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

Wills Wang
2015-12-25T18:56:21Z

Use the div64 header files from the kernel.

Signed-off-by: Wills Wang <wills.wang@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@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