add an inlined version of iter_div_u64_rem

iter_div_u64_rem is used in the x86-64 vdso, which cannot call other
kernel code.  For this case, provide the always_inlined version,
__iter_div_u64_rem.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 20 insertions, 14 deletions

diff --git a/include/linux/math64.h b/include/linux/math64.h
index 177785e1e4a3..c87f1528703a 100644
--- a/include/linux/math64.h
+++ b/include/linux/math64.h
@@ -83,4 +83,23 @@ static inline s64 div_s64(s64 dividend, s32 divisor)
 
 u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder);
 
+static __always_inline u32
+__iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder)
+{
+        u32 ret = 0;
+
+        while (dividend >= divisor) {
+                /* The following asm() prevents the compiler from
+                   optimising this loop into a modulo operation.  */
+                asm("" : "+rm"(dividend));
+
+                dividend -= divisor;
+                ret++;
+        }
+
+        *remainder = dividend;
+
+        return ret;
+}
+
 #endif /* _LINUX_MATH64_H */
diff --git a/lib/div64.c b/lib/div64.c
index 76c01542d3e1..a111eb8de9cf 100644
--- a/lib/div64.c
+++ b/lib/div64.c
@@ -105,19 +105,6 @@ EXPORT_SYMBOL(div64_u64);
  */
 u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder)
 {
-        u32 ret = 0;
-
-        while (dividend >= divisor) {
-                /* The following asm() prevents the compiler from
-                   optimising this loop into a modulo operation.  */
-                asm("" : "+rm"(dividend));
-
-                dividend -= divisor;
-                ret++;
-        }
-
-        *remainder = dividend;
-
-        return ret;
+        return __iter_div_u64_rem(dividend, divisor, remainder);
 }
 EXPORT_SYMBOL(iter_div_u64_rem);