Re: [RFC] div64_64 support

From: Stephen Hemminger
Date: Mon Feb 26 2007 - 14:29:56 EST


asm-i386.h/div64 and div64.o needs to move in Makefile to get this to work
on i386.



---
include/asm-arm/div64.h | 2 ++
include/asm-generic/div64.h | 8 ++++++++
include/asm-i386/div64.h | 5 +++++
include/asm-m68k/div64.h | 2 ++
include/asm-mips/div64.h | 8 ++++++++
include/asm-um/div64.h | 1 +
include/asm-xtensa/div64.h | 1 +
lib/Makefile | 5 +++--
lib/div64.c | 23 +++++++++++++++++++++++
net/ipv4/tcp_cubic.c | 22 ----------------------
net/netfilter/xt_connbytes.c | 16 ----------------
11 files changed, 53 insertions(+), 40 deletions(-)

--- sky2.orig/include/asm-arm/div64.h 2007-02-26 10:17:33.000000000 -0800
+++ sky2/include/asm-arm/div64.h 2007-02-26 10:17:50.000000000 -0800
@@ -221,6 +221,8 @@
__nr; \
})

+extern uint64_t div64_64(uint64_t dividend, uint64_t divisor);
+
#endif

#endif
--- sky2.orig/include/asm-generic/div64.h 2007-02-26 10:17:33.000000000 -0800
+++ sky2/include/asm-generic/div64.h 2007-02-26 10:17:50.000000000 -0800
@@ -30,9 +30,17 @@
__rem; \
})

+/*
+ * div64_64 - Divide two 64 bit numbers
+ */
+static inline uint64_t div64_64(uint64_t dividend, uint64_t divisor)
+{
+ return dividend / divisor;
+}
#elif BITS_PER_LONG == 32

extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor);
+extern uint64_t div64_64(uint64_t dividend, uint64_t divisor);

/* The unnecessary pointer compare is there
* to check for type safety (n must be 64bit)
--- sky2.orig/include/asm-m68k/div64.h 2007-02-26 10:17:33.000000000 -0800
+++ sky2/include/asm-m68k/div64.h 2007-02-26 10:17:50.000000000 -0800
@@ -23,4 +23,6 @@
__rem; \
})

+extern uint64_t div64_64(uint64_t dividend, uint64_t divisor);
+
#endif /* _M68K_DIV64_H */
--- sky2.orig/include/asm-mips/div64.h 2007-02-26 10:17:33.000000000 -0800
+++ sky2/include/asm-mips/div64.h 2007-02-26 10:17:50.000000000 -0800
@@ -78,6 +78,9 @@
__quot = __quot << 32 | __low; \
(n) = __quot; \
__mod; })
+
+extern uint64_t div64_64(uint64_t dividend, uint64_t divisor);
+
#endif /* (_MIPS_SZLONG == 32) */

#if (_MIPS_SZLONG == 64)
@@ -101,6 +104,11 @@
(n) = __quot; \
__mod; })

+static inline uint64_t div64_64(uint64_t dividend, uint64_t divisor)
+{
+ return dividend / divisor;
+}
+
#endif /* (_MIPS_SZLONG == 64) */

#endif /* _ASM_DIV64_H */
--- sky2.orig/include/asm-um/div64.h 2007-02-26 10:17:33.000000000 -0800
+++ sky2/include/asm-um/div64.h 2007-02-26 10:17:50.000000000 -0800
@@ -3,4 +3,5 @@

#include "asm/arch/div64.h"

+extern uint64_t div64_64(uint64_t dividend, uint64_t divisor);
#endif
--- sky2.orig/include/asm-xtensa/div64.h 2007-02-26 10:17:33.000000000 -0800
+++ sky2/include/asm-xtensa/div64.h 2007-02-26 10:17:50.000000000 -0800
@@ -16,4 +16,5 @@
n /= (unsigned int) base; \
__res; })

+extern uint64_t div64_64(uint64_t dividend, uint64_t divisor);
#endif
--- sky2.orig/lib/div64.c 2007-02-26 10:17:33.000000000 -0800
+++ sky2/lib/div64.c 2007-02-26 10:31:49.000000000 -0800
@@ -18,6 +18,7 @@

#include <linux/types.h>
#include <linux/module.h>
+#include <asm/bitops.h>
#include <asm/div64.h>

/* Not needed on 64bit architectures */
@@ -58,4 +59,26 @@

EXPORT_SYMBOL(__div64_32);

+/* Use scaling to do a full 64 bit division */
+uint64_t div64_64(uint64_t dividend, uint64_t divisor)
+{
+ uint32_t d = divisor;
+
+ if (divisor > 0xffffffffULL) {
+ unsigned int shift = fls(divisor >> 32);
+
+ d = divisor >> shift;
+ dividend >>= shift;
+ }
+
+ /* avoid 64 bit division if possible */
+ if (dividend >> 32)
+ do_div(dividend, d);
+ else
+ dividend = (uint32_t) dividend / d;
+
+ return dividend;
+}
+EXPORT_SYMBOL(div64_64);
+
#endif /* BITS_PER_LONG == 32 */
--- sky2.orig/net/ipv4/tcp_cubic.c 2007-02-26 10:17:33.000000000 -0800
+++ sky2/net/ipv4/tcp_cubic.c 2007-02-26 10:17:50.000000000 -0800
@@ -51,7 +51,6 @@
module_param(tcp_friendliness, int, 0644);
MODULE_PARM_DESC(tcp_friendliness, "turn on/off tcp friendliness");

-#include <asm/div64.h>

/* BIC TCP Parameters */
struct bictcp {
@@ -93,27 +92,6 @@
tcp_sk(sk)->snd_ssthresh = initial_ssthresh;
}

-/* 64bit divisor, dividend and result. dynamic precision */
-static inline u_int64_t div64_64(u_int64_t dividend, u_int64_t divisor)
-{
- u_int32_t d = divisor;
-
- if (divisor > 0xffffffffULL) {
- unsigned int shift = fls(divisor >> 32);
-
- d = divisor >> shift;
- dividend >>= shift;
- }
-
- /* avoid 64 bit division if possible */
- if (dividend >> 32)
- do_div(dividend, d);
- else
- dividend = (uint32_t) dividend / d;
-
- return dividend;
-}
-
/*
* calculate the cubic root of x using Newton-Raphson
*/
--- sky2.orig/net/netfilter/xt_connbytes.c 2007-02-26 10:17:33.000000000 -0800
+++ sky2/net/netfilter/xt_connbytes.c 2007-02-26 10:17:50.000000000 -0800
@@ -24,22 +24,6 @@
MODULE_DESCRIPTION("iptables match for matching number of pkts/bytes per connection");
MODULE_ALIAS("ipt_connbytes");

-/* 64bit divisor, dividend and result. dynamic precision */
-static u_int64_t div64_64(u_int64_t dividend, u_int64_t divisor)
-{
- u_int32_t d = divisor;
-
- if (divisor > 0xffffffffULL) {
- unsigned int shift = fls(divisor >> 32);
-
- d = divisor >> shift;
- dividend >>= shift;
- }
-
- do_div(dividend, d);
- return dividend;
-}
-
static int
match(const struct sk_buff *skb,
const struct net_device *in,
--- sky2.orig/include/asm-i386/div64.h 2007-02-26 10:36:29.000000000 -0800
+++ sky2/include/asm-i386/div64.h 2007-02-26 11:07:47.000000000 -0800
@@ -1,6 +1,8 @@
#ifndef __I386_DIV64
#define __I386_DIV64

+#include <linux/types.h>
+
/*
* do_div() is NOT a C function. It wants to return
* two values (the quotient and the remainder), but
@@ -45,4 +47,7 @@
return dum2;

}
+
+extern uint64_t div64_64(uint64_t dividend, uint64_t divisor);
+
#endif
--- sky2.orig/lib/Makefile 2007-02-26 11:24:48.000000000 -0800
+++ sky2/lib/Makefile 2007-02-26 11:26:57.000000000 -0800
@@ -4,7 +4,7 @@

lib-y := ctype.o string.o vsprintf.o cmdline.o \
rbtree.o radix-tree.o dump_stack.o \
- idr.o div64.o int_sqrt.o bitmap.o extable.o prio_tree.o \
+ idr.o int_sqrt.o bitmap.o extable.o prio_tree.o \
sha1.o irq_regs.o reciprocal_div.o

lib-$(CONFIG_MMU) += ioremap.o
@@ -12,7 +12,8 @@

lib-y += kobject.o kref.o kobject_uevent.o klist.o

-obj-y += sort.o parser.o halfmd4.o debug_locks.o random32.o bust_spinlocks.o
+obj-y += sort.o parser.o div64.o halfmd4.o debug_locks.o random32.o \
+ bust_spinlocks.o

ifeq ($(CONFIG_DEBUG_KOBJECT),y)
CFLAGS_kobject.o += -DDEBUG
-
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