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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
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+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!
 */
+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