/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 1994 by Waldorf Electronics * Copyright (C) 1995 - 2000, 01, 03 by Ralf Baechle * Copyright (C) 1999, 2000 Silicon Graphics, Inc. * Copyright (C) 2007, 2014 Maciej W. Rozycki */ #include <linux/delay.h> #include <linux/export.h> #include <linux/param.h> #include <linux/smp.h> #include <linux/stringify.h> #include <asm/asm.h> #include <asm/compiler.h> #include <asm/war.h> #ifndef [31mCONFIG_CPU_DADDI_WORKAROUNDS[0m #define GCC_DADDI_IMM_ASM() "I" #else #define GCC_DADDI_IMM_ASM() "r" #endif void __delay(unsigned long loops) { __asm__ __volatile__ ( " .set noreorder \n" " .align 3 \n" "1: bnez %0, 1b \n" " " __stringify(LONG_SUBU) " %0, %1 \n" " .set reorder \n" : "=r" (loops) : GCC_DADDI_IMM_ASM() (1), "0" (loops)); } EXPORT_SYMBOL(__delay); /* * Division by multiplication: you don't have to worry about * loss of precision. * * Use only for very small delays ( < 1 msec). Should probably use a * lookup table, really, as the multiplications take much too long with * short delays. This is a "reasonable" implementation, though (and the * first constant multiplications gets optimized away if the delay is * a constant) */ void __udelay(unsigned long us) { unsigned int lpj = raw_current_cpu_data.udelay_val; __delay((us * 0x000010c7ull * HZ * lpj) >> 32); } EXPORT_SYMBOL(__udelay); void __ndelay(unsigned long ns) { unsigned int lpj = raw_current_cpu_data.udelay_val; __delay((ns * 0x00000005ull * HZ * lpj) >> 32); } EXPORT_SYMBOL(__ndelay); |