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linux-2.6/include/asm-mn10300/div64.h
David Howells b920de1b77 mn10300: add the MN10300/AM33 architecture to the kernel
Add architecture support for the MN10300/AM33 CPUs produced by MEI to the
kernel.

This patch also adds board support for the ASB2303 with the ASB2308 daughter
board, and the ASB2305.  The only processor supported is the MN103E010, which
is an AM33v2 core plus on-chip devices.

[akpm@linux-foundation.org: nuke cvs control strings]
Signed-off-by: Masakazu Urade <urade.masakazu@jp.panasonic.com>
Signed-off-by: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:30 -08:00

104 lines
2.8 KiB
C

/* MN10300 64-bit division
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#ifndef _ASM_DIV64
#define _ASM_DIV64
#include <linux/types.h>
extern void ____unhandled_size_in_do_div___(void);
/*
* divide n by base, leaving the result in n and returning the remainder
* - we can do this quite efficiently on the MN10300 by cascading the divides
* through the MDR register
*/
#define do_div(n, base) \
({ \
unsigned __rem = 0; \
if (sizeof(n) <= 4) { \
asm("mov %1,mdr \n" \
"divu %2,%0 \n" \
"mov mdr,%1 \n" \
: "+r"(n), "=d"(__rem) \
: "r"(base), "1"(__rem) \
: "cc" \
); \
} else if (sizeof(n) <= 8) { \
union { \
unsigned long long l; \
u32 w[2]; \
} __quot; \
__quot.l = n; \
asm("mov %0,mdr \n" /* MDR = 0 */ \
"divu %3,%1 \n" \
/* __quot.MSL = __div.MSL / base, */ \
/* MDR = MDR:__div.MSL % base */ \
"divu %3,%2 \n" \
/* __quot.LSL = MDR:__div.LSL / base, */ \
/* MDR = MDR:__div.LSL % base */ \
"mov mdr,%0 \n" \
: "=d"(__rem), "=r"(__quot.w[1]), "=r"(__quot.w[0]) \
: "r"(base), "0"(__rem), "1"(__quot.w[1]), \
"2"(__quot.w[0]) \
: "cc" \
); \
n = __quot.l; \
} else { \
____unhandled_size_in_do_div___(); \
} \
__rem; \
})
/*
* do an unsigned 32-bit multiply and divide with intermediate 64-bit product
* so as not to lose accuracy
* - we use the MDR register to hold the MSW of the product
*/
static inline __attribute__((const))
unsigned __muldiv64u(unsigned val, unsigned mult, unsigned div)
{
unsigned result;
asm("mulu %2,%0 \n" /* MDR:val = val*mult */
"divu %3,%0 \n" /* val = MDR:val/div;
* MDR = MDR:val%div */
: "=r"(result)
: "0"(val), "ir"(mult), "r"(div)
);
return result;
}
/*
* do a signed 32-bit multiply and divide with intermediate 64-bit product so
* as not to lose accuracy
* - we use the MDR register to hold the MSW of the product
*/
static inline __attribute__((const))
signed __muldiv64s(signed val, signed mult, signed div)
{
signed result;
asm("mul %2,%0 \n" /* MDR:val = val*mult */
"div %3,%0 \n" /* val = MDR:val/div;
* MDR = MDR:val%div */
: "=r"(result)
: "0"(val), "ir"(mult), "r"(div)
);
return result;
}
extern __attribute__((const))
uint64_t div64_64(uint64_t dividend, uint64_t divisor);
#endif /* _ASM_DIV64 */