From 47a361634821dc66cefbfa70b9d10a91269d7f7d Mon Sep 17 00:00:00 2001 From: Crt Mori Date: Thu, 11 Jan 2018 11:19:57 +0100 Subject: lib: Add strongly typed 64bit int_sqrt There is no option to perform 64bit integer sqrt on 32bit platform. Added stronger typed int_sqrt64 enables the 64bit calculations to be performed on 32bit platforms. Using same algorithm as int_sqrt() with strong typing provides enough precision also on 32bit platforms, but it sacrifices some performance. In case values are smaller than ULONG_MAX the standard int_sqrt is used for calculation to maximize the performance due to more native calculations. Signed-off-by: Crt Mori Acked-by: Joe Perches Signed-off-by: Jonathan Cameron --- include/linux/kernel.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index ce51455e2adf..2da80e079d56 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -479,6 +479,15 @@ extern int func_ptr_is_kernel_text(void *ptr); unsigned long int_sqrt(unsigned long); +#if BITS_PER_LONG < 64 +u32 int_sqrt64(u64 x); +#else +static inline u32 int_sqrt64(u64 x) +{ + return (u32)int_sqrt(x); +} +#endif + extern void bust_spinlocks(int yes); extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ extern int panic_timeout; -- cgit v1.2.3-70-g09d2