Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit af5917f0 authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Kyle McMartin
Browse files

[PARISC] Only write to memory in test_and_set_bit/test_and_clear_bit if we're 



going to change the bit.

Signed-off-by: default avatarMatthew Wilcox <matthew@wil.cx>
Signed-off-by: default avatarKyle McMartin <kyle@parisc-linux.org>
parent d6ce8626

include/asm-parisc/bitops.h

+14 −8
Original line number Diff line number Diff line
@@ -60,31 +60,37 @@ static __inline__ void change_bit(int nr, volatile unsigned long * addr) 
static __inline__ int test_and_set_bit(int nr, volatile unsigned long * addr)

{

	unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);

	unsigned long oldbit;

	unsigned long old;

	unsigned long flags;

	int set;



	addr += (nr >> SHIFT_PER_LONG);

	_atomic_spin_lock_irqsave(addr, flags);

	oldbit = *addr;

	*addr = oldbit | mask;

	old = *addr;

	set = (old & mask) ? 1 : 0;

	if (!set)

		*addr = old | mask;

	_atomic_spin_unlock_irqrestore(addr, flags);



	return (oldbit & mask) ? 1 : 0;

	return set;

}



static __inline__ int test_and_clear_bit(int nr, volatile unsigned long * addr)

{

	unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);

	unsigned long oldbit;

	unsigned long old;

	unsigned long flags;

	int set;



	addr += (nr >> SHIFT_PER_LONG);

	_atomic_spin_lock_irqsave(addr, flags);

	oldbit = *addr;

	*addr = oldbit & ~mask;

	old = *addr;

	set = (old & mask) ? 1 : 0;

	if (set)

		*addr = old & ~mask;

	_atomic_spin_unlock_irqrestore(addr, flags);



	return (oldbit & mask) ? 1 : 0;

	return set;

}



static __inline__ int test_and_change_bit(int nr, volatile unsigned long * addr)