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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mcrfs.c (620B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include <linux/types.h>
      3#include <linux/errno.h>
      4#include <linux/uaccess.h>
      5
      6#include <asm/sfp-machine.h>
      7#include <math-emu/soft-fp.h>
      8
      9int
     10mcrfs(u32 *ccr, u32 crfD, u32 crfS)
     11{
     12	u32 value, clear;
     13
     14#ifdef DEBUG
     15	printk("%s: %p (%08x) %d %d\n", __func__, ccr, *ccr, crfD, crfS);
     16#endif
     17
     18	clear = 15 << ((7 - crfS) << 2);
     19	if (!crfS)
     20		clear = 0x90000000;
     21
     22	value = (__FPU_FPSCR >> ((7 - crfS) << 2)) & 15;
     23	__FPU_FPSCR &= ~(clear);
     24
     25	*ccr &= ~(15 << ((7 - crfD) << 2));
     26	*ccr |= (value << ((7 - crfD) << 2));
     27
     28#ifdef DEBUG
     29	printk("CR: %08x\n", __func__, *ccr);
     30#endif
     31
     32	return 0;
     33}