#ifndef _ASM_GENERIC_RWSEM_H #define _ASM_GENERIC_RWSEM_H #ifndef _LINUX_RWSEM_H #error "Please don't include directly, use instead." #endif #ifdef __KERNEL__ /* * R/W semaphores originally for PPC using the stuff in lib/rwsem.c. * Adapted largely from include/asm-i386/rwsem.h * by Paul Mackerras . */ /* * the semaphore definition */ #ifdef CONFIG_64BIT # define RWSEM_ACTIVE_MASK 0xffffffffL #else # define RWSEM_ACTIVE_MASK 0x0000ffffL #endif #define RWSEM_UNLOCKED_VALUE 0x00000000L #define RWSEM_ACTIVE_BIAS 0x00000001L #define RWSEM_WAITING_BIAS (-RWSEM_ACTIVE_MASK-1) #define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS #define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) /* * lock for reading */ static inline void __down_read(struct rw_semaphore *sem) { if (unlikely(atomic_long_inc_return_acquire((atomic_long_t *)&sem->count) <= 0)) rwsem_down_read_failed(sem); } static inline int __down_read_trylock(struct rw_semaphore *sem) { long tmp; while ((tmp = atomic_long_read(&sem->count)) >= 0) { if (tmp == atomic_long_cmpxchg_acquire(&sem->count, tmp, tmp + RWSEM_ACTIVE_READ_BIAS)) { return 1; } } return 0; } /* * lock for writing */ static inline void __down_write(struct rw_semaphore *sem) { long tmp; tmp = atomic_long_add_return_acquire(RWSEM_ACTIVE_WRITE_BIAS, (atomic_long_t *)&sem->count); if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) rwsem_down_write_failed(sem); } static inline int __down_write_killable(struct rw_semaphore *sem) { long tmp; tmp = atomic_long_add_return_acquire(RWSEM_ACTIVE_WRITE_BIAS, (atomic_long_t *)&sem->count); if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) if (IS_ERR(rwsem_down_write_failed_killable(sem))) return -EINTR; return 0; } static inline int __down_write_trylock(struct rw_semaphore *sem) { long tmp; tmp = atomic_long_cmpxchg_acquire(&sem->count, RWSEM_UNLOCKED_VALUE, RWSEM_ACTIVE_WRITE_BIAS); return tmp == RWSEM_UNLOCKED_VALUE; } /* * unlock after reading */ static inline void __up_read(struct rw_semaphore *sem) { long tmp; tmp = atomic_long_dec_return_release((atomic_long_t *)&sem->count); if (unlikely(tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0)) rwsem_wake(sem); } /* * unlock after writing */ static inline void __up_write(struct rw_semaphore *sem) { if (unlikely(atomic_long_sub_return_release(RWSEM_ACTIVE_WRITE_BIAS, (atomic_long_t *)&sem->count) < 0)) rwsem_wake(sem); } /* * downgrade write lock to read lock */ static inline void __downgrade_write(struct rw_semaphore *sem) { long tmp; /* * When downgrading from exclusive to shared ownership, * anything inside the write-locked region cannot leak * into the read side. In contrast, anything in the * read-locked region is ok to be re-ordered into the * write side. As such, rely on RELEASE semantics. */ tmp = atomic_long_add_return_release(-RWSEM_WAITING_BIAS, (atomic_long_t *)&sem->count); if (tmp < 0) rwsem_downgrade_wake(sem); } #endif /* __KERNEL__ */ #endif /* _ASM_GENERIC_RWSEM_H */ 07e3f84'>single.h
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authorAleksander Morgado <aleksander@aleksander.es>2017-01-18 21:31:31 +0100
committerJohan Hovold <johan@kernel.org>2017-01-19 09:08:37 +0100
commit24d615a694d649aa2e167c3f97f62bdad07e3f84 (patch)
tree2fe33c115bdec6bf4b01e27afd90bb16fa668e22 /include/math-emu/single.h
parent49def1853334396f948dcb4cedb9347abb318df5 (diff)
USB: serial: qcserial: add Dell DW5570 QDL
The Dell DW5570 is a re-branded Sierra Wireless MC8805 which will by default boot with vid 0x413c and pid 0x81a3. When triggered QDL download mode, the device switches to pid 0x81a6 and provides the standard TTY used for firmware upgrade. Cc: <stable@vger.kernel.org> Signed-off-by: Aleksander Morgado <aleksander@aleksander.es> Signed-off-by: Johan Hovold <johan@kernel.org>
Diffstat (limited to 'include/math-emu/single.h')