cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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delay.c (1714B)

      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
     20#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
     21#define GCC_DADDI_IMM_ASM() "I"
     22#else
     23#define GCC_DADDI_IMM_ASM() "r"
     24#endif
     25
     26#ifndef CONFIG_HAVE_PLAT_DELAY
     27
     28void __delay(unsigned long loops)
     29{
     30	__asm__ __volatile__ (
     31	"	.set	noreorder				\n"
     32	"	.align	3					\n"
     33	"1:	bnez	%0, 1b					\n"
     34	"	 " __stringify(LONG_SUBU) "	%0, %1		\n"
     35	"	.set	reorder					\n"
     36	: "=r" (loops)
     37	: GCC_DADDI_IMM_ASM() (1), "0" (loops));
     38}
     39EXPORT_SYMBOL(__delay);
     40
     41/*
     42 * Division by multiplication: you don't have to worry about
     43 * loss of precision.
     44 *
     45 * Use only for very small delays ( < 1 msec).	Should probably use a
     46 * lookup table, really, as the multiplications take much too long with
     47 * short delays.  This is a "reasonable" implementation, though (and the
     48 * first constant multiplications gets optimized away if the delay is
     49 * a constant)
     50 */
     51
     52void __udelay(unsigned long us)
     53{
     54	unsigned int lpj = raw_current_cpu_data.udelay_val;
     55
     56	__delay((us * 0x000010c7ull * HZ * lpj) >> 32);
     57}
     58EXPORT_SYMBOL(__udelay);
     59
     60void __ndelay(unsigned long ns)
     61{
     62	unsigned int lpj = raw_current_cpu_data.udelay_val;
     63
     64	__delay((ns * 0x00000005ull * HZ * lpj) >> 32);
     65}
     66EXPORT_SYMBOL(__ndelay);
     67
     68#endif