
+#include <linux/gpio/consumer.h>
+
+#include "emac.h"
+
+/* Number of seconds we wait for "MDIO complete" flag to appear */
+#define ARC_MDIO_COMPLETE_POLL_COUNT	1
+
+/**
+ * arc_mdio_complete_wait - Waits until MDIO transaction is completed.
+ * @priv:	Pointer to ARC EMAC private data structure.
+ *
+ * returns:	0 on success, -ETIMEDOUT on a timeout.
+ */
+static int arc_mdio_complete_wait(struct arc_emac_priv *priv)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARC_MDIO_COMPLETE_POLL_COUNT * 40; i++) {
+		unsigned int status = arc_reg_get(priv, R_STATUS);
+
+		status &= MDIO_MASK;
+
+		if (status) {
+			/* Reset "MDIO complete" flag */
+			arc_reg_set(priv, R_STATUS, status);
+			return 0;
+		}
+
+		msleep(25);
+	}
+
+	return -ETIMEDOUT;
+}
+
+/**
+ * arc_mdio_read - MDIO interface read function.
+ * @bus:	Pointer to MII bus structure.
+ * @phy_addr:	Address of the PHY device.
+ * @reg_num:	PHY register to read.
+ *
+ * returns:	The register contents on success, -ETIMEDOUT on a timeout.
+ *
+ * Reads the contents of the requested register from the requested PHY
+ * address.
+ */
+static int arc_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
+{
+	struct arc_emac_priv *priv = bus->priv;
+	unsigned int value;
+	int error;
+
+	arc_reg_set(priv, R_MDIO,
+		    0x60020000 | (phy_addr << 23) | (reg_num << 18));
+
+	error = arc_mdio_complete_wait(priv);
+	if (error < 0)
+		return error;
+
+	value = arc_reg_get(priv, R_MDIO) & 0xffff;
+
+	dev_dbg(priv->dev, "arc_mdio_read(phy_addr=%i, reg_num=%x) = %x\n",
+		phy_addr, reg_num, value);
+
+	return value;
+}
+
+/**
+ * arc_mdio_write - MDIO interface write function.
+ * @bus:	Pointer to MII bus structure.
+ * @phy_addr:	Address of the PHY device.
+ * @reg_num:	PHY register to write to.
+ * @value:	Value to be written into the register.
+ *
+ * returns:	0 on success, -ETIMEDOUT on a timeout.
+ *
+ * Writes the value to the requested register.
+ */
+static int arc_mdio_write(struct mii_bus *bus, int phy_addr,
+			  int reg_num, u16 value)
+{
+	struct arc_emac_priv *priv = bus->priv;
+
+	dev_dbg(priv->dev,
+		"arc_mdio_write(phy_addr=%i, reg_num=%x, value=%x)\n",
+		phy_addr, reg_num, value);
+
+	arc_reg_set(priv, R_MDIO,
+		    0x50020000 | (phy_addr << 23) | (reg_num << 18) | value);
+
+	return arc_mdio_complete_wait(priv);
+}
+
+/**
+ * arc_mdio_reset
+ * @bus: points to the mii_bus structure
+ * Description: reset the MII bus
+ */
+static int arc_mdio_reset(struct mii_bus *bus)
+{
+	struct arc_emac_priv *priv = bus->priv;
+	struct arc_emac_mdio_bus_data *data = &priv->bus_data;
+
+	if (data->reset_gpio) {
+		gpiod_set_value_cansleep(data->reset_gpio, 1);
+		msleep(data->msec);
+		gpiod_set_value_cansleep(data->reset_gpio, 0);
+	}
+
+	return 0;
+}
+
+/**
+ * arc_mdio_probe - MDIO probe function.
+ * @priv:	Pointer to ARC EMAC private data structure.
+ *
+ * returns:	0 on success, -ENOMEM when mdiobus_alloc
+ * (to allocate memory for MII bus structure) fails.
+ *
+ * Sets up and registers the MDIO interface.
+ */
+int arc_mdio_probe(struct arc_emac_priv *priv)
+{
+	struct arc_emac_mdio_bus_data *data = &priv->bus_data;
+	struct device_node *np = priv->dev->of_node;
+	const char *name = "Synopsys MII Bus";
+	struct device_node *mdio_node;
+	struct mii_bus *bus;
+	int error;
+
+	bus = mdiobus_alloc();
+	if (!bus)
+		return -ENOMEM;
+
+	priv->bus = bus;
+	bus->priv = priv;
+	bus->parent = priv->dev;
+	bus->name = name;
+	bus->read = &arc_mdio_read;
+	bus->write = &arc_mdio_write;
+	bus->reset = &arc_mdio_reset;
+
+	/* optional reset-related properties */
+	data->reset_gpio = devm_gpiod_get_optional(priv->dev, "phy-reset",
+						   GPIOD_OUT_LOW);
+	if (IS_ERR(data->reset_gpio)) {
+		mdiobus_free(bus);
+		return dev_err_probe(priv->dev, PTR_ERR(data->reset_gpio),
+				     "Failed to request gpio\n");
+	}
+
+	of_property_read_u32(np, "phy-reset-duration", &data->msec);
+	/* A sane reset duration should not be longer than 1s */
+	if (data->msec > 1000)
+		data->msec = 1;
+
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s", bus->name);
+
+	/* Backwards compatibility for EMAC nodes without MDIO subnode. */
+	mdio_node = of_get_child_by_name(np, "mdio");
+	if (!mdio_node)
+		mdio_node = of_node_get(np);
+
+	error = of_mdiobus_register(bus, mdio_node);
+	of_node_put(mdio_node);
+	if (error) {
+		mdiobus_free(bus);
+		return dev_err_probe(priv->dev, error,
+				     "cannot register MDIO bus %s\n", name);
+	}
+
+	return 0;
+}
+
+/**
+ * arc_mdio_remove - MDIO remove function.
+ * @priv:	Pointer to ARC EMAC private data structure.
+ *
+ * Unregisters the MDIO and frees any associate memory for MII bus.
+ */
+int arc_mdio_remove(struct arc_emac_priv *priv)
+{
+	mdiobus_unregister(priv->bus);
+	mdiobus_free(priv->bus);
+	priv->bus = NULL;
+
+	return 0;
+}
diff --git a/drivers/net/ethernet/arc/emac_rockchip.c b/drivers/net/ethernet/arc/emac_rockchip.c
new file mode 100644
index 000000000..780e70ea1
--- /dev/null
+++ b/drivers/net/ethernet/arc/emac_rockchip.c
@@ -0,0 +1,278 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * emac-rockchip.c - Rockchip EMAC specific glue layer
+ *
+ * Copyright (C) 2014 Romain Perier <romain.perier@gmail.com>
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_net.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
+#include "emac.h"
+
+#define DRV_NAME        "rockchip_emac"
+
+struct emac_rockchip_soc_data {
+	unsigned int grf_offset;
+	unsigned int grf_mode_offset;
+	unsigned int grf_speed_offset;
+	bool need_div_macclk;
+};
+
+struct rockchip_priv_data {
+	struct arc_emac_priv emac;
+	struct regmap *grf;
+	const struct emac_rockchip_soc_data *soc_data;
+	struct regulator *regulator;
+	struct clk *refclk;
+	struct clk *macclk;
+};
+
+static void emac_rockchip_set_mac_speed(void *priv, unsigned int speed)
+{
+	struct rockchip_priv_data *emac = priv;
+	u32 speed_offset = emac->soc_data->grf_speed_offset;
+	u32 data;
+	int err = 0;
+
+	switch (speed) {
+	case 10:
+		data = (1 << (speed_offset + 16)) | (0 << speed_offset);
+		break;
+	case 100:
+		data = (1 << (speed_offset + 16)) | (1 << speed_offset);
+		break;
+	default:
+		pr_err("speed %u not supported\n", speed);
+		return;
+	}
+
+	err = regmap_write(emac->grf, emac->soc_data->grf_offset, data);
+	if (err)
+		pr_err("unable to apply speed %u to grf (%d)\n", speed, err);
+}
+
+static const struct emac_rockchip_soc_data emac_rk3036_emac_data = {
+	.grf_offset = 0x140,   .grf_mode_offset = 8,
+	.grf_speed_offset = 9, .need_div_macclk = 1,
+};
+
+static const struct emac_rockchip_soc_data emac_rk3066_emac_data = {
+	.grf_offset = 0x154,   .grf_mode_offset = 0,
+	.grf_speed_offset = 1, .need_div_macclk = 0,
+};
+
+static const struct emac_rockchip_soc_data emac_rk3188_emac_data = {
+	.grf_offset = 0x0a4,   .grf_mode_offset = 0,
+	.grf_speed_offset = 1, .need_div_macclk = 0,
+};
+
+static const struct of_device_id emac_rockchip_dt_ids[] = {
+	{
+		.compatible = "rockchip,rk3036-emac",
+		.data = &emac_rk3036_emac_data,
+	},
+	{
+		.compatible = "rockchip,rk3066-emac",
+		.data = &emac_rk3066_emac_data,
+	},
+	{
+		.compatible = "rockchip,rk3188-emac",
+		.data = &emac_rk3188_emac_data,
+	},
+	{ /* Sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, emac_rockchip_dt_ids);
+
+static int emac_rockchip_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct net_device *ndev;
+	struct rockchip_priv_data *priv;
+	const struct of_device_id *match;
+	phy_interface_t interface;
+	u32 data;
+	int err;
+
+	if (!pdev->dev.of_node)
+		return -ENODEV;
+
+	ndev = alloc_etherdev(sizeof(struct rockchip_priv_data));
+	if (!ndev)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, ndev);
+	SET_NETDEV_DEV(ndev, dev);
+
+	priv = netdev_priv(ndev);
+	priv->emac.drv_name = DRV_NAME;
+	priv->emac.set_mac_speed = emac_rockchip_set_mac_speed;
+
+	err = of_get_phy_mode(dev->of_node, &interface);
+	if (err)
+		goto out_netdev;
+
+	/* RK3036/RK3066/RK3188 SoCs only support RMII */
+	if (interface != PHY_INTERFACE_MODE_RMII) {
+		dev_err(dev, "unsupported phy interface mode %d\n", interface);
+		err = -ENOTSUPP;
+		goto out_netdev;
+	}
+
+	priv->grf = syscon_regmap_lookup_by_phandle(dev->of_node,
+						    "rockchip,grf");
+	if (IS_ERR(priv->grf)) {
+		dev_err(dev, "failed to retrieve global register file (%ld)\n",
+			PTR_ERR(priv->grf));
+		err = PTR_ERR(priv->grf);
+		goto out_netdev;
+	}
+
+	match = of_match_node(emac_rockchip_dt_ids, dev->of_node);
+	priv->soc_data = match->data;
+
+	priv->emac.clk = devm_clk_get(dev, "hclk");
+	if (IS_ERR(priv->emac.clk)) {
+		dev_err(dev, "failed to retrieve host clock (%ld)\n",
+			PTR_ERR(priv->emac.clk));
+		err = PTR_ERR(priv->emac.clk);
+		goto out_netdev;
+	}
+
+	priv->refclk = devm_clk_get(dev, "macref");
+	if (IS_ERR(priv->refclk)) {
+		dev_err(dev, "failed to retrieve reference clock (%ld)\n",
+			PTR_ERR(priv->refclk));
+		err = PTR_ERR(priv->refclk);
+		goto out_netdev;
+	}
+
+	err = clk_prepare_enable(priv->refclk);
+	if (err) {
+		dev_err(dev, "failed to enable reference clock (%d)\n", err);
+		goto out_netdev;
+	}
+
+	/* Optional regulator for PHY */
+	priv->regulator = devm_regulator_get_optional(dev, "phy");
+	if (IS_ERR(priv->regulator)) {
+		if (PTR_ERR(priv->regulator) == -EPROBE_DEFER) {
+			err = -EPROBE_DEFER;
+			goto out_clk_disable;
+		}
+		dev_err(dev, "no regulator found\n");
+		priv->regulator = NULL;
+	}
+
+	if (priv->regulator) {
+		err = regulator_enable(priv->regulator);
+		if (err) {
+			dev_err(dev, "failed to enable phy-supply (%d)\n", err);
+			goto out_clk_disable;
+		}
+	}
+
+	/* Set speed 100M */
+	data = (1 << (priv->soc_data->grf_speed_offset + 16)) |
+	       (1 << priv->soc_data->grf_speed_offset);
+	/* Set RMII mode */
+	data |= (1 << (priv->soc_data->grf_mode_offset + 16)) |
+		(0 << priv->soc_data->grf_mode_offset);
+
+	err = regmap_write(priv->grf, priv->soc_data->grf_offset, data);
+	if (err) {
+		dev_err(dev, "unable to apply initial settings to grf (%d)\n",
+			err);
+		goto out_regulator_disable;
+	}
+
+	/* RMII interface needs always a rate of 50MHz */
+	err = clk_set_rate(priv->refclk, 50000000);
+	if (err) {
+		dev_err(dev,
+			"failed to change reference clock rate (%d)\n", err);
+		goto out_regulator_disable;
+	}
+
+	if (priv->soc_data->need_div_macclk) {
+		priv->macclk = devm_clk_get(dev, "macclk");
+		if (IS_ERR(priv->macclk)) {
+			dev_err(dev, "failed to retrieve mac clock (%ld)\n",
+				PTR_ERR(priv->macclk));
+			err = PTR_ERR(priv->macclk);
+			goto out_regulator_disable;
+		}
+
+		err = clk_prepare_enable(priv->macclk);
+		if (err) {
+			dev_err(dev, "failed to enable mac clock (%d)\n", err);
+			goto out_regulator_disable;
+		}
+
+		/* RMII TX/RX needs always a rate of 25MHz */
+		err = clk_set_rate(priv->macclk, 25000000);
+		if (err) {
+			dev_err(dev,
+				"failed to change mac clock rate (%d)\n", err);
+			goto out_clk_disable_macclk;
+		}
+	}
+
+	err = arc_emac_probe(ndev, interface);
+	if (err) {
+		dev_err(dev, "failed to probe arc emac (%d)\n", err);
+		goto out_clk_disable_macclk;
+	}
+
+	return 0;
+
+out_clk_disable_macclk:
+	if (priv->soc_data->need_div_macclk)
+		clk_disable_unprepare(priv->macclk);
+out_regulator_disable:
+	if (priv->regulator)
+		regulator_disable(priv->regulator);
+out_clk_disable:
+	clk_disable_unprepare(priv->refclk);
+out_netdev:
+	free_netdev(ndev);
+	return err;
+}
+
+static void emac_rockchip_remove(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct rockchip_priv_data *priv = netdev_priv(ndev);
+
+	arc_emac_remove(ndev);
+
+	clk_disable_unprepare(priv->refclk);
+
+	if (priv->regulator)
+		regulator_disable(priv->regulator);
+
+	if (priv->soc_data->need_div_macclk)
+		clk_disable_unprepare(priv->macclk);
+
+	free_netdev(ndev);
+}
+
+static struct platform_driver emac_rockchip_driver = {
+	.probe = emac_rockchip_probe,
+	.remove = emac_rockchip_remove,
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table  = emac_rockchip_dt_ids,
+	},
+};
+
+module_platform_driver(emac_rockchip_driver);
+
+MODULE_AUTHOR("Romain Perier <romain.perier@gmail.com>");
+MODULE_DESCRIPTION("Rockchip EMAC platform driver");
+MODULE_LICENSE("GPL");