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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clk-utils.c (733B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (c) 2018, NVIDIA CORPORATION.  All rights reserved.
      4 */
      5
      6#include <asm/div64.h>
      7
      8#include "clk.h"
      9
     10#define div_mask(w) ((1 << (w)) - 1)
     11
     12int div_frac_get(unsigned long rate, unsigned parent_rate, u8 width,
     13		 u8 frac_width, u8 flags)
     14{
     15	u64 divider_ux1 = parent_rate;
     16	int mul;
     17
     18	if (!rate)
     19		return 0;
     20
     21	mul = 1 << frac_width;
     22
     23	if (!(flags & TEGRA_DIVIDER_INT))
     24		divider_ux1 *= mul;
     25
     26	if (flags & TEGRA_DIVIDER_ROUND_UP)
     27		divider_ux1 += rate - 1;
     28
     29	do_div(divider_ux1, rate);
     30
     31	if (flags & TEGRA_DIVIDER_INT)
     32		divider_ux1 *= mul;
     33
     34	if (divider_ux1 < mul)
     35		return 0;
     36
     37	divider_ux1 -= mul;
     38
     39	if (divider_ux1 > div_mask(width))
     40		return div_mask(width);
     41
     42	return divider_ux1;
     43}