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f98a3dccfc
parisc, ia64 and powerpc32 are the only remaining architectures that
provide custom arch_{spin,read,write}_lock_flags() functions, which are
meant to re-enable interrupts while waiting for a spinlock.
However, none of these can actually run into this codepath, because
it is only called on architectures without CONFIG_GENERIC_LOCKBREAK,
or when CONFIG_DEBUG_LOCK_ALLOC is set without CONFIG_LOCKDEP, and none
of those combinations are possible on the three architectures.
Going back in the git history, it appears that arch/mn10300 may have
been able to run into this code path, but there is a good chance that
it never worked. On the architectures that still exist, it was
already impossible to hit back in 2008 after the introduction of
CONFIG_GENERIC_LOCKBREAK, and possibly earlier.
As this is all dead code, just remove it and the helper functions built
around it. For arch/ia64, the inline asm could be cleaned up, but
it seems safer to leave it untouched.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Link: https://lore.kernel.org/r/20211022120058.1031690-1-arnd@kernel.org
124 lines
4.0 KiB
C
124 lines
4.0 KiB
C
#ifndef __LINUX_RWLOCK_H
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#define __LINUX_RWLOCK_H
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#ifndef __LINUX_SPINLOCK_H
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# error "please don't include this file directly"
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#endif
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/*
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* rwlock related methods
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*
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* split out from spinlock.h
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*
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* portions Copyright 2005, Red Hat, Inc., Ingo Molnar
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* Released under the General Public License (GPL).
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*/
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#ifdef CONFIG_DEBUG_SPINLOCK
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extern void __rwlock_init(rwlock_t *lock, const char *name,
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struct lock_class_key *key);
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# define rwlock_init(lock) \
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do { \
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static struct lock_class_key __key; \
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\
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__rwlock_init((lock), #lock, &__key); \
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} while (0)
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#else
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# define rwlock_init(lock) \
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do { *(lock) = __RW_LOCK_UNLOCKED(lock); } while (0)
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#endif
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#ifdef CONFIG_DEBUG_SPINLOCK
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extern void do_raw_read_lock(rwlock_t *lock) __acquires(lock);
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extern int do_raw_read_trylock(rwlock_t *lock);
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extern void do_raw_read_unlock(rwlock_t *lock) __releases(lock);
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extern void do_raw_write_lock(rwlock_t *lock) __acquires(lock);
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extern int do_raw_write_trylock(rwlock_t *lock);
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extern void do_raw_write_unlock(rwlock_t *lock) __releases(lock);
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#else
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# define do_raw_read_lock(rwlock) do {__acquire(lock); arch_read_lock(&(rwlock)->raw_lock); } while (0)
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# define do_raw_read_trylock(rwlock) arch_read_trylock(&(rwlock)->raw_lock)
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# define do_raw_read_unlock(rwlock) do {arch_read_unlock(&(rwlock)->raw_lock); __release(lock); } while (0)
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# define do_raw_write_lock(rwlock) do {__acquire(lock); arch_write_lock(&(rwlock)->raw_lock); } while (0)
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# define do_raw_write_trylock(rwlock) arch_write_trylock(&(rwlock)->raw_lock)
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# define do_raw_write_unlock(rwlock) do {arch_write_unlock(&(rwlock)->raw_lock); __release(lock); } while (0)
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#endif
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/*
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* Define the various rw_lock methods. Note we define these
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* regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
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* methods are defined as nops in the case they are not required.
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*/
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#define read_trylock(lock) __cond_lock(lock, _raw_read_trylock(lock))
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#define write_trylock(lock) __cond_lock(lock, _raw_write_trylock(lock))
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#define write_lock(lock) _raw_write_lock(lock)
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#define read_lock(lock) _raw_read_lock(lock)
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#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
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#define read_lock_irqsave(lock, flags) \
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do { \
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typecheck(unsigned long, flags); \
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flags = _raw_read_lock_irqsave(lock); \
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} while (0)
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#define write_lock_irqsave(lock, flags) \
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do { \
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typecheck(unsigned long, flags); \
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flags = _raw_write_lock_irqsave(lock); \
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} while (0)
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#else
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#define read_lock_irqsave(lock, flags) \
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do { \
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typecheck(unsigned long, flags); \
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_raw_read_lock_irqsave(lock, flags); \
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} while (0)
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#define write_lock_irqsave(lock, flags) \
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do { \
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typecheck(unsigned long, flags); \
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_raw_write_lock_irqsave(lock, flags); \
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} while (0)
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#endif
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#define read_lock_irq(lock) _raw_read_lock_irq(lock)
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#define read_lock_bh(lock) _raw_read_lock_bh(lock)
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#define write_lock_irq(lock) _raw_write_lock_irq(lock)
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#define write_lock_bh(lock) _raw_write_lock_bh(lock)
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#define read_unlock(lock) _raw_read_unlock(lock)
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#define write_unlock(lock) _raw_write_unlock(lock)
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#define read_unlock_irq(lock) _raw_read_unlock_irq(lock)
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#define write_unlock_irq(lock) _raw_write_unlock_irq(lock)
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#define read_unlock_irqrestore(lock, flags) \
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do { \
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typecheck(unsigned long, flags); \
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_raw_read_unlock_irqrestore(lock, flags); \
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} while (0)
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#define read_unlock_bh(lock) _raw_read_unlock_bh(lock)
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#define write_unlock_irqrestore(lock, flags) \
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do { \
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typecheck(unsigned long, flags); \
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_raw_write_unlock_irqrestore(lock, flags); \
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} while (0)
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#define write_unlock_bh(lock) _raw_write_unlock_bh(lock)
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#define write_trylock_irqsave(lock, flags) \
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({ \
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local_irq_save(flags); \
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write_trylock(lock) ? \
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1 : ({ local_irq_restore(flags); 0; }); \
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})
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#ifdef arch_rwlock_is_contended
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#define rwlock_is_contended(lock) \
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arch_rwlock_is_contended(&(lock)->raw_lock)
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#else
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#define rwlock_is_contended(lock) ((void)(lock), 0)
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#endif /* arch_rwlock_is_contended */
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#endif /* __LINUX_RWLOCK_H */
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