1 /*- 2 * Copyright (c) 1990 William Jolitz. 3 * Copyright (c) 1991 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * from: @(#)npx.c 7.2 (Berkeley) 5/12/91 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/bus.h> 39 #include <sys/kernel.h> 40 #include <sys/lock.h> 41 #include <sys/malloc.h> 42 #include <sys/module.h> 43 #include <sys/mutex.h> 44 #include <sys/mutex.h> 45 #include <sys/proc.h> 46 #include <sys/sysctl.h> 47 #include <machine/bus.h> 48 #include <sys/rman.h> 49 #include <sys/signalvar.h> 50 #include <vm/uma.h> 51 52 #include <machine/cputypes.h> 53 #include <machine/frame.h> 54 #include <machine/intr_machdep.h> 55 #include <machine/md_var.h> 56 #include <machine/pcb.h> 57 #include <machine/psl.h> 58 #include <machine/resource.h> 59 #include <machine/specialreg.h> 60 #include <machine/segments.h> 61 #include <machine/ucontext.h> 62 63 /* 64 * Floating point support. 65 */ 66 67 #if defined(__GNUCLIKE_ASM) && !defined(lint) 68 69 #define fldcw(cw) __asm __volatile("fldcw %0" : : "m" (cw)) 70 #define fnclex() __asm __volatile("fnclex") 71 #define fninit() __asm __volatile("fninit") 72 #define fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr))) 73 #define fnstsw(addr) __asm __volatile("fnstsw %0" : "=am" (*(addr))) 74 #define fxrstor(addr) __asm __volatile("fxrstor %0" : : "m" (*(addr))) 75 #define fxsave(addr) __asm __volatile("fxsave %0" : "=m" (*(addr))) 76 #define ldmxcsr(csr) __asm __volatile("ldmxcsr %0" : : "m" (csr)) 77 #define stmxcsr(addr) __asm __volatile("stmxcsr %0" : : "m" (*(addr))) 78 79 static __inline void 80 xrstor(char *addr, uint64_t mask) 81 { 82 uint32_t low, hi; 83 84 low = mask; 85 hi = mask >> 32; 86 __asm __volatile("xrstor %0" : : "m" (*addr), "a" (low), "d" (hi)); 87 } 88 89 static __inline void 90 xsave(char *addr, uint64_t mask) 91 { 92 uint32_t low, hi; 93 94 low = mask; 95 hi = mask >> 32; 96 __asm __volatile("xsave %0" : "=m" (*addr) : "a" (low), "d" (hi) : 97 "memory"); 98 } 99 100 #else /* !(__GNUCLIKE_ASM && !lint) */ 101 102 void fldcw(u_short cw); 103 void fnclex(void); 104 void fninit(void); 105 void fnstcw(caddr_t addr); 106 void fnstsw(caddr_t addr); 107 void fxsave(caddr_t addr); 108 void fxrstor(caddr_t addr); 109 void ldmxcsr(u_int csr); 110 void stmxcsr(u_int *csr); 111 void xrstor(char *addr, uint64_t mask); 112 void xsave(char *addr, uint64_t mask); 113 114 #endif /* __GNUCLIKE_ASM && !lint */ 115 116 #define start_emulating() load_cr0(rcr0() | CR0_TS) 117 #define stop_emulating() clts() 118 119 CTASSERT(sizeof(struct savefpu) == 512); 120 CTASSERT(sizeof(struct xstate_hdr) == 64); 121 CTASSERT(sizeof(struct savefpu_ymm) == 832); 122 123 /* 124 * This requirement is to make it easier for asm code to calculate 125 * offset of the fpu save area from the pcb address. FPU save area 126 * must be 64-byte aligned. 127 */ 128 CTASSERT(sizeof(struct pcb) % XSAVE_AREA_ALIGN == 0); 129 130 /* 131 * Ensure the copy of XCR0 saved in a core is contained in the padding 132 * area. 133 */ 134 CTASSERT(X86_XSTATE_XCR0_OFFSET >= offsetof(struct savefpu, sv_pad) && 135 X86_XSTATE_XCR0_OFFSET + sizeof(uint64_t) <= sizeof(struct savefpu)); 136 137 static void fpu_clean_state(void); 138 139 SYSCTL_INT(_hw, HW_FLOATINGPT, floatingpoint, CTLFLAG_RD, 140 SYSCTL_NULL_INT_PTR, 1, "Floating point instructions executed in hardware"); 141 142 int use_xsave; /* non-static for cpu_switch.S */ 143 uint64_t xsave_mask; /* the same */ 144 static uma_zone_t fpu_save_area_zone; 145 static struct savefpu *fpu_initialstate; 146 147 struct xsave_area_elm_descr { 148 u_int offset; 149 u_int size; 150 } *xsave_area_desc; 151 152 void 153 fpusave(void *addr) 154 { 155 156 if (use_xsave) 157 xsave((char *)addr, xsave_mask); 158 else 159 fxsave((char *)addr); 160 } 161 162 void 163 fpurestore(void *addr) 164 { 165 166 if (use_xsave) 167 xrstor((char *)addr, xsave_mask); 168 else 169 fxrstor((char *)addr); 170 } 171 172 void 173 fpususpend(void *addr) 174 { 175 u_long cr0; 176 177 cr0 = rcr0(); 178 stop_emulating(); 179 fpusave(addr); 180 load_cr0(cr0); 181 } 182 183 void 184 fpuresume(void *addr) 185 { 186 u_long cr0; 187 188 cr0 = rcr0(); 189 stop_emulating(); 190 fninit(); 191 if (use_xsave) 192 load_xcr(XCR0, xsave_mask); 193 fpurestore(addr); 194 load_cr0(cr0); 195 } 196 197 /* 198 * Enable XSAVE if supported and allowed by user. 199 * Calculate the xsave_mask. 200 */ 201 static void 202 fpuinit_bsp1(void) 203 { 204 u_int cp[4]; 205 uint64_t xsave_mask_user; 206 207 if ((cpu_feature2 & CPUID2_XSAVE) != 0) { 208 use_xsave = 1; 209 TUNABLE_INT_FETCH("hw.use_xsave", &use_xsave); 210 } 211 if (!use_xsave) 212 return; 213 214 cpuid_count(0xd, 0x0, cp); 215 xsave_mask = XFEATURE_ENABLED_X87 | XFEATURE_ENABLED_SSE; 216 if ((cp[0] & xsave_mask) != xsave_mask) 217 panic("CPU0 does not support X87 or SSE: %x", cp[0]); 218 xsave_mask = ((uint64_t)cp[3] << 32) | cp[0]; 219 xsave_mask_user = xsave_mask; 220 TUNABLE_ULONG_FETCH("hw.xsave_mask", &xsave_mask_user); 221 xsave_mask_user |= XFEATURE_ENABLED_X87 | XFEATURE_ENABLED_SSE; 222 xsave_mask &= xsave_mask_user; 223 if ((xsave_mask & XFEATURE_AVX512) != XFEATURE_AVX512) 224 xsave_mask &= ~XFEATURE_AVX512; 225 if ((xsave_mask & XFEATURE_MPX) != XFEATURE_MPX) 226 xsave_mask &= ~XFEATURE_MPX; 227 228 cpuid_count(0xd, 0x1, cp); 229 if ((cp[0] & CPUID_EXTSTATE_XSAVEOPT) != 0) { 230 /* 231 * Patch the XSAVE instruction in the cpu_switch code 232 * to XSAVEOPT. We assume that XSAVE encoding used 233 * REX byte, and set the bit 4 of the r/m byte. 234 */ 235 ctx_switch_xsave[3] |= 0x10; 236 } 237 } 238 239 /* 240 * Calculate the fpu save area size. 241 */ 242 static void 243 fpuinit_bsp2(void) 244 { 245 u_int cp[4]; 246 247 if (use_xsave) { 248 cpuid_count(0xd, 0x0, cp); 249 cpu_max_ext_state_size = cp[1]; 250 251 /* 252 * Reload the cpu_feature2, since we enabled OSXSAVE. 253 */ 254 do_cpuid(1, cp); 255 cpu_feature2 = cp[2]; 256 } else 257 cpu_max_ext_state_size = sizeof(struct savefpu); 258 } 259 260 /* 261 * Initialize the floating point unit. 262 */ 263 void 264 fpuinit(void) 265 { 266 register_t saveintr; 267 u_int mxcsr; 268 u_short control; 269 270 if (IS_BSP()) 271 fpuinit_bsp1(); 272 273 if (use_xsave) { 274 load_cr4(rcr4() | CR4_XSAVE); 275 load_xcr(XCR0, xsave_mask); 276 } 277 278 /* 279 * XCR0 shall be set up before CPU can report the save area size. 280 */ 281 if (IS_BSP()) 282 fpuinit_bsp2(); 283 284 /* 285 * It is too early for critical_enter() to work on AP. 286 */ 287 saveintr = intr_disable(); 288 stop_emulating(); 289 fninit(); 290 control = __INITIAL_FPUCW__; 291 fldcw(control); 292 mxcsr = __INITIAL_MXCSR__; 293 ldmxcsr(mxcsr); 294 start_emulating(); 295 intr_restore(saveintr); 296 } 297 298 /* 299 * On the boot CPU we generate a clean state that is used to 300 * initialize the floating point unit when it is first used by a 301 * process. 302 */ 303 static void 304 fpuinitstate(void *arg __unused) 305 { 306 register_t saveintr; 307 int cp[4], i, max_ext_n; 308 309 fpu_initialstate = malloc(cpu_max_ext_state_size, M_DEVBUF, 310 M_WAITOK | M_ZERO); 311 saveintr = intr_disable(); 312 stop_emulating(); 313 314 fpusave(fpu_initialstate); 315 if (fpu_initialstate->sv_env.en_mxcsr_mask) 316 cpu_mxcsr_mask = fpu_initialstate->sv_env.en_mxcsr_mask; 317 else 318 cpu_mxcsr_mask = 0xFFBF; 319 320 /* 321 * The fninit instruction does not modify XMM registers or x87 322 * registers (MM/ST). The fpusave call dumped the garbage 323 * contained in the registers after reset to the initial state 324 * saved. Clear XMM and x87 registers file image to make the 325 * startup program state and signal handler XMM/x87 register 326 * content predictable. 327 */ 328 bzero(fpu_initialstate->sv_fp, sizeof(fpu_initialstate->sv_fp)); 329 bzero(fpu_initialstate->sv_xmm, sizeof(fpu_initialstate->sv_xmm)); 330 331 /* 332 * Create a table describing the layout of the CPU Extended 333 * Save Area. 334 */ 335 if (use_xsave) { 336 max_ext_n = flsl(xsave_mask); 337 xsave_area_desc = malloc(max_ext_n * sizeof(struct 338 xsave_area_elm_descr), M_DEVBUF, M_WAITOK | M_ZERO); 339 /* x87 state */ 340 xsave_area_desc[0].offset = 0; 341 xsave_area_desc[0].size = 160; 342 /* XMM */ 343 xsave_area_desc[1].offset = 160; 344 xsave_area_desc[1].size = 288 - 160; 345 346 for (i = 2; i < max_ext_n; i++) { 347 cpuid_count(0xd, i, cp); 348 xsave_area_desc[i].offset = cp[1]; 349 xsave_area_desc[i].size = cp[0]; 350 } 351 } 352 353 fpu_save_area_zone = uma_zcreate("FPU_save_area", 354 cpu_max_ext_state_size, NULL, NULL, NULL, NULL, 355 XSAVE_AREA_ALIGN - 1, 0); 356 357 start_emulating(); 358 intr_restore(saveintr); 359 } 360 SYSINIT(fpuinitstate, SI_SUB_DRIVERS, SI_ORDER_ANY, fpuinitstate, NULL); 361 362 /* 363 * Free coprocessor (if we have it). 364 */ 365 void 366 fpuexit(struct thread *td) 367 { 368 369 critical_enter(); 370 if (curthread == PCPU_GET(fpcurthread)) { 371 stop_emulating(); 372 fpusave(curpcb->pcb_save); 373 start_emulating(); 374 PCPU_SET(fpcurthread, NULL); 375 } 376 critical_exit(); 377 } 378 379 int 380 fpuformat(void) 381 { 382 383 return (_MC_FPFMT_XMM); 384 } 385 386 /* 387 * The following mechanism is used to ensure that the FPE_... value 388 * that is passed as a trapcode to the signal handler of the user 389 * process does not have more than one bit set. 390 * 391 * Multiple bits may be set if the user process modifies the control 392 * word while a status word bit is already set. While this is a sign 393 * of bad coding, we have no choise than to narrow them down to one 394 * bit, since we must not send a trapcode that is not exactly one of 395 * the FPE_ macros. 396 * 397 * The mechanism has a static table with 127 entries. Each combination 398 * of the 7 FPU status word exception bits directly translates to a 399 * position in this table, where a single FPE_... value is stored. 400 * This FPE_... value stored there is considered the "most important" 401 * of the exception bits and will be sent as the signal code. The 402 * precedence of the bits is based upon Intel Document "Numerical 403 * Applications", Chapter "Special Computational Situations". 404 * 405 * The macro to choose one of these values does these steps: 1) Throw 406 * away status word bits that cannot be masked. 2) Throw away the bits 407 * currently masked in the control word, assuming the user isn't 408 * interested in them anymore. 3) Reinsert status word bit 7 (stack 409 * fault) if it is set, which cannot be masked but must be presered. 410 * 4) Use the remaining bits to point into the trapcode table. 411 * 412 * The 6 maskable bits in order of their preference, as stated in the 413 * above referenced Intel manual: 414 * 1 Invalid operation (FP_X_INV) 415 * 1a Stack underflow 416 * 1b Stack overflow 417 * 1c Operand of unsupported format 418 * 1d SNaN operand. 419 * 2 QNaN operand (not an exception, irrelavant here) 420 * 3 Any other invalid-operation not mentioned above or zero divide 421 * (FP_X_INV, FP_X_DZ) 422 * 4 Denormal operand (FP_X_DNML) 423 * 5 Numeric over/underflow (FP_X_OFL, FP_X_UFL) 424 * 6 Inexact result (FP_X_IMP) 425 */ 426 static char fpetable[128] = { 427 0, 428 FPE_FLTINV, /* 1 - INV */ 429 FPE_FLTUND, /* 2 - DNML */ 430 FPE_FLTINV, /* 3 - INV | DNML */ 431 FPE_FLTDIV, /* 4 - DZ */ 432 FPE_FLTINV, /* 5 - INV | DZ */ 433 FPE_FLTDIV, /* 6 - DNML | DZ */ 434 FPE_FLTINV, /* 7 - INV | DNML | DZ */ 435 FPE_FLTOVF, /* 8 - OFL */ 436 FPE_FLTINV, /* 9 - INV | OFL */ 437 FPE_FLTUND, /* A - DNML | OFL */ 438 FPE_FLTINV, /* B - INV | DNML | OFL */ 439 FPE_FLTDIV, /* C - DZ | OFL */ 440 FPE_FLTINV, /* D - INV | DZ | OFL */ 441 FPE_FLTDIV, /* E - DNML | DZ | OFL */ 442 FPE_FLTINV, /* F - INV | DNML | DZ | OFL */ 443 FPE_FLTUND, /* 10 - UFL */ 444 FPE_FLTINV, /* 11 - INV | UFL */ 445 FPE_FLTUND, /* 12 - DNML | UFL */ 446 FPE_FLTINV, /* 13 - INV | DNML | UFL */ 447 FPE_FLTDIV, /* 14 - DZ | UFL */ 448 FPE_FLTINV, /* 15 - INV | DZ | UFL */ 449 FPE_FLTDIV, /* 16 - DNML | DZ | UFL */ 450 FPE_FLTINV, /* 17 - INV | DNML | DZ | UFL */ 451 FPE_FLTOVF, /* 18 - OFL | UFL */ 452 FPE_FLTINV, /* 19 - INV | OFL | UFL */ 453 FPE_FLTUND, /* 1A - DNML | OFL | UFL */ 454 FPE_FLTINV, /* 1B - INV | DNML | OFL | UFL */ 455 FPE_FLTDIV, /* 1C - DZ | OFL | UFL */ 456 FPE_FLTINV, /* 1D - INV | DZ | OFL | UFL */ 457 FPE_FLTDIV, /* 1E - DNML | DZ | OFL | UFL */ 458 FPE_FLTINV, /* 1F - INV | DNML | DZ | OFL | UFL */ 459 FPE_FLTRES, /* 20 - IMP */ 460 FPE_FLTINV, /* 21 - INV | IMP */ 461 FPE_FLTUND, /* 22 - DNML | IMP */ 462 FPE_FLTINV, /* 23 - INV | DNML | IMP */ 463 FPE_FLTDIV, /* 24 - DZ | IMP */ 464 FPE_FLTINV, /* 25 - INV | DZ | IMP */ 465 FPE_FLTDIV, /* 26 - DNML | DZ | IMP */ 466 FPE_FLTINV, /* 27 - INV | DNML | DZ | IMP */ 467 FPE_FLTOVF, /* 28 - OFL | IMP */ 468 FPE_FLTINV, /* 29 - INV | OFL | IMP */ 469 FPE_FLTUND, /* 2A - DNML | OFL | IMP */ 470 FPE_FLTINV, /* 2B - INV | DNML | OFL | IMP */ 471 FPE_FLTDIV, /* 2C - DZ | OFL | IMP */ 472 FPE_FLTINV, /* 2D - INV | DZ | OFL | IMP */ 473 FPE_FLTDIV, /* 2E - DNML | DZ | OFL | IMP */ 474 FPE_FLTINV, /* 2F - INV | DNML | DZ | OFL | IMP */ 475 FPE_FLTUND, /* 30 - UFL | IMP */ 476 FPE_FLTINV, /* 31 - INV | UFL | IMP */ 477 FPE_FLTUND, /* 32 - DNML | UFL | IMP */ 478 FPE_FLTINV, /* 33 - INV | DNML | UFL | IMP */ 479 FPE_FLTDIV, /* 34 - DZ | UFL | IMP */ 480 FPE_FLTINV, /* 35 - INV | DZ | UFL | IMP */ 481 FPE_FLTDIV, /* 36 - DNML | DZ | UFL | IMP */ 482 FPE_FLTINV, /* 37 - INV | DNML | DZ | UFL | IMP */ 483 FPE_FLTOVF, /* 38 - OFL | UFL | IMP */ 484 FPE_FLTINV, /* 39 - INV | OFL | UFL | IMP */ 485 FPE_FLTUND, /* 3A - DNML | OFL | UFL | IMP */ 486 FPE_FLTINV, /* 3B - INV | DNML | OFL | UFL | IMP */ 487 FPE_FLTDIV, /* 3C - DZ | OFL | UFL | IMP */ 488 FPE_FLTINV, /* 3D - INV | DZ | OFL | UFL | IMP */ 489 FPE_FLTDIV, /* 3E - DNML | DZ | OFL | UFL | IMP */ 490 FPE_FLTINV, /* 3F - INV | DNML | DZ | OFL | UFL | IMP */ 491 FPE_FLTSUB, /* 40 - STK */ 492 FPE_FLTSUB, /* 41 - INV | STK */ 493 FPE_FLTUND, /* 42 - DNML | STK */ 494 FPE_FLTSUB, /* 43 - INV | DNML | STK */ 495 FPE_FLTDIV, /* 44 - DZ | STK */ 496 FPE_FLTSUB, /* 45 - INV | DZ | STK */ 497 FPE_FLTDIV, /* 46 - DNML | DZ | STK */ 498 FPE_FLTSUB, /* 47 - INV | DNML | DZ | STK */ 499 FPE_FLTOVF, /* 48 - OFL | STK */ 500 FPE_FLTSUB, /* 49 - INV | OFL | STK */ 501 FPE_FLTUND, /* 4A - DNML | OFL | STK */ 502 FPE_FLTSUB, /* 4B - INV | DNML | OFL | STK */ 503 FPE_FLTDIV, /* 4C - DZ | OFL | STK */ 504 FPE_FLTSUB, /* 4D - INV | DZ | OFL | STK */ 505 FPE_FLTDIV, /* 4E - DNML | DZ | OFL | STK */ 506 FPE_FLTSUB, /* 4F - INV | DNML | DZ | OFL | STK */ 507 FPE_FLTUND, /* 50 - UFL | STK */ 508 FPE_FLTSUB, /* 51 - INV | UFL | STK */ 509 FPE_FLTUND, /* 52 - DNML | UFL | STK */ 510 FPE_FLTSUB, /* 53 - INV | DNML | UFL | STK */ 511 FPE_FLTDIV, /* 54 - DZ | UFL | STK */ 512 FPE_FLTSUB, /* 55 - INV | DZ | UFL | STK */ 513 FPE_FLTDIV, /* 56 - DNML | DZ | UFL | STK */ 514 FPE_FLTSUB, /* 57 - INV | DNML | DZ | UFL | STK */ 515 FPE_FLTOVF, /* 58 - OFL | UFL | STK */ 516 FPE_FLTSUB, /* 59 - INV | OFL | UFL | STK */ 517 FPE_FLTUND, /* 5A - DNML | OFL | UFL | STK */ 518 FPE_FLTSUB, /* 5B - INV | DNML | OFL | UFL | STK */ 519 FPE_FLTDIV, /* 5C - DZ | OFL | UFL | STK */ 520 FPE_FLTSUB, /* 5D - INV | DZ | OFL | UFL | STK */ 521 FPE_FLTDIV, /* 5E - DNML | DZ | OFL | UFL | STK */ 522 FPE_FLTSUB, /* 5F - INV | DNML | DZ | OFL | UFL | STK */ 523 FPE_FLTRES, /* 60 - IMP | STK */ 524 FPE_FLTSUB, /* 61 - INV | IMP | STK */ 525 FPE_FLTUND, /* 62 - DNML | IMP | STK */ 526 FPE_FLTSUB, /* 63 - INV | DNML | IMP | STK */ 527 FPE_FLTDIV, /* 64 - DZ | IMP | STK */ 528 FPE_FLTSUB, /* 65 - INV | DZ | IMP | STK */ 529 FPE_FLTDIV, /* 66 - DNML | DZ | IMP | STK */ 530 FPE_FLTSUB, /* 67 - INV | DNML | DZ | IMP | STK */ 531 FPE_FLTOVF, /* 68 - OFL | IMP | STK */ 532 FPE_FLTSUB, /* 69 - INV | OFL | IMP | STK */ 533 FPE_FLTUND, /* 6A - DNML | OFL | IMP | STK */ 534 FPE_FLTSUB, /* 6B - INV | DNML | OFL | IMP | STK */ 535 FPE_FLTDIV, /* 6C - DZ | OFL | IMP | STK */ 536 FPE_FLTSUB, /* 6D - INV | DZ | OFL | IMP | STK */ 537 FPE_FLTDIV, /* 6E - DNML | DZ | OFL | IMP | STK */ 538 FPE_FLTSUB, /* 6F - INV | DNML | DZ | OFL | IMP | STK */ 539 FPE_FLTUND, /* 70 - UFL | IMP | STK */ 540 FPE_FLTSUB, /* 71 - INV | UFL | IMP | STK */ 541 FPE_FLTUND, /* 72 - DNML | UFL | IMP | STK */ 542 FPE_FLTSUB, /* 73 - INV | DNML | UFL | IMP | STK */ 543 FPE_FLTDIV, /* 74 - DZ | UFL | IMP | STK */ 544 FPE_FLTSUB, /* 75 - INV | DZ | UFL | IMP | STK */ 545 FPE_FLTDIV, /* 76 - DNML | DZ | UFL | IMP | STK */ 546 FPE_FLTSUB, /* 77 - INV | DNML | DZ | UFL | IMP | STK */ 547 FPE_FLTOVF, /* 78 - OFL | UFL | IMP | STK */ 548 FPE_FLTSUB, /* 79 - INV | OFL | UFL | IMP | STK */ 549 FPE_FLTUND, /* 7A - DNML | OFL | UFL | IMP | STK */ 550 FPE_FLTSUB, /* 7B - INV | DNML | OFL | UFL | IMP | STK */ 551 FPE_FLTDIV, /* 7C - DZ | OFL | UFL | IMP | STK */ 552 FPE_FLTSUB, /* 7D - INV | DZ | OFL | UFL | IMP | STK */ 553 FPE_FLTDIV, /* 7E - DNML | DZ | OFL | UFL | IMP | STK */ 554 FPE_FLTSUB, /* 7F - INV | DNML | DZ | OFL | UFL | IMP | STK */ 555 }; 556 557 /* 558 * Read the FP status and control words, then generate si_code value 559 * for SIGFPE. The error code chosen will be one of the 560 * FPE_... macros. It will be sent as the second argument to old 561 * BSD-style signal handlers and as "siginfo_t->si_code" (second 562 * argument) to SA_SIGINFO signal handlers. 563 * 564 * Some time ago, we cleared the x87 exceptions with FNCLEX there. 565 * Clearing exceptions was necessary mainly to avoid IRQ13 bugs. The 566 * usermode code which understands the FPU hardware enough to enable 567 * the exceptions, can also handle clearing the exception state in the 568 * handler. The only consequence of not clearing the exception is the 569 * rethrow of the SIGFPE on return from the signal handler and 570 * reexecution of the corresponding instruction. 571 * 572 * For XMM traps, the exceptions were never cleared. 573 */ 574 int 575 fputrap_x87(void) 576 { 577 struct savefpu *pcb_save; 578 u_short control, status; 579 580 critical_enter(); 581 582 /* 583 * Interrupt handling (for another interrupt) may have pushed the 584 * state to memory. Fetch the relevant parts of the state from 585 * wherever they are. 586 */ 587 if (PCPU_GET(fpcurthread) != curthread) { 588 pcb_save = curpcb->pcb_save; 589 control = pcb_save->sv_env.en_cw; 590 status = pcb_save->sv_env.en_sw; 591 } else { 592 fnstcw(&control); 593 fnstsw(&status); 594 } 595 596 critical_exit(); 597 return (fpetable[status & ((~control & 0x3f) | 0x40)]); 598 } 599 600 int 601 fputrap_sse(void) 602 { 603 u_int mxcsr; 604 605 critical_enter(); 606 if (PCPU_GET(fpcurthread) != curthread) 607 mxcsr = curpcb->pcb_save->sv_env.en_mxcsr; 608 else 609 stmxcsr(&mxcsr); 610 critical_exit(); 611 return (fpetable[(mxcsr & (~mxcsr >> 7)) & 0x3f]); 612 } 613 614 /* 615 * Device Not Available (DNA, #NM) exception handler. 616 * 617 * It would be better to switch FP context here (if curthread != 618 * fpcurthread) and not necessarily for every context switch, but it 619 * is too hard to access foreign pcb's. 620 */ 621 void 622 fpudna(void) 623 { 624 625 /* 626 * This handler is entered with interrupts enabled, so context 627 * switches may occur before critical_enter() is executed. If 628 * a context switch occurs, then when we regain control, our 629 * state will have been completely restored. The CPU may 630 * change underneath us, but the only part of our context that 631 * lives in the CPU is CR0.TS and that will be "restored" by 632 * setting it on the new CPU. 633 */ 634 critical_enter(); 635 636 KASSERT((curpcb->pcb_flags & PCB_FPUNOSAVE) == 0, 637 ("fpudna while in fpu_kern_enter(FPU_KERN_NOCTX)")); 638 if (PCPU_GET(fpcurthread) == curthread) { 639 printf("fpudna: fpcurthread == curthread\n"); 640 stop_emulating(); 641 critical_exit(); 642 return; 643 } 644 if (PCPU_GET(fpcurthread) != NULL) { 645 panic("fpudna: fpcurthread = %p (%d), curthread = %p (%d)\n", 646 PCPU_GET(fpcurthread), PCPU_GET(fpcurthread)->td_tid, 647 curthread, curthread->td_tid); 648 } 649 stop_emulating(); 650 /* 651 * Record new context early in case frstor causes a trap. 652 */ 653 PCPU_SET(fpcurthread, curthread); 654 655 fpu_clean_state(); 656 657 if ((curpcb->pcb_flags & PCB_FPUINITDONE) == 0) { 658 /* 659 * This is the first time this thread has used the FPU or 660 * the PCB doesn't contain a clean FPU state. Explicitly 661 * load an initial state. 662 * 663 * We prefer to restore the state from the actual save 664 * area in PCB instead of directly loading from 665 * fpu_initialstate, to ignite the XSAVEOPT 666 * tracking engine. 667 */ 668 bcopy(fpu_initialstate, curpcb->pcb_save, 669 cpu_max_ext_state_size); 670 fpurestore(curpcb->pcb_save); 671 if (curpcb->pcb_initial_fpucw != __INITIAL_FPUCW__) 672 fldcw(curpcb->pcb_initial_fpucw); 673 if (PCB_USER_FPU(curpcb)) 674 set_pcb_flags(curpcb, 675 PCB_FPUINITDONE | PCB_USERFPUINITDONE); 676 else 677 set_pcb_flags(curpcb, PCB_FPUINITDONE); 678 } else 679 fpurestore(curpcb->pcb_save); 680 critical_exit(); 681 } 682 683 void 684 fpudrop(void) 685 { 686 struct thread *td; 687 688 td = PCPU_GET(fpcurthread); 689 KASSERT(td == curthread, ("fpudrop: fpcurthread != curthread")); 690 CRITICAL_ASSERT(td); 691 PCPU_SET(fpcurthread, NULL); 692 clear_pcb_flags(td->td_pcb, PCB_FPUINITDONE); 693 start_emulating(); 694 } 695 696 /* 697 * Get the user state of the FPU into pcb->pcb_user_save without 698 * dropping ownership (if possible). It returns the FPU ownership 699 * status. 700 */ 701 int 702 fpugetregs(struct thread *td) 703 { 704 struct pcb *pcb; 705 uint64_t *xstate_bv, bit; 706 char *sa; 707 int max_ext_n, i, owned; 708 709 pcb = td->td_pcb; 710 if ((pcb->pcb_flags & PCB_USERFPUINITDONE) == 0) { 711 bcopy(fpu_initialstate, get_pcb_user_save_pcb(pcb), 712 cpu_max_ext_state_size); 713 get_pcb_user_save_pcb(pcb)->sv_env.en_cw = 714 pcb->pcb_initial_fpucw; 715 fpuuserinited(td); 716 return (_MC_FPOWNED_PCB); 717 } 718 critical_enter(); 719 if (td == PCPU_GET(fpcurthread) && PCB_USER_FPU(pcb)) { 720 fpusave(get_pcb_user_save_pcb(pcb)); 721 owned = _MC_FPOWNED_FPU; 722 } else { 723 owned = _MC_FPOWNED_PCB; 724 } 725 critical_exit(); 726 if (use_xsave) { 727 /* 728 * Handle partially saved state. 729 */ 730 sa = (char *)get_pcb_user_save_pcb(pcb); 731 xstate_bv = (uint64_t *)(sa + sizeof(struct savefpu) + 732 offsetof(struct xstate_hdr, xstate_bv)); 733 max_ext_n = flsl(xsave_mask); 734 for (i = 0; i < max_ext_n; i++) { 735 bit = 1ULL << i; 736 if ((xsave_mask & bit) == 0 || (*xstate_bv & bit) != 0) 737 continue; 738 bcopy((char *)fpu_initialstate + 739 xsave_area_desc[i].offset, 740 sa + xsave_area_desc[i].offset, 741 xsave_area_desc[i].size); 742 *xstate_bv |= bit; 743 } 744 } 745 return (owned); 746 } 747 748 void 749 fpuuserinited(struct thread *td) 750 { 751 struct pcb *pcb; 752 753 pcb = td->td_pcb; 754 if (PCB_USER_FPU(pcb)) 755 set_pcb_flags(pcb, 756 PCB_FPUINITDONE | PCB_USERFPUINITDONE); 757 else 758 set_pcb_flags(pcb, PCB_FPUINITDONE); 759 } 760 761 int 762 fpusetxstate(struct thread *td, char *xfpustate, size_t xfpustate_size) 763 { 764 struct xstate_hdr *hdr, *ehdr; 765 size_t len, max_len; 766 uint64_t bv; 767 768 /* XXXKIB should we clear all extended state in xstate_bv instead ? */ 769 if (xfpustate == NULL) 770 return (0); 771 if (!use_xsave) 772 return (EOPNOTSUPP); 773 774 len = xfpustate_size; 775 if (len < sizeof(struct xstate_hdr)) 776 return (EINVAL); 777 max_len = cpu_max_ext_state_size - sizeof(struct savefpu); 778 if (len > max_len) 779 return (EINVAL); 780 781 ehdr = (struct xstate_hdr *)xfpustate; 782 bv = ehdr->xstate_bv; 783 784 /* 785 * Avoid #gp. 786 */ 787 if (bv & ~xsave_mask) 788 return (EINVAL); 789 790 hdr = (struct xstate_hdr *)(get_pcb_user_save_td(td) + 1); 791 792 hdr->xstate_bv = bv; 793 bcopy(xfpustate + sizeof(struct xstate_hdr), 794 (char *)(hdr + 1), len - sizeof(struct xstate_hdr)); 795 796 return (0); 797 } 798 799 /* 800 * Set the state of the FPU. 801 */ 802 int 803 fpusetregs(struct thread *td, struct savefpu *addr, char *xfpustate, 804 size_t xfpustate_size) 805 { 806 struct pcb *pcb; 807 int error; 808 809 pcb = td->td_pcb; 810 critical_enter(); 811 if (td == PCPU_GET(fpcurthread) && PCB_USER_FPU(pcb)) { 812 error = fpusetxstate(td, xfpustate, xfpustate_size); 813 if (error != 0) { 814 critical_exit(); 815 return (error); 816 } 817 bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr)); 818 fpurestore(get_pcb_user_save_td(td)); 819 critical_exit(); 820 set_pcb_flags(pcb, PCB_FPUINITDONE | PCB_USERFPUINITDONE); 821 } else { 822 critical_exit(); 823 error = fpusetxstate(td, xfpustate, xfpustate_size); 824 if (error != 0) 825 return (error); 826 bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr)); 827 fpuuserinited(td); 828 } 829 return (0); 830 } 831 832 /* 833 * On AuthenticAMD processors, the fxrstor instruction does not restore 834 * the x87's stored last instruction pointer, last data pointer, and last 835 * opcode values, except in the rare case in which the exception summary 836 * (ES) bit in the x87 status word is set to 1. 837 * 838 * In order to avoid leaking this information across processes, we clean 839 * these values by performing a dummy load before executing fxrstor(). 840 */ 841 static void 842 fpu_clean_state(void) 843 { 844 static float dummy_variable = 0.0; 845 u_short status; 846 847 /* 848 * Clear the ES bit in the x87 status word if it is currently 849 * set, in order to avoid causing a fault in the upcoming load. 850 */ 851 fnstsw(&status); 852 if (status & 0x80) 853 fnclex(); 854 855 /* 856 * Load the dummy variable into the x87 stack. This mangles 857 * the x87 stack, but we don't care since we're about to call 858 * fxrstor() anyway. 859 */ 860 __asm __volatile("ffree %%st(7); flds %0" : : "m" (dummy_variable)); 861 } 862 863 /* 864 * This really sucks. We want the acpi version only, but it requires 865 * the isa_if.h file in order to get the definitions. 866 */ 867 #include "opt_isa.h" 868 #ifdef DEV_ISA 869 #include <isa/isavar.h> 870 /* 871 * This sucks up the legacy ISA support assignments from PNPBIOS/ACPI. 872 */ 873 static struct isa_pnp_id fpupnp_ids[] = { 874 { 0x040cd041, "Legacy ISA coprocessor support" }, /* PNP0C04 */ 875 { 0 } 876 }; 877 878 static int 879 fpupnp_probe(device_t dev) 880 { 881 int result; 882 883 result = ISA_PNP_PROBE(device_get_parent(dev), dev, fpupnp_ids); 884 if (result <= 0) 885 device_quiet(dev); 886 return (result); 887 } 888 889 static int 890 fpupnp_attach(device_t dev) 891 { 892 893 return (0); 894 } 895 896 static device_method_t fpupnp_methods[] = { 897 /* Device interface */ 898 DEVMETHOD(device_probe, fpupnp_probe), 899 DEVMETHOD(device_attach, fpupnp_attach), 900 DEVMETHOD(device_detach, bus_generic_detach), 901 DEVMETHOD(device_shutdown, bus_generic_shutdown), 902 DEVMETHOD(device_suspend, bus_generic_suspend), 903 DEVMETHOD(device_resume, bus_generic_resume), 904 905 { 0, 0 } 906 }; 907 908 static driver_t fpupnp_driver = { 909 "fpupnp", 910 fpupnp_methods, 911 1, /* no softc */ 912 }; 913 914 static devclass_t fpupnp_devclass; 915 916 DRIVER_MODULE(fpupnp, acpi, fpupnp_driver, fpupnp_devclass, 0, 0); 917 #endif /* DEV_ISA */ 918 919 static MALLOC_DEFINE(M_FPUKERN_CTX, "fpukern_ctx", 920 "Kernel contexts for FPU state"); 921 922 #define FPU_KERN_CTX_FPUINITDONE 0x01 923 #define FPU_KERN_CTX_DUMMY 0x02 /* avoided save for the kern thread */ 924 #define FPU_KERN_CTX_INUSE 0x04 925 926 struct fpu_kern_ctx { 927 struct savefpu *prev; 928 uint32_t flags; 929 char hwstate1[]; 930 }; 931 932 struct fpu_kern_ctx * 933 fpu_kern_alloc_ctx(u_int flags) 934 { 935 struct fpu_kern_ctx *res; 936 size_t sz; 937 938 sz = sizeof(struct fpu_kern_ctx) + XSAVE_AREA_ALIGN + 939 cpu_max_ext_state_size; 940 res = malloc(sz, M_FPUKERN_CTX, ((flags & FPU_KERN_NOWAIT) ? 941 M_NOWAIT : M_WAITOK) | M_ZERO); 942 return (res); 943 } 944 945 void 946 fpu_kern_free_ctx(struct fpu_kern_ctx *ctx) 947 { 948 949 KASSERT((ctx->flags & FPU_KERN_CTX_INUSE) == 0, ("free'ing inuse ctx")); 950 /* XXXKIB clear the memory ? */ 951 free(ctx, M_FPUKERN_CTX); 952 } 953 954 static struct savefpu * 955 fpu_kern_ctx_savefpu(struct fpu_kern_ctx *ctx) 956 { 957 vm_offset_t p; 958 959 p = (vm_offset_t)&ctx->hwstate1; 960 p = roundup2(p, XSAVE_AREA_ALIGN); 961 return ((struct savefpu *)p); 962 } 963 964 int 965 fpu_kern_enter(struct thread *td, struct fpu_kern_ctx *ctx, u_int flags) 966 { 967 struct pcb *pcb; 968 969 pcb = td->td_pcb; 970 KASSERT((flags & FPU_KERN_NOCTX) != 0 || ctx != NULL, 971 ("ctx is required when !FPU_KERN_NOCTX")); 972 KASSERT(ctx == NULL || (ctx->flags & FPU_KERN_CTX_INUSE) == 0, 973 ("using inuse ctx")); 974 KASSERT((pcb->pcb_flags & PCB_FPUNOSAVE) == 0, 975 ("recursive fpu_kern_enter while in PCB_FPUNOSAVE state")); 976 977 if ((flags & FPU_KERN_NOCTX) != 0) { 978 critical_enter(); 979 stop_emulating(); 980 if (curthread == PCPU_GET(fpcurthread)) { 981 fpusave(curpcb->pcb_save); 982 PCPU_SET(fpcurthread, NULL); 983 } else { 984 KASSERT(PCPU_GET(fpcurthread) == NULL, 985 ("invalid fpcurthread")); 986 } 987 988 /* 989 * This breaks XSAVEOPT tracker, but 990 * PCB_FPUNOSAVE state is supposed to never need to 991 * save FPU context at all. 992 */ 993 fpurestore(fpu_initialstate); 994 set_pcb_flags(pcb, PCB_KERNFPU | PCB_FPUNOSAVE | 995 PCB_FPUINITDONE); 996 return (0); 997 } 998 if ((flags & FPU_KERN_KTHR) != 0 && is_fpu_kern_thread(0)) { 999 ctx->flags = FPU_KERN_CTX_DUMMY | FPU_KERN_CTX_INUSE; 1000 return (0); 1001 } 1002 KASSERT(!PCB_USER_FPU(pcb) || pcb->pcb_save == 1003 get_pcb_user_save_pcb(pcb), ("mangled pcb_save")); 1004 ctx->flags = FPU_KERN_CTX_INUSE; 1005 if ((pcb->pcb_flags & PCB_FPUINITDONE) != 0) 1006 ctx->flags |= FPU_KERN_CTX_FPUINITDONE; 1007 fpuexit(td); 1008 ctx->prev = pcb->pcb_save; 1009 pcb->pcb_save = fpu_kern_ctx_savefpu(ctx); 1010 set_pcb_flags(pcb, PCB_KERNFPU); 1011 clear_pcb_flags(pcb, PCB_FPUINITDONE); 1012 return (0); 1013 } 1014 1015 int 1016 fpu_kern_leave(struct thread *td, struct fpu_kern_ctx *ctx) 1017 { 1018 struct pcb *pcb; 1019 1020 pcb = td->td_pcb; 1021 1022 if ((pcb->pcb_flags & PCB_FPUNOSAVE) != 0) { 1023 KASSERT(ctx == NULL, ("non-null ctx after FPU_KERN_NOCTX")); 1024 KASSERT(PCPU_GET(fpcurthread) == NULL, 1025 ("non-NULL fpcurthread for PCB_FPUNOSAVE")); 1026 CRITICAL_ASSERT(td); 1027 1028 clear_pcb_flags(pcb, PCB_FPUNOSAVE | PCB_FPUINITDONE); 1029 start_emulating(); 1030 critical_exit(); 1031 } else { 1032 KASSERT((ctx->flags & FPU_KERN_CTX_INUSE) != 0, 1033 ("leaving not inuse ctx")); 1034 ctx->flags &= ~FPU_KERN_CTX_INUSE; 1035 1036 if (is_fpu_kern_thread(0) && 1037 (ctx->flags & FPU_KERN_CTX_DUMMY) != 0) 1038 return (0); 1039 KASSERT((ctx->flags & FPU_KERN_CTX_DUMMY) == 0, 1040 ("dummy ctx")); 1041 critical_enter(); 1042 if (curthread == PCPU_GET(fpcurthread)) 1043 fpudrop(); 1044 critical_exit(); 1045 pcb->pcb_save = ctx->prev; 1046 } 1047 1048 if (pcb->pcb_save == get_pcb_user_save_pcb(pcb)) { 1049 if ((pcb->pcb_flags & PCB_USERFPUINITDONE) != 0) { 1050 set_pcb_flags(pcb, PCB_FPUINITDONE); 1051 clear_pcb_flags(pcb, PCB_KERNFPU); 1052 } else 1053 clear_pcb_flags(pcb, PCB_FPUINITDONE | PCB_KERNFPU); 1054 } else { 1055 if ((ctx->flags & FPU_KERN_CTX_FPUINITDONE) != 0) 1056 set_pcb_flags(pcb, PCB_FPUINITDONE); 1057 else 1058 clear_pcb_flags(pcb, PCB_FPUINITDONE); 1059 KASSERT(!PCB_USER_FPU(pcb), ("unpaired fpu_kern_leave")); 1060 } 1061 return (0); 1062 } 1063 1064 int 1065 fpu_kern_thread(u_int flags) 1066 { 1067 1068 KASSERT((curthread->td_pflags & TDP_KTHREAD) != 0, 1069 ("Only kthread may use fpu_kern_thread")); 1070 KASSERT(curpcb->pcb_save == get_pcb_user_save_pcb(curpcb), 1071 ("mangled pcb_save")); 1072 KASSERT(PCB_USER_FPU(curpcb), ("recursive call")); 1073 1074 set_pcb_flags(curpcb, PCB_KERNFPU); 1075 return (0); 1076 } 1077 1078 int 1079 is_fpu_kern_thread(u_int flags) 1080 { 1081 1082 if ((curthread->td_pflags & TDP_KTHREAD) == 0) 1083 return (0); 1084 return ((curpcb->pcb_flags & PCB_KERNFPU) != 0); 1085 } 1086 1087 /* 1088 * FPU save area alloc/free/init utility routines 1089 */ 1090 struct savefpu * 1091 fpu_save_area_alloc(void) 1092 { 1093 1094 return (uma_zalloc(fpu_save_area_zone, 0)); 1095 } 1096 1097 void 1098 fpu_save_area_free(struct savefpu *fsa) 1099 { 1100 1101 uma_zfree(fpu_save_area_zone, fsa); 1102 } 1103 1104 void 1105 fpu_save_area_reset(struct savefpu *fsa) 1106 { 1107 1108 bcopy(fpu_initialstate, fsa, cpu_max_ext_state_size); 1109 } 1110