Merge branches 'release', 'bugzilla-6217', 'bugzilla-6629', 'bugzilla-6933', 'bugzill...
[linux-2.6] / arch / x86 / math-emu / load_store.c
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 static u_char const type_table[32] = {
37         _PUSH_, _PUSH_, _PUSH_, _PUSH_,
38         _null_, _null_, _null_, _null_,
39         _REG0_, _REG0_, _REG0_, _REG0_,
40         _REG0_, _REG0_, _REG0_, _REG0_,
41         _NONE_, _null_, _NONE_, _PUSH_,
42         _NONE_, _PUSH_, _null_, _PUSH_,
43         _NONE_, _null_, _NONE_, _REG0_,
44         _NONE_, _REG0_, _NONE_, _REG0_
45 };
46
47 u_char const data_sizes_16[32] = {
48         4, 4, 8, 2, 0, 0, 0, 0,
49         4, 4, 8, 2, 4, 4, 8, 2,
50         14, 0, 94, 10, 2, 10, 0, 8,
51         14, 0, 94, 10, 2, 10, 2, 8
52 };
53
54 static u_char const data_sizes_32[32] = {
55         4, 4, 8, 2, 0, 0, 0, 0,
56         4, 4, 8, 2, 4, 4, 8, 2,
57         28, 0, 108, 10, 2, 10, 0, 8,
58         28, 0, 108, 10, 2, 10, 2, 8
59 };
60
61 int FPU_load_store(u_char type, fpu_addr_modes addr_modes,
62                    void __user * data_address)
63 {
64         FPU_REG loaded_data;
65         FPU_REG *st0_ptr;
66         u_char st0_tag = TAG_Empty;     /* This is just to stop a gcc warning. */
67         u_char loaded_tag;
68
69         st0_ptr = NULL;         /* Initialized just to stop compiler warnings. */
70
71         if (addr_modes.default_mode & PROTECTED) {
72                 if (addr_modes.default_mode == SEG32) {
73                         if (access_limit < data_sizes_32[type])
74                                 math_abort(FPU_info, SIGSEGV);
75                 } else if (addr_modes.default_mode == PM16) {
76                         if (access_limit < data_sizes_16[type])
77                                 math_abort(FPU_info, SIGSEGV);
78                 }
79 #ifdef PARANOID
80                 else
81                         EXCEPTION(EX_INTERNAL | 0x140);
82 #endif /* PARANOID */
83         }
84
85         switch (type_table[type]) {
86         case _NONE_:
87                 break;
88         case _REG0_:
89                 st0_ptr = &st(0);       /* Some of these instructions pop after
90                                            storing */
91                 st0_tag = FPU_gettag0();
92                 break;
93         case _PUSH_:
94                 {
95                         if (FPU_gettagi(-1) != TAG_Empty) {
96                                 FPU_stack_overflow();
97                                 return 0;
98                         }
99                         top--;
100                         st0_ptr = &st(0);
101                 }
102                 break;
103         case _null_:
104                 FPU_illegal();
105                 return 0;
106 #ifdef PARANOID
107         default:
108                 EXCEPTION(EX_INTERNAL | 0x141);
109                 return 0;
110 #endif /* PARANOID */
111         }
112
113         switch (type) {
114         case 000:               /* fld m32real */
115                 clear_C1();
116                 loaded_tag =
117                     FPU_load_single((float __user *)data_address, &loaded_data);
118                 if ((loaded_tag == TAG_Special)
119                     && isNaN(&loaded_data)
120                     && (real_1op_NaN(&loaded_data) < 0)) {
121                         top++;
122                         break;
123                 }
124                 FPU_copy_to_reg0(&loaded_data, loaded_tag);
125                 break;
126         case 001:               /* fild m32int */
127                 clear_C1();
128                 loaded_tag =
129                     FPU_load_int32((long __user *)data_address, &loaded_data);
130                 FPU_copy_to_reg0(&loaded_data, loaded_tag);
131                 break;
132         case 002:               /* fld m64real */
133                 clear_C1();
134                 loaded_tag =
135                     FPU_load_double((double __user *)data_address,
136                                     &loaded_data);
137                 if ((loaded_tag == TAG_Special)
138                     && isNaN(&loaded_data)
139                     && (real_1op_NaN(&loaded_data) < 0)) {
140                         top++;
141                         break;
142                 }
143                 FPU_copy_to_reg0(&loaded_data, loaded_tag);
144                 break;
145         case 003:               /* fild m16int */
146                 clear_C1();
147                 loaded_tag =
148                     FPU_load_int16((short __user *)data_address, &loaded_data);
149                 FPU_copy_to_reg0(&loaded_data, loaded_tag);
150                 break;
151         case 010:               /* fst m32real */
152                 clear_C1();
153                 FPU_store_single(st0_ptr, st0_tag,
154                                  (float __user *)data_address);
155                 break;
156         case 011:               /* fist m32int */
157                 clear_C1();
158                 FPU_store_int32(st0_ptr, st0_tag, (long __user *)data_address);
159                 break;
160         case 012:               /* fst m64real */
161                 clear_C1();
162                 FPU_store_double(st0_ptr, st0_tag,
163                                  (double __user *)data_address);
164                 break;
165         case 013:               /* fist m16int */
166                 clear_C1();
167                 FPU_store_int16(st0_ptr, st0_tag, (short __user *)data_address);
168                 break;
169         case 014:               /* fstp m32real */
170                 clear_C1();
171                 if (FPU_store_single
172                     (st0_ptr, st0_tag, (float __user *)data_address))
173                         pop_0();        /* pop only if the number was actually stored
174                                            (see the 80486 manual p16-28) */
175                 break;
176         case 015:               /* fistp m32int */
177                 clear_C1();
178                 if (FPU_store_int32
179                     (st0_ptr, st0_tag, (long __user *)data_address))
180                         pop_0();        /* pop only if the number was actually stored
181                                            (see the 80486 manual p16-28) */
182                 break;
183         case 016:               /* fstp m64real */
184                 clear_C1();
185                 if (FPU_store_double
186                     (st0_ptr, st0_tag, (double __user *)data_address))
187                         pop_0();        /* pop only if the number was actually stored
188                                            (see the 80486 manual p16-28) */
189                 break;
190         case 017:               /* fistp m16int */
191                 clear_C1();
192                 if (FPU_store_int16
193                     (st0_ptr, st0_tag, (short __user *)data_address))
194                         pop_0();        /* pop only if the number was actually stored
195                                            (see the 80486 manual p16-28) */
196                 break;
197         case 020:               /* fldenv  m14/28byte */
198                 fldenv(addr_modes, (u_char __user *) data_address);
199                 /* Ensure that the values just loaded are not changed by
200                    fix-up operations. */
201                 return 1;
202         case 022:               /* frstor m94/108byte */
203                 frstor(addr_modes, (u_char __user *) data_address);
204                 /* Ensure that the values just loaded are not changed by
205                    fix-up operations. */
206                 return 1;
207         case 023:               /* fbld m80dec */
208                 clear_C1();
209                 loaded_tag = FPU_load_bcd((u_char __user *) data_address);
210                 FPU_settag0(loaded_tag);
211                 break;
212         case 024:               /* fldcw */
213                 RE_ENTRANT_CHECK_OFF;
214                 FPU_access_ok(VERIFY_READ, data_address, 2);
215                 FPU_get_user(control_word,
216                              (unsigned short __user *)data_address);
217                 RE_ENTRANT_CHECK_ON;
218                 if (partial_status & ~control_word & CW_Exceptions)
219                         partial_status |= (SW_Summary | SW_Backward);
220                 else
221                         partial_status &= ~(SW_Summary | SW_Backward);
222 #ifdef PECULIAR_486
223                 control_word |= 0x40;   /* An 80486 appears to always set this bit */
224 #endif /* PECULIAR_486 */
225                 return 1;
226         case 025:               /* fld m80real */
227                 clear_C1();
228                 loaded_tag =
229                     FPU_load_extended((long double __user *)data_address, 0);
230                 FPU_settag0(loaded_tag);
231                 break;
232         case 027:               /* fild m64int */
233                 clear_C1();
234                 loaded_tag = FPU_load_int64((long long __user *)data_address);
235                 if (loaded_tag == TAG_Error)
236                         return 0;
237                 FPU_settag0(loaded_tag);
238                 break;
239         case 030:               /* fstenv  m14/28byte */
240                 fstenv(addr_modes, (u_char __user *) data_address);
241                 return 1;
242         case 032:               /* fsave */
243                 fsave(addr_modes, (u_char __user *) data_address);
244                 return 1;
245         case 033:               /* fbstp m80dec */
246                 clear_C1();
247                 if (FPU_store_bcd
248                     (st0_ptr, st0_tag, (u_char __user *) data_address))
249                         pop_0();        /* pop only if the number was actually stored
250                                            (see the 80486 manual p16-28) */
251                 break;
252         case 034:               /* fstcw m16int */
253                 RE_ENTRANT_CHECK_OFF;
254                 FPU_access_ok(VERIFY_WRITE, data_address, 2);
255                 FPU_put_user(control_word,
256                              (unsigned short __user *)data_address);
257                 RE_ENTRANT_CHECK_ON;
258                 return 1;
259         case 035:               /* fstp m80real */
260                 clear_C1();
261                 if (FPU_store_extended
262                     (st0_ptr, st0_tag, (long double __user *)data_address))
263                         pop_0();        /* pop only if the number was actually stored
264                                            (see the 80486 manual p16-28) */
265                 break;
266         case 036:               /* fstsw m2byte */
267                 RE_ENTRANT_CHECK_OFF;
268                 FPU_access_ok(VERIFY_WRITE, data_address, 2);
269                 FPU_put_user(status_word(),
270                              (unsigned short __user *)data_address);
271                 RE_ENTRANT_CHECK_ON;
272                 return 1;
273         case 037:               /* fistp m64int */
274                 clear_C1();
275                 if (FPU_store_int64
276                     (st0_ptr, st0_tag, (long long __user *)data_address))
277                         pop_0();        /* pop only if the number was actually stored
278                                            (see the 80486 manual p16-28) */
279                 break;
280         }
281         return 0;
282 }