Commit 1697599e authored by Jakub Kicinski's avatar Jakub Kicinski Committed by David S. Miller
Browse files

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: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4f2bd6b3

drivers/net/ethernet/netronome/nfp/nfp_bpf.h

+0 −2
Original line number Diff line number Diff line
@@ -39,8 +39,6 @@ 
#include <linux/list.h>

#include <linux/types.h>



#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!

 */

include/linux/bitfield.h

+13 −0
Original line number Diff line number Diff line
@@ -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