| 1 | |
| 2 | * This file is subject to the terms and conditions of the GNU General Public
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| 3 | * License. See the file "COPYING" in the main directory of this archive
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| 4 | * for more details.
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| 5 | *
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| 6 | * Copyright (C) 1994 by Waldorf Electronics
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| 7 | * Copyright (C) 1995 - 2000, 01, 03 by Ralf Baechle
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| 8 | * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
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| 9 | * Copyright (C) 2007, 2014 Maciej W. Rozycki
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| 10 |
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| 11 | #include <linux/delay.h>
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| 12 | #include <linux/export.h>
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| 13 | #include <linux/param.h>
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| 14 | #include <linux/smp.h>
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| 15 | #include <linux/stringify.h>
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| 16 |
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| 17 | #include <asm/asm.h>
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| 18 | #include <asm/compiler.h>
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| 19 |
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| 20 | #ifndef CONFIG_CPU_DADDI_WORKAROUNDS
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| 21 | #define GCC_DADDI_IMM_ASM() "I"
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| 22 | #else
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| 23 | #define GCC_DADDI_IMM_ASM() "r"
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| 24 | #endif
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| 25 |
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| 26 | #ifndef CONFIG_HAVE_PLAT_DELAY
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| 27 |
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| 28 | void __delay(unsigned long loops)
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| 29 | {
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| 30 | __asm__ __volatile__ (
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| 31 | " .set noreorder \n"
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| 32 | " .align 3 \n"
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| 33 | "1: bnez %0, 1b \n"
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| 34 | " " __stringify(LONG_SUBU) " %0, %1 \n"
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| 35 | " .set reorder \n"
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| 36 | : "=r" (loops)
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| 37 | : GCC_DADDI_IMM_ASM() (1), "0" (loops));
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| 38 | }
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| 39 | EXPORT_SYMBOL(__delay);
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| 40 |
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| 41 | |
| 42 | * Division by multiplication: you don't have to worry about
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| 43 | * loss of precision.
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| 44 | *
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| 45 | * Use only for very small delays ( < 1 msec). Should probably use a
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| 46 | * lookup table, really, as the multiplications take much too long with
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| 47 | * short delays. This is a "reasonable" implementation, though (and the
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| 48 | * first constant multiplications gets optimized away if the delay is
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| 49 | * a constant)
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| 50 |
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| 51 |
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| 52 | void __udelay(unsigned long us)
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| 53 | {
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| 54 | unsigned int lpj = raw_current_cpu_data.udelay_val;
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| 55 |
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| 56 | __delay((us * 0x000010c7ull * HZ * lpj) >> 32);
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| 57 | }
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| 58 | EXPORT_SYMBOL(__udelay);
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| 59 |
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| 60 | void __ndelay(unsigned long ns)
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| 61 | {
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| 62 | unsigned int lpj = raw_current_cpu_data.udelay_val;
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| 63 |
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| 64 | __delay((ns * 0x00000005ull * HZ * lpj) >> 32);
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| 65 | }
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| 66 | EXPORT_SYMBOL(__ndelay);
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| 67 |
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| 68 | #endif
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