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

https://github.com/aicjofs/android_kernel_lge_v500_20d_f2fs
C | 128 lines | 63 code | 18 blank | 47 comment | 4 complexity | edc9feb7930fee290779e24b91ad80cb MD5 | raw file
  1/*
  2 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
  3 *
  4 * Floating-point emulation code
  5 *  Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
  6 *
  7 *    This program is free software; you can redistribute it and/or modify
  8 *    it under the terms of the GNU General Public License as published by
  9 *    the Free Software Foundation; either version 2, or (at your option)
 10 *    any later version.
 11 *
 12 *    This program is distributed in the hope that it will be useful,
 13 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 14 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15 *    GNU General Public License for more details.
 16 *
 17 *    You should have received a copy of the GNU General Public License
 18 *    along with this program; if not, write to the Free Software
 19 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 20 */
 21/*
 22 *  linux/arch/math-emu/driver.c.c
 23 *
 24 *	decodes and dispatches unimplemented FPU instructions
 25 *
 26 *  Copyright (C) 1999, 2000  Philipp Rumpf <prumpf@tux.org>
 27 *  Copyright (C) 2001	      Hewlett-Packard <bame@debian.org>
 28 */
 29
 30#include <linux/sched.h>
 31#include "float.h"
 32#include "math-emu.h"
 33
 34
 35#define fptpos 31
 36#define fpr1pos 10
 37#define extru(r,pos,len) (((r) >> (31-(pos))) & (( 1 << (len)) - 1))
 38
 39#define FPUDEBUG 0
 40
 41/* Format of the floating-point exception registers. */
 42struct exc_reg {
 43	unsigned int exception : 6;
 44	unsigned int ei : 26;
 45};
 46
 47/* Macros for grabbing bits of the instruction format from the 'ei'
 48   field above. */
 49/* Major opcode 0c and 0e */
 50#define FP0CE_UID(i) (((i) >> 6) & 3)
 51#define FP0CE_CLASS(i) (((i) >> 9) & 3)
 52#define FP0CE_SUBOP(i) (((i) >> 13) & 7)
 53#define FP0CE_SUBOP1(i) (((i) >> 15) & 7) /* Class 1 subopcode */
 54#define FP0C_FORMAT(i) (((i) >> 11) & 3)
 55#define FP0E_FORMAT(i) (((i) >> 11) & 1)
 56
 57/* Major opcode 0c, uid 2 (performance monitoring) */
 58#define FPPM_SUBOP(i) (((i) >> 9) & 0x1f)
 59
 60/* Major opcode 2e (fused operations).   */
 61#define FP2E_SUBOP(i)  (((i) >> 5) & 1)
 62#define FP2E_FORMAT(i) (((i) >> 11) & 1)
 63
 64/* Major opcode 26 (FMPYSUB) */
 65/* Major opcode 06 (FMPYADD) */
 66#define FPx6_FORMAT(i) ((i) & 0x1f)
 67
 68/* Flags and enable bits of the status word. */
 69#define FPSW_FLAGS(w) ((w) >> 27)
 70#define FPSW_ENABLE(w) ((w) & 0x1f)
 71#define FPSW_V (1<<4)
 72#define FPSW_Z (1<<3)
 73#define FPSW_O (1<<2)
 74#define FPSW_U (1<<1)
 75#define FPSW_I (1<<0)
 76
 77/* Handle a floating point exception.  Return zero if the faulting
 78   instruction can be completed successfully. */
 79int
 80handle_fpe(struct pt_regs *regs)
 81{
 82	extern void printbinary(unsigned long x, int nbits);
 83	struct siginfo si;
 84	unsigned int orig_sw, sw;
 85	int signalcode;
 86	/* need an intermediate copy of float regs because FPU emulation
 87	 * code expects an artificial last entry which contains zero
 88	 *
 89	 * also, the passed in fr registers contain one word that defines
 90	 * the fpu type. the fpu type information is constructed 
 91	 * inside the emulation code
 92	 */
 93	__u64 frcopy[36];
 94
 95	memcpy(frcopy, regs->fr, sizeof regs->fr);
 96	frcopy[32] = 0;
 97
 98	memcpy(&orig_sw, frcopy, sizeof(orig_sw));
 99
100	if (FPUDEBUG) {
101		printk(KERN_DEBUG "FP VZOUICxxxxCQCQCQCQCQCRMxxTDVZOUI ->\n   ");
102		printbinary(orig_sw, 32);
103		printk(KERN_DEBUG "\n");
104	}
105
106	signalcode = decode_fpu(frcopy, 0x666);
107
108	/* Status word = FR0L. */
109	memcpy(&sw, frcopy, sizeof(sw));
110	if (FPUDEBUG) {
111		printk(KERN_DEBUG "VZOUICxxxxCQCQCQCQCQCRMxxTDVZOUI decode_fpu returns %d|0x%x\n",
112			signalcode >> 24, signalcode & 0xffffff);
113		printbinary(sw, 32);
114		printk(KERN_DEBUG "\n");
115	}
116
117	memcpy(regs->fr, frcopy, sizeof regs->fr);
118	if (signalcode != 0) {
119	    si.si_signo = signalcode >> 24;
120	    si.si_errno = 0;
121	    si.si_code = signalcode & 0xffffff;
122	    si.si_addr = (void __user *) regs->iaoq[0];
123	    force_sig_info(si.si_signo, &si, current);
124	    return -1;
125	}
126
127	return signalcode ? -1 : 0;
128}