lib: crypto: fix comments for count_leading_zeros()

count_leading_zeros() is based on fls(), which is defined for x == 0,
contrary to __ffs() family. The comment in crypto/mpi erroneously
states that the function may return undef in such case.

Fix the comment together with the outdated function signature, and now
that COUNT_LEADING_ZEROS_0 is not referenced in the codebase, get rid of
it too.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Yury Norov <ynorov@nvidia.com>

diff --git a/include/linux/count_zeros.h b/include/linux/count_zeros.h
index 5b8ff5ac660da01a73582bc581a3dc1acb2c220e..4e5680327ece808c9dce5fd2cdaff86dff6bd2e0 100644 (file)
--- a/include/linux/count_zeros.h
+++ b/include/linux/count_zeros.h
@@ -18,7 +18,7 @@
  *
  * If the MSB of @x is set, the result is 0.
  * If only the LSB of @x is set, then the result is BITS_PER_LONG-1.
- * If @x is 0 then the result is COUNT_LEADING_ZEROS_0.
+ * If @x is 0 then the result is BITS_PER_LONG.
  */
 static inline int count_leading_zeros(unsigned long x)
 {
@@ -28,8 +28,6 @@ static inline int count_leading_zeros(unsigned long x)
                return BITS_PER_LONG - fls64(x);
 }
 
-#define COUNT_LEADING_ZEROS_0 BITS_PER_LONG
-
 /**
  * count_trailing_zeros - Count the number of zeros from the LSB forwards
  * @x: The value

diff --git a/lib/crypto/mpi/longlong.h b/lib/crypto/mpi/longlong.h
index b6fa1d08fb55b3a5d414dc4ae059c20faafd5744..6d31c3a729f12538a97462d8804f214c0a596048 100644 (file)
--- a/lib/crypto/mpi/longlong.h
+++ b/lib/crypto/mpi/longlong.h
@@ -66,12 +66,12 @@
  * denominator).  Like udiv_qrnnd but the numbers are signed.  The quotient
  * is rounded towards 0.
  *
- * 5) count_leading_zeros(count, x) counts the number of zero-bits from the
+ * 5) count_leading_zeros(x) counts the number of zero-bits from the
  * msb to the first non-zero bit in the UWtype X.  This is the number of
- * steps X needs to be shifted left to set the msb.  Undefined for X == 0,
- * unless the symbol COUNT_LEADING_ZEROS_0 is defined to some value.
+ * steps X needs to be shifted left to set the msb.
+ * count_leading_zeros(0) == BITS_PER_LONG
  *
- * 6) count_trailing_zeros(count, x) like count_leading_zeros, but counts
+ * 6) count_trailing_zeros() like count_leading_zeros(), but counts
  * from the least significant end.
  *
  * 7) add_ssaaaa(high_sum, low_sum, high_addend_1, low_addend_1,