removes the bc build dependency introduced when timeconst.pl was
replaced by timeconst.bc

Signed-off-by: Ethan Sommer <e5ten.a...@gmail.com>
---
 Kbuild                   |   4 +-
 kernel/time/timeconst.bc | 117 --------------------------------------
 kernel/time/timeconst.sh | 118 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 120 insertions(+), 119 deletions(-)
 delete mode 100644 kernel/time/timeconst.bc
 create mode 100755 kernel/time/timeconst.sh

diff --git a/Kbuild b/Kbuild
index 8637fd14135f..2b5f2957cf04 100644
--- a/Kbuild
+++ b/Kbuild
@@ -20,9 +20,9 @@ timeconst-file := include/generated/timeconst.h
 
 targets += $(timeconst-file)
 
-filechk_gentimeconst = echo $(CONFIG_HZ) | bc -q $<
+filechk_gentimeconst = $(CONFIG_SHELL) $< $(CONFIG_HZ)
 
-$(timeconst-file): kernel/time/timeconst.bc FORCE
+$(timeconst-file): kernel/time/timeconst.sh FORCE
        $(call filechk,gentimeconst)
 
 #####
diff --git a/kernel/time/timeconst.bc b/kernel/time/timeconst.bc
deleted file mode 100644
index 7ed0e0fb5831..000000000000
--- a/kernel/time/timeconst.bc
+++ /dev/null
@@ -1,117 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-
-scale=0
-
-define gcd(a,b) {
-       auto t;
-       while (b) {
-               t = b;
-               b = a % b;
-               a = t;
-       }
-       return a;
-}
-
-/* Division by reciprocal multiplication. */
-define fmul(b,n,d) {
-       return (2^b*n+d-1)/d;
-}
-
-/* Adjustment factor when a ceiling value is used.  Use as:
-   (imul * n) + (fmulxx * n + fadjxx) >> xx) */
-define fadj(b,n,d) {
-       auto v;
-       d = d/gcd(n,d);
-       v = 2^b*(d-1)/d;
-       return v;
-}
-
-/* Compute the appropriate mul/adj values as well as a shift count,
-   which brings the mul value into the range 2^b-1 <= x < 2^b.  Such
-   a shift value will be correct in the signed integer range and off
-   by at most one in the upper half of the unsigned range. */
-define fmuls(b,n,d) {
-       auto s, m;
-       for (s = 0; 1; s++) {
-               m = fmul(s,n,d);
-               if (m >= 2^(b-1))
-                       return s;
-       }
-       return 0;
-}
-
-define timeconst(hz) {
-       print "/* Automatically generated by kernel/time/timeconst.bc */\n"
-       print "/* Time conversion constants for HZ == ", hz, " */\n"
-       print "\n"
-
-       print "#ifndef KERNEL_TIMECONST_H\n"
-       print "#define KERNEL_TIMECONST_H\n\n"
-
-       print "#include <linux/param.h>\n"
-       print "#include <linux/types.h>\n\n"
-
-       print "#if HZ != ", hz, "\n"
-       print "#error \qinclude/generated/timeconst.h has the wrong HZ 
value!\q\n"
-       print "#endif\n\n"
-
-       if (hz < 2) {
-               print "#error Totally bogus HZ value!\n"
-       } else {
-               s=fmuls(32,1000,hz)
-               obase=16
-               print "#define HZ_TO_MSEC_MUL32\tU64_C(0x", fmul(s,1000,hz), 
")\n"
-               print "#define HZ_TO_MSEC_ADJ32\tU64_C(0x", fadj(s,1000,hz), 
")\n"
-               obase=10
-               print "#define HZ_TO_MSEC_SHR32\t", s, "\n"
-
-               s=fmuls(32,hz,1000)
-               obase=16
-               print "#define MSEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000), 
")\n"
-               print "#define MSEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000), 
")\n"
-               obase=10
-               print "#define MSEC_TO_HZ_SHR32\t", s, "\n"
-
-               obase=10
-               cd=gcd(hz,1000)
-               print "#define HZ_TO_MSEC_NUM\t\t", 1000/cd, "\n"
-               print "#define HZ_TO_MSEC_DEN\t\t", hz/cd, "\n"
-               print "#define MSEC_TO_HZ_NUM\t\t", hz/cd, "\n"
-               print "#define MSEC_TO_HZ_DEN\t\t", 1000/cd, "\n"
-               print "\n"
-
-               s=fmuls(32,1000000,hz)
-               obase=16
-               print "#define HZ_TO_USEC_MUL32\tU64_C(0x", fmul(s,1000000,hz), 
")\n"
-               print "#define HZ_TO_USEC_ADJ32\tU64_C(0x", fadj(s,1000000,hz), 
")\n"
-               obase=10
-               print "#define HZ_TO_USEC_SHR32\t", s, "\n"
-
-               s=fmuls(32,hz,1000000)
-               obase=16
-               print "#define USEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000000), 
")\n"
-               print "#define USEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000000), 
")\n"
-               obase=10
-               print "#define USEC_TO_HZ_SHR32\t", s, "\n"
-
-               obase=10
-               cd=gcd(hz,1000000)
-               print "#define HZ_TO_USEC_NUM\t\t", 1000000/cd, "\n"
-               print "#define HZ_TO_USEC_DEN\t\t", hz/cd, "\n"
-               print "#define USEC_TO_HZ_NUM\t\t", hz/cd, "\n"
-               print "#define USEC_TO_HZ_DEN\t\t", 1000000/cd, "\n"
-
-               cd=gcd(hz,1000000000)
-               print "#define HZ_TO_NSEC_NUM\t\t", 1000000000/cd, "\n"
-               print "#define HZ_TO_NSEC_DEN\t\t", hz/cd, "\n"
-               print "#define NSEC_TO_HZ_NUM\t\t", hz/cd, "\n"
-               print "#define NSEC_TO_HZ_DEN\t\t", 1000000000/cd, "\n"
-               print "\n"
-
-               print "#endif /* KERNEL_TIMECONST_H */\n"
-       }
-       halt
-}
-
-hz = read();
-timeconst(hz)
diff --git a/kernel/time/timeconst.sh b/kernel/time/timeconst.sh
new file mode 100755
index 000000000000..df821988acbf
--- /dev/null
+++ b/kernel/time/timeconst.sh
@@ -0,0 +1,118 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+if [ -z "$1" ]; then
+       printf '%s <HZ>\n' "$0"
+       exit 1
+else
+       hz="$1"
+fi
+
+# 2 to the power of n
+pot() {
+       local i=1
+    local j=1
+       while [ "${j}" -le "$1" ]; do
+               i="$((i * 2))"
+        j="$((j + 1))"
+       done
+       printf '%s\n' "${i}"
+}
+
+# Greatest common denominator
+gcd() {
+       local i="$1"
+       local j="$2"
+       local k
+       while [ "${j}" -ne 0 ]; do
+               k="${j}"
+               j="$((i % j))"
+               i="${k}"
+       done
+       printf '%s\n' "${i}"
+}
+
+# Division by reciprocal multiplication.
+fmul() {
+       printf '%s\n' "$((($(pot "$1") * $2 + $3 - 1) / $3))"
+}
+
+# Adjustment factor when a ceiling value is used.
+fadj() {
+       local i="$(gcd "$2" "$3")"
+       printf '%s\n' "$(($(pot "$1") * ($3 / i - 1) / ($3 / i)))"
+}
+
+# Compute the appropriate mul/adj values as well as a shift count,
+# which brings the mul value into the range 2^b-1 <= x < 2^b.  Such
+# a shift value will be correct in the signed integer range and off
+# by at most one in the upper half of the unsigned range.
+fmuls() {
+       local i=0
+    local j
+       while true; do
+        j="$(fmul "${i}" "$2" "$3")"
+               if [ "${j}" -ge "$(pot "$(($1 - 1))")" ]; then
+                       printf '%s\n' "${i}" && return
+               fi
+               i="$((i + 1))"
+       done
+}
+
+printf '/* Automatically generated by %s */\n' "$0"
+printf '/* Time conversion constants for HZ == %s */\n\n' "$1"
+
+printf '#ifndef KERNEL_TIMECONST_H\n'
+printf '#define KERNEL_TIMECONST_H\n\n'
+
+printf '#include <linux/param.h>\n'
+printf '#include <linux/types.h>\n\n'
+
+printf '#if HZ != %s\n' "$1"
+printf '#error \qinclude/generated/timeconst.h has the wrong HZ value!\q\n'
+printf '#endif\n\n'
+
+if [ "$1" -lt 2 ]; then
+       printf '#error Totally bogus HZ value!\n'
+       exit 1
+fi
+
+s="$(fmuls 32 1000 "$1")"
+printf '#define HZ_TO_MSEC_MUL32\tU64_C(0x%X)\n' "$(fmul "${s}" 1000 "$1")"
+printf '#define HZ_TO_MSEC_ADJ32\tU64_C(0x%X)\n' "$(fadj "${s}" 1000 "$1")"
+printf '#define HZ_TO_MSEC_SHR32\t%s\n' "${s}"
+
+s="$(fmuls 32 "$1" 1000)"
+printf '#define MSEC_TO_HZ_MUL32\tU64_C(0x%X)\n' "$(fmul "${s}" "$1" 1000)"
+printf '#define MSEC_TO_HZ_ADJ32\tU64_C(0x%X)\n' "$(fadj "${s}" "$1" 1000)"
+printf '#define MSEC_TO_HZ_SHR32\t%s\n' "${s}"
+
+cd="$(gcd "$1" 1000)"
+printf '#define HZ_TO_MSEC_NUM\t\t%s\n' "$((1000 / cd))"
+printf '#define HZ_TO_MSEC_DEN\t\t%s\n' "$((hz / cd))"
+printf '#define MSEC_TO_HZ_NUM\t\t%s\n' "$((hz / cd))"
+printf '#define MSEC_TO_HZ_DEN\t\t%s\n\n' "$((1000 / cd))"
+
+s="$(fmuls 32 1000000 "$1")"
+printf '#define HZ_TO_USEC_MUL32\tU64_C(0x%X)\n' "$(fmul "${s}" 1000000 "$1")"
+printf '#define HZ_TO_USEC_ADJ32\tU64_C(0x%X)\n' "$(fadj "${s}" 1000000 "$1")"
+printf '#define HZ_TO_USEC_SHR32\t%s\n' "${s}"
+
+s="$(fmuls 32 "$1" 1000000)"
+printf '#define USEC_TO_HZ_MUL32\tU64_C(0x%X)\n' "$(fmul "${s}" "$1" 1000000)"
+printf '#define USEC_TO_HZ_ADJ32\tU64_C(0x%X)\n' "$(fadj "${s}" "$1" 1000000)"
+printf '#define USEC_TO_HZ_SHR32\t%s\n' "${s}"
+
+cd="$(gcd "$1" 1000000)"
+printf '#define HZ_TO_USEC_NUM\t\t%s\n' "$((1000000 / cd))"
+printf '#define HZ_TO_USEC_DEN\t\t%s\n' "$((hz / cd))"
+printf '#define USEC_TO_HZ_NUM\t\t%s\n' "$((hz / cd))"
+printf '#define USEC_TO_HZ_DEN\t\t%s\n' "$((1000000 / cd))"
+
+cd="$(gcd "$1" 1000000000)"
+printf '#define HZ_TO_NSEC_NUM\t\t%s\n' "$((1000000000 / cd))"
+printf '#define HZ_TO_NSEC_DEN\t\t%s\n' "$((hz / cd))"
+printf '#define NSEC_TO_HZ_NUM\t\t%s\n' "$((hz / cd))"
+printf '#define NSEC_TO_HZ_DEN\t\t%s\n' "$((1000000000 / cd))"
+
+printf '\n#endif /* KERNEL_TIMECONST_H */\n'
-- 
2.22.0

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