mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-30 16:13:54 +08:00
d5e181f78a
iter_div_u64_rem is used in the x86-64 vdso, which cannot call other kernel code. For this case, provide the always_inlined version, __iter_div_u64_rem. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
111 lines
2.3 KiB
C
111 lines
2.3 KiB
C
/*
|
|
* Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com>
|
|
*
|
|
* Based on former do_div() implementation from asm-parisc/div64.h:
|
|
* Copyright (C) 1999 Hewlett-Packard Co
|
|
* Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
|
|
*
|
|
*
|
|
* Generic C version of 64bit/32bit division and modulo, with
|
|
* 64bit result and 32bit remainder.
|
|
*
|
|
* The fast case for (n>>32 == 0) is handled inline by do_div().
|
|
*
|
|
* Code generated for this function might be very inefficient
|
|
* for some CPUs. __div64_32() can be overridden by linking arch-specific
|
|
* assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/math64.h>
|
|
|
|
/* Not needed on 64bit architectures */
|
|
#if BITS_PER_LONG == 32
|
|
|
|
uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base)
|
|
{
|
|
uint64_t rem = *n;
|
|
uint64_t b = base;
|
|
uint64_t res, d = 1;
|
|
uint32_t high = rem >> 32;
|
|
|
|
/* Reduce the thing a bit first */
|
|
res = 0;
|
|
if (high >= base) {
|
|
high /= base;
|
|
res = (uint64_t) high << 32;
|
|
rem -= (uint64_t) (high*base) << 32;
|
|
}
|
|
|
|
while ((int64_t)b > 0 && b < rem) {
|
|
b = b+b;
|
|
d = d+d;
|
|
}
|
|
|
|
do {
|
|
if (rem >= b) {
|
|
rem -= b;
|
|
res += d;
|
|
}
|
|
b >>= 1;
|
|
d >>= 1;
|
|
} while (d);
|
|
|
|
*n = res;
|
|
return rem;
|
|
}
|
|
|
|
EXPORT_SYMBOL(__div64_32);
|
|
|
|
#ifndef div_s64_rem
|
|
s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
|
|
{
|
|
u64 quotient;
|
|
|
|
if (dividend < 0) {
|
|
quotient = div_u64_rem(-dividend, abs(divisor), (u32 *)remainder);
|
|
*remainder = -*remainder;
|
|
if (divisor > 0)
|
|
quotient = -quotient;
|
|
} else {
|
|
quotient = div_u64_rem(dividend, abs(divisor), (u32 *)remainder);
|
|
if (divisor < 0)
|
|
quotient = -quotient;
|
|
}
|
|
return quotient;
|
|
}
|
|
EXPORT_SYMBOL(div_s64_rem);
|
|
#endif
|
|
|
|
/* 64bit divisor, dividend and result. dynamic precision */
|
|
#ifndef div64_u64
|
|
u64 div64_u64(u64 dividend, u64 divisor)
|
|
{
|
|
u32 high, d;
|
|
|
|
high = divisor >> 32;
|
|
if (high) {
|
|
unsigned int shift = fls(high);
|
|
|
|
d = divisor >> shift;
|
|
dividend >>= shift;
|
|
} else
|
|
d = divisor;
|
|
|
|
return div_u64(dividend, d);
|
|
}
|
|
EXPORT_SYMBOL(div64_u64);
|
|
#endif
|
|
|
|
#endif /* BITS_PER_LONG == 32 */
|
|
|
|
/*
|
|
* Iterative div/mod for use when dividend is not expected to be much
|
|
* bigger than divisor.
|
|
*/
|
|
u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder)
|
|
{
|
|
return __iter_div_u64_rem(dividend, divisor, remainder);
|
|
}
|
|
EXPORT_SYMBOL(iter_div_u64_rem);
|