cregit-Linux how code gets into the kernel

Release 4.14 arch/parisc/math-emu/driver.c

/*
 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
 *
 * Floating-point emulation code
 *  Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
/*
 *  linux/arch/math-emu/driver.c.c
 *
 *      decodes and dispatches unimplemented FPU instructions
 *
 *  Copyright (C) 1999, 2000  Philipp Rumpf <prumpf@tux.org>
 *  Copyright (C) 2001        Hewlett-Packard <bame@debian.org>
 */

#include <linux/sched/signal.h>

#include "float.h"
#include "math-emu.h"



#define fptpos 31

#define fpr1pos 10

#define extru(r,pos,len) (((r) >> (31-(pos))) & (( 1 << (len)) - 1))


#define FPUDEBUG 0

/* Format of the floating-point exception registers. */

struct exc_reg {
	
unsigned int exception : 6;
	
unsigned int ei : 26;
};

/* Macros for grabbing bits of the instruction format from the 'ei'
   field above. */
/* Major opcode 0c and 0e */

#define FP0CE_UID(i) (((i) >> 6) & 3)

#define FP0CE_CLASS(i) (((i) >> 9) & 3)

#define FP0CE_SUBOP(i) (((i) >> 13) & 7)

#define FP0CE_SUBOP1(i) (((i) >> 15) & 7) 
/* Class 1 subopcode */

#define FP0C_FORMAT(i) (((i) >> 11) & 3)

#define FP0E_FORMAT(i) (((i) >> 11) & 1)

/* Major opcode 0c, uid 2 (performance monitoring) */

#define FPPM_SUBOP(i) (((i) >> 9) & 0x1f)

/* Major opcode 2e (fused operations).   */

#define FP2E_SUBOP(i)  (((i) >> 5) & 1)

#define FP2E_FORMAT(i) (((i) >> 11) & 1)

/* Major opcode 26 (FMPYSUB) */
/* Major opcode 06 (FMPYADD) */

#define FPx6_FORMAT(i) ((i) & 0x1f)

/* Flags and enable bits of the status word. */

#define FPSW_FLAGS(w) ((w) >> 27)

#define FPSW_ENABLE(w) ((w) & 0x1f)

#define FPSW_V (1<<4)

#define FPSW_Z (1<<3)

#define FPSW_O (1<<2)

#define FPSW_U (1<<1)

#define FPSW_I (1<<0)

/* Handle a floating point exception.  Return zero if the faulting
   instruction can be completed successfully. */

int handle_fpe(struct pt_regs *regs) { extern void printbinary(unsigned long x, int nbits); struct siginfo si; unsigned int orig_sw, sw; int signalcode; /* need an intermediate copy of float regs because FPU emulation * code expects an artificial last entry which contains zero * * also, the passed in fr registers contain one word that defines * the fpu type. the fpu type information is constructed * inside the emulation code */ __u64 frcopy[36]; memcpy(frcopy, regs->fr, sizeof regs->fr); frcopy[32] = 0; memcpy(&orig_sw, frcopy, sizeof(orig_sw)); if (FPUDEBUG) { printk(KERN_DEBUG "FP VZOUICxxxxCQCQCQCQCQCRMxxTDVZOUI ->\n "); printbinary(orig_sw, 32); printk(KERN_DEBUG "\n"); } signalcode = decode_fpu(frcopy, 0x666); /* Status word = FR0L. */ memcpy(&sw, frcopy, sizeof(sw)); if (FPUDEBUG) { printk(KERN_DEBUG "VZOUICxxxxCQCQCQCQCQCRMxxTDVZOUI decode_fpu returns %d|0x%x\n", signalcode >> 24, signalcode & 0xffffff); printbinary(sw, 32); printk(KERN_DEBUG "\n"); } memcpy(regs->fr, frcopy, sizeof regs->fr); if (signalcode != 0) { si.si_signo = signalcode >> 24; si.si_errno = 0; si.si_code = signalcode & 0xffffff; si.si_addr = (void __user *) regs->iaoq[0]; force_sig_info(si.si_signo, &si, current); return -1; } return signalcode ? -1 : 0; }

Contributors

PersonTokensPropCommitsCommitProp
Matthew Wilcox241100.00%3100.00%
Total241100.00%3100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Matthew Wilcox40599.75%480.00%
Ingo Molnar10.25%120.00%
Total406100.00%5100.00%
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