@@ -416,4 +416,10 @@ extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
#define atomic_dec_and_lock(atomic, lock) \
__cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
+int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *lock_mask,
+ unsigned int max_size, unsigned int cpu_mult,
+ gfp_t gfp);
+
+void free_bucket_spinlocks(spinlock_t *locks);
+
#endif /* __LINUX_SPINLOCK_H */
@@ -36,7 +36,7 @@ obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
gcd.o lcm.o list_sort.o uuid.o flex_array.o iov_iter.o clz_ctz.o \
bsearch.o find_bit.o llist.o memweight.o kfifo.o \
percpu-refcount.o percpu_ida.o rhashtable.o reciprocal_div.o \
- once.o
+ once.o bucket_locks.o
obj-y += string_helpers.o
obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o
obj-y += hexdump.o
new file mode 100644
@@ -0,0 +1,63 @@
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/export.h>
+
+/* Allocate an array of spinlocks to be accessed by a hash. Two arguments
+ * indicate the number of elements to allocate in the array. max_size
+ * gives the maximum number of elements to allocate. cpu_mult gives
+ * the number of locks per CPU to allocate. The size is rounded up
+ * to a power of 2 to be suitable as a hash table.
+ */
+int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask,
+ unsigned int max_size, unsigned int cpu_mult,
+ gfp_t gfp)
+{
+ unsigned int i, size;
+#if defined(CONFIG_PROVE_LOCKING)
+ unsigned int nr_pcpus = 2;
+#else
+ unsigned int nr_pcpus = num_possible_cpus();
+#endif
+ spinlock_t *tlocks = NULL;
+
+ if (cpu_mult) {
+ nr_pcpus = min_t(unsigned int, nr_pcpus, 64UL);
+ size = min_t(unsigned int, nr_pcpus * cpu_mult, max_size);
+ } else {
+ size = max_size;
+ }
+ size = roundup_pow_of_two(size);
+
+ if (!size)
+ return -EINVAL;
+
+ if (sizeof(spinlock_t) != 0) {
+#ifdef CONFIG_NUMA
+ if (size * sizeof(spinlock_t) > PAGE_SIZE &&
+ gfp == GFP_KERNEL)
+ tlocks = vmalloc(size * sizeof(spinlock_t));
+#endif
+ if (gfp != GFP_KERNEL)
+ gfp |= __GFP_NOWARN | __GFP_NORETRY;
+
+ if (!tlocks)
+ tlocks = kmalloc_array(size, sizeof(spinlock_t), gfp);
+ if (!tlocks)
+ return -ENOMEM;
+ for (i = 0; i < size; i++)
+ spin_lock_init(&tlocks[i]);
+ }
+ *locks = tlocks;
+ *locks_mask = size - 1;
+
+ return 0;
+}
+EXPORT_SYMBOL(alloc_bucket_spinlocks);
+
+void free_bucket_spinlocks(spinlock_t *locks)
+{
+ kvfree(locks);
+}
+EXPORT_SYMBOL(free_bucket_spinlocks);