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authorWill Deacon <will.deacon@arm.com>2017-10-03 19:25:27 +0100
committerIngo Molnar <mingo@kernel.org>2017-10-10 11:50:18 +0200
commita8a217c22116eff6c120d753c9934089fb229af0 (patch)
treed56f1283ba7153f9ead9fb92c1a1794143c6e4a3 /kernel/locking
parent26c4eb192c6224e5297496cead36404b62fb071b (diff)
downloadlwn-a8a217c22116eff6c120d753c9934089fb229af0.tar.gz
lwn-a8a217c22116eff6c120d753c9934089fb229af0.zip
locking/core: Remove {read,spin,write}_can_lock()
Outside of the locking code itself, {read,spin,write}_can_lock() have no users in tree. Apparmor (the last remaining user of write_can_lock()) got moved over to lockdep by the previous patch. This patch removes the use of {read,spin,write}_can_lock() from the BUILD_LOCK_OPS macro, deferring to the trylock operation for testing the lock status, and subsequently removes the unused macros altogether. They aren't guaranteed to work in a concurrent environment and can give incorrect results in the case of qrwlock. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking')
-rw-r--r--kernel/locking/spinlock.c6
1 files changed, 2 insertions, 4 deletions
diff --git a/kernel/locking/spinlock.c b/kernel/locking/spinlock.c
index 4b082b5cac9e..8fd48b5552a7 100644
--- a/kernel/locking/spinlock.c
+++ b/kernel/locking/spinlock.c
@@ -32,8 +32,6 @@
* include/linux/spinlock_api_smp.h
*/
#else
-#define raw_read_can_lock(l) read_can_lock(l)
-#define raw_write_can_lock(l) write_can_lock(l)
/*
* Some architectures can relax in favour of the CPU owning the lock.
@@ -68,7 +66,7 @@ void __lockfunc __raw_##op##_lock(locktype##_t *lock) \
\
if (!(lock)->break_lock) \
(lock)->break_lock = 1; \
- while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\
+ while ((lock)->break_lock) \
arch_##op##_relax(&lock->raw_lock); \
} \
(lock)->break_lock = 0; \
@@ -88,7 +86,7 @@ unsigned long __lockfunc __raw_##op##_lock_irqsave(locktype##_t *lock) \
\
if (!(lock)->break_lock) \
(lock)->break_lock = 1; \
- while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\
+ while ((lock)->break_lock) \
arch_##op##_relax(&lock->raw_lock); \
} \
(lock)->break_lock = 0; \