Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 897 insertions, 0 deletions

diff --git a/drivers/char/xilinx_hwicap/xilinx_hwicap.c b/drivers/char/xilinx_hwicap/xilinx_hwicap.c
new file mode 100644
index 000000000..74a4928ae
--- /dev/null
+++ b/drivers/char/xilinx_hwicap/xilinx_hwicap.c
@@ -0,0 +1,897 @@
+/*****************************************************************************
+ *
+ *     Author: Xilinx, Inc.
+ *
+ *     This program is free software; you can redistribute it and/or modify it
+ *     under the terms of the GNU General Public License as published by the
+ *     Free Software Foundation; either version 2 of the License, or (at your
+ *     option) any later version.
+ *
+ *     XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
+ *     AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
+ *     SOLUTIONS FOR XILINX DEVICES.  BY PROVIDING THIS DESIGN, CODE,
+ *     OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
+ *     APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION
+ *     THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
+ *     AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE
+ *     FOR YOUR IMPLEMENTATION.  XILINX EXPRESSLY DISCLAIMS ANY
+ *     WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
+ *     IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
+ *     REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
+ *     INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ *     FOR A PARTICULAR PURPOSE.
+ *
+ *     (c) Copyright 2002 Xilinx Inc., Systems Engineering Group
+ *     (c) Copyright 2004 Xilinx Inc., Systems Engineering Group
+ *     (c) Copyright 2007-2008 Xilinx Inc.
+ *     All rights reserved.
+ *
+ *     You should have received a copy of the GNU General Public License along
+ *     with this program; if not, write to the Free Software Foundation, Inc.,
+ *     675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *****************************************************************************/
+
+/*
+ * This is the code behind /dev/icap* -- it allows a user-space
+ * application to use the Xilinx ICAP subsystem.
+ *
+ * The following operations are possible:
+ *
+ * open         open the port and initialize for access.
+ * release      release port
+ * write        Write a bitstream to the configuration processor.
+ * read         Read a data stream from the configuration processor.
+ *
+ * After being opened, the port is initialized and accessed to avoid a
+ * corrupted first read which may occur with some hardware.  The port
+ * is left in a desynched state, requiring that a synch sequence be
+ * transmitted before any valid configuration data.  A user will have
+ * exclusive access to the device while it remains open, and the state
+ * of the ICAP cannot be guaranteed after the device is closed.  Note
+ * that a complete reset of the core and the state of the ICAP cannot
+ * be performed on many versions of the cores, hence users of this
+ * device should avoid making inconsistent accesses to the device.  In
+ * particular, accessing the read interface, without first generating
+ * a write containing a readback packet can leave the ICAP in an
+ * inaccessible state.
+ *
+ * Note that in order to use the read interface, it is first necessary
+ * to write a request packet to the write interface.  i.e., it is not
+ * possible to simply readback the bitstream (or any configuration
+ * bits) from a device without specifically requesting them first.
+ * The code to craft such packets is intended to be part of the
+ * user-space application code that uses this device.  The simplest
+ * way to use this interface is simply:
+ *
+ * cp foo.bit /dev/icap0
+ *
+ * Note that unless foo.bit is an appropriately constructed partial
+ * bitstream, this has a high likelihood of overwriting the design
+ * currently programmed in the FPGA.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/fcntl.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/mutex.h>
+#include <linux/sysctl.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+#ifdef CONFIG_OF
+/* For open firmware. */
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#endif
+
+#include "xilinx_hwicap.h"
+#include "buffer_icap.h"
+#include "fifo_icap.h"
+
+#define DRIVER_NAME "icap"
+
+#define HWICAP_REGS   (0x10000)
+
+#define XHWICAP_MAJOR 259
+#define XHWICAP_MINOR 0
+#define HWICAP_DEVICES 1
+
+/* An array, which is set to true when the device is registered. */
+static DEFINE_MUTEX(hwicap_mutex);
+static bool probed_devices[HWICAP_DEVICES];
+static struct mutex icap_sem;
+
+static struct class *icap_class;
+
+#define UNIMPLEMENTED 0xFFFF
+
+static const struct config_registers v2_config_registers = {
+	.CRC = 0,
+	.FAR = 1,
+	.FDRI = 2,
+	.FDRO = 3,
+	.CMD = 4,
+	.CTL = 5,
+	.MASK = 6,
+	.STAT = 7,
+	.LOUT = 8,
+	.COR = 9,
+	.MFWR = 10,
+	.FLR = 11,
+	.KEY = 12,
+	.CBC = 13,
+	.IDCODE = 14,
+	.AXSS = UNIMPLEMENTED,
+	.C0R_1 = UNIMPLEMENTED,
+	.CSOB = UNIMPLEMENTED,
+	.WBSTAR = UNIMPLEMENTED,
+	.TIMER = UNIMPLEMENTED,
+	.BOOTSTS = UNIMPLEMENTED,
+	.CTL_1 = UNIMPLEMENTED,
+};
+
+static const struct config_registers v4_config_registers = {
+	.CRC = 0,
+	.FAR = 1,
+	.FDRI = 2,
+	.FDRO = 3,
+	.CMD = 4,
+	.CTL = 5,
+	.MASK = 6,
+	.STAT = 7,
+	.LOUT = 8,
+	.COR = 9,
+	.MFWR = 10,
+	.FLR = UNIMPLEMENTED,
+	.KEY = UNIMPLEMENTED,
+	.CBC = 11,
+	.IDCODE = 12,
+	.AXSS = 13,
+	.C0R_1 = UNIMPLEMENTED,
+	.CSOB = UNIMPLEMENTED,
+	.WBSTAR = UNIMPLEMENTED,
+	.TIMER = UNIMPLEMENTED,
+	.BOOTSTS = UNIMPLEMENTED,
+	.CTL_1 = UNIMPLEMENTED,
+};
+
+static const struct config_registers v5_config_registers = {
+	.CRC = 0,
+	.FAR = 1,
+	.FDRI = 2,
+	.FDRO = 3,
+	.CMD = 4,
+	.CTL = 5,
+	.MASK = 6,
+	.STAT = 7,
+	.LOUT = 8,
+	.COR = 9,
+	.MFWR = 10,
+	.FLR = UNIMPLEMENTED,
+	.KEY = UNIMPLEMENTED,
+	.CBC = 11,
+	.IDCODE = 12,
+	.AXSS = 13,
+	.C0R_1 = 14,
+	.CSOB = 15,
+	.WBSTAR = 16,
+	.TIMER = 17,
+	.BOOTSTS = 18,
+	.CTL_1 = 19,
+};
+
+static const struct config_registers v6_config_registers = {
+	.CRC = 0,
+	.FAR = 1,
+	.FDRI = 2,
+	.FDRO = 3,
+	.CMD = 4,
+	.CTL = 5,
+	.MASK = 6,
+	.STAT = 7,
+	.LOUT = 8,
+	.COR = 9,
+	.MFWR = 10,
+	.FLR = UNIMPLEMENTED,
+	.KEY = UNIMPLEMENTED,
+	.CBC = 11,
+	.IDCODE = 12,
+	.AXSS = 13,
+	.C0R_1 = 14,
+	.CSOB = 15,
+	.WBSTAR = 16,
+	.TIMER = 17,
+	.BOOTSTS = 22,
+	.CTL_1 = 24,
+};
+
+/**
+ * hwicap_command_desync - Send a DESYNC command to the ICAP port.
+ * @drvdata: a pointer to the drvdata.
+ *
+ * Returns: '0' on success and failure value on error
+ *
+ * This command desynchronizes the ICAP After this command, a
+ * bitstream containing a NULL packet, followed by a SYNCH packet is
+ * required before the ICAP will recognize commands.
+ */
+static int hwicap_command_desync(struct hwicap_drvdata *drvdata)
+{
+	u32 buffer[4];
+	u32 index = 0;
+
+	/*
+	 * Create the data to be written to the ICAP.
+	 */
+	buffer[index++] = hwicap_type_1_write(drvdata->config_regs->CMD) | 1;
+	buffer[index++] = XHI_CMD_DESYNCH;
+	buffer[index++] = XHI_NOOP_PACKET;
+	buffer[index++] = XHI_NOOP_PACKET;
+
+	/*
+	 * Write the data to the FIFO and initiate the transfer of data present
+	 * in the FIFO to the ICAP device.
+	 */
+	return drvdata->config->set_configuration(drvdata,
+			&buffer[0], index);
+}
+
+/**
+ * hwicap_get_configuration_register - Query a configuration register.
+ * @drvdata: a pointer to the drvdata.
+ * @reg: a constant which represents the configuration
+ * register value to be returned.
+ * Examples: XHI_IDCODE, XHI_FLR.
+ * @reg_data: returns the value of the register.
+ *
+ * Returns: '0' on success and failure value on error
+ *
+ * Sends a query packet to the ICAP and then receives the response.
+ * The icap is left in Synched state.
+ */
+static int hwicap_get_configuration_register(struct hwicap_drvdata *drvdata,
+		u32 reg, u32 *reg_data)
+{
+	int status;
+	u32 buffer[6];
+	u32 index = 0;
+
+	/*
+	 * Create the data to be written to the ICAP.
+	 */
+	buffer[index++] = XHI_DUMMY_PACKET;
+	buffer[index++] = XHI_NOOP_PACKET;
+	buffer[index++] = XHI_SYNC_PACKET;
+	buffer[index++] = XHI_NOOP_PACKET;
+	buffer[index++] = XHI_NOOP_PACKET;
+
+	/*
+	 * Write the data to the FIFO and initiate the transfer of data present
+	 * in the FIFO to the ICAP device.
+	 */
+	status = drvdata->config->set_configuration(drvdata,
+						    &buffer[0], index);
+	if (status)
+		return status;
+
+	/* If the syncword was not found, then we need to start over. */
+	status = drvdata->config->get_status(drvdata);
+	if ((status & XHI_SR_DALIGN_MASK) != XHI_SR_DALIGN_MASK)
+		return -EIO;
+
+	index = 0;
+	buffer[index++] = hwicap_type_1_read(reg) | 1;
+	buffer[index++] = XHI_NOOP_PACKET;
+	buffer[index++] = XHI_NOOP_PACKET;
+
+	/*
+	 * Write the data to the FIFO and initiate the transfer of data present
+	 * in the FIFO to the ICAP device.
+	 */
+	status = drvdata->config->set_configuration(drvdata,
+			&buffer[0], index);
+	if (status)
+		return status;
+
+	/*
+	 * Read the configuration register
+	 */
+	status = drvdata->config->get_configuration(drvdata, reg_data, 1);
+	if (status)
+		return status;
+
+	return 0;
+}
+
+static int hwicap_initialize_hwicap(struct hwicap_drvdata *drvdata)
+{
+	int status;
+	u32 idcode;
+
+	dev_dbg(drvdata->dev, "initializing\n");
+
+	/* Abort any current transaction, to make sure we have the
+	 * ICAP in a good state.
+	 */
+	dev_dbg(drvdata->dev, "Reset...\n");
+	drvdata->config->reset(drvdata);
+
+	dev_dbg(drvdata->dev, "Desync...\n");
+	status = hwicap_command_desync(drvdata);
+	if (status)
+		return status;
+
+	/* Attempt to read the IDCODE from ICAP.  This
+	 * may not be returned correctly, due to the design of the
+	 * hardware.
+	 */
+	dev_dbg(drvdata->dev, "Reading IDCODE...\n");
+	status = hwicap_get_configuration_register(
+			drvdata, drvdata->config_regs->IDCODE, &idcode);
+	dev_dbg(drvdata->dev, "IDCODE = %x\n", idcode);
+	if (status)
+		return status;
+
+	dev_dbg(drvdata->dev, "Desync...\n");
+	status = hwicap_command_desync(drvdata);
+	if (status)
+		return status;
+
+	return 0;
+}
+
+static ssize_t
+hwicap_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+	struct hwicap_drvdata *drvdata = file->private_data;
+	ssize_t bytes_to_read = 0;
+	u32 *kbuf;
+	u32 words;
+	u32 bytes_remaining;
+	int status;
+
+	status = mutex_lock_interruptible(&drvdata->sem);
+	if (status)
+		return status;
+
+	if (drvdata->read_buffer_in_use) {
+		/* If there are leftover bytes in the buffer, just */
+		/* return them and don't try to read more from the */
+		/* ICAP device. */
+		bytes_to_read =
+			(count < drvdata->read_buffer_in_use) ? count :
+			drvdata->read_buffer_in_use;
+
+		/* Return the data currently in the read buffer. */
+		if (copy_to_user(buf, drvdata->read_buffer, bytes_to_read)) {
+			status = -EFAULT;
+			goto error;
+		}
+		drvdata->read_buffer_in_use -= bytes_to_read;
+		memmove(drvdata->read_buffer,
+		       drvdata->read_buffer + bytes_to_read,
+		       4 - bytes_to_read);
+	} else {
+		/* Get new data from the ICAP, and return what was requested. */
+		kbuf = (u32 *) get_zeroed_page(GFP_KERNEL);
+		if (!kbuf) {
+			status = -ENOMEM;
+			goto error;
+		}
+
+		/* The ICAP device is only able to read complete */
+		/* words.  If a number of bytes that do not correspond */
+		/* to complete words is requested, then we read enough */
+		/* words to get the required number of bytes, and then */
+		/* save the remaining bytes for the next read. */
+
+		/* Determine the number of words to read, rounding up */
+		/* if necessary. */
+		words = ((count + 3) >> 2);
+		bytes_to_read = words << 2;
+
+		if (bytes_to_read > PAGE_SIZE)
+			bytes_to_read = PAGE_SIZE;
+
+		/* Ensure we only read a complete number of words. */
+		bytes_remaining = bytes_to_read & 3;
+		bytes_to_read &= ~3;
+		words = bytes_to_read >> 2;
+
+		status = drvdata->config->get_configuration(drvdata,
+				kbuf, words);
+
+		/* If we didn't read correctly, then bail out. */
+		if (status) {
+			free_page((unsigned long)kbuf);
+			goto error;
+		}
+
+		/* If we fail to return the data to the user, then bail out. */
+		if (copy_to_user(buf, kbuf, bytes_to_read)) {
+			free_page((unsigned long)kbuf);
+			status = -EFAULT;
+			goto error;
+		}
+		memcpy(drvdata->read_buffer,
+		       kbuf,
+		       bytes_remaining);
+		drvdata->read_buffer_in_use = bytes_remaining;
+		free_page((unsigned long)kbuf);
+	}
+	status = bytes_to_read;
+ error:
+	mutex_unlock(&drvdata->sem);
+	return status;
+}
+
+static ssize_t
+hwicap_write(struct file *file, const char __user *buf,
+		size_t count, loff_t *ppos)
+{
+	struct hwicap_drvdata *drvdata = file->private_data;
+	ssize_t written = 0;
+	ssize_t left = count;
+	u32 *kbuf;
+	ssize_t len;
+	ssize_t status;
+
+	status = mutex_lock_interruptible(&drvdata->sem);
+	if (status)
+		return status;
+
+	left += drvdata->write_buffer_in_use;
+
+	/* Only write multiples of 4 bytes. */
+	if (left < 4) {
+		status = 0;
+		goto error;
+	}
+
+	kbuf = (u32 *) __get_free_page(GFP_KERNEL);
+	if (!kbuf) {
+		status = -ENOMEM;
+		goto error;
+	}
+
+	while (left > 3) {
+		/* only write multiples of 4 bytes, so there might */
+		/* be as many as 3 bytes left (at the end). */
+		len = left;
+
+		if (len > PAGE_SIZE)
+			len = PAGE_SIZE;
+		len &= ~3;
+
+		if (drvdata->write_buffer_in_use) {
+			memcpy(kbuf, drvdata->write_buffer,
+					drvdata->write_buffer_in_use);
+			if (copy_from_user(
+			    (((char *)kbuf) + drvdata->write_buffer_in_use),
+			    buf + written,
+			    len - (drvdata->write_buffer_in_use))) {
+				free_page((unsigned long)kbuf);
+				status = -EFAULT;
+				goto error;
+			}
+		} else {
+			if (copy_from_user(kbuf, buf + written, len)) {
+				free_page((unsigned long)kbuf);
+				status = -EFAULT;
+				goto error;
+			}
+		}
+
+		status = drvdata->config->set_configuration(drvdata,
+				kbuf, len >> 2);
+
+		if (status) {
+			free_page((unsigned long)kbuf);
+			status = -EFAULT;
+			goto error;
+		}
+		if (drvdata->write_buffer_in_use) {
+			len -= drvdata->write_buffer_in_use;
+			left -= drvdata->write_buffer_in_use;
+			drvdata->write_buffer_in_use = 0;
+		}
+		written += len;
+		left -= len;
+	}
+	if ((left > 0) && (left < 4)) {
+		if (!copy_from_user(drvdata->write_buffer,
+						buf + written, left)) {
+			drvdata->write_buffer_in_use = left;
+			written += left;
+			left = 0;
+		}
+	}
+
+	free_page((unsigned long)kbuf);
+	status = written;
+ error:
+	mutex_unlock(&drvdata->sem);
+	return status;
+}
+
+static int hwicap_open(struct inode *inode, struct file *file)
+{
+	struct hwicap_drvdata *drvdata;
+	int status;
+
+	mutex_lock(&hwicap_mutex);
+	drvdata = container_of(inode->i_cdev, struct hwicap_drvdata, cdev);
+
+	status = mutex_lock_interruptible(&drvdata->sem);
+	if (status)
+		goto out;
+
+	if (drvdata->is_open) {
+		status = -EBUSY;
+		goto error;
+	}
+
+	status = hwicap_initialize_hwicap(drvdata);
+	if (status) {
+		dev_err(drvdata->dev, "Failed to open file");
+		goto error;
+	}
+
+	file->private_data = drvdata;
+	drvdata->write_buffer_in_use = 0;
+	drvdata->read_buffer_in_use = 0;
+	drvdata->is_open = 1;
+
+ error:
+	mutex_unlock(&drvdata->sem);
+ out:
+	mutex_unlock(&hwicap_mutex);
+	return status;
+}
+
+static int hwicap_release(struct inode *inode, struct file *file)
+{
+	struct hwicap_drvdata *drvdata = file->private_data;
+	int i;
+	int status = 0;
+
+	mutex_lock(&drvdata->sem);
+
+	if (drvdata->write_buffer_in_use) {
+		/* Flush write buffer. */
+		for (i = drvdata->write_buffer_in_use; i < 4; i++)
+			drvdata->write_buffer[i] = 0;
+
+		status = drvdata->config->set_configuration(drvdata,
+				(u32 *) drvdata->write_buffer, 1);
+		if (status)
+			goto error;
+	}
+
+	status = hwicap_command_desync(drvdata);
+	if (status)
+		goto error;
+
+ error:
+	drvdata->is_open = 0;
+	mutex_unlock(&drvdata->sem);
+	return status;
+}
+
+static const struct file_operations hwicap_fops = {
+	.owner = THIS_MODULE,
+	.write = hwicap_write,
+	.read = hwicap_read,
+	.open = hwicap_open,
+	.release = hwicap_release,
+	.llseek = noop_llseek,
+};
+
+static int hwicap_setup(struct device *dev, int id,
+		const struct resource *regs_res,
+		const struct hwicap_driver_config *config,
+		const struct config_registers *config_regs)
+{
+	dev_t devt;
+	struct hwicap_drvdata *drvdata = NULL;
+	int retval = 0;
+
+	dev_info(dev, "Xilinx icap port driver\n");
+
+	mutex_lock(&icap_sem);
+
+	if (id < 0) {
+		for (id = 0; id < HWICAP_DEVICES; id++)
+			if (!probed_devices[id])
+				break;
+	}
+	if (id < 0 || id >= HWICAP_DEVICES) {
+		mutex_unlock(&icap_sem);
+		dev_err(dev, "%s%i too large\n", DRIVER_NAME, id);
+		return -EINVAL;
+	}
+	if (probed_devices[id]) {
+		mutex_unlock(&icap_sem);
+		dev_err(dev, "cannot assign to %s%i; it is already in use\n",
+			DRIVER_NAME, id);
+		return -EBUSY;
+	}
+
+	probed_devices[id] = 1;
+	mutex_unlock(&icap_sem);
+
+	devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR + id);
+
+	drvdata = kzalloc(sizeof(struct hwicap_drvdata), GFP_KERNEL);
+	if (!drvdata) {
+		retval = -ENOMEM;
+		goto failed0;
+	}
+	dev_set_drvdata(dev, (void *)drvdata);
+
+	if (!regs_res) {
+		dev_err(dev, "Couldn't get registers resource\n");
+		retval = -EFAULT;
+		goto failed1;
+	}
+
+	drvdata->mem_start = regs_res->start;
+	drvdata->mem_end = regs_res->end;
+	drvdata->mem_size = resource_size(regs_res);
+
+	if (!request_mem_region(drvdata->mem_start,
+					drvdata->mem_size, DRIVER_NAME)) {
+		dev_err(dev, "Couldn't lock memory region at %Lx\n",
+			(unsigned long long) regs_res->start);
+		retval = -EBUSY;
+		goto failed1;
+	}
+
+	drvdata->devt = devt;
+	drvdata->dev = dev;
+	drvdata->base_address = ioremap(drvdata->mem_start, drvdata->mem_size);
+	if (!drvdata->base_address) {
+		dev_err(dev, "ioremap() failed\n");
+		retval = -ENOMEM;
+		goto failed2;
+	}
+
+	drvdata->config = config;
+	drvdata->config_regs = config_regs;
+
+	mutex_init(&drvdata->sem);
+	drvdata->is_open = 0;
+
+	dev_info(dev, "ioremap %llx to %p with size %llx\n",
+		 (unsigned long long) drvdata->mem_start,
+		 drvdata->base_address,
+		 (unsigned long long) drvdata->mem_size);
+
+	cdev_init(&drvdata->cdev, &hwicap_fops);
+	drvdata->cdev.owner = THIS_MODULE;
+	retval = cdev_add(&drvdata->cdev, devt, 1);
+	if (retval) {
+		dev_err(dev, "cdev_add() failed\n");
+		goto failed3;
+	}
+
+	device_create(icap_class, dev, devt, NULL, "%s%d", DRIVER_NAME, id);
+	return 0;		/* success */
+
+ failed3:
+	iounmap(drvdata->base_address);
+
+ failed2:
+	release_mem_region(regs_res->start, drvdata->mem_size);
+
+ failed1:
+	kfree(drvdata);
+
+ failed0:
+	mutex_lock(&icap_sem);
+	probed_devices[id] = 0;
+	mutex_unlock(&icap_sem);
+
+	return retval;
+}
+
+static struct hwicap_driver_config buffer_icap_config = {
+	.get_configuration = buffer_icap_get_configuration,
+	.set_configuration = buffer_icap_set_configuration,
+	.get_status = buffer_icap_get_status,
+	.reset = buffer_icap_reset,
+};
+
+static struct hwicap_driver_config fifo_icap_config = {
+	.get_configuration = fifo_icap_get_configuration,
+	.set_configuration = fifo_icap_set_configuration,
+	.get_status = fifo_icap_get_status,
+	.reset = fifo_icap_reset,
+};
+
+static int hwicap_remove(struct device *dev)
+{
+	struct hwicap_drvdata *drvdata;
+
+	drvdata = dev_get_drvdata(dev);
+
+	if (!drvdata)
+		return 0;
+
+	device_destroy(icap_class, drvdata->devt);
+	cdev_del(&drvdata->cdev);
+	iounmap(drvdata->base_address);
+	release_mem_region(drvdata->mem_start, drvdata->mem_size);
+	kfree(drvdata);
+
+	mutex_lock(&icap_sem);
+	probed_devices[MINOR(dev->devt)-XHWICAP_MINOR] = 0;
+	mutex_unlock(&icap_sem);
+	return 0;		/* success */
+}
+
+#ifdef CONFIG_OF
+static int hwicap_of_probe(struct platform_device *op,
+				     const struct hwicap_driver_config *config)
+{
+	struct resource res;
+	const unsigned int *id;
+	const char *family;
+	int rc;
+	const struct config_registers *regs;
+
+
+	rc = of_address_to_resource(op->dev.of_node, 0, &res);
+	if (rc) {
+		dev_err(&op->dev, "invalid address\n");
+		return rc;
+	}
+
+	id = of_get_property(op->dev.of_node, "port-number", NULL);
+
+	/* It's most likely that we're using V4, if the family is not
+	 * specified
+	 */
+	regs = &v4_config_registers;
+	family = of_get_property(op->dev.of_node, "xlnx,family", NULL);
+
+	if (family) {
+		if (!strcmp(family, "virtex2p"))
+			regs = &v2_config_registers;
+		else if (!strcmp(family, "virtex4"))
+			regs = &v4_config_registers;
+		else if (!strcmp(family, "virtex5"))
+			regs = &v5_config_registers;
+		else if (!strcmp(family, "virtex6"))
+			regs = &v6_config_registers;
+	}
+	return hwicap_setup(&op->dev, id ? *id : -1, &res, config,
+			regs);
+}
+#else
+static inline int hwicap_of_probe(struct platform_device *op,
+				  const struct hwicap_driver_config *config)
+{
+	return -EINVAL;
+}
+#endif /* CONFIG_OF */
+
+static const struct of_device_id hwicap_of_match[];
+static int hwicap_drv_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct resource *res;
+	const struct config_registers *regs;
+	const char *family;
+
+	match = of_match_device(hwicap_of_match, &pdev->dev);
+	if (match)
+		return hwicap_of_probe(pdev, match->data);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	/* It's most likely that we're using V4, if the family is not
+	 * specified
+	 */
+	regs = &v4_config_registers;
+	family = pdev->dev.platform_data;
+
+	if (family) {
+		if (!strcmp(family, "virtex2p"))
+			regs = &v2_config_registers;
+		else if (!strcmp(family, "virtex4"))
+			regs = &v4_config_registers;
+		else if (!strcmp(family, "virtex5"))
+			regs = &v5_config_registers;
+		else if (!strcmp(family, "virtex6"))
+			regs = &v6_config_registers;
+	}
+
+	return hwicap_setup(&pdev->dev, pdev->id, res,
+			&buffer_icap_config, regs);
+}
+
+static int hwicap_drv_remove(struct platform_device *pdev)
+{
+	return hwicap_remove(&pdev->dev);
+}
+
+#ifdef CONFIG_OF
+/* Match table for device tree binding */
+static const struct of_device_id hwicap_of_match[] = {
+	{ .compatible = "xlnx,opb-hwicap-1.00.b", .data = &buffer_icap_config},
+	{ .compatible = "xlnx,xps-hwicap-1.00.a", .data = &fifo_icap_config},
+	{},
+};
+MODULE_DEVICE_TABLE(of, hwicap_of_match);
+#else
+#define hwicap_of_match NULL
+#endif
+
+static struct platform_driver hwicap_platform_driver = {
+	.probe = hwicap_drv_probe,
+	.remove = hwicap_drv_remove,
+	.driver = {
+		.name = DRIVER_NAME,
+		.of_match_table = hwicap_of_match,
+	},
+};
+
+static int __init hwicap_module_init(void)
+{
+	dev_t devt;
+	int retval;
+
+	icap_class = class_create(THIS_MODULE, "xilinx_config");
+	mutex_init(&icap_sem);
+
+	devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR);
+	retval = register_chrdev_region(devt,
+					HWICAP_DEVICES,
+					DRIVER_NAME);
+	if (retval < 0)
+		return retval;
+
+	retval = platform_driver_register(&hwicap_platform_driver);
+	if (retval)
+		goto failed;
+
+	return retval;
+
+ failed:
+	unregister_chrdev_region(devt, HWICAP_DEVICES);
+
+	return retval;
+}
+
+static void __exit hwicap_module_cleanup(void)
+{
+	dev_t devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR);
+
+	class_destroy(icap_class);
+
+	platform_driver_unregister(&hwicap_platform_driver);
+
+	unregister_chrdev_region(devt, HWICAP_DEVICES);
+}
+
+module_init(hwicap_module_init);
+module_exit(hwicap_module_cleanup);
+
+MODULE_AUTHOR("Xilinx, Inc; Xilinx Research Labs Group");
+MODULE_DESCRIPTION("Xilinx ICAP Port Driver");
+MODULE_LICENSE("GPL");