2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 1994 by Waldorf Electronics
7 * Copyright (C) 1995 - 2000, 01, 03 by Ralf Baechle
8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
9 * Copyright (C) 2007, 2014 Maciej W. Rozycki
11 #include <linux/module.h>
12 #include <linux/param.h>
13 #include <linux/smp.h>
14 #include <linux/stringify.h>
17 #include <asm/compiler.h>
20 #ifndef CONFIG_CPU_DADDI_WORKAROUNDS
21 #define GCC_DADDI_IMM_ASM() "I"
23 #define GCC_DADDI_IMM_ASM() "r"
26 void __delay(unsigned long loops
)
28 __asm__
__volatile__ (
32 " " __stringify(LONG_SUBU
) " %0, %1 \n"
35 : GCC_DADDI_IMM_ASM() (1), "0" (loops
));
37 EXPORT_SYMBOL(__delay
);
40 * Division by multiplication: you don't have to worry about
43 * Use only for very small delays ( < 1 msec). Should probably use a
44 * lookup table, really, as the multiplications take much too long with
45 * short delays. This is a "reasonable" implementation, though (and the
46 * first constant multiplications gets optimized away if the delay is
50 void __udelay(unsigned long us
)
52 unsigned int lpj
= raw_current_cpu_data
.udelay_val
;
54 __delay((us
* 0x000010c7ull
* HZ
* lpj
) >> 32);
56 EXPORT_SYMBOL(__udelay
);
58 void __ndelay(unsigned long ns
)
60 unsigned int lpj
= raw_current_cpu_data
.udelay_val
;
62 __delay((ns
* 0x00000005ull
* HZ
* lpj
) >> 32);
64 EXPORT_SYMBOL(__ndelay
);