[444] | 1 | /* |
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| 2 | * Copyright (c) 2011 Aeroflex Gaisler |
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| 3 | * |
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| 4 | * BSD license: |
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| 5 | * |
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| 6 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
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| 7 | * of this software and associated documentation files (the "Software"), to deal |
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| 8 | * in the Software without restriction, including without limitation the rights |
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| 9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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| 10 | * copies of the Software, and to permit persons to whom the Software is |
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| 11 | * furnished to do so, subject to the following conditions: |
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| 12 | * |
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| 13 | * The above copyright notice and this permission notice shall be included in |
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| 14 | * all copies or substantial portions of the Software. |
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| 15 | * |
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| 16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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| 17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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| 18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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| 19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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| 20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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| 21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
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| 22 | * THE SOFTWARE. |
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| 23 | */ |
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| 24 | |
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| 25 | |
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| 26 | #ifndef _LINUX_JIFFIES_H |
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| 27 | #define _LINUX_JIFFIES_H |
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| 28 | |
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| 29 | #include <asm-leon/types.h> |
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| 30 | #include <asm-leon/clock.h> |
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| 31 | #include <asm-leon/linkage.h> |
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| 32 | |
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| 33 | /* Suppose we want to devide two numbers NOM and DEN: NOM/DEN, the we can |
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| 34 | * improve accuracy by shifting LSH bits, hence calculating: |
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| 35 | * (NOM << LSH) / DEN |
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| 36 | * This however means trouble for large NOM, because (NOM << LSH) may no |
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| 37 | * longer fit in 32 bits. The following way of calculating this gives us |
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| 38 | * some slack, under the following conditions: |
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| 39 | * - (NOM / DEN) fits in (32 - LSH) bits. |
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| 40 | * - (NOM % DEN) fits in (32 - LSH) bits. |
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| 41 | */ |
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| 42 | #define SH_DIV(NOM,DEN,LSH) ( ((NOM / DEN) << LSH) \ |
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| 43 | + (((NOM % DEN) << LSH) + DEN / 2) / DEN) |
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| 44 | |
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| 45 | /* TICK_NSEC is the time between ticks in nsec assuming real ACTHZ */ |
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| 46 | #define TICK_NSEC (SH_DIV (1000000UL * 1000, (HZ<<8), 8)) |
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| 47 | |
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| 48 | /* |
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| 49 | * The 64-bit value is not volatile - you MUST NOT read it |
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| 50 | * without sampling the sequence number in xtime_lock. |
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| 51 | */ |
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| 52 | extern u64 jiffies_64; |
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| 53 | extern struct timespec xtime __attribute__ ((aligned (16))); |
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| 54 | #define jiffies (*((unsigned long *)(((unsigned long)(&jiffies_64))+4))) |
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| 55 | |
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| 56 | /* |
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| 57 | * These inlines deal with timer wrapping correctly. You are |
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| 58 | * strongly encouraged to use them |
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| 59 | * 1. Because people otherwise forget |
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| 60 | * 2. Because if the timer wrap changes in future you won't have to |
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| 61 | * alter your driver code. |
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| 62 | * |
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| 63 | * time_after(a,b) returns true if the time a is after time b. |
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| 64 | * |
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| 65 | * Do this with "<0" and ">=0" to only test the sign of the result. A |
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| 66 | * good compiler would generate better code (and a really good compiler |
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| 67 | * wouldn't care). Gcc is currently neither. |
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| 68 | */ |
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| 69 | #define time_after(a,b) \ |
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| 70 | (typecheck(unsigned long, a) && \ |
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| 71 | typecheck(unsigned long, b) && \ |
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| 72 | ((long)(b) - (long)(a) < 0)) |
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| 73 | #define time_before(a,b) time_after(b,a) |
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| 74 | |
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| 75 | #define time_after_eq(a,b) \ |
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| 76 | (typecheck(unsigned long, a) && \ |
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| 77 | typecheck(unsigned long, b) && \ |
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| 78 | ((long)(a) - (long)(b) >= 0)) |
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| 79 | #define time_before_eq(a,b) time_after_eq(b,a) |
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| 80 | |
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| 81 | /* |
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| 82 | * Have the 32 bit jiffies value wrap 5 minutes after boot |
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| 83 | * so jiffies wrap bugs show up earlier. |
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| 84 | */ |
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| 85 | #define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ)) |
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| 86 | |
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| 87 | static inline void |
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| 88 | set_normalized_timespec (struct timespec *ts, time_t sec, long nsec) |
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| 89 | { |
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| 90 | while (nsec > NSEC_PER_SEC) |
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| 91 | { |
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| 92 | nsec -= NSEC_PER_SEC; |
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| 93 | ++sec; |
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| 94 | } |
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| 95 | while (nsec < 0) |
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| 96 | { |
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| 97 | nsec += NSEC_PER_SEC; |
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| 98 | --sec; |
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| 99 | } |
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| 100 | ts->tv_sec = sec; |
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| 101 | ts->tv_nsec = nsec; |
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| 102 | } |
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| 103 | |
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| 104 | #endif |
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