X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=include%2Fasm-x86%2Fdiv64.h;h=c7892cfe9ce65d5e92e09bdd011791c04e24274b;hb=2418f4f28f8467b92a6177af32d05737ebf6206c;hp=8ac7da6ca284b90b2c31d1c4dd363fccd36ac42f;hpb=e86908614f2c7fec401827e5cefd7a6ea9407f85;p=linux-2.6

diff --git a/include/asm-x86/div64.h b/include/asm-x86/div64.h
index 8ac7da6ca2..c7892cfe9c 100644
--- a/include/asm-x86/div64.h
+++ b/include/asm-x86/div64.h
@@ -1,5 +1,80 @@
+#ifndef _ASM_X86_DIV64_H
+#define _ASM_X86_DIV64_H
+
 #ifdef CONFIG_X86_32
-# include "div64_32.h"
+
+#include <linux/types.h>
+
+/*
+ * do_div() is NOT a C function. It wants to return
+ * two values (the quotient and the remainder), but
+ * since that doesn't work very well in C, what it
+ * does is:
+ *
+ * - modifies the 64-bit dividend _in_place_
+ * - returns the 32-bit remainder
+ *
+ * This ends up being the most efficient "calling
+ * convention" on x86.
+ */
+#define do_div(n, base)						\
+({								\
+	unsigned long __upper, __low, __high, __mod, __base;	\
+	__base = (base);					\
+	asm("":"=a" (__low), "=d" (__high) : "A" (n));		\
+	__upper = __high;					\
+	if (__high) {						\
+		__upper = __high % (__base);			\
+		__high = __high / (__base);			\
+	}							\
+	asm("divl %2":"=a" (__low), "=d" (__mod)		\
+	    : "rm" (__base), "0" (__low), "1" (__upper));	\
+	asm("":"=A" (n) : "a" (__low), "d" (__high));		\
+	__mod;							\
+})
+
+/*
+ * (long)X = ((long long)divs) / (long)div
+ * (long)rem = ((long long)divs) % (long)div
+ *
+ * Warning, this will do an exception if X overflows.
+ */
+#define div_long_long_rem(a, b, c) div_ll_X_l_rem(a, b, c)
+
+static inline long div_ll_X_l_rem(long long divs, long div, long *rem)
+{
+	long dum2;
+	asm("divl %2":"=a"(dum2), "=d"(*rem)
+	    : "rm"(div), "A"(divs));
+
+	return dum2;
+
+}
+
+static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
+{
+	union {
+		u64 v64;
+		u32 v32[2];
+	} d = { dividend };
+	u32 upper;
+
+	upper = d.v32[1];
+	d.v32[1] = 0;
+	if (upper >= divisor) {
+		d.v32[1] = upper / divisor;
+		upper %= divisor;
+	}
+	asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) :
+		"rm" (divisor), "0" (d.v32[0]), "1" (upper));
+	return d.v64;
+}
+#define div_u64_rem	div_u64_rem
+
+extern uint64_t div64_64(uint64_t dividend, uint64_t divisor);
+
 #else
-# include "div64_64.h"
-#endif
+# include <asm-generic/div64.h>
+#endif /* CONFIG_X86_32 */
+
+#endif /* _ASM_X86_DIV64_H */