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, 664 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-virtio.c b/drivers/gpio/gpio-virtio.c
new file mode 100644
index 000000000..fcc5e8c08
--- /dev/null
+++ b/drivers/gpio/gpio-virtio.c
@@ -0,0 +1,664 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * GPIO driver for virtio-based virtual GPIO controllers
+ *
+ * Copyright (C) 2021 metux IT consult
+ * Enrico Weigelt, metux IT consult <info@metux.net>
+ *
+ * Copyright (C) 2021 Linaro.
+ * Viresh Kumar <viresh.kumar@linaro.org>
+ */
+
+#include <linux/completion.h>
+#include <linux/err.h>
+#include <linux/gpio/driver.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/virtio_config.h>
+#include <uapi/linux/virtio_gpio.h>
+#include <uapi/linux/virtio_ids.h>
+
+struct virtio_gpio_line {
+	struct mutex lock; /* Protects line operation */
+	struct completion completion;
+	struct virtio_gpio_request req ____cacheline_aligned;
+	struct virtio_gpio_response res ____cacheline_aligned;
+	unsigned int rxlen;
+};
+
+struct vgpio_irq_line {
+	u8 type;
+	bool disabled;
+	bool masked;
+	bool queued;
+	bool update_pending;
+	bool queue_pending;
+
+	struct virtio_gpio_irq_request ireq ____cacheline_aligned;
+	struct virtio_gpio_irq_response ires ____cacheline_aligned;
+};
+
+struct virtio_gpio {
+	struct virtio_device *vdev;
+	struct mutex lock; /* Protects virtqueue operation */
+	struct gpio_chip gc;
+	struct virtio_gpio_line *lines;
+	struct virtqueue *request_vq;
+
+	/* irq support */
+	struct virtqueue *event_vq;
+	struct mutex irq_lock; /* Protects irq operation */
+	raw_spinlock_t eventq_lock; /* Protects queuing of the buffer */
+	struct vgpio_irq_line *irq_lines;
+};
+
+static int _virtio_gpio_req(struct virtio_gpio *vgpio, u16 type, u16 gpio,
+			    u8 txvalue, u8 *rxvalue, void *response, u32 rxlen)
+{
+	struct virtio_gpio_line *line = &vgpio->lines[gpio];
+	struct virtio_gpio_request *req = &line->req;
+	struct virtio_gpio_response *res = response;
+	struct scatterlist *sgs[2], req_sg, res_sg;
+	struct device *dev = &vgpio->vdev->dev;
+	int ret;
+
+	/*
+	 * Prevent concurrent requests for the same line since we have
+	 * pre-allocated request/response buffers for each GPIO line. Moreover
+	 * Linux always accesses a GPIO line sequentially, so this locking shall
+	 * always go through without any delays.
+	 */
+	mutex_lock(&line->lock);
+
+	req->type = cpu_to_le16(type);
+	req->gpio = cpu_to_le16(gpio);
+	req->value = cpu_to_le32(txvalue);
+
+	sg_init_one(&req_sg, req, sizeof(*req));
+	sg_init_one(&res_sg, res, rxlen);
+	sgs[0] = &req_sg;
+	sgs[1] = &res_sg;
+
+	line->rxlen = 0;
+	reinit_completion(&line->completion);
+
+	/*
+	 * Virtqueue callers need to ensure they don't call its APIs with other
+	 * virtqueue operations at the same time.
+	 */
+	mutex_lock(&vgpio->lock);
+	ret = virtqueue_add_sgs(vgpio->request_vq, sgs, 1, 1, line, GFP_KERNEL);
+	if (ret) {
+		dev_err(dev, "failed to add request to vq\n");
+		mutex_unlock(&vgpio->lock);
+		goto out;
+	}
+
+	virtqueue_kick(vgpio->request_vq);
+	mutex_unlock(&vgpio->lock);
+
+	wait_for_completion(&line->completion);
+
+	if (unlikely(res->status != VIRTIO_GPIO_STATUS_OK)) {
+		dev_err(dev, "GPIO request failed: %d\n", gpio);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (unlikely(line->rxlen != rxlen)) {
+		dev_err(dev, "GPIO operation returned incorrect len (%u : %u)\n",
+			rxlen, line->rxlen);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (rxvalue)
+		*rxvalue = res->value;
+
+out:
+	mutex_unlock(&line->lock);
+	return ret;
+}
+
+static int virtio_gpio_req(struct virtio_gpio *vgpio, u16 type, u16 gpio,
+			   u8 txvalue, u8 *rxvalue)
+{
+	struct virtio_gpio_line *line = &vgpio->lines[gpio];
+	struct virtio_gpio_response *res = &line->res;
+
+	return _virtio_gpio_req(vgpio, type, gpio, txvalue, rxvalue, res,
+				sizeof(*res));
+}
+
+static void virtio_gpio_free(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct virtio_gpio *vgpio = gpiochip_get_data(gc);
+
+	virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_SET_DIRECTION, gpio,
+			VIRTIO_GPIO_DIRECTION_NONE, NULL);
+}
+
+static int virtio_gpio_get_direction(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct virtio_gpio *vgpio = gpiochip_get_data(gc);
+	u8 direction;
+	int ret;
+
+	ret = virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_GET_DIRECTION, gpio, 0,
+			      &direction);
+	if (ret)
+		return ret;
+
+	switch (direction) {
+	case VIRTIO_GPIO_DIRECTION_IN:
+		return GPIO_LINE_DIRECTION_IN;
+	case VIRTIO_GPIO_DIRECTION_OUT:
+		return GPIO_LINE_DIRECTION_OUT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int virtio_gpio_direction_input(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct virtio_gpio *vgpio = gpiochip_get_data(gc);
+
+	return virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_SET_DIRECTION, gpio,
+			       VIRTIO_GPIO_DIRECTION_IN, NULL);
+}
+
+static int virtio_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio,
+					int value)
+{
+	struct virtio_gpio *vgpio = gpiochip_get_data(gc);
+	int ret;
+
+	ret = virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_SET_VALUE, gpio, value, NULL);
+	if (ret)
+		return ret;
+
+	return virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_SET_DIRECTION, gpio,
+			       VIRTIO_GPIO_DIRECTION_OUT, NULL);
+}
+
+static int virtio_gpio_get(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct virtio_gpio *vgpio = gpiochip_get_data(gc);
+	u8 value;
+	int ret;
+
+	ret = virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_GET_VALUE, gpio, 0, &value);
+	return ret ? ret : value;
+}
+
+static void virtio_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value)
+{
+	struct virtio_gpio *vgpio = gpiochip_get_data(gc);
+
+	virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_SET_VALUE, gpio, value, NULL);
+}
+
+/* Interrupt handling */
+static void virtio_gpio_irq_prepare(struct virtio_gpio *vgpio, u16 gpio)
+{
+	struct vgpio_irq_line *irq_line = &vgpio->irq_lines[gpio];
+	struct virtio_gpio_irq_request *ireq = &irq_line->ireq;
+	struct virtio_gpio_irq_response *ires = &irq_line->ires;
+	struct scatterlist *sgs[2], req_sg, res_sg;
+	int ret;
+
+	if (WARN_ON(irq_line->queued || irq_line->masked || irq_line->disabled))
+		return;
+
+	ireq->gpio = cpu_to_le16(gpio);
+	sg_init_one(&req_sg, ireq, sizeof(*ireq));
+	sg_init_one(&res_sg, ires, sizeof(*ires));
+	sgs[0] = &req_sg;
+	sgs[1] = &res_sg;
+
+	ret = virtqueue_add_sgs(vgpio->event_vq, sgs, 1, 1, irq_line, GFP_ATOMIC);
+	if (ret) {
+		dev_err(&vgpio->vdev->dev, "failed to add request to eventq\n");
+		return;
+	}
+
+	irq_line->queued = true;
+	virtqueue_kick(vgpio->event_vq);
+}
+
+static void virtio_gpio_irq_enable(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct virtio_gpio *vgpio = gpiochip_get_data(gc);
+	struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq];
+
+	raw_spin_lock(&vgpio->eventq_lock);
+	irq_line->disabled = false;
+	irq_line->masked = false;
+	irq_line->queue_pending = true;
+	raw_spin_unlock(&vgpio->eventq_lock);
+
+	irq_line->update_pending = true;
+}
+
+static void virtio_gpio_irq_disable(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct virtio_gpio *vgpio = gpiochip_get_data(gc);
+	struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq];
+
+	raw_spin_lock(&vgpio->eventq_lock);
+	irq_line->disabled = true;
+	irq_line->masked = true;
+	irq_line->queue_pending = false;
+	raw_spin_unlock(&vgpio->eventq_lock);
+
+	irq_line->update_pending = true;
+}
+
+static void virtio_gpio_irq_mask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct virtio_gpio *vgpio = gpiochip_get_data(gc);
+	struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq];
+
+	raw_spin_lock(&vgpio->eventq_lock);
+	irq_line->masked = true;
+	raw_spin_unlock(&vgpio->eventq_lock);
+}
+
+static void virtio_gpio_irq_unmask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct virtio_gpio *vgpio = gpiochip_get_data(gc);
+	struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq];
+
+	raw_spin_lock(&vgpio->eventq_lock);
+	irq_line->masked = false;
+
+	/* Queue the buffer unconditionally on unmask */
+	virtio_gpio_irq_prepare(vgpio, d->hwirq);
+	raw_spin_unlock(&vgpio->eventq_lock);
+}
+
+static int virtio_gpio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct virtio_gpio *vgpio = gpiochip_get_data(gc);
+	struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq];
+
+	switch (type) {
+	case IRQ_TYPE_EDGE_RISING:
+		type = VIRTIO_GPIO_IRQ_TYPE_EDGE_RISING;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		type = VIRTIO_GPIO_IRQ_TYPE_EDGE_FALLING;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		type = VIRTIO_GPIO_IRQ_TYPE_EDGE_BOTH;
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		type = VIRTIO_GPIO_IRQ_TYPE_LEVEL_LOW;
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		type = VIRTIO_GPIO_IRQ_TYPE_LEVEL_HIGH;
+		break;
+	default:
+		dev_err(&vgpio->vdev->dev, "unsupported irq type: %u\n", type);
+		return -EINVAL;
+	}
+
+	irq_line->type = type;
+	irq_line->update_pending = true;
+
+	return 0;
+}
+
+static void virtio_gpio_irq_bus_lock(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct virtio_gpio *vgpio = gpiochip_get_data(gc);
+
+	mutex_lock(&vgpio->irq_lock);
+}
+
+static void virtio_gpio_irq_bus_sync_unlock(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct virtio_gpio *vgpio = gpiochip_get_data(gc);
+	struct vgpio_irq_line *irq_line = &vgpio->irq_lines[d->hwirq];
+	u8 type = irq_line->disabled ? VIRTIO_GPIO_IRQ_TYPE_NONE : irq_line->type;
+	unsigned long flags;
+
+	if (irq_line->update_pending) {
+		irq_line->update_pending = false;
+		virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_IRQ_TYPE, d->hwirq, type,
+				NULL);
+
+		/* Queue the buffer only after interrupt is enabled */
+		raw_spin_lock_irqsave(&vgpio->eventq_lock, flags);
+		if (irq_line->queue_pending) {
+			irq_line->queue_pending = false;
+			virtio_gpio_irq_prepare(vgpio, d->hwirq);
+		}
+		raw_spin_unlock_irqrestore(&vgpio->eventq_lock, flags);
+	}
+
+	mutex_unlock(&vgpio->irq_lock);
+}
+
+static struct irq_chip vgpio_irq_chip = {
+	.name			= "virtio-gpio",
+	.irq_enable		= virtio_gpio_irq_enable,
+	.irq_disable		= virtio_gpio_irq_disable,
+	.irq_mask		= virtio_gpio_irq_mask,
+	.irq_unmask		= virtio_gpio_irq_unmask,
+	.irq_set_type		= virtio_gpio_irq_set_type,
+
+	/* These are required to implement irqchip for slow busses */
+	.irq_bus_lock		= virtio_gpio_irq_bus_lock,
+	.irq_bus_sync_unlock	= virtio_gpio_irq_bus_sync_unlock,
+};
+
+static bool ignore_irq(struct virtio_gpio *vgpio, int gpio,
+		       struct vgpio_irq_line *irq_line)
+{
+	bool ignore = false;
+
+	raw_spin_lock(&vgpio->eventq_lock);
+	irq_line->queued = false;
+
+	/* Interrupt is disabled currently */
+	if (irq_line->masked || irq_line->disabled) {
+		ignore = true;
+		goto unlock;
+	}
+
+	/*
+	 * Buffer is returned as the interrupt was disabled earlier, but is
+	 * enabled again now. Requeue the buffers.
+	 */
+	if (irq_line->ires.status == VIRTIO_GPIO_IRQ_STATUS_INVALID) {
+		virtio_gpio_irq_prepare(vgpio, gpio);
+		ignore = true;
+		goto unlock;
+	}
+
+	if (WARN_ON(irq_line->ires.status != VIRTIO_GPIO_IRQ_STATUS_VALID))
+		ignore = true;
+
+unlock:
+	raw_spin_unlock(&vgpio->eventq_lock);
+
+	return ignore;
+}
+
+static void virtio_gpio_event_vq(struct virtqueue *vq)
+{
+	struct virtio_gpio *vgpio = vq->vdev->priv;
+	struct device *dev = &vgpio->vdev->dev;
+	struct vgpio_irq_line *irq_line;
+	int gpio, ret;
+	unsigned int len;
+
+	while (true) {
+		irq_line = virtqueue_get_buf(vgpio->event_vq, &len);
+		if (!irq_line)
+			break;
+
+		if (len != sizeof(irq_line->ires)) {
+			dev_err(dev, "irq with incorrect length (%u : %u)\n",
+				len, (unsigned int)sizeof(irq_line->ires));
+			continue;
+		}
+
+		/*
+		 * Find GPIO line number from the offset of irq_line within the
+		 * irq_lines block. We can also get GPIO number from
+		 * irq-request, but better not to rely on a buffer returned by
+		 * remote.
+		 */
+		gpio = irq_line - vgpio->irq_lines;
+		WARN_ON(gpio >= vgpio->gc.ngpio);
+
+		if (unlikely(ignore_irq(vgpio, gpio, irq_line)))
+			continue;
+
+		ret = generic_handle_domain_irq(vgpio->gc.irq.domain, gpio);
+		if (ret)
+			dev_err(dev, "failed to handle interrupt: %d\n", ret);
+	}
+}
+
+static void virtio_gpio_request_vq(struct virtqueue *vq)
+{
+	struct virtio_gpio_line *line;
+	unsigned int len;
+
+	do {
+		line = virtqueue_get_buf(vq, &len);
+		if (!line)
+			return;
+
+		line->rxlen = len;
+		complete(&line->completion);
+	} while (1);
+}
+
+static void virtio_gpio_free_vqs(struct virtio_device *vdev)
+{
+	virtio_reset_device(vdev);
+	vdev->config->del_vqs(vdev);
+}
+
+static int virtio_gpio_alloc_vqs(struct virtio_gpio *vgpio,
+				 struct virtio_device *vdev)
+{
+	const char * const names[] = { "requestq", "eventq" };
+	vq_callback_t *cbs[] = {
+		virtio_gpio_request_vq,
+		virtio_gpio_event_vq,
+	};
+	struct virtqueue *vqs[2] = { NULL, NULL };
+	int ret;
+
+	ret = virtio_find_vqs(vdev, vgpio->irq_lines ? 2 : 1, vqs, cbs, names, NULL);
+	if (ret) {
+		dev_err(&vdev->dev, "failed to find vqs: %d\n", ret);
+		return ret;
+	}
+
+	if (!vqs[0]) {
+		dev_err(&vdev->dev, "failed to find requestq vq\n");
+		goto out;
+	}
+	vgpio->request_vq = vqs[0];
+
+	if (vgpio->irq_lines && !vqs[1]) {
+		dev_err(&vdev->dev, "failed to find eventq vq\n");
+		goto out;
+	}
+	vgpio->event_vq = vqs[1];
+
+	return 0;
+
+out:
+	if (vqs[0] || vqs[1])
+		virtio_gpio_free_vqs(vdev);
+
+	return -ENODEV;
+}
+
+static const char **virtio_gpio_get_names(struct virtio_gpio *vgpio,
+					  u32 gpio_names_size, u16 ngpio)
+{
+	struct virtio_gpio_response_get_names *res;
+	struct device *dev = &vgpio->vdev->dev;
+	u8 *gpio_names, *str;
+	const char **names;
+	int i, ret, len;
+
+	if (!gpio_names_size)
+		return NULL;
+
+	len = sizeof(*res) + gpio_names_size;
+	res = devm_kzalloc(dev, len, GFP_KERNEL);
+	if (!res)
+		return NULL;
+	gpio_names = res->value;
+
+	ret = _virtio_gpio_req(vgpio, VIRTIO_GPIO_MSG_GET_NAMES, 0, 0, NULL,
+			       res, len);
+	if (ret) {
+		dev_err(dev, "Failed to get GPIO names: %d\n", ret);
+		return NULL;
+	}
+
+	names = devm_kcalloc(dev, ngpio, sizeof(*names), GFP_KERNEL);
+	if (!names)
+		return NULL;
+
+	/* NULL terminate the string instead of checking it */
+	gpio_names[gpio_names_size - 1] = '\0';
+
+	for (i = 0, str = gpio_names; i < ngpio; i++) {
+		names[i] = str;
+		str += strlen(str) + 1; /* zero-length strings are allowed */
+
+		if (str > gpio_names + gpio_names_size) {
+			dev_err(dev, "gpio_names block is too short (%d)\n", i);
+			return NULL;
+		}
+	}
+
+	return names;
+}
+
+static int virtio_gpio_probe(struct virtio_device *vdev)
+{
+	struct virtio_gpio_config config;
+	struct device *dev = &vdev->dev;
+	struct virtio_gpio *vgpio;
+	u32 gpio_names_size;
+	u16 ngpio;
+	int ret, i;
+
+	vgpio = devm_kzalloc(dev, sizeof(*vgpio), GFP_KERNEL);
+	if (!vgpio)
+		return -ENOMEM;
+
+	/* Read configuration */
+	virtio_cread_bytes(vdev, 0, &config, sizeof(config));
+	gpio_names_size = le32_to_cpu(config.gpio_names_size);
+	ngpio = le16_to_cpu(config.ngpio);
+	if (!ngpio) {
+		dev_err(dev, "Number of GPIOs can't be zero\n");
+		return -EINVAL;
+	}
+
+	vgpio->lines = devm_kcalloc(dev, ngpio, sizeof(*vgpio->lines), GFP_KERNEL);
+	if (!vgpio->lines)
+		return -ENOMEM;
+
+	for (i = 0; i < ngpio; i++) {
+		mutex_init(&vgpio->lines[i].lock);
+		init_completion(&vgpio->lines[i].completion);
+	}
+
+	mutex_init(&vgpio->lock);
+	vdev->priv = vgpio;
+
+	vgpio->vdev			= vdev;
+	vgpio->gc.free			= virtio_gpio_free;
+	vgpio->gc.get_direction		= virtio_gpio_get_direction;
+	vgpio->gc.direction_input	= virtio_gpio_direction_input;
+	vgpio->gc.direction_output	= virtio_gpio_direction_output;
+	vgpio->gc.get			= virtio_gpio_get;
+	vgpio->gc.set			= virtio_gpio_set;
+	vgpio->gc.ngpio			= ngpio;
+	vgpio->gc.base			= -1; /* Allocate base dynamically */
+	vgpio->gc.label			= dev_name(dev);
+	vgpio->gc.parent		= dev;
+	vgpio->gc.owner			= THIS_MODULE;
+	vgpio->gc.can_sleep		= true;
+
+	/* Interrupt support */
+	if (virtio_has_feature(vdev, VIRTIO_GPIO_F_IRQ)) {
+		vgpio->irq_lines = devm_kcalloc(dev, ngpio, sizeof(*vgpio->irq_lines), GFP_KERNEL);
+		if (!vgpio->irq_lines)
+			return -ENOMEM;
+
+		/* The event comes from the outside so no parent handler */
+		vgpio->gc.irq.parent_handler	= NULL;
+		vgpio->gc.irq.num_parents	= 0;
+		vgpio->gc.irq.parents		= NULL;
+		vgpio->gc.irq.default_type	= IRQ_TYPE_NONE;
+		vgpio->gc.irq.handler		= handle_level_irq;
+		vgpio->gc.irq.chip		= &vgpio_irq_chip;
+
+		for (i = 0; i < ngpio; i++) {
+			vgpio->irq_lines[i].type = VIRTIO_GPIO_IRQ_TYPE_NONE;
+			vgpio->irq_lines[i].disabled = true;
+			vgpio->irq_lines[i].masked = true;
+		}
+
+		mutex_init(&vgpio->irq_lock);
+		raw_spin_lock_init(&vgpio->eventq_lock);
+	}
+
+	ret = virtio_gpio_alloc_vqs(vgpio, vdev);
+	if (ret)
+		return ret;
+
+	/* Mark the device ready to perform operations from within probe() */
+	virtio_device_ready(vdev);
+
+	vgpio->gc.names = virtio_gpio_get_names(vgpio, gpio_names_size, ngpio);
+
+	ret = gpiochip_add_data(&vgpio->gc, vgpio);
+	if (ret) {
+		virtio_gpio_free_vqs(vdev);
+		dev_err(dev, "Failed to add virtio-gpio controller\n");
+	}
+
+	return ret;
+}
+
+static void virtio_gpio_remove(struct virtio_device *vdev)
+{
+	struct virtio_gpio *vgpio = vdev->priv;
+
+	gpiochip_remove(&vgpio->gc);
+	virtio_gpio_free_vqs(vdev);
+}
+
+static const struct virtio_device_id id_table[] = {
+	{ VIRTIO_ID_GPIO, VIRTIO_DEV_ANY_ID },
+	{},
+};
+MODULE_DEVICE_TABLE(virtio, id_table);
+
+static const unsigned int features[] = {
+	VIRTIO_GPIO_F_IRQ,
+};
+
+static struct virtio_driver virtio_gpio_driver = {
+	.feature_table		= features,
+	.feature_table_size	= ARRAY_SIZE(features),
+	.id_table		= id_table,
+	.probe			= virtio_gpio_probe,
+	.remove			= virtio_gpio_remove,
+	.driver			= {
+		.name		= KBUILD_MODNAME,
+		.owner		= THIS_MODULE,
+	},
+};
+module_virtio_driver(virtio_gpio_driver);
+
+MODULE_AUTHOR("Enrico Weigelt, metux IT consult <info@metux.net>");
+MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
+MODULE_DESCRIPTION("VirtIO GPIO driver");
+MODULE_LICENSE("GPL");