aboutsummaryrefslogtreecommitdiff
path: root/include/linux/hwspinlock.h
diff options
context:
space:
mode:
authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /include/linux/hwspinlock.h
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
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(). ...
Diffstat (limited to 'include/linux/hwspinlock.h')
-rw-r--r--include/linux/hwspinlock.h460
1 files changed, 460 insertions, 0 deletions
diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h
new file mode 100644
index 000000000..bfe7c1f1a
--- /dev/null
+++ b/include/linux/hwspinlock.h
@@ -0,0 +1,460 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Hardware spinlock public header
+ *
+ * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * Contact: Ohad Ben-Cohen <ohad@wizery.com>
+ */
+
+#ifndef __LINUX_HWSPINLOCK_H
+#define __LINUX_HWSPINLOCK_H
+
+#include <linux/err.h>
+#include <linux/sched.h>
+
+/* hwspinlock mode argument */
+#define HWLOCK_IRQSTATE 0x01 /* Disable interrupts, save state */
+#define HWLOCK_IRQ 0x02 /* Disable interrupts, don't save state */
+#define HWLOCK_RAW 0x03
+#define HWLOCK_IN_ATOMIC 0x04 /* Called while in atomic context */
+
+struct device;
+struct device_node;
+struct hwspinlock;
+struct hwspinlock_device;
+struct hwspinlock_ops;
+
+/**
+ * struct hwspinlock_pdata - platform data for hwspinlock drivers
+ * @base_id: base id for this hwspinlock device
+ *
+ * hwspinlock devices provide system-wide hardware locks that are used
+ * by remote processors that have no other way to achieve synchronization.
+ *
+ * To achieve that, each physical lock must have a system-wide id number
+ * that is agreed upon, otherwise remote processors can't possibly assume
+ * they're using the same hardware lock.
+ *
+ * Usually boards have a single hwspinlock device, which provides several
+ * hwspinlocks, and in this case, they can be trivially numbered 0 to
+ * (num-of-locks - 1).
+ *
+ * In case boards have several hwspinlocks devices, a different base id
+ * should be used for each hwspinlock device (they can't all use 0 as
+ * a starting id!).
+ *
+ * This platform data structure should be used to provide the base id
+ * for each device (which is trivially 0 when only a single hwspinlock
+ * device exists). It can be shared between different platforms, hence
+ * its location.
+ */
+struct hwspinlock_pdata {
+ int base_id;
+};
+
+#ifdef CONFIG_HWSPINLOCK
+
+int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev,
+ const struct hwspinlock_ops *ops, int base_id, int num_locks);
+int hwspin_lock_unregister(struct hwspinlock_device *bank);
+struct hwspinlock *hwspin_lock_request(void);
+struct hwspinlock *hwspin_lock_request_specific(unsigned int id);
+int hwspin_lock_free(struct hwspinlock *hwlock);
+int of_hwspin_lock_get_id(struct device_node *np, int index);
+int hwspin_lock_get_id(struct hwspinlock *hwlock);
+int __hwspin_lock_timeout(struct hwspinlock *, unsigned int, int,
+ unsigned long *);
+int __hwspin_trylock(struct hwspinlock *, int, unsigned long *);
+void __hwspin_unlock(struct hwspinlock *, int, unsigned long *);
+int of_hwspin_lock_get_id_byname(struct device_node *np, const char *name);
+int devm_hwspin_lock_free(struct device *dev, struct hwspinlock *hwlock);
+struct hwspinlock *devm_hwspin_lock_request(struct device *dev);
+struct hwspinlock *devm_hwspin_lock_request_specific(struct device *dev,
+ unsigned int id);
+int devm_hwspin_lock_unregister(struct device *dev,
+ struct hwspinlock_device *bank);
+int devm_hwspin_lock_register(struct device *dev,
+ struct hwspinlock_device *bank,
+ const struct hwspinlock_ops *ops,
+ int base_id, int num_locks);
+
+#else /* !CONFIG_HWSPINLOCK */
+
+/*
+ * We don't want these functions to fail if CONFIG_HWSPINLOCK is not
+ * enabled. We prefer to silently succeed in this case, and let the
+ * code path get compiled away. This way, if CONFIG_HWSPINLOCK is not
+ * required on a given setup, users will still work.
+ *
+ * The only exception is hwspin_lock_register/hwspin_lock_unregister, with which
+ * we _do_ want users to fail (no point in registering hwspinlock instances if
+ * the framework is not available).
+ *
+ * Note: ERR_PTR(-ENODEV) will still be considered a success for NULL-checking
+ * users. Others, which care, can still check this with IS_ERR.
+ */
+static inline struct hwspinlock *hwspin_lock_request(void)
+{
+ return ERR_PTR(-ENODEV);
+}
+
+static inline struct hwspinlock *hwspin_lock_request_specific(unsigned int id)
+{
+ return ERR_PTR(-ENODEV);
+}
+
+static inline int hwspin_lock_free(struct hwspinlock *hwlock)
+{
+ return 0;
+}
+
+static inline
+int __hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int to,
+ int mode, unsigned long *flags)
+{
+ return 0;
+}
+
+static inline
+int __hwspin_trylock(struct hwspinlock *hwlock, int mode, unsigned long *flags)
+{
+ return 0;
+}
+
+static inline
+void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags)
+{
+}
+
+static inline int of_hwspin_lock_get_id(struct device_node *np, int index)
+{
+ return 0;
+}
+
+static inline int hwspin_lock_get_id(struct hwspinlock *hwlock)
+{
+ return 0;
+}
+
+static inline
+int of_hwspin_lock_get_id_byname(struct device_node *np, const char *name)
+{
+ return 0;
+}
+
+static inline
+int devm_hwspin_lock_free(struct device *dev, struct hwspinlock *hwlock)
+{
+ return 0;
+}
+
+static inline struct hwspinlock *devm_hwspin_lock_request(struct device *dev)
+{
+ return ERR_PTR(-ENODEV);
+}
+
+static inline
+struct hwspinlock *devm_hwspin_lock_request_specific(struct device *dev,
+ unsigned int id)
+{
+ return ERR_PTR(-ENODEV);
+}
+
+#endif /* !CONFIG_HWSPINLOCK */
+
+/**
+ * hwspin_trylock_irqsave() - try to lock an hwspinlock, disable interrupts
+ * @hwlock: an hwspinlock which we want to trylock
+ * @flags: a pointer to where the caller's interrupt state will be saved at
+ *
+ * This function attempts to lock the underlying hwspinlock, and will
+ * immediately fail if the hwspinlock is already locked.
+ *
+ * Upon a successful return from this function, preemption and local
+ * interrupts are disabled (previous interrupts state is saved at @flags),
+ * so the caller must not sleep, and is advised to release the hwspinlock
+ * as soon as possible.
+ *
+ * Returns 0 if we successfully locked the hwspinlock, -EBUSY if
+ * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid.
+ */
+static inline
+int hwspin_trylock_irqsave(struct hwspinlock *hwlock, unsigned long *flags)
+{
+ return __hwspin_trylock(hwlock, HWLOCK_IRQSTATE, flags);
+}
+
+/**
+ * hwspin_trylock_irq() - try to lock an hwspinlock, disable interrupts
+ * @hwlock: an hwspinlock which we want to trylock
+ *
+ * This function attempts to lock the underlying hwspinlock, and will
+ * immediately fail if the hwspinlock is already locked.
+ *
+ * Upon a successful return from this function, preemption and local
+ * interrupts are disabled, so the caller must not sleep, and is advised
+ * to release the hwspinlock as soon as possible.
+ *
+ * Returns 0 if we successfully locked the hwspinlock, -EBUSY if
+ * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid.
+ */
+static inline int hwspin_trylock_irq(struct hwspinlock *hwlock)
+{
+ return __hwspin_trylock(hwlock, HWLOCK_IRQ, NULL);
+}
+
+/**
+ * hwspin_trylock_raw() - attempt to lock a specific hwspinlock
+ * @hwlock: an hwspinlock which we want to trylock
+ *
+ * This function attempts to lock an hwspinlock, and will immediately fail
+ * if the hwspinlock is already taken.
+ *
+ * Caution: User must protect the routine of getting hardware lock with mutex
+ * or spinlock to avoid dead-lock, that will let user can do some time-consuming
+ * or sleepable operations under the hardware lock.
+ *
+ * Returns 0 if we successfully locked the hwspinlock, -EBUSY if
+ * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid.
+ */
+static inline int hwspin_trylock_raw(struct hwspinlock *hwlock)
+{
+ return __hwspin_trylock(hwlock, HWLOCK_RAW, NULL);
+}
+
+/**
+ * hwspin_trylock_in_atomic() - attempt to lock a specific hwspinlock
+ * @hwlock: an hwspinlock which we want to trylock
+ *
+ * This function attempts to lock an hwspinlock, and will immediately fail
+ * if the hwspinlock is already taken.
+ *
+ * This function shall be called only from an atomic context.
+ *
+ * Returns 0 if we successfully locked the hwspinlock, -EBUSY if
+ * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid.
+ */
+static inline int hwspin_trylock_in_atomic(struct hwspinlock *hwlock)
+{
+ return __hwspin_trylock(hwlock, HWLOCK_IN_ATOMIC, NULL);
+}
+
+/**
+ * hwspin_trylock() - attempt to lock a specific hwspinlock
+ * @hwlock: an hwspinlock which we want to trylock
+ *
+ * This function attempts to lock an hwspinlock, and will immediately fail
+ * if the hwspinlock is already taken.
+ *
+ * Upon a successful return from this function, preemption is disabled,
+ * so the caller must not sleep, and is advised to release the hwspinlock
+ * as soon as possible. This is required in order to minimize remote cores
+ * polling on the hardware interconnect.
+ *
+ * Returns 0 if we successfully locked the hwspinlock, -EBUSY if
+ * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid.
+ */
+static inline int hwspin_trylock(struct hwspinlock *hwlock)
+{
+ return __hwspin_trylock(hwlock, 0, NULL);
+}
+
+/**
+ * hwspin_lock_timeout_irqsave() - lock hwspinlock, with timeout, disable irqs
+ * @hwlock: the hwspinlock to be locked
+ * @to: timeout value in msecs
+ * @flags: a pointer to where the caller's interrupt state will be saved at
+ *
+ * This function locks the underlying @hwlock. If the @hwlock
+ * is already taken, the function will busy loop waiting for it to
+ * be released, but give up when @timeout msecs have elapsed.
+ *
+ * Upon a successful return from this function, preemption and local interrupts
+ * are disabled (plus previous interrupt state is saved), so the caller must
+ * not sleep, and is advised to release the hwspinlock as soon as possible.
+ *
+ * Returns 0 when the @hwlock was successfully taken, and an appropriate
+ * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still
+ * busy after @timeout msecs). The function will never sleep.
+ */
+static inline int hwspin_lock_timeout_irqsave(struct hwspinlock *hwlock,
+ unsigned int to, unsigned long *flags)
+{
+ return __hwspin_lock_timeout(hwlock, to, HWLOCK_IRQSTATE, flags);
+}
+
+/**
+ * hwspin_lock_timeout_irq() - lock hwspinlock, with timeout, disable irqs
+ * @hwlock: the hwspinlock to be locked
+ * @to: timeout value in msecs
+ *
+ * This function locks the underlying @hwlock. If the @hwlock
+ * is already taken, the function will busy loop waiting for it to
+ * be released, but give up when @timeout msecs have elapsed.
+ *
+ * Upon a successful return from this function, preemption and local interrupts
+ * are disabled so the caller must not sleep, and is advised to release the
+ * hwspinlock as soon as possible.
+ *
+ * Returns 0 when the @hwlock was successfully taken, and an appropriate
+ * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still
+ * busy after @timeout msecs). The function will never sleep.
+ */
+static inline
+int hwspin_lock_timeout_irq(struct hwspinlock *hwlock, unsigned int to)
+{
+ return __hwspin_lock_timeout(hwlock, to, HWLOCK_IRQ, NULL);
+}
+
+/**
+ * hwspin_lock_timeout_raw() - lock an hwspinlock with timeout limit
+ * @hwlock: the hwspinlock to be locked
+ * @to: timeout value in msecs
+ *
+ * This function locks the underlying @hwlock. If the @hwlock
+ * is already taken, the function will busy loop waiting for it to
+ * be released, but give up when @timeout msecs have elapsed.
+ *
+ * Caution: User must protect the routine of getting hardware lock with mutex
+ * or spinlock to avoid dead-lock, that will let user can do some time-consuming
+ * or sleepable operations under the hardware lock.
+ *
+ * Returns 0 when the @hwlock was successfully taken, and an appropriate
+ * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still
+ * busy after @timeout msecs). The function will never sleep.
+ */
+static inline
+int hwspin_lock_timeout_raw(struct hwspinlock *hwlock, unsigned int to)
+{
+ return __hwspin_lock_timeout(hwlock, to, HWLOCK_RAW, NULL);
+}
+
+/**
+ * hwspin_lock_timeout_in_atomic() - lock an hwspinlock with timeout limit
+ * @hwlock: the hwspinlock to be locked
+ * @to: timeout value in msecs
+ *
+ * This function locks the underlying @hwlock. If the @hwlock
+ * is already taken, the function will busy loop waiting for it to
+ * be released, but give up when @timeout msecs have elapsed.
+ *
+ * This function shall be called only from an atomic context and the timeout
+ * value shall not exceed a few msecs.
+ *
+ * Returns 0 when the @hwlock was successfully taken, and an appropriate
+ * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still
+ * busy after @timeout msecs). The function will never sleep.
+ */
+static inline
+int hwspin_lock_timeout_in_atomic(struct hwspinlock *hwlock, unsigned int to)
+{
+ return __hwspin_lock_timeout(hwlock, to, HWLOCK_IN_ATOMIC, NULL);
+}
+
+/**
+ * hwspin_lock_timeout() - lock an hwspinlock with timeout limit
+ * @hwlock: the hwspinlock to be locked
+ * @to: timeout value in msecs
+ *
+ * This function locks the underlying @hwlock. If the @hwlock
+ * is already taken, the function will busy loop waiting for it to
+ * be released, but give up when @timeout msecs have elapsed.
+ *
+ * Upon a successful return from this function, preemption is disabled
+ * so the caller must not sleep, and is advised to release the hwspinlock
+ * as soon as possible.
+ * This is required in order to minimize remote cores polling on the
+ * hardware interconnect.
+ *
+ * Returns 0 when the @hwlock was successfully taken, and an appropriate
+ * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still
+ * busy after @timeout msecs). The function will never sleep.
+ */
+static inline
+int hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int to)
+{
+ return __hwspin_lock_timeout(hwlock, to, 0, NULL);
+}
+
+/**
+ * hwspin_unlock_irqrestore() - unlock hwspinlock, restore irq state
+ * @hwlock: a previously-acquired hwspinlock which we want to unlock
+ * @flags: previous caller's interrupt state to restore
+ *
+ * This function will unlock a specific hwspinlock, enable preemption and
+ * restore the previous state of the local interrupts. It should be used
+ * to undo, e.g., hwspin_trylock_irqsave().
+ *
+ * @hwlock must be already locked before calling this function: it is a bug
+ * to call unlock on a @hwlock that is already unlocked.
+ */
+static inline void hwspin_unlock_irqrestore(struct hwspinlock *hwlock,
+ unsigned long *flags)
+{
+ __hwspin_unlock(hwlock, HWLOCK_IRQSTATE, flags);
+}
+
+/**
+ * hwspin_unlock_irq() - unlock hwspinlock, enable interrupts
+ * @hwlock: a previously-acquired hwspinlock which we want to unlock
+ *
+ * This function will unlock a specific hwspinlock, enable preemption and
+ * enable local interrupts. Should be used to undo hwspin_lock_irq().
+ *
+ * @hwlock must be already locked (e.g. by hwspin_trylock_irq()) before
+ * calling this function: it is a bug to call unlock on a @hwlock that is
+ * already unlocked.
+ */
+static inline void hwspin_unlock_irq(struct hwspinlock *hwlock)
+{
+ __hwspin_unlock(hwlock, HWLOCK_IRQ, NULL);
+}
+
+/**
+ * hwspin_unlock_raw() - unlock hwspinlock
+ * @hwlock: a previously-acquired hwspinlock which we want to unlock
+ *
+ * This function will unlock a specific hwspinlock.
+ *
+ * @hwlock must be already locked (e.g. by hwspin_trylock()) before calling
+ * this function: it is a bug to call unlock on a @hwlock that is already
+ * unlocked.
+ */
+static inline void hwspin_unlock_raw(struct hwspinlock *hwlock)
+{
+ __hwspin_unlock(hwlock, HWLOCK_RAW, NULL);
+}
+
+/**
+ * hwspin_unlock_in_atomic() - unlock hwspinlock
+ * @hwlock: a previously-acquired hwspinlock which we want to unlock
+ *
+ * This function will unlock a specific hwspinlock.
+ *
+ * @hwlock must be already locked (e.g. by hwspin_trylock()) before calling
+ * this function: it is a bug to call unlock on a @hwlock that is already
+ * unlocked.
+ */
+static inline void hwspin_unlock_in_atomic(struct hwspinlock *hwlock)
+{
+ __hwspin_unlock(hwlock, HWLOCK_IN_ATOMIC, NULL);
+}
+
+/**
+ * hwspin_unlock() - unlock hwspinlock
+ * @hwlock: a previously-acquired hwspinlock which we want to unlock
+ *
+ * This function will unlock a specific hwspinlock and enable preemption
+ * back.
+ *
+ * @hwlock must be already locked (e.g. by hwspin_trylock()) before calling
+ * this function: it is a bug to call unlock on a @hwlock that is already
+ * unlocked.
+ */
+static inline void hwspin_unlock(struct hwspinlock *hwlock)
+{
+ __hwspin_unlock(hwlock, 0, NULL);
+}
+
+#endif /* __LINUX_HWSPINLOCK_H */