diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Makefile | 5 | ||||
| -rw-r--r-- | lib/div64.c | 22 |
2 files changed, 25 insertions, 2 deletions
diff --git a/lib/Makefile b/lib/Makefile index 992a39ef9ffd..ae57f357fec0 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -4,7 +4,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ rbtree.o radix-tree.o dump_stack.o \ - idr.o div64.o int_sqrt.o bitmap.o extable.o prio_tree.o \ + idr.o int_sqrt.o bitmap.o extable.o prio_tree.o \ sha1.o irq_regs.o reciprocal_div.o lib-$(CONFIG_MMU) += ioremap.o @@ -12,7 +12,8 @@ lib-$(CONFIG_SMP) += cpumask.o lib-y += kobject.o kref.o kobject_uevent.o klist.o -obj-y += sort.o parser.o halfmd4.o debug_locks.o random32.o bust_spinlocks.o +obj-y += div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ + bust_spinlocks.o ifeq ($(CONFIG_DEBUG_KOBJECT),y) CFLAGS_kobject.o += -DDEBUG diff --git a/lib/div64.c b/lib/div64.c index 365719f84832..c3d7655cdfb5 100644 --- a/lib/div64.c +++ b/lib/div64.c @@ -58,4 +58,26 @@ uint32_t __div64_32(uint64_t *n, uint32_t base) EXPORT_SYMBOL(__div64_32); +/* 64bit divisor, dividend and result. dynamic precision */ +uint64_t div64_64(uint64_t dividend, uint64_t divisor) +{ + uint32_t d = divisor; + + if (divisor > 0xffffffffULL) { + unsigned int shift = fls(divisor >> 32); + + d = divisor >> shift; + dividend >>= shift; + } + + /* avoid 64 bit division if possible */ + if (dividend >> 32) + do_div(dividend, d); + else + dividend = (uint32_t) dividend / d; + + return dividend; +} +EXPORT_SYMBOL(div64_64); + #endif /* BITS_PER_LONG == 32 */ |