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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fmsub.c (1161B)


      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#include <math-emu/double.h>
      9
     10int
     11fmsub(void *frD, void *frA, void *frB, void *frC)
     12{
     13	FP_DECL_D(R);
     14	FP_DECL_D(A);
     15	FP_DECL_D(B);
     16	FP_DECL_D(C);
     17	FP_DECL_D(T);
     18	FP_DECL_EX;
     19
     20#ifdef DEBUG
     21	printk("%s: %p %p %p %p\n", __func__, frD, frA, frB, frC);
     22#endif
     23
     24	FP_UNPACK_DP(A, frA);
     25	FP_UNPACK_DP(B, frB);
     26	FP_UNPACK_DP(C, frC);
     27
     28#ifdef DEBUG
     29	printk("A: %ld %lu %lu %ld (%ld)\n", A_s, A_f1, A_f0, A_e, A_c);
     30	printk("B: %ld %lu %lu %ld (%ld)\n", B_s, B_f1, B_f0, B_e, B_c);
     31	printk("C: %ld %lu %lu %ld (%ld)\n", C_s, C_f1, C_f0, C_e, C_c);
     32#endif
     33
     34	if ((A_c == FP_CLS_INF && C_c == FP_CLS_ZERO) ||
     35	    (A_c == FP_CLS_ZERO && C_c == FP_CLS_INF))
     36		FP_SET_EXCEPTION(EFLAG_VXIMZ);
     37
     38	FP_MUL_D(T, A, C);
     39
     40	if (B_c != FP_CLS_NAN)
     41		B_s ^= 1;
     42
     43	if (T_s != B_s && T_c == FP_CLS_INF && B_c == FP_CLS_INF)
     44		FP_SET_EXCEPTION(EFLAG_VXISI);
     45
     46	FP_ADD_D(R, T, B);
     47
     48#ifdef DEBUG
     49	printk("D: %ld %lu %lu %ld (%ld)\n", R_s, R_f1, R_f0, R_e, R_c);
     50#endif
     51
     52	__FP_PACK_D(frD, R);
     53
     54	return FP_CUR_EXCEPTIONS;
     55}