From dd472da380c3819740d740cfd70b7f8e700e834b Mon Sep 17 00:00:00 2001 From: Richard Kuo Date: Mon, 31 Oct 2011 18:47:33 -0500 Subject: Hexagon: Add locking types and functions Signed-off-by: Richard Kuo Acked-by: Arnd Bergmann Signed-off-by: Linus Torvalds --- include/asm-generic/rwsem.h | 132 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 132 insertions(+) create mode 100644 include/asm-generic/rwsem.h (limited to 'include/asm-generic') diff --git a/include/asm-generic/rwsem.h b/include/asm-generic/rwsem.h new file mode 100644 index 000000000000..bb1e2cdeb9bf --- /dev/null +++ b/include/asm-generic/rwsem.h @@ -0,0 +1,132 @@ +#ifndef _ASM_POWERPC_RWSEM_H +#define _ASM_POWERPC_RWSEM_H + +#ifndef _LINUX_RWSEM_H +#error "Please don't include directly, use instead." +#endif + +#ifdef __KERNEL__ + +/* + * R/W semaphores 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_PPC64 +# 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((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 = sem->count) >= 0) { + if (tmp == cmpxchg(&sem->count, tmp, + tmp + RWSEM_ACTIVE_READ_BIAS)) { + return 1; + } + } + return 0; +} + +/* + * lock for writing + */ +static inline void __down_write_nested(struct rw_semaphore *sem, int subclass) +{ + long tmp; + + tmp = atomic_long_add_return(RWSEM_ACTIVE_WRITE_BIAS, + (atomic_long_t *)&sem->count); + if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) + rwsem_down_write_failed(sem); +} + +static inline void __down_write(struct rw_semaphore *sem) +{ + __down_write_nested(sem, 0); +} + +static inline int __down_write_trylock(struct rw_semaphore *sem) +{ + long tmp; + + tmp = cmpxchg(&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((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(RWSEM_ACTIVE_WRITE_BIAS, + (atomic_long_t *)&sem->count) < 0)) + rwsem_wake(sem); +} + +/* + * implement atomic add functionality + */ +static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem) +{ + atomic_long_add(delta, (atomic_long_t *)&sem->count); +} + +/* + * downgrade write lock to read lock + */ +static inline void __downgrade_write(struct rw_semaphore *sem) +{ + long tmp; + + tmp = atomic_long_add_return(-RWSEM_WAITING_BIAS, + (atomic_long_t *)&sem->count); + if (tmp < 0) + rwsem_downgrade_wake(sem); +} + +/* + * implement exchange and add functionality + */ +static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem) +{ + return atomic_long_add_return(delta, (atomic_long_t *)&sem->count); +} + +#endif /* __KERNEL__ */ +#endif /* _ASM_POWERPC_RWSEM_H */ -- cgit v1.2.3 From 4e29198e1cd7728c30c96a8483a6068c71b34e4e Mon Sep 17 00:00:00 2001 From: Linas Vepstas Date: Mon, 31 Oct 2011 18:56:59 -0500 Subject: Add extra arch overrides to asm-generic/checksum.h There are plausible reasons for architectures to provide their own versions of csum_partial_copy_nocheck and csum_tcpudp_magic. By protecting these, the architecture can still re-use the asm-generic checksum.h, instead of copying it. Signed-off-by: Linas Vepstas Acked-by: Arnd Bergmann Signed-off-by: Richard Kuo Signed-off-by: Linus Torvalds --- include/asm-generic/checksum.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/asm-generic') diff --git a/include/asm-generic/checksum.h b/include/asm-generic/checksum.h index 4647c762d970..c084767c88bc 100644 --- a/include/asm-generic/checksum.h +++ b/include/asm-generic/checksum.h @@ -33,8 +33,10 @@ extern __wsum csum_partial_copy(const void *src, void *dst, int len, __wsum sum) extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *csum_err); +#ifndef csum_partial_copy_nocheck #define csum_partial_copy_nocheck(src, dst, len, sum) \ csum_partial_copy((src), (dst), (len), (sum)) +#endif /* * This is a version of ip_compute_csum() optimized for IP headers, @@ -63,12 +65,14 @@ csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len, unsigned short proto, __wsum sum); #endif +#ifndef csum_tcpudp_magic static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len, unsigned short proto, __wsum sum) { return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); } +#endif /* * this routine is used for miscellaneous IP-like checksums, mainly -- cgit v1.2.3