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, 817 insertions, 0 deletions

diff --git a/drivers/mtd/maps/vmu-flash.c b/drivers/mtd/maps/vmu-flash.c
new file mode 100644
index 000000000..a7ec947a3
--- /dev/null
+++ b/drivers/mtd/maps/vmu-flash.c
@@ -0,0 +1,817 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* vmu-flash.c
+ * Driver for SEGA Dreamcast Visual Memory Unit
+ *
+ * Copyright (c) Adrian McMenamin 2002 - 2009
+ * Copyright (c) Paul Mundt 2001
+ */
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/maple.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/map.h>
+
+struct vmu_cache {
+	unsigned char *buffer;		/* Cache */
+	unsigned int block;		/* Which block was cached */
+	unsigned long jiffies_atc;	/* When was it cached? */
+	int valid;
+};
+
+struct mdev_part {
+	struct maple_device *mdev;
+	int partition;
+};
+
+struct vmupart {
+	u16 user_blocks;
+	u16 root_block;
+	u16 numblocks;
+	char *name;
+	struct vmu_cache *pcache;
+};
+
+struct memcard {
+	u16 tempA;
+	u16 tempB;
+	u32 partitions;
+	u32 blocklen;
+	u32 writecnt;
+	u32 readcnt;
+	u32 removable;
+	int partition;
+	int read;
+	unsigned char *blockread;
+	struct vmupart *parts;
+	struct mtd_info *mtd;
+};
+
+struct vmu_block {
+	unsigned int num; /* block number */
+	unsigned int ofs; /* block offset */
+};
+
+static struct vmu_block *ofs_to_block(unsigned long src_ofs,
+	struct mtd_info *mtd, int partition)
+{
+	struct vmu_block *vblock;
+	struct maple_device *mdev;
+	struct memcard *card;
+	struct mdev_part *mpart;
+	int num;
+
+	mpart = mtd->priv;
+	mdev = mpart->mdev;
+	card = maple_get_drvdata(mdev);
+
+	if (src_ofs >= card->parts[partition].numblocks * card->blocklen)
+		goto failed;
+
+	num = src_ofs / card->blocklen;
+	if (num > card->parts[partition].numblocks)
+		goto failed;
+
+	vblock = kmalloc(sizeof(struct vmu_block), GFP_KERNEL);
+	if (!vblock)
+		goto failed;
+
+	vblock->num = num;
+	vblock->ofs = src_ofs % card->blocklen;
+	return vblock;
+
+failed:
+	return NULL;
+}
+
+/* Maple bus callback function for reads */
+static void vmu_blockread(struct mapleq *mq)
+{
+	struct maple_device *mdev;
+	struct memcard *card;
+
+	mdev = mq->dev;
+	card = maple_get_drvdata(mdev);
+	/* copy the read in data */
+
+	if (unlikely(!card->blockread))
+		return;
+
+	memcpy(card->blockread, mq->recvbuf->buf + 12,
+		card->blocklen/card->readcnt);
+
+}
+
+/* Interface with maple bus to read blocks
+ * caching the results so that other parts
+ * of the driver can access block reads */
+static int maple_vmu_read_block(unsigned int num, unsigned char *buf,
+	struct mtd_info *mtd)
+{
+	struct memcard *card;
+	struct mdev_part *mpart;
+	struct maple_device *mdev;
+	int partition, error = 0, x, wait;
+	unsigned char *blockread = NULL;
+	struct vmu_cache *pcache;
+	__be32 sendbuf;
+
+	mpart = mtd->priv;
+	mdev = mpart->mdev;
+	partition = mpart->partition;
+	card = maple_get_drvdata(mdev);
+	pcache = card->parts[partition].pcache;
+	pcache->valid = 0;
+
+	/* prepare the cache for this block */
+	if (!pcache->buffer) {
+		pcache->buffer = kmalloc(card->blocklen, GFP_KERNEL);
+		if (!pcache->buffer) {
+			dev_err(&mdev->dev, "VMU at (%d, %d) - read fails due"
+				" to lack of memory\n", mdev->port,
+				mdev->unit);
+			error = -ENOMEM;
+			goto outB;
+		}
+	}
+
+	/*
+	* Reads may be phased - again the hardware spec
+	* supports this - though may not be any devices in
+	* the wild that implement it, but we will here
+	*/
+	for (x = 0; x < card->readcnt; x++) {
+		sendbuf = cpu_to_be32(partition << 24 | x << 16 | num);
+
+		if (atomic_read(&mdev->busy) == 1) {
+			wait_event_interruptible_timeout(mdev->maple_wait,
+				atomic_read(&mdev->busy) == 0, HZ);
+			if (atomic_read(&mdev->busy) == 1) {
+				dev_notice(&mdev->dev, "VMU at (%d, %d)"
+					" is busy\n", mdev->port, mdev->unit);
+				error = -EAGAIN;
+				goto outB;
+			}
+		}
+
+		atomic_set(&mdev->busy, 1);
+		blockread = kmalloc(card->blocklen/card->readcnt, GFP_KERNEL);
+		if (!blockread) {
+			error = -ENOMEM;
+			atomic_set(&mdev->busy, 0);
+			goto outB;
+		}
+		card->blockread = blockread;
+
+		maple_getcond_callback(mdev, vmu_blockread, 0,
+			MAPLE_FUNC_MEMCARD);
+		error = maple_add_packet(mdev, MAPLE_FUNC_MEMCARD,
+				MAPLE_COMMAND_BREAD, 2, &sendbuf);
+		/* Very long timeouts seem to be needed when box is stressed */
+		wait = wait_event_interruptible_timeout(mdev->maple_wait,
+			(atomic_read(&mdev->busy) == 0 ||
+			atomic_read(&mdev->busy) == 2), HZ * 3);
+		/*
+		* MTD layer does not handle hotplugging well
+		* so have to return errors when VMU is unplugged
+		* in the middle of a read (busy == 2)
+		*/
+		if (error || atomic_read(&mdev->busy) == 2) {
+			if (atomic_read(&mdev->busy) == 2)
+				error = -ENXIO;
+			atomic_set(&mdev->busy, 0);
+			card->blockread = NULL;
+			goto outA;
+		}
+		if (wait == 0 || wait == -ERESTARTSYS) {
+			card->blockread = NULL;
+			atomic_set(&mdev->busy, 0);
+			error = -EIO;
+			list_del_init(&(mdev->mq->list));
+			kfree(mdev->mq->sendbuf);
+			mdev->mq->sendbuf = NULL;
+			if (wait == -ERESTARTSYS) {
+				dev_warn(&mdev->dev, "VMU read on (%d, %d)"
+					" interrupted on block 0x%X\n",
+					mdev->port, mdev->unit, num);
+			} else
+				dev_notice(&mdev->dev, "VMU read on (%d, %d)"
+					" timed out on block 0x%X\n",
+					mdev->port, mdev->unit, num);
+			goto outA;
+		}
+
+		memcpy(buf + (card->blocklen/card->readcnt) * x, blockread,
+			card->blocklen/card->readcnt);
+
+		memcpy(pcache->buffer + (card->blocklen/card->readcnt) * x,
+			card->blockread, card->blocklen/card->readcnt);
+		card->blockread = NULL;
+		pcache->block = num;
+		pcache->jiffies_atc = jiffies;
+		pcache->valid = 1;
+		kfree(blockread);
+	}
+
+	return error;
+
+outA:
+	kfree(blockread);
+outB:
+	return error;
+}
+
+/* communicate with maple bus for phased writing */
+static int maple_vmu_write_block(unsigned int num, const unsigned char *buf,
+	struct mtd_info *mtd)
+{
+	struct memcard *card;
+	struct mdev_part *mpart;
+	struct maple_device *mdev;
+	int partition, error, locking, x, phaselen, wait;
+	__be32 *sendbuf;
+
+	mpart = mtd->priv;
+	mdev = mpart->mdev;
+	partition = mpart->partition;
+	card = maple_get_drvdata(mdev);
+
+	phaselen = card->blocklen/card->writecnt;
+
+	sendbuf = kmalloc(phaselen + 4, GFP_KERNEL);
+	if (!sendbuf) {
+		error = -ENOMEM;
+		goto fail_nosendbuf;
+	}
+	for (x = 0; x < card->writecnt; x++) {
+		sendbuf[0] = cpu_to_be32(partition << 24 | x << 16 | num);
+		memcpy(&sendbuf[1], buf + phaselen * x, phaselen);
+		/* wait until the device is not busy doing something else
+		* or 1 second - which ever is longer */
+		if (atomic_read(&mdev->busy) == 1) {
+			wait_event_interruptible_timeout(mdev->maple_wait,
+				atomic_read(&mdev->busy) == 0, HZ);
+			if (atomic_read(&mdev->busy) == 1) {
+				error = -EBUSY;
+				dev_notice(&mdev->dev, "VMU write at (%d, %d)"
+					"failed - device is busy\n",
+					mdev->port, mdev->unit);
+				goto fail_nolock;
+			}
+		}
+		atomic_set(&mdev->busy, 1);
+
+		locking = maple_add_packet(mdev, MAPLE_FUNC_MEMCARD,
+			MAPLE_COMMAND_BWRITE, phaselen / 4 + 2, sendbuf);
+		wait = wait_event_interruptible_timeout(mdev->maple_wait,
+			atomic_read(&mdev->busy) == 0, HZ/10);
+		if (locking) {
+			error = -EIO;
+			atomic_set(&mdev->busy, 0);
+			goto fail_nolock;
+		}
+		if (atomic_read(&mdev->busy) == 2) {
+			atomic_set(&mdev->busy, 0);
+		} else if (wait == 0 || wait == -ERESTARTSYS) {
+			error = -EIO;
+			dev_warn(&mdev->dev, "Write at (%d, %d) of block"
+				" 0x%X at phase %d failed: could not"
+				" communicate with VMU", mdev->port,
+				mdev->unit, num, x);
+			atomic_set(&mdev->busy, 0);
+			kfree(mdev->mq->sendbuf);
+			mdev->mq->sendbuf = NULL;
+			list_del_init(&(mdev->mq->list));
+			goto fail_nolock;
+		}
+	}
+	kfree(sendbuf);
+
+	return card->blocklen;
+
+fail_nolock:
+	kfree(sendbuf);
+fail_nosendbuf:
+	dev_err(&mdev->dev, "VMU (%d, %d): write failed\n", mdev->port,
+		mdev->unit);
+	return error;
+}
+
+/* mtd function to simulate reading byte by byte */
+static unsigned char vmu_flash_read_char(unsigned long ofs, int *retval,
+	struct mtd_info *mtd)
+{
+	struct vmu_block *vblock;
+	struct memcard *card;
+	struct mdev_part *mpart;
+	struct maple_device *mdev;
+	unsigned char *buf, ret;
+	int partition, error;
+
+	mpart = mtd->priv;
+	mdev = mpart->mdev;
+	partition = mpart->partition;
+	card = maple_get_drvdata(mdev);
+	*retval =  0;
+
+	buf = kmalloc(card->blocklen, GFP_KERNEL);
+	if (!buf) {
+		*retval = 1;
+		ret = -ENOMEM;
+		goto finish;
+	}
+
+	vblock = ofs_to_block(ofs, mtd, partition);
+	if (!vblock) {
+		*retval = 3;
+		ret = -ENOMEM;
+		goto out_buf;
+	}
+
+	error = maple_vmu_read_block(vblock->num, buf, mtd);
+	if (error) {
+		ret = error;
+		*retval = 2;
+		goto out_vblock;
+	}
+
+	ret = buf[vblock->ofs];
+
+out_vblock:
+	kfree(vblock);
+out_buf:
+	kfree(buf);
+finish:
+	return ret;
+}
+
+/* mtd higher order function to read flash */
+static int vmu_flash_read(struct mtd_info *mtd, loff_t from, size_t len,
+	size_t *retlen,  u_char *buf)
+{
+	struct maple_device *mdev;
+	struct memcard *card;
+	struct mdev_part *mpart;
+	struct vmu_cache *pcache;
+	struct vmu_block *vblock;
+	int index = 0, retval, partition, leftover, numblocks;
+	unsigned char cx;
+
+	mpart = mtd->priv;
+	mdev = mpart->mdev;
+	partition = mpart->partition;
+	card = maple_get_drvdata(mdev);
+
+	numblocks = card->parts[partition].numblocks;
+	if (from + len > numblocks * card->blocklen)
+		len = numblocks * card->blocklen - from;
+	if (len == 0)
+		return -EIO;
+	/* Have we cached this bit already? */
+	pcache = card->parts[partition].pcache;
+	do {
+		vblock =  ofs_to_block(from + index, mtd, partition);
+		if (!vblock)
+			return -ENOMEM;
+		/* Have we cached this and is the cache valid and timely? */
+		if (pcache->valid &&
+			time_before(jiffies, pcache->jiffies_atc + HZ) &&
+			(pcache->block == vblock->num)) {
+			/* we have cached it, so do necessary copying */
+			leftover = card->blocklen - vblock->ofs;
+			if (vblock->ofs + len - index < card->blocklen) {
+				/* only a bit of this block to copy */
+				memcpy(buf + index,
+					pcache->buffer + vblock->ofs,
+					len - index);
+				index = len;
+			} else {
+				/* otherwise copy remainder of whole block */
+				memcpy(buf + index, pcache->buffer +
+					vblock->ofs, leftover);
+				index += leftover;
+			}
+		} else {
+			/*
+			* Not cached so read one byte -
+			* but cache the rest of the block
+			*/
+			cx = vmu_flash_read_char(from + index, &retval, mtd);
+			if (retval) {
+				*retlen = index;
+				kfree(vblock);
+				return cx;
+			}
+			memset(buf + index, cx, 1);
+			index++;
+		}
+		kfree(vblock);
+	} while (len > index);
+	*retlen = index;
+
+	return 0;
+}
+
+static int vmu_flash_write(struct mtd_info *mtd, loff_t to, size_t len,
+	size_t *retlen, const u_char *buf)
+{
+	struct maple_device *mdev;
+	struct memcard *card;
+	struct mdev_part *mpart;
+	int index = 0, partition, error = 0, numblocks;
+	struct vmu_cache *pcache;
+	struct vmu_block *vblock;
+	unsigned char *buffer;
+
+	mpart = mtd->priv;
+	mdev = mpart->mdev;
+	partition = mpart->partition;
+	card = maple_get_drvdata(mdev);
+
+	numblocks = card->parts[partition].numblocks;
+	if (to + len > numblocks * card->blocklen)
+		len = numblocks * card->blocklen - to;
+	if (len == 0) {
+		error = -EIO;
+		goto failed;
+	}
+
+	vblock = ofs_to_block(to, mtd, partition);
+	if (!vblock) {
+		error = -ENOMEM;
+		goto failed;
+	}
+
+	buffer = kmalloc(card->blocklen, GFP_KERNEL);
+	if (!buffer) {
+		error = -ENOMEM;
+		goto fail_buffer;
+	}
+
+	do {
+		/* Read in the block we are to write to */
+		error = maple_vmu_read_block(vblock->num, buffer, mtd);
+		if (error)
+			goto fail_io;
+
+		do {
+			buffer[vblock->ofs] = buf[index];
+			vblock->ofs++;
+			index++;
+			if (index >= len)
+				break;
+		} while (vblock->ofs < card->blocklen);
+
+		/* write out new buffer */
+		error = maple_vmu_write_block(vblock->num, buffer, mtd);
+		/* invalidate the cache */
+		pcache = card->parts[partition].pcache;
+		pcache->valid = 0;
+
+		if (error != card->blocklen)
+			goto fail_io;
+
+		vblock->num++;
+		vblock->ofs = 0;
+	} while (len > index);
+
+	kfree(buffer);
+	*retlen = index;
+	kfree(vblock);
+	return 0;
+
+fail_io:
+	kfree(buffer);
+fail_buffer:
+	kfree(vblock);
+failed:
+	dev_err(&mdev->dev, "VMU write failing with error %d\n", error);
+	return error;
+}
+
+static void vmu_flash_sync(struct mtd_info *mtd)
+{
+	/* Do nothing here */
+}
+
+/* Maple bus callback function to recursively query hardware details */
+static void vmu_queryblocks(struct mapleq *mq)
+{
+	struct maple_device *mdev;
+	unsigned short *res;
+	struct memcard *card;
+	__be32 partnum;
+	struct vmu_cache *pcache;
+	struct mdev_part *mpart;
+	struct mtd_info *mtd_cur;
+	struct vmupart *part_cur;
+	int error;
+
+	mdev = mq->dev;
+	card = maple_get_drvdata(mdev);
+	res = (unsigned short *) (mq->recvbuf->buf);
+	card->tempA = res[12];
+	card->tempB = res[6];
+
+	dev_info(&mdev->dev, "VMU device at partition %d has %d user "
+		"blocks with a root block at %d\n", card->partition,
+		card->tempA, card->tempB);
+
+	part_cur = &card->parts[card->partition];
+	part_cur->user_blocks = card->tempA;
+	part_cur->root_block = card->tempB;
+	part_cur->numblocks = card->tempB + 1;
+	part_cur->name = kmalloc(12, GFP_KERNEL);
+	if (!part_cur->name)
+		goto fail_name;
+
+	sprintf(part_cur->name, "vmu%d.%d.%d",
+		mdev->port, mdev->unit, card->partition);
+	mtd_cur = &card->mtd[card->partition];
+	mtd_cur->name = part_cur->name;
+	mtd_cur->type = 8;
+	mtd_cur->flags = MTD_WRITEABLE|MTD_NO_ERASE;
+	mtd_cur->size = part_cur->numblocks * card->blocklen;
+	mtd_cur->erasesize = card->blocklen;
+	mtd_cur->_write = vmu_flash_write;
+	mtd_cur->_read = vmu_flash_read;
+	mtd_cur->_sync = vmu_flash_sync;
+	mtd_cur->writesize = card->blocklen;
+
+	mpart = kmalloc(sizeof(struct mdev_part), GFP_KERNEL);
+	if (!mpart)
+		goto fail_mpart;
+
+	mpart->mdev = mdev;
+	mpart->partition = card->partition;
+	mtd_cur->priv = mpart;
+	mtd_cur->owner = THIS_MODULE;
+
+	pcache = kzalloc(sizeof(struct vmu_cache), GFP_KERNEL);
+	if (!pcache)
+		goto fail_cache_create;
+	part_cur->pcache = pcache;
+
+	error = mtd_device_register(mtd_cur, NULL, 0);
+	if (error)
+		goto fail_mtd_register;
+
+	maple_getcond_callback(mdev, NULL, 0,
+		MAPLE_FUNC_MEMCARD);
+
+	/*
+	* Set up a recursive call to the (probably theoretical)
+	* second or more partition
+	*/
+	if (++card->partition < card->partitions) {
+		partnum = cpu_to_be32(card->partition << 24);
+		maple_getcond_callback(mdev, vmu_queryblocks, 0,
+			MAPLE_FUNC_MEMCARD);
+		maple_add_packet(mdev, MAPLE_FUNC_MEMCARD,
+			MAPLE_COMMAND_GETMINFO, 2, &partnum);
+	}
+	return;
+
+fail_mtd_register:
+	dev_err(&mdev->dev, "Could not register maple device at (%d, %d)"
+		"error is 0x%X\n", mdev->port, mdev->unit, error);
+	for (error = 0; error <= card->partition; error++) {
+		kfree(((card->parts)[error]).pcache);
+		((card->parts)[error]).pcache = NULL;
+	}
+fail_cache_create:
+fail_mpart:
+	for (error = 0; error <= card->partition; error++) {
+		kfree(((card->mtd)[error]).priv);
+		((card->mtd)[error]).priv = NULL;
+	}
+	maple_getcond_callback(mdev, NULL, 0,
+		MAPLE_FUNC_MEMCARD);
+	kfree(part_cur->name);
+fail_name:
+	return;
+}
+
+/* Handles very basic info about the flash, queries for details */
+static int vmu_connect(struct maple_device *mdev)
+{
+	unsigned long test_flash_data, basic_flash_data;
+	int c, error;
+	struct memcard *card;
+	u32 partnum = 0;
+
+	test_flash_data = be32_to_cpu(mdev->devinfo.function);
+	/* Need to count how many bits are set - to find out which
+	 * function_data element has details of the memory card
+	 */
+	c = hweight_long(test_flash_data);
+
+	basic_flash_data = be32_to_cpu(mdev->devinfo.function_data[c - 1]);
+
+	card = kmalloc(sizeof(struct memcard), GFP_KERNEL);
+	if (!card) {
+		error = -ENOMEM;
+		goto fail_nomem;
+	}
+
+	card->partitions = (basic_flash_data >> 24 & 0xFF) + 1;
+	card->blocklen = ((basic_flash_data >> 16 & 0xFF) + 1) << 5;
+	card->writecnt = basic_flash_data >> 12 & 0xF;
+	card->readcnt = basic_flash_data >> 8 & 0xF;
+	card->removable = basic_flash_data >> 7 & 1;
+
+	card->partition = 0;
+
+	/*
+	* Not sure there are actually any multi-partition devices in the
+	* real world, but the hardware supports them, so, so will we
+	*/
+	card->parts = kmalloc_array(card->partitions, sizeof(struct vmupart),
+				    GFP_KERNEL);
+	if (!card->parts) {
+		error = -ENOMEM;
+		goto fail_partitions;
+	}
+
+	card->mtd = kmalloc_array(card->partitions, sizeof(struct mtd_info),
+				  GFP_KERNEL);
+	if (!card->mtd) {
+		error = -ENOMEM;
+		goto fail_mtd_info;
+	}
+
+	maple_set_drvdata(mdev, card);
+
+	/*
+	* We want to trap meminfo not get cond
+	* so set interval to zero, but rely on maple bus
+	* driver to pass back the results of the meminfo
+	*/
+	maple_getcond_callback(mdev, vmu_queryblocks, 0,
+		MAPLE_FUNC_MEMCARD);
+
+	/* Make sure we are clear to go */
+	if (atomic_read(&mdev->busy) == 1) {
+		wait_event_interruptible_timeout(mdev->maple_wait,
+			atomic_read(&mdev->busy) == 0, HZ);
+		if (atomic_read(&mdev->busy) == 1) {
+			dev_notice(&mdev->dev, "VMU at (%d, %d) is busy\n",
+				mdev->port, mdev->unit);
+			error = -EAGAIN;
+			goto fail_device_busy;
+		}
+	}
+
+	atomic_set(&mdev->busy, 1);
+
+	/*
+	* Set up the minfo call: vmu_queryblocks will handle
+	* the information passed back
+	*/
+	error = maple_add_packet(mdev, MAPLE_FUNC_MEMCARD,
+		MAPLE_COMMAND_GETMINFO, 2, &partnum);
+	if (error) {
+		dev_err(&mdev->dev, "Could not lock VMU at (%d, %d)"
+			" error is 0x%X\n", mdev->port, mdev->unit, error);
+		goto fail_mtd_info;
+	}
+	return 0;
+
+fail_device_busy:
+	kfree(card->mtd);
+fail_mtd_info:
+	kfree(card->parts);
+fail_partitions:
+	kfree(card);
+fail_nomem:
+	return error;
+}
+
+static void vmu_disconnect(struct maple_device *mdev)
+{
+	struct memcard *card;
+	struct mdev_part *mpart;
+	int x;
+
+	mdev->callback = NULL;
+	card = maple_get_drvdata(mdev);
+	for (x = 0; x < card->partitions; x++) {
+		mpart = ((card->mtd)[x]).priv;
+		mpart->mdev = NULL;
+		mtd_device_unregister(&((card->mtd)[x]));
+		kfree(((card->parts)[x]).name);
+	}
+	kfree(card->parts);
+	kfree(card->mtd);
+	kfree(card);
+}
+
+/* Callback to handle eccentricities of both mtd subsystem
+ * and general flakyness of Dreamcast VMUs
+ */
+static int vmu_can_unload(struct maple_device *mdev)
+{
+	struct memcard *card;
+	int x;
+	struct mtd_info *mtd;
+
+	card = maple_get_drvdata(mdev);
+	for (x = 0; x < card->partitions; x++) {
+		mtd = &((card->mtd)[x]);
+		if (mtd->usecount > 0)
+			return 0;
+	}
+	return 1;
+}
+
+#define ERRSTR "VMU at (%d, %d) file error -"
+
+static void vmu_file_error(struct maple_device *mdev, void *recvbuf)
+{
+	enum maple_file_errors error = ((int *)recvbuf)[1];
+
+	switch (error) {
+
+	case MAPLE_FILEERR_INVALID_PARTITION:
+		dev_notice(&mdev->dev, ERRSTR " invalid partition number\n",
+			mdev->port, mdev->unit);
+		break;
+
+	case MAPLE_FILEERR_PHASE_ERROR:
+		dev_notice(&mdev->dev, ERRSTR " phase error\n",
+			mdev->port, mdev->unit);
+		break;
+
+	case MAPLE_FILEERR_INVALID_BLOCK:
+		dev_notice(&mdev->dev, ERRSTR " invalid block number\n",
+			mdev->port, mdev->unit);
+		break;
+
+	case MAPLE_FILEERR_WRITE_ERROR:
+		dev_notice(&mdev->dev, ERRSTR " write error\n",
+			mdev->port, mdev->unit);
+		break;
+
+	case MAPLE_FILEERR_INVALID_WRITE_LENGTH:
+		dev_notice(&mdev->dev, ERRSTR " invalid write length\n",
+			mdev->port, mdev->unit);
+		break;
+
+	case MAPLE_FILEERR_BAD_CRC:
+		dev_notice(&mdev->dev, ERRSTR " bad CRC\n",
+			mdev->port, mdev->unit);
+		break;
+
+	default:
+		dev_notice(&mdev->dev, ERRSTR " 0x%X\n",
+			mdev->port, mdev->unit, error);
+	}
+}
+
+
+static int probe_maple_vmu(struct device *dev)
+{
+	struct maple_device *mdev = to_maple_dev(dev);
+	struct maple_driver *mdrv = to_maple_driver(dev->driver);
+
+	mdev->can_unload = vmu_can_unload;
+	mdev->fileerr_handler = vmu_file_error;
+	mdev->driver = mdrv;
+
+	return vmu_connect(mdev);
+}
+
+static int remove_maple_vmu(struct device *dev)
+{
+	struct maple_device *mdev = to_maple_dev(dev);
+
+	vmu_disconnect(mdev);
+	return 0;
+}
+
+static struct maple_driver vmu_flash_driver = {
+	.function =	MAPLE_FUNC_MEMCARD,
+	.drv = {
+		.name =		"Dreamcast_visual_memory",
+		.probe =	probe_maple_vmu,
+		.remove =	remove_maple_vmu,
+	},
+};
+
+static int __init vmu_flash_map_init(void)
+{
+	return maple_driver_register(&vmu_flash_driver);
+}
+
+static void __exit vmu_flash_map_exit(void)
+{
+	maple_driver_unregister(&vmu_flash_driver);
+}
+
+module_init(vmu_flash_map_init);
+module_exit(vmu_flash_map_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Adrian McMenamin");
+MODULE_DESCRIPTION("Flash mapping for Sega Dreamcast visual memory");