From e0d02285f16e8d5810f3d5d5e8a5886ca0015d3b Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 12 Oct 2017 13:20:47 +0100 Subject: locking/qrwlock: Use 'struct qrwlock' instead of 'struct __qrwlock' There's no good reason to keep the internal structure of struct qrwlock hidden from qrwlock.h, particularly as it's actually needed for unlock and ends up being abstracted independently behind the __qrwlock_write_byte() function. Stop pretending we can hide this stuff, and move the __qrwlock definition into qrwlock, removing the __qrwlock_write_byte() nastiness and using the same struct definition everywhere instead. Signed-off-by: Will Deacon Acked-by: Peter Zijlstra Cc: Boqun Feng Cc: Jeremy.Linton@arm.com Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Thomas Gleixner Cc: Waiman Long Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1507810851-306-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar --- include/asm-generic/qrwlock.h | 12 +----------- include/asm-generic/qrwlock_types.h | 15 +++++++++++++-- 2 files changed, 14 insertions(+), 13 deletions(-) (limited to 'include/asm-generic') diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h index 50925327b0a8..02c0a768e6b0 100644 --- a/include/asm-generic/qrwlock.h +++ b/include/asm-generic/qrwlock.h @@ -128,23 +128,13 @@ static inline void queued_read_unlock(struct qrwlock *lock) (void)atomic_sub_return_release(_QR_BIAS, &lock->cnts); } -/** - * __qrwlock_write_byte - retrieve the write byte address of a queue rwlock - * @lock : Pointer to queue rwlock structure - * Return: the write byte address of a queue rwlock - */ -static inline u8 *__qrwlock_write_byte(struct qrwlock *lock) -{ - return (u8 *)lock + 3 * IS_BUILTIN(CONFIG_CPU_BIG_ENDIAN); -} - /** * queued_write_unlock - release write lock of a queue rwlock * @lock : Pointer to queue rwlock structure */ static inline void queued_write_unlock(struct qrwlock *lock) { - smp_store_release(__qrwlock_write_byte(lock), 0); + smp_store_release(&lock->wmode, 0); } /* diff --git a/include/asm-generic/qrwlock_types.h b/include/asm-generic/qrwlock_types.h index 0abc6b6062fb..507f2dc51bba 100644 --- a/include/asm-generic/qrwlock_types.h +++ b/include/asm-generic/qrwlock_types.h @@ -9,12 +9,23 @@ */ typedef struct qrwlock { - atomic_t cnts; + union { + atomic_t cnts; + struct { +#ifdef __LITTLE_ENDIAN + u8 wmode; /* Writer mode */ + u8 rcnts[3]; /* Reader counts */ +#else + u8 rcnts[3]; /* Reader counts */ + u8 wmode; /* Writer mode */ +#endif + }; + }; arch_spinlock_t wait_lock; } arch_rwlock_t; #define __ARCH_RW_LOCK_UNLOCKED { \ - .cnts = ATOMIC_INIT(0), \ + { .cnts = ATOMIC_INIT(0), }, \ .wait_lock = __ARCH_SPIN_LOCK_UNLOCKED, \ } -- cgit v1.2.3