diff options
| -rw-r--r-- | Documentation/devicetree/bindings/hwlock/omap-hwspinlock.txt | 25 | ||||
| -rw-r--r-- | Documentation/hwspinlock.txt | 81 | ||||
| -rw-r--r-- | drivers/hwspinlock/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/hwspinlock/hwspinlock_core.c | 48 | ||||
| -rw-r--r-- | drivers/hwspinlock/omap_hwspinlock.c | 4 | ||||
| -rw-r--r-- | drivers/hwspinlock/stm32_hwspinlock.c | 7 | ||||
| -rw-r--r-- | include/linux/hwspinlock.h | 61 |
7 files changed, 206 insertions, 22 deletions
diff --git a/Documentation/devicetree/bindings/hwlock/omap-hwspinlock.txt b/Documentation/devicetree/bindings/hwlock/omap-hwspinlock.txt index 2c9804f4f4ac..8d365f89694c 100644 --- a/Documentation/devicetree/bindings/hwlock/omap-hwspinlock.txt +++ b/Documentation/devicetree/bindings/hwlock/omap-hwspinlock.txt @@ -1,12 +1,16 @@ -OMAP4+ HwSpinlock Driver -======================== +TI HwSpinlock for OMAP and K3 based SoCs +========================================= Required properties: -- compatible: Should be "ti,omap4-hwspinlock" for - OMAP44xx, OMAP54xx, AM33xx, AM43xx, DRA7xx SoCs +- compatible: Should be one of the following, + "ti,omap4-hwspinlock" for + OMAP44xx, OMAP54xx, AM33xx, AM43xx, DRA7xx SoCs + "ti,am654-hwspinlock" for + K3 AM65x and J721E SoCs - reg: Contains the hwspinlock module register address space (base address and length) - ti,hwmods: Name of the hwmod associated with the hwspinlock device + (for OMAP architecture based SoCs only) - #hwlock-cells: Should be 1. The OMAP hwspinlock users will use a 0-indexed relative hwlock number as the argument specifier value for requesting a specific hwspinlock @@ -17,10 +21,21 @@ Please look at the generic hwlock binding for usage information for consumers, Example: -/* OMAP4 */ +1. OMAP4 SoCs hwspinlock: spinlock@4a0f6000 { compatible = "ti,omap4-hwspinlock"; reg = <0x4a0f6000 0x1000>; ti,hwmods = "spinlock"; #hwlock-cells = <1>; }; + +2. AM65x SoCs and J721E SoCs +&cbass_main { + cbass_main_navss: interconnect0 { + hwspinlock: spinlock@30e00000 { + compatible = "ti,am654-hwspinlock"; + reg = <0x00 0x30e00000 0x00 0x1000>; + #hwlock-cells = <1>; + }; + }; +}; diff --git a/Documentation/hwspinlock.txt b/Documentation/hwspinlock.txt index ed640a278185..6f03713b7003 100644 --- a/Documentation/hwspinlock.txt +++ b/Documentation/hwspinlock.txt @@ -136,6 +136,39 @@ The function will never sleep. :: + int hwspin_lock_timeout_raw(struct hwspinlock *hwlock, unsigned int timeout); + +Lock a previously-assigned hwspinlock with a timeout limit (specified in +msecs). If the hwspinlock is already taken, the function will busy loop +waiting for it to be released, but give up when the timeout elapses. + +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 successful and an appropriate error code otherwise (most +notably -ETIMEDOUT if the hwspinlock is still busy after timeout msecs). + +The function will never sleep. + +:: + + int hwspin_lock_timeout_in_atomic(struct hwspinlock *hwlock, unsigned int to); + +Lock a previously-assigned hwspinlock with a timeout limit (specified in +msecs). If the hwspinlock is already taken, the function will busy loop +waiting for it to be released, but give up when the timeout elapses. + +This function shall be called only from an atomic context and the timeout +value shall not exceed a few msecs. + +Returns 0 when successful and an appropriate error code otherwise (most +notably -ETIMEDOUT if the hwspinlock is still busy after timeout msecs). + +The function will never sleep. + +:: + int hwspin_trylock(struct hwspinlock *hwlock); @@ -186,6 +219,34 @@ The function will never sleep. :: + int hwspin_trylock_raw(struct hwspinlock *hwlock); + +Attempt to lock a previously-assigned hwspinlock, but immediately fail if +it 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 on success and an appropriate error code otherwise (most +notably -EBUSY if the hwspinlock was already taken). +The function will never sleep. + +:: + + int hwspin_trylock_in_atomic(struct hwspinlock *hwlock); + +Attempt to lock a previously-assigned hwspinlock, but immediately fail if +it is already taken. + +This function shall be called only from an atomic context. + +Returns 0 on success and an appropriate error code otherwise (most +notably -EBUSY if the hwspinlock was already taken). +The function will never sleep. + +:: + void hwspin_unlock(struct hwspinlock *hwlock); Unlock a previously-locked hwspinlock. Always succeed, and can be called @@ -222,6 +283,26 @@ the given flags. This function will never sleep. :: + void hwspin_unlock_raw(struct hwspinlock *hwlock); + +Unlock a previously-locked hwspinlock. + +The caller should **never** unlock an hwspinlock which is already unlocked. +Doing so is considered a bug (there is no protection against this). +This function will never sleep. + +:: + + void hwspin_unlock_in_atomic(struct hwspinlock *hwlock); + +Unlock a previously-locked hwspinlock. + +The caller should **never** unlock an hwspinlock which is already unlocked. +Doing so is considered a bug (there is no protection against this). +This function will never sleep. + +:: + int hwspin_lock_get_id(struct hwspinlock *hwlock); Retrieve id number of a given hwspinlock. This is needed when an diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig index 7869c67e5b6b..37740e992cfa 100644 --- a/drivers/hwspinlock/Kconfig +++ b/drivers/hwspinlock/Kconfig @@ -9,7 +9,7 @@ menuconfig HWSPINLOCK config HWSPINLOCK_OMAP tristate "OMAP Hardware Spinlock device" depends on HWSPINLOCK - depends on ARCH_OMAP4 || SOC_OMAP5 || SOC_DRA7XX || SOC_AM33XX || SOC_AM43XX + depends on ARCH_OMAP4 || SOC_OMAP5 || SOC_DRA7XX || SOC_AM33XX || SOC_AM43XX || ARCH_K3 help Say y here to support the OMAP Hardware Spinlock device (firstly introduced in OMAP4). diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c index 2bad40d42210..8862445aa858 100644 --- a/drivers/hwspinlock/hwspinlock_core.c +++ b/drivers/hwspinlock/hwspinlock_core.c @@ -9,6 +9,7 @@ #define pr_fmt(fmt) "%s: " fmt, __func__ +#include <linux/delay.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/spinlock.h> @@ -23,6 +24,9 @@ #include "hwspinlock_internal.h" +/* retry delay used in atomic context */ +#define HWSPINLOCK_RETRY_DELAY_US 100 + /* radix tree tags */ #define HWSPINLOCK_UNUSED (0) /* tags an hwspinlock as unused */ @@ -68,11 +72,11 @@ static DEFINE_MUTEX(hwspinlock_tree_lock); * user need some time-consuming or sleepable operations under the hardware * lock, they need one sleepable lock (like mutex) to protect the operations. * - * If the mode is not HWLOCK_RAW, upon a successful return from this function, - * preemption (and possibly interrupts) 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. + * If the mode is neither HWLOCK_IN_ATOMIC nor HWLOCK_RAW, upon a successful + * return from this function, preemption (and possibly interrupts) 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. * * The user decides whether local interrupts are disabled or not, and if yes, * whether he wants their previous state to be saved. It is up to the user @@ -112,6 +116,7 @@ int __hwspin_trylock(struct hwspinlock *hwlock, int mode, unsigned long *flags) ret = spin_trylock_irq(&hwlock->lock); break; case HWLOCK_RAW: + case HWLOCK_IN_ATOMIC: ret = 1; break; default: @@ -136,6 +141,7 @@ int __hwspin_trylock(struct hwspinlock *hwlock, int mode, unsigned long *flags) spin_unlock_irq(&hwlock->lock); break; case HWLOCK_RAW: + case HWLOCK_IN_ATOMIC: /* Nothing to do */ break; default: @@ -179,11 +185,14 @@ EXPORT_SYMBOL_GPL(__hwspin_trylock); * user need some time-consuming or sleepable operations under the hardware * lock, they need one sleepable lock (like mutex) to protect the operations. * - * If the mode is not HWLOCK_RAW, upon a successful return from this function, - * preemption is disabled (and possibly local interrupts, too), 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. + * If the mode is HWLOCK_IN_ATOMIC (called from an atomic context) the timeout + * is handled with busy-waiting delays, hence shall not exceed few msecs. + * + * If the mode is neither HWLOCK_IN_ATOMIC nor HWLOCK_RAW, upon a successful + * return from this function, preemption (and possibly interrupts) 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. * * The user decides whether local interrupts are disabled or not, and if yes, * whether he wants their previous state to be saved. It is up to the user @@ -198,7 +207,7 @@ int __hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int to, int mode, unsigned long *flags) { int ret; - unsigned long expire; + unsigned long expire, atomic_delay = 0; expire = msecs_to_jiffies(to) + jiffies; @@ -212,8 +221,15 @@ int __hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int to, * The lock is already taken, let's check if the user wants * us to try again */ - if (time_is_before_eq_jiffies(expire)) - return -ETIMEDOUT; + if (mode == HWLOCK_IN_ATOMIC) { + udelay(HWSPINLOCK_RETRY_DELAY_US); + atomic_delay += HWSPINLOCK_RETRY_DELAY_US; + if (atomic_delay > to * 1000) + return -ETIMEDOUT; + } else { + if (time_is_before_eq_jiffies(expire)) + return -ETIMEDOUT; + } /* * Allow platform-specific relax handlers to prevent @@ -276,6 +292,7 @@ void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags) spin_unlock_irq(&hwlock->lock); break; case HWLOCK_RAW: + case HWLOCK_IN_ATOMIC: /* Nothing to do */ break; default: @@ -333,6 +350,11 @@ int of_hwspin_lock_get_id(struct device_node *np, int index) if (ret) return ret; + if (!of_device_is_available(args.np)) { + ret = -ENOENT; + goto out; + } + /* Find the hwspinlock device: we need its base_id */ ret = -EPROBE_DEFER; rcu_read_lock(); diff --git a/drivers/hwspinlock/omap_hwspinlock.c b/drivers/hwspinlock/omap_hwspinlock.c index 625844e0abef..14e1a532ebb5 100644 --- a/drivers/hwspinlock/omap_hwspinlock.c +++ b/drivers/hwspinlock/omap_hwspinlock.c @@ -140,6 +140,9 @@ static int omap_hwspinlock_probe(struct platform_device *pdev) if (ret) goto reg_fail; + dev_dbg(&pdev->dev, "Registered %d locks with HwSpinlock core\n", + num_locks); + return 0; reg_fail: @@ -171,6 +174,7 @@ static int omap_hwspinlock_remove(struct platform_device *pdev) static const struct of_device_id omap_hwspinlock_of_match[] = { { .compatible = "ti,omap4-hwspinlock", }, + { .compatible = "ti,am654-hwspinlock", }, { /* end */ }, }; MODULE_DEVICE_TABLE(of, omap_hwspinlock_of_match); diff --git a/drivers/hwspinlock/stm32_hwspinlock.c b/drivers/hwspinlock/stm32_hwspinlock.c index 441839288893..c8eacf4f9692 100644 --- a/drivers/hwspinlock/stm32_hwspinlock.c +++ b/drivers/hwspinlock/stm32_hwspinlock.c @@ -5,6 +5,7 @@ */ #include <linux/clk.h> +#include <linux/delay.h> #include <linux/hwspinlock.h> #include <linux/io.h> #include <linux/kernel.h> @@ -42,9 +43,15 @@ static void stm32_hwspinlock_unlock(struct hwspinlock *lock) writel(STM32_MUTEX_COREID, lock_addr); } +static void stm32_hwspinlock_relax(struct hwspinlock *lock) +{ + ndelay(50); +} + static const struct hwspinlock_ops stm32_hwspinlock_ops = { .trylock = stm32_hwspinlock_trylock, .unlock = stm32_hwspinlock_unlock, + .relax = stm32_hwspinlock_relax, }; static int stm32_hwspinlock_probe(struct platform_device *pdev) diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h index 0afe693be5f4..bfe7c1f1ac6d 100644 --- a/include/linux/hwspinlock.h +++ b/include/linux/hwspinlock.h @@ -14,9 +14,10 @@ #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_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; @@ -223,6 +224,23 @@ static inline int hwspin_trylock_raw(struct hwspinlock *hwlock) } /** + * 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 * @@ -313,6 +331,28 @@ int hwspin_lock_timeout_raw(struct hwspinlock *hwlock, unsigned int to) } /** + * 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 @@ -387,6 +427,21 @@ static inline void hwspin_unlock_raw(struct hwspinlock *hwlock) } /** + * 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 * |