diff options
Diffstat (limited to 'include/qemu')
| -rw-r--r-- | include/qemu/atomic.h | 12 | ||||
| -rw-r--r-- | include/qemu/bitmap.h | 4 | ||||
| -rw-r--r-- | include/qemu/bitops.h | 14 |
3 files changed, 27 insertions, 3 deletions
diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h index 98e05ca875..bd2c075343 100644 --- a/include/qemu/atomic.h +++ b/include/qemu/atomic.h @@ -99,7 +99,13 @@ #ifndef smp_wmb #ifdef __ATOMIC_RELEASE -#define smp_wmb() __atomic_thread_fence(__ATOMIC_RELEASE) +/* __atomic_thread_fence does not include a compiler barrier; instead, + * the barrier is part of __atomic_load/__atomic_store's "volatile-like" + * semantics. If smp_wmb() is a no-op, absence of the barrier means that + * the compiler is free to reorder stores on each side of the barrier. + * Add one here, and similarly in smp_rmb() and smp_read_barrier_depends(). + */ +#define smp_wmb() ({ barrier(); __atomic_thread_fence(__ATOMIC_RELEASE); barrier(); }) #else #define smp_wmb() __sync_synchronize() #endif @@ -107,7 +113,7 @@ #ifndef smp_rmb #ifdef __ATOMIC_ACQUIRE -#define smp_rmb() __atomic_thread_fence(__ATOMIC_ACQUIRE) +#define smp_rmb() ({ barrier(); __atomic_thread_fence(__ATOMIC_ACQUIRE); barrier(); }) #else #define smp_rmb() __sync_synchronize() #endif @@ -115,7 +121,7 @@ #ifndef smp_read_barrier_depends #ifdef __ATOMIC_CONSUME -#define smp_read_barrier_depends() __atomic_thread_fence(__ATOMIC_CONSUME) +#define smp_read_barrier_depends() ({ barrier(); __atomic_thread_fence(__ATOMIC_CONSUME); barrier(); }) #else #define smp_read_barrier_depends() barrier() #endif diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h index f0273c965f..86dd9cd5fc 100644 --- a/include/qemu/bitmap.h +++ b/include/qemu/bitmap.h @@ -39,7 +39,9 @@ * bitmap_empty(src, nbits) Are all bits zero in *src? * bitmap_full(src, nbits) Are all bits set in *src? * bitmap_set(dst, pos, nbits) Set specified bit area + * bitmap_set_atomic(dst, pos, nbits) Set specified bit area with atomic ops * bitmap_clear(dst, pos, nbits) Clear specified bit area + * bitmap_test_and_clear_atomic(dst, pos, nbits) Test and clear area * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area */ @@ -226,7 +228,9 @@ static inline int bitmap_intersects(const unsigned long *src1, } void bitmap_set(unsigned long *map, long i, long len); +void bitmap_set_atomic(unsigned long *map, long i, long len); void bitmap_clear(unsigned long *map, long start, long nr); +bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr); unsigned long bitmap_find_next_zero_area(unsigned long *map, unsigned long size, unsigned long start, diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h index 8abdcf9077..8164225152 100644 --- a/include/qemu/bitops.h +++ b/include/qemu/bitops.h @@ -16,6 +16,7 @@ #include <assert.h> #include "host-utils.h" +#include "atomic.h" #define BITS_PER_BYTE CHAR_BIT #define BITS_PER_LONG (sizeof (unsigned long) * BITS_PER_BYTE) @@ -39,6 +40,19 @@ static inline void set_bit(long nr, unsigned long *addr) } /** + * set_bit_atomic - Set a bit in memory atomically + * @nr: the bit to set + * @addr: the address to start counting from + */ +static inline void set_bit_atomic(long nr, unsigned long *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = addr + BIT_WORD(nr); + + atomic_or(p, mask); +} + +/** * clear_bit - Clears a bit in memory * @nr: Bit to clear * @addr: Address to start counting from |