1 files changed, 80 insertions, 0 deletions

diff --git a/include/linux/math64.h b/include/linux/math64.h
index c45c089bfdac..6e8b5b270ffe 100644
--- a/include/linux/math64.h
+++ b/include/linux/math64.h
@@ -142,6 +142,13 @@ static inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift)
 }
 #endif /* mul_u64_u32_shr */
 
+#ifndef mul_u64_u64_shr
+static inline u64 mul_u64_u64_shr(u64 a, u64 mul, unsigned int shift)
+{
+        return (u64)(((unsigned __int128)a * mul) >> shift);
+}
+#endif /* mul_u64_u64_shr */
+
 #else
 
 #ifndef mul_u64_u32_shr
@@ -161,6 +168,79 @@ static inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift)
 }
 #endif /* mul_u64_u32_shr */
 
+#ifndef mul_u64_u64_shr
+static inline u64 mul_u64_u64_shr(u64 a, u64 b, unsigned int shift)
+{
+        union {
+                u64 ll;
+                struct {
+#ifdef __BIG_ENDIAN
+                        u32 high, low;
+#else
+                        u32 low, high;
+#endif
+                } l;
+        } rl, rm, rn, rh, a0, b0;
+        u64 c;
+
+        a0.ll = a;
+        b0.ll = b;
+
+        rl.ll = (u64)a0.l.low * b0.l.low;
+        rm.ll = (u64)a0.l.low * b0.l.high;
+        rn.ll = (u64)a0.l.high * b0.l.low;
+        rh.ll = (u64)a0.l.high * b0.l.high;
+
+        /*
+         * Each of these lines computes a 64-bit intermediate result into "c",
+         * starting at bits 32-95.  The low 32-bits go into the result of the
+         * multiplication, the high 32-bits are carried into the next step.
+         */
+        rl.l.high = c = (u64)rl.l.high + rm.l.low + rn.l.low;
+        rh.l.low = c = (c >> 32) + rm.l.high + rn.l.high + rh.l.low;
+        rh.l.high = (c >> 32) + rh.l.high;
+
+        /*
+         * The 128-bit result of the multiplication is in rl.ll and rh.ll,
+         * shift it right and throw away the high part of the result.
+         */
+        if (shift == 0)
+                return rl.ll;
+        if (shift < 64)
+                return (rl.ll >> shift) | (rh.ll << (64 - shift));
+        return rh.ll >> (shift & 63);
+}
+#endif /* mul_u64_u64_shr */
+
 #endif
 
+#ifndef mul_u64_u32_div
+static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor)
+{
+        union {
+                u64 ll;
+                struct {
+#ifdef __BIG_ENDIAN
+                        u32 high, low;
+#else
+                        u32 low, high;
+#endif
+                } l;
+        } u, rl, rh;
+
+        u.ll = a;
+        rl.ll = (u64)u.l.low * mul;
+        rh.ll = (u64)u.l.high * mul + rl.l.high;
+
+        /* Bits 32-63 of the result will be in rh.l.low. */
+        rl.l.high = do_div(rh.ll, divisor);
+
+        /* Bits 0-31 of the result will be in rl.l.low. */
+        do_div(rl.ll, divisor);
+
+        rl.l.high = rh.l.low;
+        return rl.ll;
+}
+#endif /* mul_u64_u32_div */
+
 #endif /* _LINUX_MATH64_H */