1/*---------------------------------------------------------------------------+
2 |  load_store.c                                                             |
3 |                                                                           |
4 | This file contains most of the code to interpret the FPU instructions     |
5 | which load and store from user memory.                                    |
6 |                                                                           |
7 | Copyright (C) 1992,1993,1994,1997                                         |
8 |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
9 |                       Australia.  E-mail   billm@suburbia.net             |
10 |                                                                           |
11 |                                                                           |
12 +---------------------------------------------------------------------------*/
13
14/*---------------------------------------------------------------------------+
15 | Note:                                                                     |
16 |    The file contains code which accesses user memory.                     |
17 |    Emulator static data may change when user memory is accessed, due to   |
18 |    other processes using the emulator while swapping is in progress.      |
19 +---------------------------------------------------------------------------*/
20
21#include <asm/uaccess.h>
22
23#include "fpu_system.h"
24#include "exception.h"
25#include "fpu_emu.h"
26#include "status_w.h"
27#include "control_w.h"
28
29#define _NONE_ 0		/* st0_ptr etc not needed */
30#define _REG0_ 1		/* Will be storing st(0) */
31#define _PUSH_ 3		/* Need to check for space to push onto stack */
32#define _null_ 4		/* Function illegal or not implemented */
33
34#define pop_0()	{ FPU_settag0(TAG_Empty); top++; }
35
36/* index is a 5-bit value: (3-bit FPU_modrm.reg field | opcode[2,1]) */
37static u_char const type_table[32] = {
38	_PUSH_, _PUSH_, _PUSH_, _PUSH_, /* /0: d9:fld f32,  db:fild m32,  dd:fld f64,  df:fild m16 */
39	_null_, _REG0_, _REG0_, _REG0_, /* /1: d9:undef,    db,dd,df:fisttp m32/64/16 */
40	_REG0_, _REG0_, _REG0_, _REG0_, /* /2: d9:fst f32,  db:fist m32,  dd:fst f64,  df:fist m16 */
41	_REG0_, _REG0_, _REG0_, _REG0_, /* /3: d9:fstp f32, db:fistp m32, dd:fstp f64, df:fistp m16 */
42	_NONE_, _null_, _NONE_, _PUSH_,
43	_NONE_, _PUSH_, _null_, _PUSH_,
44	_NONE_, _null_, _NONE_, _REG0_,
45	_NONE_, _REG0_, _NONE_, _REG0_
46};
47
48u_char const data_sizes_16[32] = {
49	4, 4, 8, 2,
50	0, 4, 8, 2, /* /1: d9:undef, db,dd,df:fisttp */
51	4, 4, 8, 2,
52	4, 4, 8, 2,
53	14, 0, 94, 10, 2, 10, 0, 8,
54	14, 0, 94, 10, 2, 10, 2, 8
55};
56
57static u_char const data_sizes_32[32] = {
58	4, 4, 8, 2,
59	0, 4, 8, 2, /* /1: d9:undef, db,dd,df:fisttp */
60	4, 4, 8, 2,
61	4, 4, 8, 2,
62	28, 0, 108, 10, 2, 10, 0, 8,
63	28, 0, 108, 10, 2, 10, 2, 8
64};
65
66int FPU_load_store(u_char type, fpu_addr_modes addr_modes,
67		   void __user * data_address)
68{
69	FPU_REG loaded_data;
70	FPU_REG *st0_ptr;
71	u_char st0_tag = TAG_Empty;	/* This is just to stop a gcc warning. */
72	u_char loaded_tag;
73	int sv_cw;
74
75	st0_ptr = NULL;		/* Initialized just to stop compiler warnings. */
76
77	if (addr_modes.default_mode & PROTECTED) {
78		if (addr_modes.default_mode == SEG32) {
79			if (access_limit < data_sizes_32[type])
80				math_abort(FPU_info, SIGSEGV);
81		} else if (addr_modes.default_mode == PM16) {
82			if (access_limit < data_sizes_16[type])
83				math_abort(FPU_info, SIGSEGV);
84		}
85#ifdef PARANOID
86		else
87			EXCEPTION(EX_INTERNAL | 0x140);
88#endif /* PARANOID */
89	}
90
91	switch (type_table[type]) {
92	case _NONE_:
93		break;
94	case _REG0_:
95		st0_ptr = &st(0);	/* Some of these instructions pop after
96					   storing */
97		st0_tag = FPU_gettag0();
98		break;
99	case _PUSH_:
100		{
101			if (FPU_gettagi(-1) != TAG_Empty) {
102				FPU_stack_overflow();
103				return 0;
104			}
105			top--;
106			st0_ptr = &st(0);
107		}
108		break;
109	case _null_:
110		FPU_illegal();
111		return 0;
112#ifdef PARANOID
113	default:
114		EXCEPTION(EX_INTERNAL | 0x141);
115		return 0;
116#endif /* PARANOID */
117	}
118
119	switch (type) {
120	/* type is a 5-bit value: (3-bit FPU_modrm.reg field | opcode[2,1]) */
121	case 000:		/* fld m32real (d9 /0) */
122		clear_C1();
123		loaded_tag =
124		    FPU_load_single((float __user *)data_address, &loaded_data);
125		if ((loaded_tag == TAG_Special)
126		    && isNaN(&loaded_data)
127		    && (real_1op_NaN(&loaded_data) < 0)) {
128			top++;
129			break;
130		}
131		FPU_copy_to_reg0(&loaded_data, loaded_tag);
132		break;
133	case 001:		/* fild m32int (db /0) */
134		clear_C1();
135		loaded_tag =
136		    FPU_load_int32((long __user *)data_address, &loaded_data);
137		FPU_copy_to_reg0(&loaded_data, loaded_tag);
138		break;
139	case 002:		/* fld m64real (dd /0) */
140		clear_C1();
141		loaded_tag =
142		    FPU_load_double((double __user *)data_address,
143				    &loaded_data);
144		if ((loaded_tag == TAG_Special)
145		    && isNaN(&loaded_data)
146		    && (real_1op_NaN(&loaded_data) < 0)) {
147			top++;
148			break;
149		}
150		FPU_copy_to_reg0(&loaded_data, loaded_tag);
151		break;
152	case 003:		/* fild m16int (df /0) */
153		clear_C1();
154		loaded_tag =
155		    FPU_load_int16((short __user *)data_address, &loaded_data);
156		FPU_copy_to_reg0(&loaded_data, loaded_tag);
157		break;
158	/* case 004: undefined (d9 /1) */
159	/* fisttp are enabled if CPUID(1).ECX(0) "sse3" is set */
160	case 005:		/* fisttp m32int (db /1) */
161		clear_C1();
162		sv_cw = control_word;
163		control_word |= RC_CHOP;
164		if (FPU_store_int32
165		    (st0_ptr, st0_tag, (long __user *)data_address))
166			pop_0();	/* pop only if the number was actually stored
167					   (see the 80486 manual p16-28) */
168		control_word = sv_cw;
169		break;
170	case 006:		/* fisttp m64int (dd /1) */
171		clear_C1();
172		sv_cw = control_word;
173		control_word |= RC_CHOP;
174		if (FPU_store_int64
175		    (st0_ptr, st0_tag, (long long __user *)data_address))
176			pop_0();	/* pop only if the number was actually stored
177					   (see the 80486 manual p16-28) */
178		control_word = sv_cw;
179		break;
180	case 007:		/* fisttp m16int (df /1) */
181		clear_C1();
182		sv_cw = control_word;
183		control_word |= RC_CHOP;
184		if (FPU_store_int16
185		    (st0_ptr, st0_tag, (short __user *)data_address))
186			pop_0();	/* pop only if the number was actually stored
187					   (see the 80486 manual p16-28) */
188		control_word = sv_cw;
189		break;
190	case 010:		/* fst m32real */
191		clear_C1();
192		FPU_store_single(st0_ptr, st0_tag,
193				 (float __user *)data_address);
194		break;
195	case 011:		/* fist m32int */
196		clear_C1();
197		FPU_store_int32(st0_ptr, st0_tag, (long __user *)data_address);
198		break;
199	case 012:		/* fst m64real */
200		clear_C1();
201		FPU_store_double(st0_ptr, st0_tag,
202				 (double __user *)data_address);
203		break;
204	case 013:		/* fist m16int */
205		clear_C1();
206		FPU_store_int16(st0_ptr, st0_tag, (short __user *)data_address);
207		break;
208	case 014:		/* fstp m32real */
209		clear_C1();
210		if (FPU_store_single
211		    (st0_ptr, st0_tag, (float __user *)data_address))
212			pop_0();	/* pop only if the number was actually stored
213					   (see the 80486 manual p16-28) */
214		break;
215	case 015:		/* fistp m32int */
216		clear_C1();
217		if (FPU_store_int32
218		    (st0_ptr, st0_tag, (long __user *)data_address))
219			pop_0();	/* pop only if the number was actually stored
220					   (see the 80486 manual p16-28) */
221		break;
222	case 016:		/* fstp m64real */
223		clear_C1();
224		if (FPU_store_double
225		    (st0_ptr, st0_tag, (double __user *)data_address))
226			pop_0();	/* pop only if the number was actually stored
227					   (see the 80486 manual p16-28) */
228		break;
229	case 017:		/* fistp m16int */
230		clear_C1();
231		if (FPU_store_int16
232		    (st0_ptr, st0_tag, (short __user *)data_address))
233			pop_0();	/* pop only if the number was actually stored
234					   (see the 80486 manual p16-28) */
235		break;
236	case 020:		/* fldenv  m14/28byte */
237		fldenv(addr_modes, (u_char __user *) data_address);
238		/* Ensure that the values just loaded are not changed by
239		   fix-up operations. */
240		return 1;
241	case 022:		/* frstor m94/108byte */
242		frstor(addr_modes, (u_char __user *) data_address);
243		/* Ensure that the values just loaded are not changed by
244		   fix-up operations. */
245		return 1;
246	case 023:		/* fbld m80dec */
247		clear_C1();
248		loaded_tag = FPU_load_bcd((u_char __user *) data_address);
249		FPU_settag0(loaded_tag);
250		break;
251	case 024:		/* fldcw */
252		RE_ENTRANT_CHECK_OFF;
253		FPU_access_ok(VERIFY_READ, data_address, 2);
254		FPU_get_user(control_word,
255			     (unsigned short __user *)data_address);
256		RE_ENTRANT_CHECK_ON;
257		if (partial_status & ~control_word & CW_Exceptions)
258			partial_status |= (SW_Summary | SW_Backward);
259		else
260			partial_status &= ~(SW_Summary | SW_Backward);
261#ifdef PECULIAR_486
262		control_word |= 0x40;	/* An 80486 appears to always set this bit */
263#endif /* PECULIAR_486 */
264		return 1;
265	case 025:		/* fld m80real */
266		clear_C1();
267		loaded_tag =
268		    FPU_load_extended((long double __user *)data_address, 0);
269		FPU_settag0(loaded_tag);
270		break;
271	case 027:		/* fild m64int */
272		clear_C1();
273		loaded_tag = FPU_load_int64((long long __user *)data_address);
274		if (loaded_tag == TAG_Error)
275			return 0;
276		FPU_settag0(loaded_tag);
277		break;
278	case 030:		/* fstenv  m14/28byte */
279		fstenv(addr_modes, (u_char __user *) data_address);
280		return 1;
281	case 032:		/* fsave */
282		fsave(addr_modes, (u_char __user *) data_address);
283		return 1;
284	case 033:		/* fbstp m80dec */
285		clear_C1();
286		if (FPU_store_bcd
287		    (st0_ptr, st0_tag, (u_char __user *) data_address))
288			pop_0();	/* pop only if the number was actually stored
289					   (see the 80486 manual p16-28) */
290		break;
291	case 034:		/* fstcw m16int */
292		RE_ENTRANT_CHECK_OFF;
293		FPU_access_ok(VERIFY_WRITE, data_address, 2);
294		FPU_put_user(control_word,
295			     (unsigned short __user *)data_address);
296		RE_ENTRANT_CHECK_ON;
297		return 1;
298	case 035:		/* fstp m80real */
299		clear_C1();
300		if (FPU_store_extended
301		    (st0_ptr, st0_tag, (long double __user *)data_address))
302			pop_0();	/* pop only if the number was actually stored
303					   (see the 80486 manual p16-28) */
304		break;
305	case 036:		/* fstsw m2byte */
306		RE_ENTRANT_CHECK_OFF;
307		FPU_access_ok(VERIFY_WRITE, data_address, 2);
308		FPU_put_user(status_word(),
309			     (unsigned short __user *)data_address);
310		RE_ENTRANT_CHECK_ON;
311		return 1;
312	case 037:		/* fistp m64int */
313		clear_C1();
314		if (FPU_store_int64
315		    (st0_ptr, st0_tag, (long long __user *)data_address))
316			pop_0();	/* pop only if the number was actually stored
317					   (see the 80486 manual p16-28) */
318		break;
319	}
320	return 0;
321}
322