Introduce size_to_shift() for future users that need to obtain shift of a huge-page which is other than pmd_psize().
Suggested-by: David Hildenbrand (Arm) <[email protected]> Reviewed-by: Lorenzo Stoakes (ARM) <[email protected]> Signed-off-by: Yeoreum Yun <[email protected]> --- tools/testing/selftests/mm/vm_util.c | 2 +- tools/testing/selftests/mm/vm_util.h | 12 ++++++++++++ 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c index 8f80e73dc22a5..970671058397d 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -194,7 +194,7 @@ uint64_t pmd_pshift(void) if (__pmd_psize != -1ull) __pmd_psize = pmd_psize(); - __pmd_pshift = (__pmd_psize > 0) ? ffsl(__pmd_psize) - 1 : 0; + __pmd_pshift = size_to_shift(__pmd_psize); return __pmd_pshift; } diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h index 71af4804f8f24..6e37c90f3c3a5 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -148,6 +148,18 @@ static inline int sz2ord(size_t size, size_t pagesize) return __builtin_ctzll(size / pagesize); } +static inline uint64_t size_to_shift(uint64_t size) +{ + /* + * The function returns the corresponding shift only when the size + * is a power of two; otherwise, it returns 0. + */ + if (!size || (size & (size - 1))) + return 0; + + return ffsl(size) - 1; +} + void *sys_mremap(void *old_address, unsigned long old_size, unsigned long new_size, int flags, void *new_address); -- 2.43.0

