From 1697599ee301a52cded6499a09bd609f7f63fd06 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 9 Feb 2017 09:17:27 -0800 Subject: [PATCH] bitfield.h: add FIELD_FIT() helper Add a helper for checking at runtime that a value will fit inside a specified field/mask. Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller --- drivers/net/ethernet/netronome/nfp/nfp_bpf.h | 2 -- include/linux/bitfield.h | 13 +++++++++++++ 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/nfp_bpf.h b/drivers/net/ethernet/netronome/nfp/nfp_bpf.h index 76a19f1796af..9513c80f7be5 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_bpf.h +++ b/drivers/net/ethernet/netronome/nfp/nfp_bpf.h @@ -39,8 +39,6 @@ #include #include -#define FIELD_FIT(mask, val) (!((((u64)val) << __bf_shf(mask)) & ~(mask))) - /* For branch fixup logic use up-most byte of branch instruction as scratch * area. Remember to clear this before sending instructions to HW! */ diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h index f6505d83069d..8b9d6fff002d 100644 --- a/include/linux/bitfield.h +++ b/include/linux/bitfield.h @@ -62,6 +62,19 @@ (1ULL << __bf_shf(_mask))); \ }) +/** + * FIELD_FIT() - check if value fits in the field + * @_mask: shifted mask defining the field's length and position + * @_val: value to test against the field + * + * Return: true if @_val can fit inside @_mask, false if @_val is too big. + */ +#define FIELD_FIT(_mask, _val) \ + ({ \ + __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_FIT: "); \ + !((((typeof(_mask))_val) << __bf_shf(_mask)) & ~(_mask)); \ + }) + /** * FIELD_PREP() - prepare a bitfield element * @_mask: shifted mask defining the field's length and position -- 2.20.1