summaryrefslogtreecommitdiffstats
path: root/LICENSE.txt
AgeCommit message (Expand)Author
2020-07-05Rename NOTES*, README*, VERSION, HACKING, LICENSE to .md or .txtDr. David von Oheimb
id='n69' href='#n69'>69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282
/*---------------------------------------------------------------------------+
 |  load_store.c                                                             |
 |                                                                           |
 | This file contains most of the code to interpret the FPU instructions     |
 | which load and store from user memory.                                    |
 |                                                                           |
 | Copyright (C) 1992,1993,1994,1997                                         |
 |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
 |                       Australia.  E-mail   billm@suburbia.net             |
 |                                                                           |
 |                                                                           |
 +---------------------------------------------------------------------------*/

/*---------------------------------------------------------------------------+
 | Note:                                                                     |
 |    The file contains code which accesses user memory.                     |
 |    Emulator static data may change when user memory is accessed, due to   |
 |    other processes using the emulator while swapping is in progress.      |
 +---------------------------------------------------------------------------*/

#include <asm/uaccess.h>

#include "fpu_system.h"
#include "exception.h"
#include "fpu_emu.h"
#include "status_w.h"
#include "control_w.h"

#define _NONE_ 0		/* st0_ptr etc not needed */
#define _REG0_ 1		/* Will be storing st(0) */
#define _PUSH_ 3		/* Need to check for space to push onto stack */
#define _null_ 4		/* Function illegal or not implemented */

#define pop_0()	{ FPU_settag0(TAG_Empty); top++; }

static u_char const type_table[32] = {
	_PUSH_, _PUSH_, _PUSH_, _PUSH_,
	_null_, _null_, _null_, _null_,
	_REG0_, _REG0_, _REG0_, _REG0_,
	_REG0_, _REG0_, _REG0_, _REG0_,
	_NONE_, _null_, _NONE_, _PUSH_,
	_NONE_, _PUSH_, _null_, _PUSH_,
	_NONE_, _null_, _NONE_, _REG0_,
	_NONE_, _REG0_, _NONE_, _REG0_
};

u_char const data_sizes_16[32] = {
	4, 4, 8, 2, 0, 0, 0, 0,
	4, 4, 8, 2, 4, 4, 8, 2,
	14, 0, 94, 10, 2, 10, 0, 8,
	14, 0, 94, 10, 2, 10, 2, 8
};

static u_char const data_sizes_32[32] = {
	4, 4, 8, 2, 0, 0, 0, 0,
	4, 4, 8, 2, 4, 4, 8, 2,
	28, 0, 108, 10, 2, 10, 0, 8,
	28, 0, 108, 10, 2, 10, 2, 8
};

int FPU_load_store(u_char type, fpu_addr_modes addr_modes,
		   void __user * data_address)
{
	FPU_REG loaded_data;
	FPU_REG *st0_ptr;
	u_char st0_tag = TAG_Empty;	/* This is just to stop a gcc warning. */
	u_char loaded_tag;

	st0_ptr = NULL;		/* Initialized just to stop compiler warnings. */

	if (addr_modes.default_mode & PROTECTED) {
		if (addr_modes.default_mode == SEG32) {
			if (access_limit < data_sizes_32[type])
				math_abort(FPU_info, SIGSEGV);
		} else if (addr_modes.default_mode == PM16) {
			if (access_limit < data_sizes_16[type])
				math_abort(FPU_info, SIGSEGV);
		}
#ifdef PARANOID
		else
			EXCEPTION(EX_INTERNAL | 0x140);
#endif /* PARANOID */
	}

	switch (type_table[type]) {
	case _NONE_:
		break;
	case _REG0_:
		st0_ptr = &st(0);	/* Some of these instructions pop after
					   storing */
		st0_tag = FPU_gettag0();
		break;
	case _PUSH_:
		{
			if (FPU_gettagi(-1) != TAG_Empty) {
				FPU_stack_overflow();
				return 0;
			}
			top--;
			st0_ptr = &st(0);
		}
		break;
	case _null_:
		FPU_illegal();
		return 0;
#ifdef PARANOID
	default:
		EXCEPTION(EX_INTERNAL | 0x141);
		return 0;
#endif /* PARANOID */
	}

	switch (type) {
	case 000:		/* fld m32real */
		clear_C1();
		loaded_tag =
		    FPU_load_single((float __user *)data_address, &loaded_data);
		if ((loaded_tag == TAG_Special)
		    && isNaN(&loaded_data)
		    && (real_1op_NaN(&loaded_data) < 0)) {
			top++;
			break;
		}
		FPU_copy_to_reg0(&loaded_data, loaded_tag);
		break;
	case 001:		/* fild m32int */
		clear_C1();
		loaded_tag =
		    FPU_load_int32((long __user *)data_address, &loaded_data);
		FPU_copy_to_reg0(&loaded_data, loaded_tag);
		break;
	case 002:		/* fld m64real */
		clear_C1();
		loaded_tag =
		    FPU_load_double((double __user *)data_address,
				    &loaded_data);
		if ((loaded_tag == TAG_Special)
		    && isNaN(&loaded_data)
		    && (real_1op_NaN(&loaded_data) < 0)) {
			top++;
			break;
		}
		FPU_copy_to_reg0(&loaded_data, loaded_tag);
		break;
	case 003:		/* fild m16int */
		clear_C1();
		loaded_tag =
		    FPU_load_int16((short __user *)data_address, &loaded_data);
		FPU_copy_to_reg0(&loaded_data, loaded_tag);
		break;
	case 010:		/* fst m32real */
		clear_C1();
		FPU_store_single(st0_ptr, st0_tag,
				 (float __user *)data_address);
		break;
	case 011:		/* fist m32int */
		clear_C1();
		FPU_store_int32(st0_ptr, st0_tag, (long __user *)data_address);
		break;
	case 012:		/* fst m64real */
		clear_C1();
		FPU_store_double(st0_ptr, st0_tag,
				 (double __user *)data_address);
		break;
	case 013:		/* fist m16int */
		clear_C1();
		FPU_store_int16(st0_ptr, st0_tag, (short __user *)data_address);
		break;
	case 014:		/* fstp m32real */
		clear_C1();
		if (FPU_store_single
		    (st0_ptr, st0_tag, (float __user *)data_address))
			pop_0();	/* pop only if the number was actually stored
					   (see the 80486 manual p16-28) */
		break;
	case 015:		/* fistp m32int */
		clear_C1();
		if (FPU_store_int32
		    (st0_ptr, st0_tag, (long __user *)data_address))
			pop_0();	/* pop only if the number was actually stored
					   (see the 80486 manual p16-28) */
		break;
	case 016:		/* fstp m64real */
		clear_C1();
		if (FPU_store_double
		    (st0_ptr, st0_tag, (double __user *)data_address))
			pop_0();	/* pop only if the number was actually stored
					   (see the 80486 manual p16-28) */
		break;
	case 017:		/* fistp m16int */
		clear_C1();
		if (FPU_store_int16
		    (st0_ptr, st0_tag, (short __user *)data_address))
			pop_0();	/* pop only if the number was actually stored
					   (see the 80486 manual p16-28) */
		break;
	case 020:		/* fldenv  m14/28byte */
		fldenv(addr_modes, (u_char __user *) data_address);
		/* Ensure that the values just loaded are not changed by
		   fix-up operations. */
		return 1;
	case 022:		/* frstor m94/108byte */
		frstor(addr_modes, (u_char __user *) data_address);
		/* Ensure that the values just loaded are not changed by
		   fix-up operations. */
		return 1;
	case 023:		/* fbld m80dec */
		clear_C1();
		loaded_tag = FPU_load_bcd((u_char __user *) data_address);
		FPU_settag0(loaded_tag);
		break;
	case 024:		/* fldcw */
		RE_ENTRANT_CHECK_OFF;
		FPU_access_ok(VERIFY_READ, data_address, 2);
		FPU_get_user(control_word,
			     (unsigned short __user *)data_address);
		RE_ENTRANT_CHECK_ON;
		if (partial_status & ~control_word & CW_Exceptions)
			partial_status |= (SW_Summary | SW_Backward);
		else
			partial_status &= ~(SW_Summary | SW_Backward);
#ifdef PECULIAR_486
		control_word |= 0x40;	/* An 80486 appears to always set this bit */
#endif /* PECULIAR_486 */
		return 1;
	case 025:		/* fld m80real */
		clear_C1();
		loaded_tag =
		    FPU_load_extended((long double __user *)data_address, 0);
		FPU_settag0(loaded_tag);
		break;
	case 027:		/* fild m64int */
		clear_C1();
		loaded_tag = FPU_load_int64((long long __user *)data_address);
		if (loaded_tag == TAG_Error)
			return 0;
		FPU_settag0(loaded_tag);
		break;
	case 030:		/* fstenv  m14/28byte */
		fstenv(addr_modes, (u_char __user *) data_address);
		return 1;
	case 032:		/* fsave */
		fsave(addr_modes, (u_char __user *) data_address);
		return 1;
	case 033:		/* fbstp m80dec */
		clear_C1();
		if (FPU_store_bcd
		    (st0_ptr, st0_tag, (u_char __user *) data_address))
			pop_0();	/* pop only if the number was actually stored
					   (see the 80486 manual p16-28) */
		break;
	case 034:		/* fstcw m16int */
		RE_ENTRANT_CHECK_OFF;
		FPU_access_ok(VERIFY_WRITE, data_address, 2);
		FPU_put_user(control_word,
			     (unsigned short __user *)data_address);
		RE_ENTRANT_CHECK_ON;
		return 1;
	case 035:		/* fstp m80real */
		clear_C1();
		if (FPU_store_extended
		    (st0_ptr, st0_tag, (long double __user *)data_address))
			pop_0();	/* pop only if the number was actually stored
					   (see the 80486 manual p1