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, 626 insertions, 0 deletions

diff --git a/drivers/char/nwflash.c b/drivers/char/nwflash.c
new file mode 100644
index 000000000..0973c2c2b
--- /dev/null
+++ b/drivers/char/nwflash.c
@@ -0,0 +1,626 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Flash memory interface rev.5 driver for the Intel
+ * Flash chips used on the NetWinder.
+ *
+ * 20/08/2000	RMK	use __ioremap to map flash into virtual memory
+ *			make a few more places use "volatile"
+ * 22/05/2001	RMK	- Lock read against write
+ *			- merge printk level changes (with mods) from Alan Cox.
+ *			- use *ppos as the file position, not file->f_pos.
+ *			- fix check for out of range pos and r/w size
+ *
+ * Please note that we are tampering with the only flash chip in the
+ * machine, which contains the bootup code.  We therefore have the
+ * power to convert these machines into doorstops...
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/proc_fs.h>
+#include <linux/miscdevice.h>
+#include <linux/spinlock.h>
+#include <linux/rwsem.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/jiffies.h>
+
+#include <asm/hardware/dec21285.h>
+#include <asm/io.h>
+#include <asm/mach-types.h>
+#include <linux/uaccess.h>
+
+/*****************************************************************************/
+#include <asm/nwflash.h>
+
+#define	NWFLASH_VERSION "6.4"
+
+static DEFINE_MUTEX(flash_mutex);
+static void kick_open(void);
+static int get_flash_id(void);
+static int erase_block(int nBlock);
+static int write_block(unsigned long p, const char __user *buf, int count);
+
+#define KFLASH_SIZE	1024*1024	//1 Meg
+#define KFLASH_SIZE4	4*1024*1024	//4 Meg
+#define KFLASH_ID	0x89A6		//Intel flash
+#define KFLASH_ID4	0xB0D4		//Intel flash 4Meg
+
+static bool flashdebug;		//if set - we will display progress msgs
+
+static int gbWriteEnable;
+static int gbWriteBase64Enable;
+static volatile unsigned char *FLASH_BASE;
+static int gbFlashSize = KFLASH_SIZE;
+static DEFINE_MUTEX(nwflash_mutex);
+
+static int get_flash_id(void)
+{
+	volatile unsigned int c1, c2;
+
+	/*
+	 * try to get flash chip ID
+	 */
+	kick_open();
+	c2 = inb(0x80);
+	*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x90;
+	udelay(15);
+	c1 = *(volatile unsigned char *) FLASH_BASE;
+	c2 = inb(0x80);
+
+	/*
+	 * on 4 Meg flash the second byte is actually at offset 2...
+	 */
+	if (c1 == 0xB0)
+		c2 = *(volatile unsigned char *) (FLASH_BASE + 2);
+	else
+		c2 = *(volatile unsigned char *) (FLASH_BASE + 1);
+
+	c2 += (c1 << 8);
+
+	/*
+	 * set it back to read mode
+	 */
+	*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
+
+	if (c2 == KFLASH_ID4)
+		gbFlashSize = KFLASH_SIZE4;
+
+	return c2;
+}
+
+static long flash_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
+{
+	mutex_lock(&flash_mutex);
+	switch (cmd) {
+	case CMD_WRITE_DISABLE:
+		gbWriteBase64Enable = 0;
+		gbWriteEnable = 0;
+		break;
+
+	case CMD_WRITE_ENABLE:
+		gbWriteEnable = 1;
+		break;
+
+	case CMD_WRITE_BASE64K_ENABLE:
+		gbWriteBase64Enable = 1;
+		break;
+
+	default:
+		gbWriteBase64Enable = 0;
+		gbWriteEnable = 0;
+		mutex_unlock(&flash_mutex);
+		return -EINVAL;
+	}
+	mutex_unlock(&flash_mutex);
+	return 0;
+}
+
+static ssize_t flash_read(struct file *file, char __user *buf, size_t size,
+			  loff_t *ppos)
+{
+	ssize_t ret;
+
+	if (flashdebug)
+		printk(KERN_DEBUG "flash_read: flash_read: offset=0x%llx, "
+		       "buffer=%p, count=0x%zx.\n", *ppos, buf, size);
+	/*
+	 * We now lock against reads and writes. --rmk
+	 */
+	if (mutex_lock_interruptible(&nwflash_mutex))
+		return -ERESTARTSYS;
+
+	ret = simple_read_from_buffer(buf, size, ppos, (void *)FLASH_BASE, gbFlashSize);
+	mutex_unlock(&nwflash_mutex);
+
+	return ret;
+}
+
+static ssize_t flash_write(struct file *file, const char __user *buf,
+			   size_t size, loff_t * ppos)
+{
+	unsigned long p = *ppos;
+	unsigned int count = size;
+	int written;
+	int nBlock, temp, rc;
+	int i, j;
+
+	if (flashdebug)
+		printk("flash_write: offset=0x%lX, buffer=0x%p, count=0x%X.\n",
+		       p, buf, count);
+
+	if (!gbWriteEnable)
+		return -EINVAL;
+
+	if (p < 64 * 1024 && (!gbWriteBase64Enable))
+		return -EINVAL;
+
+	/*
+	 * check for out of range pos or count
+	 */
+	if (p >= gbFlashSize)
+		return count ? -ENXIO : 0;
+
+	if (count > gbFlashSize - p)
+		count = gbFlashSize - p;
+			
+	if (!access_ok(buf, count))
+		return -EFAULT;
+
+	/*
+	 * We now lock against reads and writes. --rmk
+	 */
+	if (mutex_lock_interruptible(&nwflash_mutex))
+		return -ERESTARTSYS;
+
+	written = 0;
+
+	nBlock = (int) p >> 16;	//block # of 64K bytes
+
+	/*
+	 * # of 64K blocks to erase and write
+	 */
+	temp = ((int) (p + count) >> 16) - nBlock + 1;
+
+	/*
+	 * write ends at exactly 64k boundary?
+	 */
+	if (((int) (p + count) & 0xFFFF) == 0)
+		temp -= 1;
+
+	if (flashdebug)
+		printk(KERN_DEBUG "flash_write: writing %d block(s) "
+			"starting at %d.\n", temp, nBlock);
+
+	for (; temp; temp--, nBlock++) {
+		if (flashdebug)
+			printk(KERN_DEBUG "flash_write: erasing block %d.\n", nBlock);
+
+		/*
+		 * first we have to erase the block(s), where we will write...
+		 */
+		i = 0;
+		j = 0;
+	  RetryBlock:
+		do {
+			rc = erase_block(nBlock);
+			i++;
+		} while (rc && i < 10);
+
+		if (rc) {
+			printk(KERN_ERR "flash_write: erase error %x\n", rc);
+			break;
+		}
+		if (flashdebug)
+			printk(KERN_DEBUG "flash_write: writing offset %lX, "
+			       "from buf %p, bytes left %X.\n", p, buf,
+			       count - written);
+
+		/*
+		 * write_block will limit write to space left in this block
+		 */
+		rc = write_block(p, buf, count - written);
+		j++;
+
+		/*
+		 * if somehow write verify failed? Can't happen??
+		 */
+		if (!rc) {
+			/*
+			 * retry up to 10 times
+			 */
+			if (j < 10)
+				goto RetryBlock;
+			else
+				/*
+				 * else quit with error...
+				 */
+				rc = -1;
+
+		}
+		if (rc < 0) {
+			printk(KERN_ERR "flash_write: write error %X\n", rc);
+			break;
+		}
+		p += rc;
+		buf += rc;
+		written += rc;
+		*ppos += rc;
+
+		if (flashdebug)
+			printk(KERN_DEBUG "flash_write: written 0x%X bytes OK.\n", written);
+	}
+
+	mutex_unlock(&nwflash_mutex);
+
+	return written;
+}
+
+
+/*
+ * The memory devices use the full 32/64 bits of the offset, and so we cannot
+ * check against negative addresses: they are ok. The return value is weird,
+ * though, in that case (0).
+ *
+ * also note that seeking relative to the "end of file" isn't supported:
+ * it has no meaning, so it returns -EINVAL.
+ */
+static loff_t flash_llseek(struct file *file, loff_t offset, int orig)
+{
+	loff_t ret;
+
+	mutex_lock(&flash_mutex);
+	if (flashdebug)
+		printk(KERN_DEBUG "flash_llseek: offset=0x%X, orig=0x%X.\n",
+		       (unsigned int) offset, orig);
+
+	ret = no_seek_end_llseek_size(file, offset, orig, gbFlashSize);
+	mutex_unlock(&flash_mutex);
+	return ret;
+}
+
+
+/*
+ * assume that main Write routine did the parameter checking...
+ * so just go ahead and erase, what requested!
+ */
+
+static int erase_block(int nBlock)
+{
+	volatile unsigned int c1;
+	volatile unsigned char *pWritePtr;
+	unsigned long timeout;
+	int temp, temp1;
+
+	/*
+	 * reset footbridge to the correct offset 0 (...0..3)
+	 */
+	*CSR_ROMWRITEREG = 0;
+
+	/*
+	 * dummy ROM read
+	 */
+	c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
+
+	kick_open();
+	/*
+	 * reset status if old errors
+	 */
+	*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
+
+	/*
+	 * erase a block...
+	 * aim at the middle of a current block...
+	 */
+	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + 0x8000 + (nBlock << 16)));
+	/*
+	 * dummy read
+	 */
+	c1 = *pWritePtr;
+
+	kick_open();
+	/*
+	 * erase
+	 */
+	*(volatile unsigned char *) pWritePtr = 0x20;
+
+	/*
+	 * confirm
+	 */
+	*(volatile unsigned char *) pWritePtr = 0xD0;
+
+	/*
+	 * wait 10 ms
+	 */
+	msleep(10);
+
+	/*
+	 * wait while erasing in process (up to 10 sec)
+	 */
+	timeout = jiffies + 10 * HZ;
+	c1 = 0;
+	while (!(c1 & 0x80) && time_before(jiffies, timeout)) {
+		msleep(10);
+		/*
+		 * read any address
+		 */
+		c1 = *(volatile unsigned char *) (pWritePtr);
+		//              printk("Flash_erase: status=%X.\n",c1);
+	}
+
+	/*
+	 * set flash for normal read access
+	 */
+	kick_open();
+//      *(volatile unsigned char*)(FLASH_BASE+0x8000) = 0xFF;
+	*(volatile unsigned char *) pWritePtr = 0xFF;	//back to normal operation
+
+	/*
+	 * check if erase errors were reported
+	 */
+	if (c1 & 0x20) {
+		printk(KERN_ERR "flash_erase: err at %p\n", pWritePtr);
+
+		/*
+		 * reset error
+		 */
+		*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
+		return -2;
+	}
+
+	/*
+	 * just to make sure - verify if erased OK...
+	 */
+	msleep(10);
+
+	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + (nBlock << 16)));
+
+	for (temp = 0; temp < 16 * 1024; temp++, pWritePtr += 4) {
+		if ((temp1 = *(volatile unsigned int *) pWritePtr) != 0xFFFFFFFF) {
+			printk(KERN_ERR "flash_erase: verify err at %p = %X\n",
+			       pWritePtr, temp1);
+			return -1;
+		}
+	}
+
+	return 0;
+
+}
+
+/*
+ * write_block will limit number of bytes written to the space in this block
+ */
+static int write_block(unsigned long p, const char __user *buf, int count)
+{
+	volatile unsigned int c1;
+	volatile unsigned int c2;
+	unsigned char *pWritePtr;
+	unsigned int uAddress;
+	unsigned int offset;
+	unsigned long timeout;
+	unsigned long timeout1;
+
+	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
+
+	/*
+	 * check if write will end in this block....
+	 */
+	offset = p & 0xFFFF;
+
+	if (offset + count > 0x10000)
+		count = 0x10000 - offset;
+
+	/*
+	 * wait up to 30 sec for this block
+	 */
+	timeout = jiffies + 30 * HZ;
+
+	for (offset = 0; offset < count; offset++, pWritePtr++) {
+		uAddress = (unsigned int) pWritePtr;
+		uAddress &= 0xFFFFFFFC;
+		if (__get_user(c2, buf + offset))
+			return -EFAULT;
+
+	  WriteRetry:
+	  	/*
+	  	 * dummy read
+	  	 */
+		c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
+
+		/*
+		 * kick open the write gate
+		 */
+		kick_open();
+
+		/*
+		 * program footbridge to the correct offset...0..3
+		 */
+		*CSR_ROMWRITEREG = (unsigned int) pWritePtr & 3;
+
+		/*
+		 * write cmd
+		 */
+		*(volatile unsigned char *) (uAddress) = 0x40;
+
+		/*
+		 * data to write
+		 */
+		*(volatile unsigned char *) (uAddress) = c2;
+
+		/*
+		 * get status
+		 */
+		*(volatile unsigned char *) (FLASH_BASE + 0x10000) = 0x70;
+
+		c1 = 0;
+
+		/*
+		 * wait up to 1 sec for this byte
+		 */
+		timeout1 = jiffies + 1 * HZ;
+
+		/*
+		 * while not ready...
+		 */
+		while (!(c1 & 0x80) && time_before(jiffies, timeout1))
+			c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
+
+		/*
+		 * if timeout getting status
+		 */
+		if (time_after_eq(jiffies, timeout1)) {
+			kick_open();
+			/*
+			 * reset err
+			 */
+			*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
+
+			goto WriteRetry;
+		}
+		/*
+		 * switch on read access, as a default flash operation mode
+		 */
+		kick_open();
+		/*
+		 * read access
+		 */
+		*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
+
+		/*
+		 * if hardware reports an error writing, and not timeout - 
+		 * reset the chip and retry
+		 */
+		if (c1 & 0x10) {
+			kick_open();
+			/*
+			 * reset err
+			 */
+			*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
+
+			/*
+			 * before timeout?
+			 */
+			if (time_before(jiffies, timeout)) {
+				if (flashdebug)
+					printk(KERN_DEBUG "write_block: Retrying write at 0x%X)n",
+					       pWritePtr - FLASH_BASE);
+
+				/*
+				 * wait couple ms
+				 */
+				msleep(10);
+
+				goto WriteRetry;
+			} else {
+				printk(KERN_ERR "write_block: timeout at 0x%X\n",
+				       pWritePtr - FLASH_BASE);
+				/*
+				 * return error -2
+				 */
+				return -2;
+
+			}
+		}
+	}
+
+	msleep(10);
+
+	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
+
+	for (offset = 0; offset < count; offset++) {
+		char c, c1;
+		if (__get_user(c, buf))
+			return -EFAULT;
+		buf++;
+		if ((c1 = *pWritePtr++) != c) {
+			printk(KERN_ERR "write_block: verify error at 0x%X (%02X!=%02X)\n",
+			       pWritePtr - FLASH_BASE, c1, c);
+			return 0;
+		}
+	}
+
+	return count;
+}
+
+
+static void kick_open(void)
+{
+	unsigned long flags;
+
+	/*
+	 * we want to write a bit pattern XXX1 to Xilinx to enable
+	 * the write gate, which will be open for about the next 2ms.
+	 */
+	raw_spin_lock_irqsave(&nw_gpio_lock, flags);
+	nw_cpld_modify(CPLD_FLASH_WR_ENABLE, CPLD_FLASH_WR_ENABLE);
+	raw_spin_unlock_irqrestore(&nw_gpio_lock, flags);
+
+	/*
+	 * let the ISA bus to catch on...
+	 */
+	udelay(25);
+}
+
+static const struct file_operations flash_fops =
+{
+	.owner		= THIS_MODULE,
+	.llseek		= flash_llseek,
+	.read		= flash_read,
+	.write		= flash_write,
+	.unlocked_ioctl	= flash_ioctl,
+};
+
+static struct miscdevice flash_miscdev =
+{
+	NWFLASH_MINOR,
+	"nwflash",
+	&flash_fops
+};
+
+static int __init nwflash_init(void)
+{
+	int ret = -ENODEV;
+
+	if (machine_is_netwinder()) {
+		int id;
+
+		FLASH_BASE = ioremap(DC21285_FLASH, KFLASH_SIZE4);
+		if (!FLASH_BASE)
+			goto out;
+
+		id = get_flash_id();
+		if ((id != KFLASH_ID) && (id != KFLASH_ID4)) {
+			ret = -ENXIO;
+			iounmap((void *)FLASH_BASE);
+			printk("Flash: incorrect ID 0x%04X.\n", id);
+			goto out;
+		}
+
+		printk("Flash ROM driver v.%s, flash device ID 0x%04X, size %d Mb.\n",
+		       NWFLASH_VERSION, id, gbFlashSize / (1024 * 1024));
+
+		ret = misc_register(&flash_miscdev);
+		if (ret < 0) {
+			iounmap((void *)FLASH_BASE);
+		}
+	}
+out:
+	return ret;
+}
+
+static void __exit nwflash_exit(void)
+{
+	misc_deregister(&flash_miscdev);
+	iounmap((void *)FLASH_BASE);
+}
+
+MODULE_LICENSE("GPL");
+
+module_param(flashdebug, bool, 0644);
+
+module_init(nwflash_init);
+module_exit(nwflash_exit);