Allow rwlocks to re-enable interrupts

Pass the original flags to rwlock arch-code, so that it can re-enable
interrupts if implemented for that architecture.

Initially, make __raw_read_lock_flags and __raw_write_lock_flags stubs
which just do the same thing as non-flags variants.

Signed-off-by: Petr Tesarik <[e-mail]>
Signed-off-by: Robin Holt <[e-mail]>
Acked-by: Peter Zijlstra <[e-mail]>
Cc: <[e-mail]>
Acked-by: Ingo Molnar <[e-mail]>
Cc: "Luck, Tony" <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/alpha/include/asm/spinlock.h

···
 	lock->lock = 0;
 }
 
+#define __raw_read_lock_flags(lock, flags) __raw_read_lock(lock)
+#define __raw_write_lock_flags(lock, flags) __raw_write_lock(lock)
+
 #define _raw_spin_relax(lock)	cpu_relax()
 #define _raw_read_relax(lock)	cpu_relax()
 #define _raw_write_relax(lock)	cpu_relax()

arch/arm/include/asm/spinlock.h

···
 /* read_can_lock - would read_trylock() succeed? */
 #define __raw_read_can_lock(x)		((x)->lock < 0x80000000)
 
+#define __raw_read_lock_flags(lock, flags) __raw_read_lock(lock)
+#define __raw_write_lock_flags(lock, flags) __raw_write_lock(lock)
+
 #define _raw_spin_relax(lock)	cpu_relax()
 #define _raw_read_relax(lock)	cpu_relax()
 #define _raw_write_relax(lock)	cpu_relax()

arch/cris/include/arch-v32/arch/spinlock.h

···
 	return 1;
 }
 
+#define _raw_read_lock_flags(lock, flags) _raw_read_lock(lock)
+#define _raw_write_lock_flags(lock, flags) _raw_write_lock(lock)
 
 #define _raw_spin_relax(lock)	cpu_relax()
 #define _raw_read_relax(lock)	cpu_relax()

arch/ia64/include/asm/spinlock.h

···
 	return (u32)ia64_cmpxchg4_acq((__u32 *)(x), new.word, old.word) == old.word;
 }
 
+#define __raw_read_lock_flags(lock, flags) __raw_read_lock(lock)
+#define __raw_write_lock_flags(lock, flags) __raw_write_lock(lock)
+
 #define _raw_spin_relax(lock)	cpu_relax()
 #define _raw_read_relax(lock)	cpu_relax()
 #define _raw_write_relax(lock)	cpu_relax()

arch/mips/include/asm/spinlock.h

···
 	return ret;
 }
 
+#define __raw_read_lock_flags(lock, flags) __raw_read_lock(lock)
+#define __raw_write_lock_flags(lock, flags) __raw_write_lock(lock)
 
 #define _raw_spin_relax(lock)	cpu_relax()
 #define _raw_read_relax(lock)	cpu_relax()

arch/parisc/include/asm/spinlock.h

···
 	return !rw->counter;
 }
 
+#define __raw_read_lock_flags(lock, flags) __raw_read_lock(lock)
+#define __raw_write_lock_flags(lock, flags) __raw_write_lock(lock)
+
 #define _raw_spin_relax(lock)	cpu_relax()
 #define _raw_read_relax(lock)	cpu_relax()
 #define _raw_write_relax(lock)	cpu_relax()

arch/powerpc/include/asm/spinlock.h

···
 	rw->lock = 0;
 }
 
+#define __raw_read_lock_flags(lock, flags) __raw_read_lock(lock)
+#define __raw_write_lock_flags(lock, flags) __raw_write_lock(lock)
+
 #define _raw_spin_relax(lock)	__spin_yield(lock)
 #define _raw_read_relax(lock)	__rw_yield(lock)
 #define _raw_write_relax(lock)	__rw_yield(lock)

arch/s390/include/asm/spinlock.h

···
 	return _raw_write_trylock_retry(rw);
 }
 
+#define __raw_read_lock_flags(lock, flags) __raw_read_lock(lock)
+#define __raw_write_lock_flags(lock, flags) __raw_write_lock(lock)
+
 #define _raw_read_relax(lock)	cpu_relax()
 #define _raw_write_relax(lock)	cpu_relax()
 

arch/sh/include/asm/spinlock.h

···
 	return (oldval > (RW_LOCK_BIAS - 1));
 }
 
+#define __raw_read_lock_flags(lock, flags) __raw_read_lock(lock)
+#define __raw_write_lock_flags(lock, flags) __raw_write_lock(lock)
+
 #define _raw_spin_relax(lock)	cpu_relax()
 #define _raw_read_relax(lock)	cpu_relax()
 #define _raw_write_relax(lock)	cpu_relax()

arch/sparc/include/asm/spinlock_32.h

···
 #define __raw_write_unlock(rw)	do { (rw)->lock = 0; } while(0)
 
 #define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
+#define __raw_read_lock_flags(rw, flags)   __raw_read_lock(rw)
+#define __raw_write_lock_flags(rw, flags)  __raw_write_lock(rw)
 
 #define _raw_spin_relax(lock)	cpu_relax()
 #define _raw_read_relax(lock)	cpu_relax()

arch/sparc/include/asm/spinlock_64.h

···
 }
 
 #define __raw_read_lock(p)	__read_lock(p)
+#define __raw_read_lock_flags(p, f) __read_lock(p)
 #define __raw_read_trylock(p)	__read_trylock(p)
 #define __raw_read_unlock(p)	__read_unlock(p)
 #define __raw_write_lock(p)	__write_lock(p)
+#define __raw_write_lock_flags(p, f) __write_lock(p)
 #define __raw_write_unlock(p)	__write_unlock(p)
 #define __raw_write_trylock(p)	__write_trylock(p)
 

arch/x86/include/asm/spinlock.h

···
 		     : "+m" (rw->lock) : "i" (RW_LOCK_BIAS) : "memory");
 }
 
+#define __raw_read_lock_flags(lock, flags) __raw_read_lock(lock)
+#define __raw_write_lock_flags(lock, flags) __raw_write_lock(lock)
+
 #define _raw_spin_relax(lock)	cpu_relax()
 #define _raw_read_relax(lock)	cpu_relax()
 #define _raw_write_relax(lock)	cpu_relax()

include/asm-m32r/spinlock.h

···
 	return 0;
 }
 
+#define __raw_read_lock_flags(lock, flags) __raw_read_lock(lock)
+#define __raw_write_lock_flags(lock, flags) __raw_write_lock(lock)
+
 #define _raw_spin_relax(lock)	cpu_relax()
 #define _raw_read_relax(lock)	cpu_relax()
 #define _raw_write_relax(lock)	cpu_relax()

include/linux/spinlock.h

···
  extern int _raw_spin_trylock(spinlock_t *lock);
  extern void _raw_spin_unlock(spinlock_t *lock);
  extern void _raw_read_lock(rwlock_t *lock);
+#define _raw_read_lock_flags(lock, flags) _raw_read_lock(lock)
  extern int _raw_read_trylock(rwlock_t *lock);
  extern void _raw_read_unlock(rwlock_t *lock);
  extern void _raw_write_lock(rwlock_t *lock);
+#define _raw_write_lock_flags(lock, flags) _raw_write_lock(lock)
  extern int _raw_write_trylock(rwlock_t *lock);
  extern void _raw_write_unlock(rwlock_t *lock);
 #else
···
 # define _raw_spin_trylock(lock)	__raw_spin_trylock(&(lock)->raw_lock)
 # define _raw_spin_unlock(lock)		__raw_spin_unlock(&(lock)->raw_lock)
 # define _raw_read_lock(rwlock)		__raw_read_lock(&(rwlock)->raw_lock)
+# define _raw_read_lock_flags(lock, flags) \
+		__raw_read_lock_flags(&(lock)->raw_lock, *(flags))
 # define _raw_read_trylock(rwlock)	__raw_read_trylock(&(rwlock)->raw_lock)
 # define _raw_read_unlock(rwlock)	__raw_read_unlock(&(rwlock)->raw_lock)
 # define _raw_write_lock(rwlock)	__raw_write_lock(&(rwlock)->raw_lock)
+# define _raw_write_lock_flags(lock, flags) \
+		__raw_write_lock_flags(&(lock)->raw_lock, *(flags))
 # define _raw_write_trylock(rwlock)	__raw_write_trylock(&(rwlock)->raw_lock)
 # define _raw_write_unlock(rwlock)	__raw_write_unlock(&(rwlock)->raw_lock)
 #endif

kernel/spinlock.c

···
 	local_irq_save(flags);
 	preempt_disable();
 	rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
-	LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
+	LOCK_CONTENDED_FLAGS(lock, _raw_read_trylock, _raw_read_lock,
+			     _raw_read_lock_flags, &flags);
 	return flags;
 }
 EXPORT_SYMBOL(_read_lock_irqsave);
···
 	local_irq_save(flags);
 	preempt_disable();
 	rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
-	LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
+	LOCK_CONTENDED_FLAGS(lock, _raw_write_trylock, _raw_write_lock,
+			     _raw_write_lock_flags, &flags);
 	return flags;
 }
 EXPORT_SYMBOL(_write_lock_irqsave);