diff options
Diffstat (limited to 'include/linux/ptr_ring.h')
| -rw-r--r-- | include/linux/ptr_ring.h | 45 |
1 files changed, 36 insertions, 9 deletions
diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h index 2052011bf9fb..b83507c0640c 100644 --- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -111,6 +111,11 @@ static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) return 0; } +/* + * Note: resize (below) nests producer lock within consumer lock, so if you + * consume in interrupt or BH context, you must disable interrupts/BH when + * calling this. + */ static inline int ptr_ring_produce(struct ptr_ring *r, void *ptr) { int ret; @@ -242,6 +247,11 @@ static inline void *__ptr_ring_consume(struct ptr_ring *r) return ptr; } +/* + * Note: resize (below) nests producer lock within consumer lock, so if you + * call this in interrupt or BH context, you must disable interrupts/BH when + * producing. + */ static inline void *ptr_ring_consume(struct ptr_ring *r) { void *ptr; @@ -330,9 +340,9 @@ static inline void *ptr_ring_consume_bh(struct ptr_ring *r) __PTR_RING_PEEK_CALL_v; \ }) -static inline void **__ptr_ring_init_queue_alloc(int size, gfp_t gfp) +static inline void **__ptr_ring_init_queue_alloc(unsigned int size, gfp_t gfp) { - return kzalloc(ALIGN(size * sizeof(void *), SMP_CACHE_BYTES), gfp); + return kcalloc(size, sizeof(void *), gfp); } static inline int ptr_ring_init(struct ptr_ring *r, int size, gfp_t gfp) @@ -357,7 +367,7 @@ static inline void **__ptr_ring_swap_queue(struct ptr_ring *r, void **queue, void **old; void *ptr; - while ((ptr = ptr_ring_consume(r))) + while ((ptr = __ptr_ring_consume(r))) if (producer < size) queue[producer++] = ptr; else if (destroy) @@ -372,6 +382,12 @@ static inline void **__ptr_ring_swap_queue(struct ptr_ring *r, void **queue, return old; } +/* + * Note: producer lock is nested within consumer lock, so if you + * resize you must make sure all uses nest correctly. + * In particular if you consume ring in interrupt or BH context, you must + * disable interrupts/BH when doing so. + */ static inline int ptr_ring_resize(struct ptr_ring *r, int size, gfp_t gfp, void (*destroy)(void *)) { @@ -382,18 +398,27 @@ static inline int ptr_ring_resize(struct ptr_ring *r, int size, gfp_t gfp, if (!queue) return -ENOMEM; - spin_lock_irqsave(&(r)->producer_lock, flags); + spin_lock_irqsave(&(r)->consumer_lock, flags); + spin_lock(&(r)->producer_lock); old = __ptr_ring_swap_queue(r, queue, size, gfp, destroy); - spin_unlock_irqrestore(&(r)->producer_lock, flags); + spin_unlock(&(r)->producer_lock); + spin_unlock_irqrestore(&(r)->consumer_lock, flags); kfree(old); return 0; } -static inline int ptr_ring_resize_multiple(struct ptr_ring **rings, int nrings, +/* + * Note: producer lock is nested within consumer lock, so if you + * resize you must make sure all uses nest correctly. + * In particular if you consume ring in interrupt or BH context, you must + * disable interrupts/BH when doing so. + */ +static inline int ptr_ring_resize_multiple(struct ptr_ring **rings, + unsigned int nrings, int size, gfp_t gfp, void (*destroy)(void *)) { @@ -401,7 +426,7 @@ static inline int ptr_ring_resize_multiple(struct ptr_ring **rings, int nrings, void ***queues; int i; - queues = kmalloc(nrings * sizeof *queues, gfp); + queues = kmalloc_array(nrings, sizeof(*queues), gfp); if (!queues) goto noqueues; @@ -412,10 +437,12 @@ static inline int ptr_ring_resize_multiple(struct ptr_ring **rings, int nrings, } for (i = 0; i < nrings; ++i) { - spin_lock_irqsave(&(rings[i])->producer_lock, flags); + spin_lock_irqsave(&(rings[i])->consumer_lock, flags); + spin_lock(&(rings[i])->producer_lock); queues[i] = __ptr_ring_swap_queue(rings[i], queues[i], size, gfp, destroy); - spin_unlock_irqrestore(&(rings[i])->producer_lock, flags); + spin_unlock(&(rings[i])->producer_lock); + spin_unlock_irqrestore(&(rings[i])->consumer_lock, flags); } for (i = 0; i < nrings; ++i) |