diff options
Diffstat (limited to 'arch/mips/lib/delay.c')
-rw-r--r-- | arch/mips/lib/delay.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/arch/mips/lib/delay.c b/arch/mips/lib/delay.c new file mode 100644 index 000000000..2e8dfc1d5 --- /dev/null +++ b/arch/mips/lib/delay.c | |||
@@ -0,0 +1,69 @@ | |||
1 | /* | ||
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 | ||
4 | * for more details. | ||
5 | * | ||
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 | ||
10 | */ | ||
11 | #include <linux/delay.h> | ||
12 | #include <linux/export.h> | ||
13 | #include <linux/param.h> | ||
14 | #include <linux/smp.h> | ||
15 | #include <linux/stringify.h> | ||
16 | |||
17 | #include <asm/asm.h> | ||
18 | #include <asm/compiler.h> | ||
19 | #include <asm/war.h> | ||
20 | |||
21 | #ifndef CONFIG_CPU_DADDI_WORKAROUNDS | ||
22 | #define GCC_DADDI_IMM_ASM() "I" | ||
23 | #else | ||
24 | #define GCC_DADDI_IMM_ASM() "r" | ||
25 | #endif | ||
26 | |||
27 | #ifndef CONFIG_HAVE_PLAT_DELAY | ||
28 | |||
29 | void __delay(unsigned long loops) | ||
30 | { | ||
31 | __asm__ __volatile__ ( | ||
32 | " .set noreorder \n" | ||
33 | " .align 3 \n" | ||
34 | "1: bnez %0, 1b \n" | ||
35 | " " __stringify(LONG_SUBU) " %0, %1 \n" | ||
36 | " .set reorder \n" | ||
37 | : "=r" (loops) | ||
38 | : GCC_DADDI_IMM_ASM() (1), "0" (loops)); | ||
39 | } | ||
40 | EXPORT_SYMBOL(__delay); | ||
41 | |||
42 | /* | ||
43 | * Division by multiplication: you don't have to worry about | ||
44 | * loss of precision. | ||
45 | * | ||
46 | * Use only for very small delays ( < 1 msec). Should probably use a | ||
47 | * lookup table, really, as the multiplications take much too long with | ||
48 | * short delays. This is a "reasonable" implementation, though (and the | ||
49 | * first constant multiplications gets optimized away if the delay is | ||
50 | * a constant) | ||
51 | */ | ||
52 | |||
53 | void __udelay(unsigned long us) | ||
54 | { | ||
55 | unsigned int lpj = raw_current_cpu_data.udelay_val; | ||
56 | |||
57 | __delay((us * 0x000010c7ull * HZ * lpj) >> 32); | ||
58 | } | ||
59 | EXPORT_SYMBOL(__udelay); | ||
60 | |||
61 | void __ndelay(unsigned long ns) | ||
62 | { | ||
63 | unsigned int lpj = raw_current_cpu_data.udelay_val; | ||
64 | |||
65 | __delay((ns * 0x00000005ull * HZ * lpj) >> 32); | ||
66 | } | ||
67 | EXPORT_SYMBOL(__ndelay); | ||
68 | |||
69 | #endif | ||