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Annotation of Gnu-Mach/linux/src/arch/i386/lib/delay.c, revision 1.1.1.1

1.1       root        1: /*
                      2:  *     Precise Delay Loops for i386
                      3:  *
                      4:  *     Copyright (C) 1993 Linus Torvalds
                      5:  *     Copyright (C) 1997 Martin Mares <[email protected]>
                      6:  *
                      7:  *     The __delay function must _NOT_ be inlined as its execution time
                      8:  *     depends wildly on alignment on many x86 processors. The additional
                      9:  *     jump magic is needed to get the timing stable on all the CPU's
                     10:  *     we have to worry about.
                     11:  */
                     12: 
                     13: #include <linux/sched.h>
                     14: #include <linux/delay.h>
                     15: 
                     16: #ifdef __SMP__
                     17: #include <asm/smp.h>
                     18: #endif
                     19: 
                     20: void __delay(unsigned long loops)
                     21: {
                     22:        int d0;
                     23:        __asm__ __volatile__(
                     24:                "\tjmp 1f\n"
                     25:                ".align 16\n"
                     26:                "1:\tjmp 2f\n"
                     27:                ".align 16\n"
                     28:                "2:\tdecl %0\n\tjns 2b"
                     29:                :"=&a" (d0)
                     30:                :"0" (loops));
                     31: }
                     32: 
                     33: inline void __const_udelay(unsigned long xloops)
                     34: {
                     35:        int d0;
                     36:        __asm__("mull %0"
                     37:                :"=d" (xloops), "=&a" (d0)
                     38:                :"1" (xloops),"0" (loops_per_sec));
                     39:         __delay(xloops);
                     40: }
                     41: 
                     42: void __udelay(unsigned long usecs)
                     43: {
                     44:        __const_udelay(usecs * 0x000010c6);  /* 2**32 / 1000000 */
                     45: }

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