kernel.h: split out mathematical helpers

kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out
mathematical helpers.

At the same time convert users in header and lib folder to use new
header.  Though for time being include new header back to kernel.h to
avoid twisted indirected includes for existing users.

[sfr@canb.auug.org.au: fix powerpc build]
  Link: https://lkml.kernel.org/r/20201029150809.13059608@canb.auug.org.au

Link: https://lkml.kernel.org/r/20201028173212.41768-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

7 files changed, 16 insertions, 7 deletions

diff --git a/lib/errname.c b/lib/errname.c
index 0c4d3e66170e..05cbf731545f 100644
--- a/lib/errname.c
+++ b/lib/errname.c
@@ -3,6 +3,7 @@
 #include <linux/errno.h>
 #include <linux/errname.h>
 #include <linux/kernel.h>
+#include <linux/math.h>
 
 /*
  * Ensure these tables do not accidentally become gigantic if some
diff --git a/lib/errseq.c b/lib/errseq.c
index 81f9e33aa7e7..93e9b94358dc 100644
--- a/lib/errseq.c
+++ b/lib/errseq.c
@@ -3,6 +3,7 @@
 #include <linux/bug.h>
 #include <linux/atomic.h>
 #include <linux/errseq.h>
+#include <linux/log2.h>
 
 /*
  * An errseq_t is a way of recording errors in one place, and allowing any
diff --git a/lib/find_bit.c b/lib/find_bit.c
index 4a8751010d59..f67f86fd2f62 100644
--- a/lib/find_bit.c
+++ b/lib/find_bit.c
@@ -15,8 +15,9 @@
 #include <linux/bitops.h>
 #include <linux/bitmap.h>
 #include <linux/export.h>
-#include <linux/kernel.h>
+#include <linux/math.h>
 #include <linux/minmax.h>
+#include <linux/swab.h>
 
 #if !defined(find_next_bit) || !defined(find_next_zero_bit) ||			\
 	!defined(find_next_bit_le) || !defined(find_next_zero_bit_le) ||	\
diff --git a/lib/math/div64.c b/lib/math/div64.c
index 3952a07130d8..064d68a5391a 100644
--- a/lib/math/div64.c
+++ b/lib/math/div64.c
@@ -18,9 +18,11 @@
  * or by defining a preprocessor macro in arch/include/asm/div64.h.
  */
 
+#include <linux/bitops.h>
 #include <linux/export.h>
-#include <linux/kernel.h>
+#include <linux/math.h>
 #include <linux/math64.h>
+#include <linux/log2.h>
 
 /* Not needed on 64bit architectures */
 #if BITS_PER_LONG == 32
diff --git a/lib/math/int_pow.c b/lib/math/int_pow.c
index 622fc1ab3c74..0cf426e69bda 100644
--- a/lib/math/int_pow.c
+++ b/lib/math/int_pow.c
@@ -6,7 +6,7 @@
  */
 
 #include <linux/export.h>
-#include <linux/kernel.h>
+#include <linux/math.h>
 #include <linux/types.h>
 
 /**
diff --git a/lib/math/int_sqrt.c b/lib/math/int_sqrt.c
index 30e0f9770f88..a8170bb9142f 100644
--- a/lib/math/int_sqrt.c
+++ b/lib/math/int_sqrt.c
@@ -6,9 +6,10 @@
  *  square root from Guy L. Steele.
  */
 
-#include <linux/kernel.h>
 #include <linux/export.h>
 #include <linux/bitops.h>
+#include <linux/limits.h>
+#include <linux/math.h>
 
 /**
  * int_sqrt - computes the integer square root
diff --git a/lib/math/reciprocal_div.c b/lib/math/reciprocal_div.c
index 32436dd4171e..6cb4adbb81d2 100644
--- a/lib/math/reciprocal_div.c
+++ b/lib/math/reciprocal_div.c
@@ -1,10 +1,13 @@
 // SPDX-License-Identifier: GPL-2.0
+#include <linux/bitops.h>
 #include <linux/bug.h>
-#include <linux/kernel.h>
-#include <asm/div64.h>
-#include <linux/reciprocal_div.h>
 #include <linux/export.h>
+#include <linux/limits.h>
+#include <linux/math.h>
 #include <linux/minmax.h>
+#include <linux/types.h>
+
+#include <linux/reciprocal_div.h>
 
 /*
  * For a description of the algorithm please have a look at