// SPDX-License-Identifier: GPL-2.0
/*---------------------------------------------------------------------------+
| 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 <linux/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++; }
/* index is a 5-bit value: (3-bit FPU_modrm.reg field | opcode[2,1]) */
static u_char const type_table[32] = {
_PUSH_, _PUSH_, _PUSH_, _PUSH_, /* /0: d9:fld f32, db:fild m32, dd:fld f64, df:fild m16 */
_null_, _REG0_, _REG0_, _REG0_, /* /1: d9:undef, db,dd,df:fisttp m32/64/16 */
_REG0_, _REG0_, _REG0_, _REG0_, /* /2: d9:fst f32, db:fist m32, dd:fst f64, df:fist m16 */
_REG0_, _REG0_, _REG0_, _REG0_, /* /3: d9:fstp f32, db:fistp m32, dd:fstp f64, df:fistp m16 */
_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, 4, 8, 2, /* /1: d9:undef, db,dd,df:fisttp */
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, 4, 8, 2, /* /1: d9:undef, db,dd,df:fisttp */
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;
int sv_cw;
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) {
/* type is a 5-bit value: (3-bit FPU_modrm.reg field | opcode[2,1]) */
case 000: /* fld m32real (d9 /0) */
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 (db /0) */
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 (dd /0) */
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 (df /0) */
clear_C1();
loaded_tag =
FPU_load_int16((short __user *)data_address, &loaded_data);
FPU_copy_to_reg0(&loaded_data, loaded_tag);
break;
/* case 004: undefined (d9 /1) */
/* fisttp are enabled if CPUID(1).ECX(0) "sse3" is set */
case 005: /* fisttp m32int (db /1) */
clear_C1();
sv_cw = control_word;
control_word |= RC_CHOP;
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) */
control_word = sv_cw;
break;
case 006: /* fisttp m64int (dd /1) */
clear_C1();
sv_cw = control_word;
control_word |= RC_CHOP;
if (FPU_store_int64
(st0_ptr, st0_tag, (long long __user *)data_address))
pop_0(); /* pop only if the number was actually stored
(see the 80486 manual p16-28) */
control_word = sv_cw;
break;
case 007: /* fisttp m16int (df /1) */
clear_C1();
sv_cw = control_word;
control_word |= RC_CHOP;
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) */
control_word = sv_cw;
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 */
FPU_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(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(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 p16-28) */
break;
case 036: /* fstsw m2byte */
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(data_address, 2);
FPU_put_user(status_word(),
(unsigned short __user *)data_address);
RE_ENTRANT_CHECK_ON;
return 1;
case 037: /* fistp m64int */
clear_C1();
if (FPU_store_int64
(st0_ptr, st0_tag, (long long __user *)data_address))
pop_0(); /* pop only if the number was actually stored
(see the 80486 manual p16-28) */
break;
}
return 0;
}