[U-Boot] [PATCH v4 1/8] include: Add support for "do_div" macro

[Wills Wang]

Use the div64 header files from the kernel.

Signed-off-by: Wills Wang <wills.wang at live.com>
---

Changes in v4: None
Changes in v3: None
Changes in v2: None

 arch/mips/include/asm/div64.h | 68 +++++++++++++++++++++++++++++++++++++++++++
 include/asm-generic/div64.h   | 59 +++++++++++++++++++++++++++++++++++++
 2 files changed, 127 insertions(+)
 create mode 100644 arch/mips/include/asm/div64.h
 create mode 100644 include/asm-generic/div64.h

diff --git a/arch/mips/include/asm/div64.h b/arch/mips/include/asm/div64.h
new file mode 100644
index 0000000..e5e6782
--- /dev/null
+++ b/arch/mips/include/asm/div64.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2000, 2004  Maciej W. Rozycki
+ * Copyright (C) 2003, 07 Ralf Baechle (ralf at linux-mips.org)
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#ifndef __ASM_DIV64_H
+#define __ASM_DIV64_H
+
+#include <asm-generic/div64.h>
+
+#if BITS_PER_LONG == 64
+
+#include <linux/types.h>
+
+/*
+ * No traps on overflows for any of these...
+ */
+
+#define __div64_32(n, base)						\
+({									\
+	unsigned long __cf, __tmp, __tmp2, __i;				\
+	unsigned long __quot32, __mod32;				\
+	unsigned long __high, __low;					\
+	unsigned long long __n;						\
+									\
+	__high = *__n >> 32;						\
+	__low = __n;							\
+	__asm__(							\
+	"	.set	push\n"						\
+	"	.set	noat\n"						\
+	"	.set	noreorder\n"					\
+	"	move	%2, $0\n"					\
+	"	move	%3, $0\n"					\
+	"	b	1f\n"						\
+	"	 li	%4, 0x21\n"					\
+	"0:\n"								\
+	"	sll	$1, %0, 0x1\n"					\
+	"	srl	%3, %0, 0x1f\n"					\
+	"	or	%0, $1, %5\n"					\
+	"	sll	%1, %1, 0x1\n"					\
+	"	sll	%2, %2, 0x1\n"					\
+	"1:\n"								\
+	"	bnez	%3, 2f\n"					\
+	"	 sltu	%5, %0, %z6\n"					\
+	"	bnez	%5, 3f\n"					\
+	"2:\n"								\
+	"	 addiu	%4, %4, -1\n"					\
+	"	subu	%0, %0, %z6\n"					\
+	"	addiu	%2, %2, 1\n"					\
+	"3:\n"								\
+	"	bnez	%4, 0b\n\t"					\
+	"	 srl	%5, %1, 0x1f\n\t"				\
+	"	.set	pop"						\
+	: "=&r" (__mod32), "=&r" (__tmp),				\
+	  "=&r" (__quot32), "=&r" (__cf),				\
+	  "=&r" (__i), "=&r" (__tmp2)					\
+	: "Jr" (base), "0" (__high), "1" (__low));			\
+									\
+	(__n) = __quot32;						\
+	__mod32;							\
+})
+
+#endif /* BITS_PER_LONG == 64 */
+
+#endif /* __ASM_DIV64_H */
diff --git a/include/asm-generic/div64.h b/include/asm-generic/div64.h
new file mode 100644
index 0000000..d689fc4
--- /dev/null
+++ b/include/asm-generic/div64.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2003 Bernardo Innocenti <bernie at develer.com>
+ * Based on former asm-ppc/div64.h and asm-m68knommu/div64.h
+ *
+ * The semantics of do_div() are:
+ *
+ * uint32_t do_div(uint64_t *n, uint32_t base)
+ * {
+ *  uint32_t remainder = *n % base;
+ *  *n = *n / base;
+ *  return remainder;
+ * }
+ *
+ * NOTE: macro parameter n is evaluated multiple times,
+ *       beware of side effects!
+ */
+
+#ifndef _ASM_GENERIC_DIV64_H
+#define _ASM_GENERIC_DIV64_H
+
+#include <linux/types.h>
+#include <linux/compiler.h>
+
+#if BITS_PER_LONG == 64
+
+# define do_div(n, base) ({					\
+	uint32_t __base = (base);				\
+	uint32_t __rem;						\
+	__rem = ((uint64_t)(n)) % __base;			\
+	(n) = ((uint64_t)(n)) / __base;				\
+	__rem;							\
+})
+
+#elif BITS_PER_LONG == 32
+
+extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor);
+
+/* The unnecessary pointer compare is there
+ * to check for type safety (n must be 64bit)
+ */
+# define do_div(n, base) ({				\
+	uint32_t __base = (base);			\
+	uint32_t __rem;					\
+	(void)(((typeof((n)) *)0) == ((uint64_t *)0));	\
+	if (likely(((n) >> 32) == 0)) {			\
+		__rem = (uint32_t)(n) % __base;		\
+		(n) = (uint32_t)(n) / __base;		\
+	} else						\
+		__rem = __div64_32(&(n), __base);	\
+	__rem;						\
+})
+
+#else /* BITS_PER_LONG == ?? */
+
+# error do_div() does not yet support the C64
+
+#endif /* BITS_PER_LONG */
+
+#endif /* _ASM_GENERIC_DIV64_H */
-- 
1.9.1