| Message ID | 20180629080320.320144-3-dplotnikov@virtuozzo.com |
|---|---|
| State | New |
| Headers | show |
| Series | Background snapshots | expand |
* Denis Plotnikov (dplotnikov@virtuozzo.com) wrote: > 1. test bit > 2. test and set bit > > Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com> > --- > include/qemu/bitops.h | 24 ++++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h > index 3f0926cf40..7b1c8c7baf 100644 > --- a/include/qemu/bitops.h > +++ b/include/qemu/bitops.h > @@ -94,6 +94,21 @@ static inline int test_and_set_bit(long nr, unsigned long *addr) > return (old & mask) != 0; > } > > +/** > + * test_and_set_bit_atomic - Set a bit atomically and return its old value > + * @nr: Bit to set > + * @addr: Address to count from > + */ > +static inline int test_and_set_bit_atomic(long nr, unsigned long *addr) > +{ > + unsigned long mask = BIT_MASK(nr); > + unsigned long *p = addr + BIT_WORD(nr); > + unsigned long old; > + > + old = atomic_fetch_or(p, mask); > + return (old & mask) != 0; > +} > + > /** > * test_and_clear_bit - Clear a bit and return its old value > * @nr: Bit to clear > @@ -134,6 +149,15 @@ static inline int test_bit(long nr, const unsigned long *addr) > return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1))); > } > > +/** > + * test_bit_atomic - Determine whether a bit is set atomicallly > + * @nr: bit number to test > + * @addr: Address to start counting from > + */ > +static inline int test_bit_atomic(long nr, const unsigned long *addr) > +{ > + return 1UL & (atomic_read(&addr[BIT_WORD(nr)]) >> (nr & (BITS_PER_LONG-1))); Note that fails the style check because it's expecting spaces around the '-', (which would then take you over 80 chars); your patch is consistent with the other places in the file though. It's probably best if you make the style checker happy. So, Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > +} > /** > * find_last_bit - find the last set bit in a memory region > * @addr: The address to start the search at > -- > 2.17.0 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h index 3f0926cf40..7b1c8c7baf 100644 --- a/include/qemu/bitops.h +++ b/include/qemu/bitops.h @@ -94,6 +94,21 @@ static inline int test_and_set_bit(long nr, unsigned long *addr) return (old & mask) != 0; } +/** + * test_and_set_bit_atomic - Set a bit atomically and return its old value + * @nr: Bit to set + * @addr: Address to count from + */ +static inline int test_and_set_bit_atomic(long nr, unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = addr + BIT_WORD(nr); + unsigned long old; + + old = atomic_fetch_or(p, mask); + return (old & mask) != 0; +} + /** * test_and_clear_bit - Clear a bit and return its old value * @nr: Bit to clear @@ -134,6 +149,15 @@ static inline int test_bit(long nr, const unsigned long *addr) return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1))); } +/** + * test_bit_atomic - Determine whether a bit is set atomicallly + * @nr: bit number to test + * @addr: Address to start counting from + */ +static inline int test_bit_atomic(long nr, const unsigned long *addr) +{ + return 1UL & (atomic_read(&addr[BIT_WORD(nr)]) >> (nr & (BITS_PER_LONG-1))); +} /** * find_last_bit - find the last set bit in a memory region * @addr: The address to start the search at
1. test bit 2. test and set bit Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com> --- include/qemu/bitops.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)