1 /*- 2 * Copyright (c) 1982, 1986 The Regents of the University of California. 3 * Copyright (c) 1989, 1990 William Jolitz 4 * Copyright (c) 1994 John Dyson 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * the Systems Programming Group of the University of Utah Computer 9 * Science Department, and William Jolitz. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91 40 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$ 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include "opt_npx.h" 47 #ifdef PC98 48 #include "opt_pc98.h" 49 #endif 50 #include "opt_reset.h" 51 #include "opt_isa.h" 52 #include "opt_kstack_pages.h" 53 54 #include <sys/param.h> 55 #include <sys/systm.h> 56 #include <sys/malloc.h> 57 #include <sys/proc.h> 58 #include <sys/kse.h> 59 #include <sys/bio.h> 60 #include <sys/buf.h> 61 #include <sys/vnode.h> 62 #include <sys/vmmeter.h> 63 #include <sys/kernel.h> 64 #include <sys/ktr.h> 65 #include <sys/mutex.h> 66 #include <sys/smp.h> 67 #include <sys/sysctl.h> 68 #include <sys/unistd.h> 69 70 #include <machine/cpu.h> 71 #include <machine/md_var.h> 72 #include <machine/pcb.h> 73 #include <machine/pcb_ext.h> 74 #include <machine/vm86.h> 75 76 #include <vm/vm.h> 77 #include <vm/vm_param.h> 78 #include <sys/lock.h> 79 #include <vm/vm_kern.h> 80 #include <vm/vm_page.h> 81 #include <vm/vm_map.h> 82 #include <vm/vm_extern.h> 83 84 #include <sys/user.h> 85 86 #ifdef PC98 87 #include <pc98/pc98/pc98.h> 88 #else 89 #include <i386/isa/isa.h> 90 #endif 91 92 static void cpu_reset_real(void); 93 #ifdef SMP 94 static void cpu_reset_proxy(void); 95 static u_int cpu_reset_proxyid; 96 static volatile u_int cpu_reset_proxy_active; 97 #endif 98 extern int _ucodesel, _udatasel; 99 100 /* 101 * Finish a fork operation, with process p2 nearly set up. 102 * Copy and update the pcb, set up the stack so that the child 103 * ready to run and return to user mode. 104 */ 105 void 106 cpu_fork(td1, p2, td2, flags) 107 register struct thread *td1; 108 register struct proc *p2; 109 struct thread *td2; 110 int flags; 111 { 112 register struct proc *p1; 113 struct pcb *pcb2; 114 struct mdproc *mdp2; 115 #ifdef DEV_NPX 116 register_t savecrit; 117 #endif 118 119 p1 = td1->td_proc; 120 if ((flags & RFPROC) == 0) { 121 if ((flags & RFMEM) == 0) { 122 /* unshare user LDT */ 123 struct mdproc *mdp1 = &p1->p_md; 124 struct proc_ldt *pldt = mdp1->md_ldt; 125 if (pldt && pldt->ldt_refcnt > 1) { 126 pldt = user_ldt_alloc(mdp1, pldt->ldt_len); 127 if (pldt == NULL) 128 panic("could not copy LDT"); 129 mdp1->md_ldt = pldt; 130 set_user_ldt(mdp1); 131 user_ldt_free(td1); 132 } 133 } 134 return; 135 } 136 137 /* Ensure that p1's pcb is up to date. */ 138 #ifdef DEV_NPX 139 if (td1 == curthread) 140 td1->td_pcb->pcb_gs = rgs(); 141 savecrit = intr_disable(); 142 if (PCPU_GET(fpcurthread) == td1) 143 npxsave(&td1->td_pcb->pcb_save); 144 intr_restore(savecrit); 145 #endif 146 147 /* Point the pcb to the top of the stack */ 148 pcb2 = (struct pcb *)(td2->td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1; 149 td2->td_pcb = pcb2; 150 151 /* Copy p1's pcb */ 152 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 153 154 /* Point mdproc and then copy over td1's contents */ 155 mdp2 = &p2->p_md; 156 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 157 158 /* 159 * Create a new fresh stack for the new process. 160 * Copy the trap frame for the return to user mode as if from a 161 * syscall. This copies most of the user mode register values. 162 * The -16 is so we can expand the trapframe if we go to vm86. 163 */ 164 td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb - 16) - 1; 165 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 166 167 td2->td_frame->tf_eax = 0; /* Child returns zero */ 168 td2->td_frame->tf_eflags &= ~PSL_C; /* success */ 169 td2->td_frame->tf_edx = 1; 170 171 /* 172 * Set registers for trampoline to user mode. Leave space for the 173 * return address on stack. These are the kernel mode register values. 174 */ 175 #ifdef PAE 176 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdpt); 177 #else 178 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir); 179 #endif 180 pcb2->pcb_edi = 0; 181 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */ 182 pcb2->pcb_ebp = 0; 183 pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *); 184 pcb2->pcb_ebx = (int)td2; /* fork_trampoline argument */ 185 pcb2->pcb_eip = (int)fork_trampoline; 186 pcb2->pcb_psl = PSL_KERNEL; /* ints disabled */ 187 pcb2->pcb_gs = rgs(); 188 /*- 189 * pcb2->pcb_dr*: cloned above. 190 * pcb2->pcb_savefpu: cloned above. 191 * pcb2->pcb_flags: cloned above. 192 * pcb2->pcb_onfault: cloned above (always NULL here?). 193 * pcb2->pcb_gs: cloned above. 194 * pcb2->pcb_ext: cleared below. 195 */ 196 197 /* 198 * XXX don't copy the i/o pages. this should probably be fixed. 199 */ 200 pcb2->pcb_ext = 0; 201 202 /* Copy the LDT, if necessary. */ 203 mtx_lock_spin(&sched_lock); 204 if (mdp2->md_ldt != 0) { 205 if (flags & RFMEM) { 206 mdp2->md_ldt->ldt_refcnt++; 207 } else { 208 mdp2->md_ldt = user_ldt_alloc(mdp2, 209 mdp2->md_ldt->ldt_len); 210 if (mdp2->md_ldt == NULL) 211 panic("could not copy LDT"); 212 } 213 } 214 mtx_unlock_spin(&sched_lock); 215 216 /* 217 * Now, cpu_switch() can schedule the new process. 218 * pcb_esp is loaded pointing to the cpu_switch() stack frame 219 * containing the return address when exiting cpu_switch. 220 * This will normally be to fork_trampoline(), which will have 221 * %ebx loaded with the new proc's pointer. fork_trampoline() 222 * will set up a stack to call fork_return(p, frame); to complete 223 * the return to user-mode. 224 */ 225 } 226 227 /* 228 * Intercept the return address from a freshly forked process that has NOT 229 * been scheduled yet. 230 * 231 * This is needed to make kernel threads stay in kernel mode. 232 */ 233 void 234 cpu_set_fork_handler(td, func, arg) 235 struct thread *td; 236 void (*func)(void *); 237 void *arg; 238 { 239 /* 240 * Note that the trap frame follows the args, so the function 241 * is really called like this: func(arg, frame); 242 */ 243 td->td_pcb->pcb_esi = (int) func; /* function */ 244 td->td_pcb->pcb_ebx = (int) arg; /* first arg */ 245 } 246 247 void 248 cpu_exit(struct thread *td) 249 { 250 struct mdproc *mdp; 251 struct pcb *pcb = td->td_pcb; 252 253 254 /* Reset pc->pcb_gs and %gs before possibly invalidating it. */ 255 mdp = &td->td_proc->p_md; 256 if (mdp->md_ldt) { 257 td->td_pcb->pcb_gs = _udatasel; 258 load_gs(_udatasel); 259 user_ldt_free(td); 260 } 261 if (pcb->pcb_flags & PCB_DBREGS) { 262 /* disable all hardware breakpoints */ 263 reset_dbregs(); 264 pcb->pcb_flags &= ~PCB_DBREGS; 265 } 266 } 267 268 void 269 cpu_thread_exit(struct thread *td) 270 { 271 struct pcb *pcb = td->td_pcb; 272 #ifdef DEV_NPX 273 npxexit(td); 274 #endif 275 if (pcb->pcb_flags & PCB_DBREGS) { 276 /* disable all hardware breakpoints */ 277 reset_dbregs(); 278 pcb->pcb_flags &= ~PCB_DBREGS; 279 } 280 } 281 282 void 283 cpu_thread_clean(struct thread *td) 284 { 285 struct pcb *pcb; 286 287 pcb = td->td_pcb; 288 if (pcb->pcb_ext != 0) { 289 /* XXXKSE XXXSMP not SMP SAFE.. what locks do we have? */ 290 /* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */ 291 /* 292 * XXX do we need to move the TSS off the allocated pages 293 * before freeing them? (not done here) 294 */ 295 mtx_lock(&Giant); 296 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext, 297 ctob(IOPAGES + 1)); 298 mtx_unlock(&Giant); 299 pcb->pcb_ext = 0; 300 } 301 } 302 303 void 304 cpu_sched_exit(td) 305 register struct thread *td; 306 { 307 } 308 309 void 310 cpu_thread_setup(struct thread *td) 311 { 312 313 td->td_pcb = 314 (struct pcb *)(td->td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1; 315 td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb - 16) - 1; 316 td->td_pcb->pcb_ext = NULL; 317 } 318 319 /* 320 * Initialize machine state (pcb and trap frame) for a new thread about to 321 * upcall. Pu t enough state in the new thread's PCB to get it to go back 322 * userret(), where we can intercept it again to set the return (upcall) 323 * Address and stack, along with those from upcals that are from other sources 324 * such as those generated in thread_userret() itself. 325 */ 326 void 327 cpu_set_upcall(struct thread *td, struct thread *td0) 328 { 329 struct pcb *pcb2; 330 331 /* Point the pcb to the top of the stack. */ 332 pcb2 = td->td_pcb; 333 334 /* 335 * Copy the upcall pcb. This loads kernel regs. 336 * Those not loaded individually below get their default 337 * values here. 338 * 339 * XXXKSE It might be a good idea to simply skip this as 340 * the values of the other registers may be unimportant. 341 * This would remove any requirement for knowing the KSE 342 * at this time (see the matching comment below for 343 * more analysis) (need a good safe default). 344 */ 345 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2)); 346 347 /* 348 * Create a new fresh stack for the new thread. 349 * The -16 is so we can expand the trapframe if we go to vm86. 350 * Don't forget to set this stack value into whatever supplies 351 * the address for the fault handlers. 352 * The contexts are filled in at the time we actually DO the 353 * upcall as only then do we know which KSE we got. 354 */ 355 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 356 357 /* 358 * Set registers for trampoline to user mode. Leave space for the 359 * return address on stack. These are the kernel mode register values. 360 */ 361 #ifdef PAE 362 pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdpt); 363 #else 364 pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdir); 365 #endif 366 pcb2->pcb_edi = 0; 367 pcb2->pcb_esi = (int)fork_return; /* trampoline arg */ 368 pcb2->pcb_ebp = 0; 369 pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */ 370 pcb2->pcb_ebx = (int)td; /* trampoline arg */ 371 pcb2->pcb_eip = (int)fork_trampoline; 372 pcb2->pcb_psl &= ~(PSL_I); /* interrupts must be disabled */ 373 pcb2->pcb_gs = rgs(); 374 /* 375 * If we didn't copy the pcb, we'd need to do the following registers: 376 * pcb2->pcb_dr*: cloned above. 377 * pcb2->pcb_savefpu: cloned above. 378 * pcb2->pcb_flags: cloned above. 379 * pcb2->pcb_onfault: cloned above (always NULL here?). 380 * pcb2->pcb_gs: cloned above. XXXKSE ??? 381 * pcb2->pcb_ext: cleared below. 382 */ 383 pcb2->pcb_ext = NULL; 384 } 385 386 /* 387 * Set that machine state for performing an upcall that has to 388 * be done in thread_userret() so that those upcalls generated 389 * in thread_userret() itself can be done as well. 390 */ 391 void 392 cpu_set_upcall_kse(struct thread *td, struct kse_upcall *ku) 393 { 394 395 /* 396 * Do any extra cleaning that needs to be done. 397 * The thread may have optional components 398 * that are not present in a fresh thread. 399 * This may be a recycled thread so make it look 400 * as though it's newly allocated. 401 */ 402 cpu_thread_clean(td); 403 404 /* 405 * Set the trap frame to point at the beginning of the uts 406 * function. 407 */ 408 td->td_frame->tf_esp = 409 (int)ku->ku_stack.ss_sp + ku->ku_stack.ss_size - 16; 410 td->td_frame->tf_eip = (int)ku->ku_func; 411 412 /* 413 * Pass the address of the mailbox for this kse to the uts 414 * function as a parameter on the stack. 415 */ 416 suword((void *)(td->td_frame->tf_esp + sizeof(void *)), 417 (int)ku->ku_mailbox); 418 } 419 420 /* 421 * Convert kernel VA to physical address 422 */ 423 vm_paddr_t 424 kvtop(void *addr) 425 { 426 vm_paddr_t pa; 427 428 pa = pmap_kextract((vm_offset_t)addr); 429 if (pa == 0) 430 panic("kvtop: zero page frame"); 431 return (pa); 432 } 433 434 /* 435 * Force reset the processor by invalidating the entire address space! 436 */ 437 438 #ifdef SMP 439 static void 440 cpu_reset_proxy() 441 { 442 443 cpu_reset_proxy_active = 1; 444 while (cpu_reset_proxy_active == 1) 445 ; /* Wait for other cpu to see that we've started */ 446 stop_cpus((1<<cpu_reset_proxyid)); 447 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid); 448 DELAY(1000000); 449 cpu_reset_real(); 450 } 451 #endif 452 453 void 454 cpu_reset() 455 { 456 #ifdef SMP 457 if (smp_active == 0) { 458 cpu_reset_real(); 459 /* NOTREACHED */ 460 } else { 461 462 u_int map; 463 int cnt; 464 printf("cpu_reset called on cpu#%d\n", PCPU_GET(cpuid)); 465 466 map = PCPU_GET(other_cpus) & ~ stopped_cpus; 467 468 if (map != 0) { 469 printf("cpu_reset: Stopping other CPUs\n"); 470 stop_cpus(map); /* Stop all other CPUs */ 471 } 472 473 if (PCPU_GET(cpuid) == 0) { 474 DELAY(1000000); 475 cpu_reset_real(); 476 /* NOTREACHED */ 477 } else { 478 /* We are not BSP (CPU #0) */ 479 480 cpu_reset_proxyid = PCPU_GET(cpuid); 481 cpustop_restartfunc = cpu_reset_proxy; 482 cpu_reset_proxy_active = 0; 483 printf("cpu_reset: Restarting BSP\n"); 484 started_cpus = (1<<0); /* Restart CPU #0 */ 485 486 cnt = 0; 487 while (cpu_reset_proxy_active == 0 && cnt < 10000000) 488 cnt++; /* Wait for BSP to announce restart */ 489 if (cpu_reset_proxy_active == 0) 490 printf("cpu_reset: Failed to restart BSP\n"); 491 enable_intr(); 492 cpu_reset_proxy_active = 2; 493 494 while (1); 495 /* NOTREACHED */ 496 } 497 } 498 #else 499 cpu_reset_real(); 500 #endif 501 } 502 503 static void 504 cpu_reset_real() 505 { 506 507 #ifdef PC98 508 /* 509 * Attempt to do a CPU reset via CPU reset port. 510 */ 511 disable_intr(); 512 if ((inb(0x35) & 0xa0) != 0xa0) { 513 outb(0x37, 0x0f); /* SHUT0 = 0. */ 514 outb(0x37, 0x0b); /* SHUT1 = 0. */ 515 } 516 outb(0xf0, 0x00); /* Reset. */ 517 #else 518 /* 519 * Attempt to do a CPU reset via the keyboard controller, 520 * do not turn of the GateA20, as any machine that fails 521 * to do the reset here would then end up in no man's land. 522 */ 523 524 #if !defined(BROKEN_KEYBOARD_RESET) 525 outb(IO_KBD + 4, 0xFE); 526 DELAY(500000); /* wait 0.5 sec to see if that did it */ 527 printf("Keyboard reset did not work, attempting CPU shutdown\n"); 528 DELAY(1000000); /* wait 1 sec for printf to complete */ 529 #endif 530 #endif /* PC98 */ 531 /* force a shutdown by unmapping entire address space ! */ 532 bzero((caddr_t)PTD, NBPTD); 533 534 /* "good night, sweet prince .... <THUNK!>" */ 535 invltlb(); 536 /* NOTREACHED */ 537 while(1); 538 } 539 540 /* 541 * Software interrupt handler for queued VM system processing. 542 */ 543 void 544 swi_vm(void *dummy) 545 { 546 if (busdma_swi_pending != 0) 547 busdma_swi(); 548 } 549 550 /* 551 * Tell whether this address is in some physical memory region. 552 * Currently used by the kernel coredump code in order to avoid 553 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 554 * or other unpredictable behaviour. 555 */ 556 557 int 558 is_physical_memory(addr) 559 vm_offset_t addr; 560 { 561 562 #ifdef DEV_ISA 563 /* The ISA ``memory hole''. */ 564 if (addr >= 0xa0000 && addr < 0x100000) 565 return 0; 566 #endif 567 568 /* 569 * stuff other tests for known memory-mapped devices (PCI?) 570 * here 571 */ 572 573 return 1; 574 } 575