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, 553 insertions, 0 deletions

diff --git a/drivers/input/ff-memless.c b/drivers/input/ff-memless.c
new file mode 100644
index 000000000..c321cdabd
--- /dev/null
+++ b/drivers/input/ff-memless.c
@@ -0,0 +1,553 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Force feedback support for memoryless devices
+ *
+ *  Copyright (c) 2006 Anssi Hannula <anssi.hannula@gmail.com>
+ *  Copyright (c) 2006 Dmitry Torokhov <dtor@mail.ru>
+ */
+
+/* #define DEBUG */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/jiffies.h>
+#include <linux/fixp-arith.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Anssi Hannula <anssi.hannula@gmail.com>");
+MODULE_DESCRIPTION("Force feedback support for memoryless devices");
+
+/* Number of effects handled with memoryless devices */
+#define FF_MEMLESS_EFFECTS	16
+
+/* Envelope update interval in ms */
+#define FF_ENVELOPE_INTERVAL	50
+
+#define FF_EFFECT_STARTED	0
+#define FF_EFFECT_PLAYING	1
+#define FF_EFFECT_ABORTING	2
+
+struct ml_effect_state {
+	struct ff_effect *effect;
+	unsigned long flags;	/* effect state (STARTED, PLAYING, etc) */
+	int count;		/* loop count of the effect */
+	unsigned long play_at;	/* start time */
+	unsigned long stop_at;	/* stop time */
+	unsigned long adj_at;	/* last time the effect was sent */
+};
+
+struct ml_device {
+	void *private;
+	struct ml_effect_state states[FF_MEMLESS_EFFECTS];
+	int gain;
+	struct timer_list timer;
+	struct input_dev *dev;
+
+	int (*play_effect)(struct input_dev *dev, void *data,
+			   struct ff_effect *effect);
+};
+
+static const struct ff_envelope *get_envelope(const struct ff_effect *effect)
+{
+	static const struct ff_envelope empty_envelope;
+
+	switch (effect->type) {
+	case FF_PERIODIC:
+		return &effect->u.periodic.envelope;
+
+	case FF_CONSTANT:
+		return &effect->u.constant.envelope;
+
+	default:
+		return &empty_envelope;
+	}
+}
+
+/*
+ * Check for the next time envelope requires an update on memoryless devices
+ */
+static unsigned long calculate_next_time(struct ml_effect_state *state)
+{
+	const struct ff_envelope *envelope = get_envelope(state->effect);
+	unsigned long attack_stop, fade_start, next_fade;
+
+	if (envelope->attack_length) {
+		attack_stop = state->play_at +
+			msecs_to_jiffies(envelope->attack_length);
+		if (time_before(state->adj_at, attack_stop))
+			return state->adj_at +
+					msecs_to_jiffies(FF_ENVELOPE_INTERVAL);
+	}
+
+	if (state->effect->replay.length) {
+		if (envelope->fade_length) {
+			/* check when fading should start */
+			fade_start = state->stop_at -
+					msecs_to_jiffies(envelope->fade_length);
+
+			if (time_before(state->adj_at, fade_start))
+				return fade_start;
+
+			/* already fading, advance to next checkpoint */
+			next_fade = state->adj_at +
+					msecs_to_jiffies(FF_ENVELOPE_INTERVAL);
+			if (time_before(next_fade, state->stop_at))
+				return next_fade;
+		}
+
+		return state->stop_at;
+	}
+
+	return state->play_at;
+}
+
+static void ml_schedule_timer(struct ml_device *ml)
+{
+	struct ml_effect_state *state;
+	unsigned long now = jiffies;
+	unsigned long earliest = 0;
+	unsigned long next_at;
+	int events = 0;
+	int i;
+
+	pr_debug("calculating next timer\n");
+
+	for (i = 0; i < FF_MEMLESS_EFFECTS; i++) {
+
+		state = &ml->states[i];
+
+		if (!test_bit(FF_EFFECT_STARTED, &state->flags))
+			continue;
+
+		if (test_bit(FF_EFFECT_PLAYING, &state->flags))
+			next_at = calculate_next_time(state);
+		else
+			next_at = state->play_at;
+
+		if (time_before_eq(now, next_at) &&
+		    (++events == 1 || time_before(next_at, earliest)))
+			earliest = next_at;
+	}
+
+	if (!events) {
+		pr_debug("no actions\n");
+		del_timer(&ml->timer);
+	} else {
+		pr_debug("timer set\n");
+		mod_timer(&ml->timer, earliest);
+	}
+}
+
+/*
+ * Apply an envelope to a value
+ */
+static int apply_envelope(struct ml_effect_state *state, int value,
+			  struct ff_envelope *envelope)
+{
+	struct ff_effect *effect = state->effect;
+	unsigned long now = jiffies;
+	int time_from_level;
+	int time_of_envelope;
+	int envelope_level;
+	int difference;
+
+	if (envelope->attack_length &&
+	    time_before(now,
+			state->play_at + msecs_to_jiffies(envelope->attack_length))) {
+		pr_debug("value = 0x%x, attack_level = 0x%x\n",
+			 value, envelope->attack_level);
+		time_from_level = jiffies_to_msecs(now - state->play_at);
+		time_of_envelope = envelope->attack_length;
+		envelope_level = min_t(u16, envelope->attack_level, 0x7fff);
+
+	} else if (envelope->fade_length && effect->replay.length &&
+		   time_after(now,
+			      state->stop_at - msecs_to_jiffies(envelope->fade_length)) &&
+		   time_before(now, state->stop_at)) {
+		time_from_level = jiffies_to_msecs(state->stop_at - now);
+		time_of_envelope = envelope->fade_length;
+		envelope_level = min_t(u16, envelope->fade_level, 0x7fff);
+	} else
+		return value;
+
+	difference = abs(value) - envelope_level;
+
+	pr_debug("difference = %d\n", difference);
+	pr_debug("time_from_level = 0x%x\n", time_from_level);
+	pr_debug("time_of_envelope = 0x%x\n", time_of_envelope);
+
+	difference = difference * time_from_level / time_of_envelope;
+
+	pr_debug("difference = %d\n", difference);
+
+	return value < 0 ?
+		-(difference + envelope_level) : (difference + envelope_level);
+}
+
+/*
+ * Return the type the effect has to be converted into (memless devices)
+ */
+static int get_compatible_type(struct ff_device *ff, int effect_type)
+{
+
+	if (test_bit(effect_type, ff->ffbit))
+		return effect_type;
+
+	if (effect_type == FF_PERIODIC && test_bit(FF_RUMBLE, ff->ffbit))
+		return FF_RUMBLE;
+
+	pr_err("invalid type in get_compatible_type()\n");
+
+	return 0;
+}
+
+/*
+ * Only left/right direction should be used (under/over 0x8000) for
+ * forward/reverse motor direction (to keep calculation fast & simple).
+ */
+static u16 ml_calculate_direction(u16 direction, u16 force,
+				  u16 new_direction, u16 new_force)
+{
+	if (!force)
+		return new_direction;
+	if (!new_force)
+		return direction;
+	return (((u32)(direction >> 1) * force +
+		 (new_direction >> 1) * new_force) /
+		(force + new_force)) << 1;
+}
+
+#define FRAC_N 8
+static inline s16 fixp_new16(s16 a)
+{
+	return ((s32)a) >> (16 - FRAC_N);
+}
+
+static inline s16 fixp_mult(s16 a, s16 b)
+{
+	a = ((s32)a * 0x100) / 0x7fff;
+	return ((s32)(a * b)) >> FRAC_N;
+}
+
+/*
+ * Combine two effects and apply gain.
+ */
+static void ml_combine_effects(struct ff_effect *effect,
+			       struct ml_effect_state *state,
+			       int gain)
+{
+	struct ff_effect *new = state->effect;
+	unsigned int strong, weak, i;
+	int x, y;
+	s16 level;
+
+	switch (new->type) {
+	case FF_CONSTANT:
+		i = new->direction * 360 / 0xffff;
+		level = fixp_new16(apply_envelope(state,
+					new->u.constant.level,
+					&new->u.constant.envelope));
+		x = fixp_mult(fixp_sin16(i), level) * gain / 0xffff;
+		y = fixp_mult(-fixp_cos16(i), level) * gain / 0xffff;
+		/*
+		 * here we abuse ff_ramp to hold x and y of constant force
+		 * If in future any driver wants something else than x and y
+		 * in s8, this should be changed to something more generic
+		 */
+		effect->u.ramp.start_level =
+			clamp_val(effect->u.ramp.start_level + x, -0x80, 0x7f);
+		effect->u.ramp.end_level =
+			clamp_val(effect->u.ramp.end_level + y, -0x80, 0x7f);
+		break;
+
+	case FF_RUMBLE:
+		strong = (u32)new->u.rumble.strong_magnitude * gain / 0xffff;
+		weak = (u32)new->u.rumble.weak_magnitude * gain / 0xffff;
+
+		if (effect->u.rumble.strong_magnitude + strong)
+			effect->direction = ml_calculate_direction(
+				effect->direction,
+				effect->u.rumble.strong_magnitude,
+				new->direction, strong);
+		else if (effect->u.rumble.weak_magnitude + weak)
+			effect->direction = ml_calculate_direction(
+				effect->direction,
+				effect->u.rumble.weak_magnitude,
+				new->direction, weak);
+		else
+			effect->direction = 0;
+		effect->u.rumble.strong_magnitude =
+			min(strong + effect->u.rumble.strong_magnitude,
+			    0xffffU);
+		effect->u.rumble.weak_magnitude =
+			min(weak + effect->u.rumble.weak_magnitude, 0xffffU);
+		break;
+
+	case FF_PERIODIC:
+		i = apply_envelope(state, abs(new->u.periodic.magnitude),
+				   &new->u.periodic.envelope);
+
+		/* here we also scale it 0x7fff => 0xffff */
+		i = i * gain / 0x7fff;
+
+		if (effect->u.rumble.strong_magnitude + i)
+			effect->direction = ml_calculate_direction(
+				effect->direction,
+				effect->u.rumble.strong_magnitude,
+				new->direction, i);
+		else
+			effect->direction = 0;
+		effect->u.rumble.strong_magnitude =
+			min(i + effect->u.rumble.strong_magnitude, 0xffffU);
+		effect->u.rumble.weak_magnitude =
+			min(i + effect->u.rumble.weak_magnitude, 0xffffU);
+		break;
+
+	default:
+		pr_err("invalid type in ml_combine_effects()\n");
+		break;
+	}
+
+}
+
+
+/*
+ * Because memoryless devices have only one effect per effect type active
+ * at one time we have to combine multiple effects into one
+ */
+static int ml_get_combo_effect(struct ml_device *ml,
+			       unsigned long *effect_handled,
+			       struct ff_effect *combo_effect)
+{
+	struct ff_effect *effect;
+	struct ml_effect_state *state;
+	int effect_type;
+	int i;
+
+	memset(combo_effect, 0, sizeof(struct ff_effect));
+
+	for (i = 0; i < FF_MEMLESS_EFFECTS; i++) {
+		if (__test_and_set_bit(i, effect_handled))
+			continue;
+
+		state = &ml->states[i];
+		effect = state->effect;
+
+		if (!test_bit(FF_EFFECT_STARTED, &state->flags))
+			continue;
+
+		if (time_before(jiffies, state->play_at))
+			continue;
+
+		/*
+		 * here we have started effects that are either
+		 * currently playing (and may need be aborted)
+		 * or need to start playing.
+		 */
+		effect_type = get_compatible_type(ml->dev->ff, effect->type);
+		if (combo_effect->type != effect_type) {
+			if (combo_effect->type != 0) {
+				__clear_bit(i, effect_handled);
+				continue;
+			}
+			combo_effect->type = effect_type;
+		}
+
+		if (__test_and_clear_bit(FF_EFFECT_ABORTING, &state->flags)) {
+			__clear_bit(FF_EFFECT_PLAYING, &state->flags);
+			__clear_bit(FF_EFFECT_STARTED, &state->flags);
+		} else if (effect->replay.length &&
+			   time_after_eq(jiffies, state->stop_at)) {
+
+			__clear_bit(FF_EFFECT_PLAYING, &state->flags);
+
+			if (--state->count <= 0) {
+				__clear_bit(FF_EFFECT_STARTED, &state->flags);
+			} else {
+				state->play_at = jiffies +
+					msecs_to_jiffies(effect->replay.delay);
+				state->stop_at = state->play_at +
+					msecs_to_jiffies(effect->replay.length);
+			}
+		} else {
+			__set_bit(FF_EFFECT_PLAYING, &state->flags);
+			state->adj_at = jiffies;
+			ml_combine_effects(combo_effect, state, ml->gain);
+		}
+	}
+
+	return combo_effect->type != 0;
+}
+
+static void ml_play_effects(struct ml_device *ml)
+{
+	struct ff_effect effect;
+	DECLARE_BITMAP(handled_bm, FF_MEMLESS_EFFECTS);
+
+	memset(handled_bm, 0, sizeof(handled_bm));
+
+	while (ml_get_combo_effect(ml, handled_bm, &effect))
+		ml->play_effect(ml->dev, ml->private, &effect);
+
+	ml_schedule_timer(ml);
+}
+
+static void ml_effect_timer(struct timer_list *t)
+{
+	struct ml_device *ml = from_timer(ml, t, timer);
+	struct input_dev *dev = ml->dev;
+	unsigned long flags;
+
+	pr_debug("timer: updating effects\n");
+
+	spin_lock_irqsave(&dev->event_lock, flags);
+	ml_play_effects(ml);
+	spin_unlock_irqrestore(&dev->event_lock, flags);
+}
+
+/*
+ * Sets requested gain for FF effects. Called with dev->event_lock held.
+ */
+static void ml_ff_set_gain(struct input_dev *dev, u16 gain)
+{
+	struct ml_device *ml = dev->ff->private;
+	int i;
+
+	ml->gain = gain;
+
+	for (i = 0; i < FF_MEMLESS_EFFECTS; i++)
+		__clear_bit(FF_EFFECT_PLAYING, &ml->states[i].flags);
+
+	ml_play_effects(ml);
+}
+
+/*
+ * Start/stop specified FF effect. Called with dev->event_lock held.
+ */
+static int ml_ff_playback(struct input_dev *dev, int effect_id, int value)
+{
+	struct ml_device *ml = dev->ff->private;
+	struct ml_effect_state *state = &ml->states[effect_id];
+
+	if (value > 0) {
+		pr_debug("initiated play\n");
+
+		__set_bit(FF_EFFECT_STARTED, &state->flags);
+		state->count = value;
+		state->play_at = jiffies +
+				 msecs_to_jiffies(state->effect->replay.delay);
+		state->stop_at = state->play_at +
+				 msecs_to_jiffies(state->effect->replay.length);
+		state->adj_at = state->play_at;
+
+	} else {
+		pr_debug("initiated stop\n");
+
+		if (test_bit(FF_EFFECT_PLAYING, &state->flags))
+			__set_bit(FF_EFFECT_ABORTING, &state->flags);
+		else
+			__clear_bit(FF_EFFECT_STARTED, &state->flags);
+	}
+
+	ml_play_effects(ml);
+
+	return 0;
+}
+
+static int ml_ff_upload(struct input_dev *dev,
+			struct ff_effect *effect, struct ff_effect *old)
+{
+	struct ml_device *ml = dev->ff->private;
+	struct ml_effect_state *state = &ml->states[effect->id];
+
+	spin_lock_irq(&dev->event_lock);
+
+	if (test_bit(FF_EFFECT_STARTED, &state->flags)) {
+		__clear_bit(FF_EFFECT_PLAYING, &state->flags);
+		state->play_at = jiffies +
+				 msecs_to_jiffies(state->effect->replay.delay);
+		state->stop_at = state->play_at +
+				 msecs_to_jiffies(state->effect->replay.length);
+		state->adj_at = state->play_at;
+		ml_schedule_timer(ml);
+	}
+
+	spin_unlock_irq(&dev->event_lock);
+
+	return 0;
+}
+
+static void ml_ff_destroy(struct ff_device *ff)
+{
+	struct ml_device *ml = ff->private;
+
+	/*
+	 * Even though we stop all playing effects when tearing down
+	 * an input device (via input_device_flush() that calls into
+	 * input_ff_flush() that stops and erases all effects), we
+	 * do not actually stop the timer, and therefore we should
+	 * do it here.
+	 */
+	del_timer_sync(&ml->timer);
+
+	kfree(ml->private);
+}
+
+/**
+ * input_ff_create_memless() - create memoryless force-feedback device
+ * @dev: input device supporting force-feedback
+ * @data: driver-specific data to be passed into @play_effect
+ * @play_effect: driver-specific method for playing FF effect
+ */
+int input_ff_create_memless(struct input_dev *dev, void *data,
+		int (*play_effect)(struct input_dev *, void *, struct ff_effect *))
+{
+	struct ml_device *ml;
+	struct ff_device *ff;
+	int error;
+	int i;
+
+	ml = kzalloc(sizeof(struct ml_device), GFP_KERNEL);
+	if (!ml)
+		return -ENOMEM;
+
+	ml->dev = dev;
+	ml->private = data;
+	ml->play_effect = play_effect;
+	ml->gain = 0xffff;
+	timer_setup(&ml->timer, ml_effect_timer, 0);
+
+	set_bit(FF_GAIN, dev->ffbit);
+
+	error = input_ff_create(dev, FF_MEMLESS_EFFECTS);
+	if (error) {
+		kfree(ml);
+		return error;
+	}
+
+	ff = dev->ff;
+	ff->private = ml;
+	ff->upload = ml_ff_upload;
+	ff->playback = ml_ff_playback;
+	ff->set_gain = ml_ff_set_gain;
+	ff->destroy = ml_ff_destroy;
+
+	/* we can emulate periodic effects with RUMBLE */
+	if (test_bit(FF_RUMBLE, ff->ffbit)) {
+		set_bit(FF_PERIODIC, dev->ffbit);
+		set_bit(FF_SINE, dev->ffbit);
+		set_bit(FF_TRIANGLE, dev->ffbit);
+		set_bit(FF_SQUARE, dev->ffbit);
+	}
+
+	for (i = 0; i < FF_MEMLESS_EFFECTS; i++)
+		ml->states[i].effect = &ff->effects[i];
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(input_ff_create_memless);