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1da177e4 LT |
1 | /*---------------------------------------------------------------------------+ |
2 | | fpu_entry.c | | |
3 | | | | |
4 | | The entry functions for wm-FPU-emu | | |
5 | | | | |
6 | | Copyright (C) 1992,1993,1994,1996,1997 | | |
7 | | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia | | |
8 | | E-mail billm@suburbia.net | | |
9 | | | | |
10 | | See the files "README" and "COPYING" for further copyright and warranty | | |
11 | | information. | | |
12 | | | | |
13 | +---------------------------------------------------------------------------*/ | |
14 | ||
15 | /*---------------------------------------------------------------------------+ | |
16 | | Note: | | |
17 | | The file contains code which accesses user memory. | | |
18 | | Emulator static data may change when user memory is accessed, due to | | |
19 | | other processes using the emulator while swapping is in progress. | | |
20 | +---------------------------------------------------------------------------*/ | |
21 | ||
22 | /*---------------------------------------------------------------------------+ | |
23 | | math_emulate(), restore_i387_soft() and save_i387_soft() are the only | | |
24 | | entry points for wm-FPU-emu. | | |
25 | +---------------------------------------------------------------------------*/ | |
26 | ||
27 | #include <linux/signal.h> | |
ff0ebb23 | 28 | #include <linux/regset.h> |
1da177e4 LT |
29 | |
30 | #include <asm/uaccess.h> | |
51e7dc70 | 31 | #include <asm/traps.h> |
1da177e4 | 32 | #include <asm/desc.h> |
ff0ebb23 | 33 | #include <asm/user.h> |
e8a496ac | 34 | #include <asm/i387.h> |
1da177e4 LT |
35 | |
36 | #include "fpu_system.h" | |
37 | #include "fpu_emu.h" | |
38 | #include "exception.h" | |
39 | #include "control_w.h" | |
40 | #include "status_w.h" | |
41 | ||
3d0d14f9 | 42 | #define __BAD__ FPU_illegal /* Illegal on an 80486, causes SIGILL */ |
1da177e4 | 43 | |
3d0d14f9 | 44 | #ifndef NO_UNDOC_CODE /* Un-documented FPU op-codes supported by default. */ |
1da177e4 LT |
45 | |
46 | /* WARNING: These codes are not documented by Intel in their 80486 manual | |
47 | and may not work on FPU clones or later Intel FPUs. */ | |
48 | ||
49 | /* Changes to support the un-doc codes provided by Linus Torvalds. */ | |
50 | ||
3d0d14f9 IM |
51 | #define _d9_d8_ fstp_i /* unofficial code (19) */ |
52 | #define _dc_d0_ fcom_st /* unofficial code (14) */ | |
53 | #define _dc_d8_ fcompst /* unofficial code (1c) */ | |
54 | #define _dd_c8_ fxch_i /* unofficial code (0d) */ | |
55 | #define _de_d0_ fcompst /* unofficial code (16) */ | |
56 | #define _df_c0_ ffreep /* unofficial code (07) ffree + pop */ | |
57 | #define _df_c8_ fxch_i /* unofficial code (0f) */ | |
58 | #define _df_d0_ fstp_i /* unofficial code (17) */ | |
59 | #define _df_d8_ fstp_i /* unofficial code (1f) */ | |
1da177e4 LT |
60 | |
61 | static FUNC const st_instr_table[64] = { | |
3d0d14f9 IM |
62 | fadd__, fld_i_, __BAD__, __BAD__, fadd_i, ffree_, faddp_, _df_c0_, |
63 | fmul__, fxch_i, __BAD__, __BAD__, fmul_i, _dd_c8_, fmulp_, _df_c8_, | |
64 | fcom_st, fp_nop, __BAD__, __BAD__, _dc_d0_, fst_i_, _de_d0_, _df_d0_, | |
65 | fcompst, _d9_d8_, __BAD__, __BAD__, _dc_d8_, fstp_i, fcompp, _df_d8_, | |
66 | fsub__, FPU_etc, __BAD__, finit_, fsubri, fucom_, fsubrp, fstsw_, | |
67 | fsubr_, fconst, fucompp, __BAD__, fsub_i, fucomp, fsubp_, __BAD__, | |
68 | fdiv__, FPU_triga, __BAD__, __BAD__, fdivri, __BAD__, fdivrp, __BAD__, | |
69 | fdivr_, FPU_trigb, __BAD__, __BAD__, fdiv_i, __BAD__, fdivp_, __BAD__, | |
1da177e4 LT |
70 | }; |
71 | ||
3d0d14f9 | 72 | #else /* Support only documented FPU op-codes */ |
1da177e4 LT |
73 | |
74 | static FUNC const st_instr_table[64] = { | |
3d0d14f9 IM |
75 | fadd__, fld_i_, __BAD__, __BAD__, fadd_i, ffree_, faddp_, __BAD__, |
76 | fmul__, fxch_i, __BAD__, __BAD__, fmul_i, __BAD__, fmulp_, __BAD__, | |
77 | fcom_st, fp_nop, __BAD__, __BAD__, __BAD__, fst_i_, __BAD__, __BAD__, | |
78 | fcompst, __BAD__, __BAD__, __BAD__, __BAD__, fstp_i, fcompp, __BAD__, | |
79 | fsub__, FPU_etc, __BAD__, finit_, fsubri, fucom_, fsubrp, fstsw_, | |
80 | fsubr_, fconst, fucompp, __BAD__, fsub_i, fucomp, fsubp_, __BAD__, | |
81 | fdiv__, FPU_triga, __BAD__, __BAD__, fdivri, __BAD__, fdivrp, __BAD__, | |
82 | fdivr_, FPU_trigb, __BAD__, __BAD__, fdiv_i, __BAD__, fdivp_, __BAD__, | |
1da177e4 LT |
83 | }; |
84 | ||
85 | #endif /* NO_UNDOC_CODE */ | |
86 | ||
3d0d14f9 IM |
87 | #define _NONE_ 0 /* Take no special action */ |
88 | #define _REG0_ 1 /* Need to check for not empty st(0) */ | |
89 | #define _REGI_ 2 /* Need to check for not empty st(0) and st(rm) */ | |
90 | #define _REGi_ 0 /* Uses st(rm) */ | |
91 | #define _PUSH_ 3 /* Need to check for space to push onto stack */ | |
92 | #define _null_ 4 /* Function illegal or not implemented */ | |
93 | #define _REGIi 5 /* Uses st(0) and st(rm), result to st(rm) */ | |
94 | #define _REGIp 6 /* Uses st(0) and st(rm), result to st(rm) then pop */ | |
95 | #define _REGIc 0 /* Compare st(0) and st(rm) */ | |
96 | #define _REGIn 0 /* Uses st(0) and st(rm), but handle checks later */ | |
1da177e4 LT |
97 | |
98 | #ifndef NO_UNDOC_CODE | |
99 | ||
100 | /* Un-documented FPU op-codes supported by default. (see above) */ | |
101 | ||
102 | static u_char const type_table[64] = { | |
3d0d14f9 IM |
103 | _REGI_, _NONE_, _null_, _null_, _REGIi, _REGi_, _REGIp, _REGi_, |
104 | _REGI_, _REGIn, _null_, _null_, _REGIi, _REGI_, _REGIp, _REGI_, | |
105 | _REGIc, _NONE_, _null_, _null_, _REGIc, _REG0_, _REGIc, _REG0_, | |
106 | _REGIc, _REG0_, _null_, _null_, _REGIc, _REG0_, _REGIc, _REG0_, | |
107 | _REGI_, _NONE_, _null_, _NONE_, _REGIi, _REGIc, _REGIp, _NONE_, | |
108 | _REGI_, _NONE_, _REGIc, _null_, _REGIi, _REGIc, _REGIp, _null_, | |
109 | _REGI_, _NONE_, _null_, _null_, _REGIi, _null_, _REGIp, _null_, | |
110 | _REGI_, _NONE_, _null_, _null_, _REGIi, _null_, _REGIp, _null_ | |
1da177e4 LT |
111 | }; |
112 | ||
3d0d14f9 | 113 | #else /* Support only documented FPU op-codes */ |
1da177e4 LT |
114 | |
115 | static u_char const type_table[64] = { | |
3d0d14f9 IM |
116 | _REGI_, _NONE_, _null_, _null_, _REGIi, _REGi_, _REGIp, _null_, |
117 | _REGI_, _REGIn, _null_, _null_, _REGIi, _null_, _REGIp, _null_, | |
118 | _REGIc, _NONE_, _null_, _null_, _null_, _REG0_, _null_, _null_, | |
119 | _REGIc, _null_, _null_, _null_, _null_, _REG0_, _REGIc, _null_, | |
120 | _REGI_, _NONE_, _null_, _NONE_, _REGIi, _REGIc, _REGIp, _NONE_, | |
121 | _REGI_, _NONE_, _REGIc, _null_, _REGIi, _REGIc, _REGIp, _null_, | |
122 | _REGI_, _NONE_, _null_, _null_, _REGIi, _null_, _REGIp, _null_, | |
123 | _REGI_, _NONE_, _null_, _null_, _REGIi, _null_, _REGIp, _null_ | |
1da177e4 LT |
124 | }; |
125 | ||
126 | #endif /* NO_UNDOC_CODE */ | |
127 | ||
1da177e4 | 128 | #ifdef RE_ENTRANT_CHECKING |
3d0d14f9 | 129 | u_char emulating = 0; |
1da177e4 LT |
130 | #endif /* RE_ENTRANT_CHECKING */ |
131 | ||
e8d591dc | 132 | static int valid_prefix(u_char *Byte, u_char __user ** fpu_eip, |
3d0d14f9 | 133 | overrides * override); |
1da177e4 | 134 | |
d315760f | 135 | void math_emulate(struct math_emu_info *info) |
1da177e4 | 136 | { |
3d0d14f9 IM |
137 | u_char FPU_modrm, byte1; |
138 | unsigned short code; | |
139 | fpu_addr_modes addr_modes; | |
140 | int unmasked; | |
141 | FPU_REG loaded_data; | |
142 | FPU_REG *st0_ptr; | |
143 | u_char loaded_tag, st0_tag; | |
144 | void __user *data_address; | |
145 | struct address data_sel_off; | |
146 | struct address entry_sel_off; | |
147 | unsigned long code_base = 0; | |
148 | unsigned long code_limit = 0; /* Initialized to stop compiler warnings */ | |
149 | struct desc_struct code_descriptor; | |
1da177e4 | 150 | |
e8a496ac SS |
151 | if (!used_math()) { |
152 | if (init_fpu(current)) { | |
153 | do_group_exit(SIGKILL); | |
154 | return; | |
155 | } | |
156 | } | |
157 | ||
1da177e4 | 158 | #ifdef RE_ENTRANT_CHECKING |
3d0d14f9 IM |
159 | if (emulating) { |
160 | printk("ERROR: wm-FPU-emu is not RE-ENTRANT!\n"); | |
161 | } | |
162 | RE_ENTRANT_CHECK_ON; | |
1da177e4 LT |
163 | #endif /* RE_ENTRANT_CHECKING */ |
164 | ||
d315760f | 165 | FPU_info = info; |
3d0d14f9 IM |
166 | |
167 | FPU_ORIG_EIP = FPU_EIP; | |
168 | ||
169 | if ((FPU_EFLAGS & 0x00020000) != 0) { | |
170 | /* Virtual 8086 mode */ | |
171 | addr_modes.default_mode = VM86; | |
172 | FPU_EIP += code_base = FPU_CS << 4; | |
173 | code_limit = code_base + 0xffff; /* Assumes code_base <= 0xffff0000 */ | |
174 | } else if (FPU_CS == __USER_CS && FPU_DS == __USER_DS) { | |
175 | addr_modes.default_mode = 0; | |
176 | } else if (FPU_CS == __KERNEL_CS) { | |
177 | printk("math_emulate: %04x:%08lx\n", FPU_CS, FPU_EIP); | |
178 | panic("Math emulation needed in kernel"); | |
179 | } else { | |
180 | ||
181 | if ((FPU_CS & 4) != 4) { /* Must be in the LDT */ | |
182 | /* Can only handle segmented addressing via the LDT | |
183 | for now, and it must be 16 bit */ | |
184 | printk("FPU emulator: Unsupported addressing mode\n"); | |
185 | math_abort(FPU_info, SIGILL); | |
186 | } | |
187 | ||
188 | code_descriptor = LDT_DESCRIPTOR(FPU_CS); | |
189 | if (SEG_D_SIZE(code_descriptor)) { | |
190 | /* The above test may be wrong, the book is not clear */ | |
191 | /* Segmented 32 bit protected mode */ | |
192 | addr_modes.default_mode = SEG32; | |
193 | } else { | |
194 | /* 16 bit protected mode */ | |
195 | addr_modes.default_mode = PM16; | |
196 | } | |
197 | FPU_EIP += code_base = SEG_BASE_ADDR(code_descriptor); | |
198 | code_limit = code_base | |
199 | + (SEG_LIMIT(code_descriptor) + | |
200 | 1) * SEG_GRANULARITY(code_descriptor) | |
201 | - 1; | |
202 | if (code_limit < code_base) | |
203 | code_limit = 0xffffffff; | |
1da177e4 | 204 | } |
3d0d14f9 | 205 | |
ff0ebb23 | 206 | FPU_lookahead = !(FPU_EFLAGS & X86_EFLAGS_TF); |
3d0d14f9 IM |
207 | |
208 | if (!valid_prefix(&byte1, (u_char __user **) & FPU_EIP, | |
209 | &addr_modes.override)) { | |
210 | RE_ENTRANT_CHECK_OFF; | |
211 | printk | |
212 | ("FPU emulator: Unknown prefix byte 0x%02x, probably due to\n" | |
213 | "FPU emulator: self-modifying code! (emulation impossible)\n", | |
214 | byte1); | |
215 | RE_ENTRANT_CHECK_ON; | |
216 | EXCEPTION(EX_INTERNAL | 0x126); | |
217 | math_abort(FPU_info, SIGILL); | |
1da177e4 | 218 | } |
3d0d14f9 IM |
219 | |
220 | do_another_FPU_instruction: | |
221 | ||
222 | no_ip_update = 0; | |
223 | ||
224 | FPU_EIP++; /* We have fetched the prefix and first code bytes. */ | |
225 | ||
226 | if (addr_modes.default_mode) { | |
227 | /* This checks for the minimum instruction bytes. | |
228 | We also need to check any extra (address mode) code access. */ | |
229 | if (FPU_EIP > code_limit) | |
230 | math_abort(FPU_info, SIGSEGV); | |
1da177e4 | 231 | } |
3d0d14f9 IM |
232 | |
233 | if ((byte1 & 0xf8) != 0xd8) { | |
234 | if (byte1 == FWAIT_OPCODE) { | |
235 | if (partial_status & SW_Summary) | |
236 | goto do_the_FPU_interrupt; | |
237 | else | |
238 | goto FPU_fwait_done; | |
239 | } | |
1da177e4 | 240 | #ifdef PARANOID |
3d0d14f9 IM |
241 | EXCEPTION(EX_INTERNAL | 0x128); |
242 | math_abort(FPU_info, SIGILL); | |
1da177e4 | 243 | #endif /* PARANOID */ |
1da177e4 LT |
244 | } |
245 | ||
3d0d14f9 IM |
246 | RE_ENTRANT_CHECK_OFF; |
247 | FPU_code_access_ok(1); | |
248 | FPU_get_user(FPU_modrm, (u_char __user *) FPU_EIP); | |
249 | RE_ENTRANT_CHECK_ON; | |
250 | FPU_EIP++; | |
251 | ||
252 | if (partial_status & SW_Summary) { | |
253 | /* Ignore the error for now if the current instruction is a no-wait | |
254 | control instruction */ | |
255 | /* The 80486 manual contradicts itself on this topic, | |
256 | but a real 80486 uses the following instructions: | |
257 | fninit, fnstenv, fnsave, fnstsw, fnstenv, fnclex. | |
258 | */ | |
259 | code = (FPU_modrm << 8) | byte1; | |
260 | if (!((((code & 0xf803) == 0xe003) || /* fnclex, fninit, fnstsw */ | |
261 | (((code & 0x3003) == 0x3001) && /* fnsave, fnstcw, fnstenv, | |
262 | fnstsw */ | |
263 | ((code & 0xc000) != 0xc000))))) { | |
264 | /* | |
265 | * We need to simulate the action of the kernel to FPU | |
266 | * interrupts here. | |
267 | */ | |
268 | do_the_FPU_interrupt: | |
269 | ||
270 | FPU_EIP = FPU_ORIG_EIP; /* Point to current FPU instruction. */ | |
271 | ||
272 | RE_ENTRANT_CHECK_OFF; | |
51e7dc70 | 273 | current->thread.trap_nr = X86_TRAP_MF; |
3d0d14f9 IM |
274 | current->thread.error_code = 0; |
275 | send_sig(SIGFPE, current, 1); | |
276 | return; | |
1da177e4 | 277 | } |
3d0d14f9 | 278 | } |
1da177e4 | 279 | |
3d0d14f9 IM |
280 | entry_sel_off.offset = FPU_ORIG_EIP; |
281 | entry_sel_off.selector = FPU_CS; | |
282 | entry_sel_off.opcode = (byte1 << 8) | FPU_modrm; | |
cc7594e4 | 283 | entry_sel_off.empty = 0; |
1da177e4 | 284 | |
3d0d14f9 | 285 | FPU_rm = FPU_modrm & 7; |
1da177e4 | 286 | |
3d0d14f9 IM |
287 | if (FPU_modrm < 0300) { |
288 | /* All of these instructions use the mod/rm byte to get a data address */ | |
1da177e4 | 289 | |
3d0d14f9 IM |
290 | if ((addr_modes.default_mode & SIXTEEN) |
291 | ^ (addr_modes.override.address_size == ADDR_SIZE_PREFIX)) | |
292 | data_address = | |
293 | FPU_get_address_16(FPU_modrm, &FPU_EIP, | |
294 | &data_sel_off, addr_modes); | |
295 | else | |
296 | data_address = | |
297 | FPU_get_address(FPU_modrm, &FPU_EIP, &data_sel_off, | |
298 | addr_modes); | |
299 | ||
300 | if (addr_modes.default_mode) { | |
301 | if (FPU_EIP - 1 > code_limit) | |
302 | math_abort(FPU_info, SIGSEGV); | |
1da177e4 | 303 | } |
3d0d14f9 IM |
304 | |
305 | if (!(byte1 & 1)) { | |
306 | unsigned short status1 = partial_status; | |
307 | ||
308 | st0_ptr = &st(0); | |
309 | st0_tag = FPU_gettag0(); | |
310 | ||
311 | /* Stack underflow has priority */ | |
312 | if (NOT_EMPTY_ST0) { | |
313 | if (addr_modes.default_mode & PROTECTED) { | |
314 | /* This table works for 16 and 32 bit protected mode */ | |
315 | if (access_limit < | |
316 | data_sizes_16[(byte1 >> 1) & 3]) | |
317 | math_abort(FPU_info, SIGSEGV); | |
318 | } | |
319 | ||
320 | unmasked = 0; /* Do this here to stop compiler warnings. */ | |
321 | switch ((byte1 >> 1) & 3) { | |
322 | case 0: | |
323 | unmasked = | |
324 | FPU_load_single((float __user *) | |
325 | data_address, | |
326 | &loaded_data); | |
327 | loaded_tag = unmasked & 0xff; | |
328 | unmasked &= ~0xff; | |
329 | break; | |
330 | case 1: | |
331 | loaded_tag = | |
332 | FPU_load_int32((long __user *) | |
333 | data_address, | |
334 | &loaded_data); | |
335 | break; | |
336 | case 2: | |
337 | unmasked = | |
338 | FPU_load_double((double __user *) | |
339 | data_address, | |
340 | &loaded_data); | |
341 | loaded_tag = unmasked & 0xff; | |
342 | unmasked &= ~0xff; | |
343 | break; | |
344 | case 3: | |
345 | default: /* Used here to suppress gcc warnings. */ | |
346 | loaded_tag = | |
347 | FPU_load_int16((short __user *) | |
348 | data_address, | |
349 | &loaded_data); | |
350 | break; | |
351 | } | |
352 | ||
353 | /* No more access to user memory, it is safe | |
354 | to use static data now */ | |
355 | ||
356 | /* NaN operands have the next priority. */ | |
357 | /* We have to delay looking at st(0) until after | |
358 | loading the data, because that data might contain an SNaN */ | |
359 | if (((st0_tag == TAG_Special) && isNaN(st0_ptr)) | |
360 | || ((loaded_tag == TAG_Special) | |
361 | && isNaN(&loaded_data))) { | |
362 | /* Restore the status word; we might have loaded a | |
363 | denormal. */ | |
364 | partial_status = status1; | |
365 | if ((FPU_modrm & 0x30) == 0x10) { | |
366 | /* fcom or fcomp */ | |
367 | EXCEPTION(EX_Invalid); | |
368 | setcc(SW_C3 | SW_C2 | SW_C0); | |
369 | if ((FPU_modrm & 0x08) | |
370 | && (control_word & | |
371 | CW_Invalid)) | |
372 | FPU_pop(); /* fcomp, masked, so we pop. */ | |
373 | } else { | |
374 | if (loaded_tag == TAG_Special) | |
375 | loaded_tag = | |
376 | FPU_Special | |
377 | (&loaded_data); | |
378 | #ifdef PECULIAR_486 | |
379 | /* This is not really needed, but gives behaviour | |
380 | identical to an 80486 */ | |
381 | if ((FPU_modrm & 0x28) == 0x20) | |
382 | /* fdiv or fsub */ | |
383 | real_2op_NaN | |
384 | (&loaded_data, | |
385 | loaded_tag, 0, | |
386 | &loaded_data); | |
387 | else | |
388 | #endif /* PECULIAR_486 */ | |
389 | /* fadd, fdivr, fmul, or fsubr */ | |
390 | real_2op_NaN | |
391 | (&loaded_data, | |
392 | loaded_tag, 0, | |
393 | st0_ptr); | |
394 | } | |
395 | goto reg_mem_instr_done; | |
396 | } | |
397 | ||
398 | if (unmasked && !((FPU_modrm & 0x30) == 0x10)) { | |
399 | /* Is not a comparison instruction. */ | |
400 | if ((FPU_modrm & 0x38) == 0x38) { | |
401 | /* fdivr */ | |
402 | if ((st0_tag == TAG_Zero) && | |
403 | ((loaded_tag == TAG_Valid) | |
404 | || (loaded_tag == | |
405 | TAG_Special | |
406 | && | |
407 | isdenormal | |
408 | (&loaded_data)))) { | |
409 | if (FPU_divide_by_zero | |
410 | (0, | |
411 | getsign | |
412 | (&loaded_data)) | |
413 | < 0) { | |
414 | /* We use the fact here that the unmasked | |
415 | exception in the loaded data was for a | |
416 | denormal operand */ | |
417 | /* Restore the state of the denormal op bit */ | |
418 | partial_status | |
419 | &= | |
420 | ~SW_Denorm_Op; | |
421 | partial_status | |
422 | |= | |
423 | status1 & | |
424 | SW_Denorm_Op; | |
425 | } else | |
426 | setsign(st0_ptr, | |
427 | getsign | |
428 | (&loaded_data)); | |
429 | } | |
430 | } | |
431 | goto reg_mem_instr_done; | |
432 | } | |
433 | ||
434 | switch ((FPU_modrm >> 3) & 7) { | |
435 | case 0: /* fadd */ | |
436 | clear_C1(); | |
437 | FPU_add(&loaded_data, loaded_tag, 0, | |
438 | control_word); | |
439 | break; | |
440 | case 1: /* fmul */ | |
441 | clear_C1(); | |
442 | FPU_mul(&loaded_data, loaded_tag, 0, | |
443 | control_word); | |
444 | break; | |
445 | case 2: /* fcom */ | |
446 | FPU_compare_st_data(&loaded_data, | |
447 | loaded_tag); | |
448 | break; | |
449 | case 3: /* fcomp */ | |
450 | if (!FPU_compare_st_data | |
451 | (&loaded_data, loaded_tag) | |
452 | && !unmasked) | |
453 | FPU_pop(); | |
454 | break; | |
455 | case 4: /* fsub */ | |
456 | clear_C1(); | |
457 | FPU_sub(LOADED | loaded_tag, | |
458 | (int)&loaded_data, | |
459 | control_word); | |
460 | break; | |
461 | case 5: /* fsubr */ | |
462 | clear_C1(); | |
463 | FPU_sub(REV | LOADED | loaded_tag, | |
464 | (int)&loaded_data, | |
465 | control_word); | |
466 | break; | |
467 | case 6: /* fdiv */ | |
468 | clear_C1(); | |
469 | FPU_div(LOADED | loaded_tag, | |
470 | (int)&loaded_data, | |
471 | control_word); | |
472 | break; | |
473 | case 7: /* fdivr */ | |
474 | clear_C1(); | |
475 | if (st0_tag == TAG_Zero) | |
476 | partial_status = status1; /* Undo any denorm tag, | |
477 | zero-divide has priority. */ | |
478 | FPU_div(REV | LOADED | loaded_tag, | |
479 | (int)&loaded_data, | |
480 | control_word); | |
481 | break; | |
482 | } | |
483 | } else { | |
484 | if ((FPU_modrm & 0x30) == 0x10) { | |
485 | /* The instruction is fcom or fcomp */ | |
486 | EXCEPTION(EX_StackUnder); | |
487 | setcc(SW_C3 | SW_C2 | SW_C0); | |
488 | if ((FPU_modrm & 0x08) | |
489 | && (control_word & CW_Invalid)) | |
490 | FPU_pop(); /* fcomp */ | |
491 | } else | |
492 | FPU_stack_underflow(); | |
493 | } | |
494 | reg_mem_instr_done: | |
495 | operand_address = data_sel_off; | |
496 | } else { | |
497 | if (!(no_ip_update = | |
498 | FPU_load_store(((FPU_modrm & 0x38) | (byte1 & 6)) | |
499 | >> 1, addr_modes, data_address))) { | |
500 | operand_address = data_sel_off; | |
501 | } | |
1da177e4 | 502 | } |
1da177e4 | 503 | |
3d0d14f9 IM |
504 | } else { |
505 | /* None of these instructions access user memory */ | |
506 | u_char instr_index = (FPU_modrm & 0x38) | (byte1 & 7); | |
1da177e4 LT |
507 | |
508 | #ifdef PECULIAR_486 | |
3d0d14f9 IM |
509 | /* This is supposed to be undefined, but a real 80486 seems |
510 | to do this: */ | |
511 | operand_address.offset = 0; | |
512 | operand_address.selector = FPU_DS; | |
1da177e4 LT |
513 | #endif /* PECULIAR_486 */ |
514 | ||
3d0d14f9 IM |
515 | st0_ptr = &st(0); |
516 | st0_tag = FPU_gettag0(); | |
517 | switch (type_table[(int)instr_index]) { | |
518 | case _NONE_: /* also _REGIc: _REGIn */ | |
519 | break; | |
520 | case _REG0_: | |
521 | if (!NOT_EMPTY_ST0) { | |
522 | FPU_stack_underflow(); | |
523 | goto FPU_instruction_done; | |
524 | } | |
525 | break; | |
526 | case _REGIi: | |
527 | if (!NOT_EMPTY_ST0 || !NOT_EMPTY(FPU_rm)) { | |
528 | FPU_stack_underflow_i(FPU_rm); | |
529 | goto FPU_instruction_done; | |
530 | } | |
531 | break; | |
532 | case _REGIp: | |
533 | if (!NOT_EMPTY_ST0 || !NOT_EMPTY(FPU_rm)) { | |
534 | FPU_stack_underflow_pop(FPU_rm); | |
535 | goto FPU_instruction_done; | |
536 | } | |
537 | break; | |
538 | case _REGI_: | |
539 | if (!NOT_EMPTY_ST0 || !NOT_EMPTY(FPU_rm)) { | |
540 | FPU_stack_underflow(); | |
541 | goto FPU_instruction_done; | |
542 | } | |
543 | break; | |
544 | case _PUSH_: /* Only used by the fld st(i) instruction */ | |
545 | break; | |
546 | case _null_: | |
547 | FPU_illegal(); | |
548 | goto FPU_instruction_done; | |
549 | default: | |
550 | EXCEPTION(EX_INTERNAL | 0x111); | |
551 | goto FPU_instruction_done; | |
552 | } | |
553 | (*st_instr_table[(int)instr_index]) (); | |
1da177e4 | 554 | |
3d0d14f9 IM |
555 | FPU_instruction_done: |
556 | ; | |
557 | } | |
1da177e4 | 558 | |
3d0d14f9 IM |
559 | if (!no_ip_update) |
560 | instruction_address = entry_sel_off; | |
1da177e4 | 561 | |
3d0d14f9 | 562 | FPU_fwait_done: |
1da177e4 LT |
563 | |
564 | #ifdef DEBUG | |
3d0d14f9 IM |
565 | RE_ENTRANT_CHECK_OFF; |
566 | FPU_printall(); | |
567 | RE_ENTRANT_CHECK_ON; | |
1da177e4 LT |
568 | #endif /* DEBUG */ |
569 | ||
3d0d14f9 IM |
570 | if (FPU_lookahead && !need_resched()) { |
571 | FPU_ORIG_EIP = FPU_EIP - code_base; | |
572 | if (valid_prefix(&byte1, (u_char __user **) & FPU_EIP, | |
573 | &addr_modes.override)) | |
574 | goto do_another_FPU_instruction; | |
575 | } | |
1da177e4 | 576 | |
3d0d14f9 IM |
577 | if (addr_modes.default_mode) |
578 | FPU_EIP -= code_base; | |
1da177e4 | 579 | |
3d0d14f9 | 580 | RE_ENTRANT_CHECK_OFF; |
1da177e4 LT |
581 | } |
582 | ||
1da177e4 LT |
583 | /* Support for prefix bytes is not yet complete. To properly handle |
584 | all prefix bytes, further changes are needed in the emulator code | |
585 | which accesses user address space. Access to separate segments is | |
586 | important for msdos emulation. */ | |
e8d591dc | 587 | static int valid_prefix(u_char *Byte, u_char __user **fpu_eip, |
3d0d14f9 | 588 | overrides * override) |
1da177e4 | 589 | { |
3d0d14f9 IM |
590 | u_char byte; |
591 | u_char __user *ip = *fpu_eip; | |
592 | ||
593 | *override = (overrides) { | |
594 | 0, 0, PREFIX_DEFAULT}; /* defaults */ | |
595 | ||
596 | RE_ENTRANT_CHECK_OFF; | |
597 | FPU_code_access_ok(1); | |
598 | FPU_get_user(byte, ip); | |
599 | RE_ENTRANT_CHECK_ON; | |
600 | ||
601 | while (1) { | |
602 | switch (byte) { | |
603 | case ADDR_SIZE_PREFIX: | |
604 | override->address_size = ADDR_SIZE_PREFIX; | |
605 | goto do_next_byte; | |
606 | ||
607 | case OP_SIZE_PREFIX: | |
608 | override->operand_size = OP_SIZE_PREFIX; | |
609 | goto do_next_byte; | |
610 | ||
611 | case PREFIX_CS: | |
612 | override->segment = PREFIX_CS_; | |
613 | goto do_next_byte; | |
614 | case PREFIX_ES: | |
615 | override->segment = PREFIX_ES_; | |
616 | goto do_next_byte; | |
617 | case PREFIX_SS: | |
618 | override->segment = PREFIX_SS_; | |
619 | goto do_next_byte; | |
620 | case PREFIX_FS: | |
621 | override->segment = PREFIX_FS_; | |
622 | goto do_next_byte; | |
623 | case PREFIX_GS: | |
624 | override->segment = PREFIX_GS_; | |
625 | goto do_next_byte; | |
626 | case PREFIX_DS: | |
627 | override->segment = PREFIX_DS_; | |
628 | goto do_next_byte; | |
1da177e4 LT |
629 | |
630 | /* lock is not a valid prefix for FPU instructions, | |
631 | let the cpu handle it to generate a SIGILL. */ | |
632 | /* case PREFIX_LOCK: */ | |
633 | ||
3d0d14f9 IM |
634 | /* rep.. prefixes have no meaning for FPU instructions */ |
635 | case PREFIX_REPE: | |
636 | case PREFIX_REPNE: | |
637 | ||
638 | do_next_byte: | |
639 | ip++; | |
640 | RE_ENTRANT_CHECK_OFF; | |
641 | FPU_code_access_ok(1); | |
642 | FPU_get_user(byte, ip); | |
643 | RE_ENTRANT_CHECK_ON; | |
644 | break; | |
645 | case FWAIT_OPCODE: | |
646 | *Byte = byte; | |
647 | return 1; | |
648 | default: | |
649 | if ((byte & 0xf8) == 0xd8) { | |
650 | *Byte = byte; | |
651 | *fpu_eip = ip; | |
652 | return 1; | |
653 | } else { | |
654 | /* Not a valid sequence of prefix bytes followed by | |
655 | an FPU instruction. */ | |
656 | *Byte = byte; /* Needed for error message. */ | |
657 | return 0; | |
658 | } | |
659 | } | |
1da177e4 | 660 | } |
1da177e4 LT |
661 | } |
662 | ||
ae6af41f | 663 | void math_abort(struct math_emu_info *info, unsigned int signal) |
1da177e4 LT |
664 | { |
665 | FPU_EIP = FPU_ORIG_EIP; | |
51e7dc70 | 666 | current->thread.trap_nr = X86_TRAP_MF; |
1da177e4 | 667 | current->thread.error_code = 0; |
3d0d14f9 | 668 | send_sig(signal, current, 1); |
1da177e4 | 669 | RE_ENTRANT_CHECK_OFF; |
3d0d14f9 | 670 | __asm__("movl %0,%%esp ; ret": :"g"(((long)info) - 4)); |
1da177e4 | 671 | #ifdef PARANOID |
3d0d14f9 | 672 | printk("ERROR: wm-FPU-emu math_abort failed!\n"); |
1da177e4 LT |
673 | #endif /* PARANOID */ |
674 | } | |
675 | ||
1da177e4 LT |
676 | #define S387 ((struct i387_soft_struct *)s387) |
677 | #define sstatus_word() \ | |
678 | ((S387->swd & ~SW_Top & 0xffff) | ((S387->ftop << SW_Top_Shift) & SW_Top)) | |
679 | ||
ff0ebb23 RM |
680 | int fpregs_soft_set(struct task_struct *target, |
681 | const struct user_regset *regset, | |
682 | unsigned int pos, unsigned int count, | |
683 | const void *kbuf, const void __user *ubuf) | |
1da177e4 | 684 | { |
c3f8978e | 685 | struct i387_soft_struct *s387 = &target->thread.fpu.state->soft; |
ff0ebb23 RM |
686 | void *space = s387->st_space; |
687 | int ret; | |
3d0d14f9 IM |
688 | int offset, other, i, tags, regnr, tag, newtop; |
689 | ||
690 | RE_ENTRANT_CHECK_OFF; | |
ff0ebb23 RM |
691 | ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, s387, 0, |
692 | offsetof(struct i387_soft_struct, st_space)); | |
3d0d14f9 IM |
693 | RE_ENTRANT_CHECK_ON; |
694 | ||
ff0ebb23 RM |
695 | if (ret) |
696 | return ret; | |
3d0d14f9 IM |
697 | |
698 | S387->ftop = (S387->swd >> SW_Top_Shift) & 7; | |
699 | offset = (S387->ftop & 7) * 10; | |
700 | other = 80 - offset; | |
701 | ||
702 | RE_ENTRANT_CHECK_OFF; | |
ff0ebb23 | 703 | |
3d0d14f9 | 704 | /* Copy all registers in stack order. */ |
ff0ebb23 RM |
705 | ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, |
706 | space + offset, 0, other); | |
707 | if (!ret && offset) | |
708 | ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, | |
709 | space, 0, offset); | |
710 | ||
3d0d14f9 IM |
711 | RE_ENTRANT_CHECK_ON; |
712 | ||
713 | /* The tags may need to be corrected now. */ | |
714 | tags = S387->twd; | |
715 | newtop = S387->ftop; | |
716 | for (i = 0; i < 8; i++) { | |
717 | regnr = (i + newtop) & 7; | |
718 | if (((tags >> ((regnr & 7) * 2)) & 3) != TAG_Empty) { | |
719 | /* The loaded data over-rides all other cases. */ | |
720 | tag = | |
721 | FPU_tagof((FPU_REG *) ((u_char *) S387->st_space + | |
722 | 10 * regnr)); | |
723 | tags &= ~(3 << (regnr * 2)); | |
724 | tags |= (tag & 3) << (regnr * 2); | |
725 | } | |
1da177e4 | 726 | } |
3d0d14f9 | 727 | S387->twd = tags; |
1da177e4 | 728 | |
ff0ebb23 | 729 | return ret; |
1da177e4 LT |
730 | } |
731 | ||
ff0ebb23 RM |
732 | int fpregs_soft_get(struct task_struct *target, |
733 | const struct user_regset *regset, | |
734 | unsigned int pos, unsigned int count, | |
735 | void *kbuf, void __user *ubuf) | |
1da177e4 | 736 | { |
c3f8978e | 737 | struct i387_soft_struct *s387 = &target->thread.fpu.state->soft; |
ff0ebb23 RM |
738 | const void *space = s387->st_space; |
739 | int ret; | |
3d0d14f9 | 740 | int offset = (S387->ftop & 7) * 10, other = 80 - offset; |
1da177e4 | 741 | |
3d0d14f9 | 742 | RE_ENTRANT_CHECK_OFF; |
ff0ebb23 | 743 | |
1da177e4 | 744 | #ifdef PECULIAR_486 |
3d0d14f9 IM |
745 | S387->cwd &= ~0xe080; |
746 | /* An 80486 sets nearly all of the reserved bits to 1. */ | |
747 | S387->cwd |= 0xffff0040; | |
748 | S387->swd = sstatus_word() | 0xffff0000; | |
749 | S387->twd |= 0xffff0000; | |
750 | S387->fcs &= ~0xf8000000; | |
751 | S387->fos |= 0xffff0000; | |
1da177e4 | 752 | #endif /* PECULIAR_486 */ |
3d0d14f9 | 753 | |
ff0ebb23 RM |
754 | ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, s387, 0, |
755 | offsetof(struct i387_soft_struct, st_space)); | |
3d0d14f9 | 756 | |
3d0d14f9 | 757 | /* Copy all registers in stack order. */ |
ff0ebb23 RM |
758 | if (!ret) |
759 | ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, | |
760 | space + offset, 0, other); | |
761 | if (!ret) | |
762 | ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, | |
763 | space, 0, offset); | |
764 | ||
3d0d14f9 IM |
765 | RE_ENTRANT_CHECK_ON; |
766 | ||
ff0ebb23 RM |
767 | return ret; |
768 | } |