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 * $FreeBSD$ 42 */ 43 44 #include "opt_npx.h" 45 #ifdef PC98 46 #include "opt_pc98.h" 47 #endif 48 #include "opt_reset.h" 49 #include "opt_isa.h" 50 #include "opt_kstack_pages.h" 51 52 #include <sys/param.h> 53 #include <sys/systm.h> 54 #include <sys/malloc.h> 55 #include <sys/proc.h> 56 #include <sys/kse.h> 57 #include <sys/bio.h> 58 #include <sys/buf.h> 59 #include <sys/vnode.h> 60 #include <sys/vmmeter.h> 61 #include <sys/kernel.h> 62 #include <sys/ktr.h> 63 #include <sys/mutex.h> 64 #include <sys/smp.h> 65 #include <sys/sysctl.h> 66 #include <sys/unistd.h> 67 68 #include <machine/cpu.h> 69 #include <machine/md_var.h> 70 #include <machine/pcb.h> 71 #include <machine/pcb_ext.h> 72 #include <machine/vm86.h> 73 74 #include <vm/vm.h> 75 #include <vm/vm_param.h> 76 #include <sys/lock.h> 77 #include <vm/vm_kern.h> 78 #include <vm/vm_page.h> 79 #include <vm/vm_map.h> 80 #include <vm/vm_extern.h> 81 82 #include <sys/user.h> 83 84 #ifdef PC98 85 #include <pc98/pc98/pc98.h> 86 #else 87 #include <i386/isa/isa.h> 88 #endif 89 90 static void cpu_reset_real(void); 91 #ifdef SMP 92 static void cpu_reset_proxy(void); 93 static u_int cpu_reset_proxyid; 94 static volatile u_int cpu_reset_proxy_active; 95 #endif 96 extern int _ucodesel, _udatasel; 97 98 /* 99 * quick version of vm_fault 100 */ 101 int 102 vm_fault_quick(v, prot) 103 caddr_t v; 104 int prot; 105 { 106 int r; 107 108 if (prot & VM_PROT_WRITE) 109 r = subyte(v, fubyte(v)); 110 else 111 r = fubyte(v); 112 return(r); 113 } 114 115 /* 116 * Finish a fork operation, with process p2 nearly set up. 117 * Copy and update the pcb, set up the stack so that the child 118 * ready to run and return to user mode. 119 */ 120 void 121 cpu_fork(td1, p2, td2, flags) 122 register struct thread *td1; 123 register struct proc *p2; 124 struct thread *td2; 125 int flags; 126 { 127 register struct proc *p1; 128 struct pcb *pcb2; 129 struct mdproc *mdp2; 130 #ifdef DEV_NPX 131 register_t savecrit; 132 #endif 133 134 p1 = td1->td_proc; 135 if ((flags & RFPROC) == 0) { 136 if ((flags & RFMEM) == 0) { 137 /* unshare user LDT */ 138 struct mdproc *mdp1 = &p1->p_md; 139 struct proc_ldt *pldt = mdp1->md_ldt; 140 if (pldt && pldt->ldt_refcnt > 1) { 141 pldt = user_ldt_alloc(mdp1, pldt->ldt_len); 142 if (pldt == NULL) 143 panic("could not copy LDT"); 144 mdp1->md_ldt = pldt; 145 set_user_ldt(mdp1); 146 user_ldt_free(td1); 147 } 148 } 149 return; 150 } 151 152 /* Ensure that p1's pcb is up to date. */ 153 #ifdef DEV_NPX 154 if (td1 == curthread) 155 td1->td_pcb->pcb_gs = rgs(); 156 savecrit = intr_disable(); 157 if (PCPU_GET(fpcurthread) == td1) 158 npxsave(&td1->td_pcb->pcb_save); 159 intr_restore(savecrit); 160 #endif 161 162 /* Point the pcb to the top of the stack */ 163 pcb2 = (struct pcb *)(td2->td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1; 164 td2->td_pcb = pcb2; 165 166 /* Copy p1's pcb */ 167 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 168 169 /* Point mdproc and then copy over td1's contents */ 170 mdp2 = &p2->p_md; 171 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 172 173 /* 174 * Create a new fresh stack for the new process. 175 * Copy the trap frame for the return to user mode as if from a 176 * syscall. This copies most of the user mode register values. 177 * The -16 is so we can expand the trapframe if we go to vm86. 178 */ 179 td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb - 16) - 1; 180 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 181 182 td2->td_frame->tf_eax = 0; /* Child returns zero */ 183 td2->td_frame->tf_eflags &= ~PSL_C; /* success */ 184 td2->td_frame->tf_edx = 1; 185 186 /* 187 * Set registers for trampoline to user mode. Leave space for the 188 * return address on stack. These are the kernel mode register values. 189 */ 190 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir); 191 pcb2->pcb_edi = 0; 192 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */ 193 pcb2->pcb_ebp = 0; 194 pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *); 195 pcb2->pcb_ebx = (int)td2; /* fork_trampoline argument */ 196 pcb2->pcb_eip = (int)fork_trampoline; 197 pcb2->pcb_psl = td2->td_frame->tf_eflags & ~PSL_I; /* ints disabled */ 198 /*- 199 * pcb2->pcb_dr*: cloned above. 200 * pcb2->pcb_savefpu: cloned above. 201 * pcb2->pcb_flags: cloned above. 202 * pcb2->pcb_onfault: cloned above (always NULL here?). 203 * pcb2->pcb_gs: cloned above. 204 * pcb2->pcb_ext: cleared below. 205 */ 206 207 /* 208 * XXX don't copy the i/o pages. this should probably be fixed. 209 */ 210 pcb2->pcb_ext = 0; 211 212 /* Copy the LDT, if necessary. */ 213 mtx_lock_spin(&sched_lock); 214 if (mdp2->md_ldt != 0) { 215 if (flags & RFMEM) { 216 mdp2->md_ldt->ldt_refcnt++; 217 } else { 218 mdp2->md_ldt = user_ldt_alloc(mdp2, 219 mdp2->md_ldt->ldt_len); 220 if (mdp2->md_ldt == NULL) 221 panic("could not copy LDT"); 222 } 223 } 224 mtx_unlock_spin(&sched_lock); 225 226 /* 227 * Now, cpu_switch() can schedule the new process. 228 * pcb_esp is loaded pointing to the cpu_switch() stack frame 229 * containing the return address when exiting cpu_switch. 230 * This will normally be to fork_trampoline(), which will have 231 * %ebx loaded with the new proc's pointer. fork_trampoline() 232 * will set up a stack to call fork_return(p, frame); to complete 233 * the return to user-mode. 234 */ 235 } 236 237 /* 238 * Intercept the return address from a freshly forked process that has NOT 239 * been scheduled yet. 240 * 241 * This is needed to make kernel threads stay in kernel mode. 242 */ 243 void 244 cpu_set_fork_handler(td, func, arg) 245 struct thread *td; 246 void (*func)(void *); 247 void *arg; 248 { 249 /* 250 * Note that the trap frame follows the args, so the function 251 * is really called like this: func(arg, frame); 252 */ 253 td->td_pcb->pcb_esi = (int) func; /* function */ 254 td->td_pcb->pcb_ebx = (int) arg; /* first arg */ 255 } 256 257 void 258 cpu_exit(struct thread *td) 259 { 260 struct mdproc *mdp; 261 262 mdp = &td->td_proc->p_md; 263 if (mdp->md_ldt) 264 user_ldt_free(td); 265 reset_dbregs(); 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_ext != 0) { 276 /* XXXKSE XXXSMP not SMP SAFE.. what locks do we have? */ 277 /* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */ 278 /* 279 * XXX do we need to move the TSS off the allocated pages 280 * before freeing them? (not done here) 281 */ 282 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext, 283 ctob(IOPAGES + 1)); 284 pcb->pcb_ext = 0; 285 } 286 if (pcb->pcb_flags & PCB_DBREGS) { 287 /* 288 * disable all hardware breakpoints 289 */ 290 reset_dbregs(); 291 pcb->pcb_flags &= ~PCB_DBREGS; 292 } 293 } 294 295 void 296 cpu_sched_exit(td) 297 register struct thread *td; 298 { 299 } 300 301 void 302 cpu_thread_setup(struct thread *td) 303 { 304 305 td->td_pcb = 306 (struct pcb *)(td->td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1; 307 td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb - 16) - 1; 308 } 309 310 /* 311 * Initialize machine state (pcb and trap frame) for a new thread about to 312 * upcall. Pu t enough state in the new thread's PCB to get it to go back 313 * userret(), where we can intercept it again to set the return (upcall) 314 * Address and stack, along with those from upcals that are from other sources 315 * such as those generated in thread_userret() itself. 316 */ 317 void 318 cpu_set_upcall(struct thread *td, void *pcb) 319 { 320 struct pcb *pcb2; 321 322 td->td_flags |= TDF_UPCALLING; 323 324 /* Point the pcb to the top of the stack. */ 325 pcb2 = td->td_pcb; 326 327 /* 328 * Copy the upcall pcb. This loads kernel regs. 329 * Those not loaded individually below get their default 330 * values here. 331 * 332 * XXXKSE It might be a good idea to simply skip this as 333 * the values of the other registers may be unimportant. 334 * This would remove any requirement for knowing the KSE 335 * at this time (see the matching comment below for 336 * more analysis) (need a good safe default). 337 */ 338 bcopy(pcb, pcb2, sizeof(*pcb2)); 339 340 /* 341 * Create a new fresh stack for the new thread. 342 * The -16 is so we can expand the trapframe if we go to vm86. 343 * Don't forget to set this stack value into whatever supplies 344 * the address for the fault handlers. 345 * The contexts are filled in at the time we actually DO the 346 * upcall as only then do we know which KSE we got. 347 */ 348 td->td_frame = (struct trapframe *)((caddr_t)pcb2 - 16) - 1; 349 350 /* 351 * Set registers for trampoline to user mode. Leave space for the 352 * return address on stack. These are the kernel mode register values. 353 */ 354 pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdir); 355 pcb2->pcb_edi = 0; 356 pcb2->pcb_esi = (int)fork_return; /* trampoline arg */ 357 pcb2->pcb_ebp = 0; 358 pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */ 359 pcb2->pcb_ebx = (int)td; /* trampoline arg */ 360 pcb2->pcb_eip = (int)fork_trampoline; 361 pcb2->pcb_psl &= ~(PSL_I); /* interrupts must be disabled */ 362 /* 363 * If we didn't copy the pcb, we'd need to do the following registers: 364 * pcb2->pcb_dr*: cloned above. 365 * pcb2->pcb_savefpu: cloned above. 366 * pcb2->pcb_flags: cloned above. 367 * pcb2->pcb_onfault: cloned above (always NULL here?). 368 * pcb2->pcb_gs: cloned above. XXXKSE ??? 369 * pcb2->pcb_ext: cleared below. 370 */ 371 pcb2->pcb_ext = NULL; 372 } 373 374 /* 375 * Set that machine state for performing an upcall that has to 376 * be done in thread_userret() so that those upcalls generated 377 * in thread_userret() itself can be done as well. 378 */ 379 void 380 cpu_set_upcall_kse(struct thread *td, struct kse *ke) 381 { 382 383 /* 384 * Set the trap frame to point at the beginning of the uts 385 * function. 386 */ 387 td->td_frame->tf_esp = 388 (int)ke->ke_stack.ss_sp + ke->ke_stack.ss_size - 16; 389 td->td_frame->tf_eip = (int)ke->ke_upcall; 390 391 /* 392 * Pass the address of the mailbox for this kse to the uts 393 * function as a parameter on the stack. 394 */ 395 suword((void *)(td->td_frame->tf_esp + sizeof(void *)), 396 (int)ke->ke_mailbox); 397 } 398 399 void 400 cpu_wait(p) 401 struct proc *p; 402 { 403 } 404 405 /* 406 * Convert kernel VA to physical address 407 */ 408 u_long 409 kvtop(void *addr) 410 { 411 vm_offset_t va; 412 413 va = pmap_kextract((vm_offset_t)addr); 414 if (va == 0) 415 panic("kvtop: zero page frame"); 416 return((int)va); 417 } 418 419 /* 420 * Map an IO request into kernel virtual address space. 421 * 422 * All requests are (re)mapped into kernel VA space. 423 * Notice that we use b_bufsize for the size of the buffer 424 * to be mapped. b_bcount might be modified by the driver. 425 */ 426 void 427 vmapbuf(bp) 428 register struct buf *bp; 429 { 430 register caddr_t addr, kva; 431 vm_offset_t pa; 432 int pidx; 433 struct vm_page *m; 434 435 GIANT_REQUIRED; 436 437 if ((bp->b_flags & B_PHYS) == 0) 438 panic("vmapbuf"); 439 440 for (addr = (caddr_t)trunc_page((vm_offset_t)bp->b_data), pidx = 0; 441 addr < bp->b_data + bp->b_bufsize; 442 addr += PAGE_SIZE, pidx++) { 443 /* 444 * Do the vm_fault if needed; do the copy-on-write thing 445 * when reading stuff off device into memory. 446 */ 447 vm_fault_quick((addr >= bp->b_data) ? addr : bp->b_data, 448 (bp->b_iocmd == BIO_READ)?(VM_PROT_READ|VM_PROT_WRITE):VM_PROT_READ); 449 pa = trunc_page(pmap_kextract((vm_offset_t) addr)); 450 if (pa == 0) 451 panic("vmapbuf: page not present"); 452 m = PHYS_TO_VM_PAGE(pa); 453 vm_page_hold(m); 454 bp->b_pages[pidx] = m; 455 } 456 if (pidx > btoc(MAXPHYS)) 457 panic("vmapbuf: mapped more than MAXPHYS"); 458 pmap_qenter((vm_offset_t)bp->b_saveaddr, bp->b_pages, pidx); 459 460 kva = bp->b_saveaddr; 461 bp->b_npages = pidx; 462 bp->b_saveaddr = bp->b_data; 463 bp->b_data = kva + (((vm_offset_t) bp->b_data) & PAGE_MASK); 464 } 465 466 /* 467 * Free the io map PTEs associated with this IO operation. 468 * We also invalidate the TLB entries and restore the original b_addr. 469 */ 470 void 471 vunmapbuf(bp) 472 register struct buf *bp; 473 { 474 int pidx; 475 int npages; 476 vm_page_t *m; 477 478 GIANT_REQUIRED; 479 480 if ((bp->b_flags & B_PHYS) == 0) 481 panic("vunmapbuf"); 482 483 npages = bp->b_npages; 484 pmap_qremove(trunc_page((vm_offset_t)bp->b_data), 485 npages); 486 m = bp->b_pages; 487 for (pidx = 0; pidx < npages; pidx++) 488 vm_page_unhold(*m++); 489 490 bp->b_data = bp->b_saveaddr; 491 } 492 493 /* 494 * Force reset the processor by invalidating the entire address space! 495 */ 496 497 #ifdef SMP 498 static void 499 cpu_reset_proxy() 500 { 501 502 cpu_reset_proxy_active = 1; 503 while (cpu_reset_proxy_active == 1) 504 ; /* Wait for other cpu to see that we've started */ 505 stop_cpus((1<<cpu_reset_proxyid)); 506 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid); 507 DELAY(1000000); 508 cpu_reset_real(); 509 } 510 #endif 511 512 void 513 cpu_reset() 514 { 515 #ifdef SMP 516 if (smp_active == 0) { 517 cpu_reset_real(); 518 /* NOTREACHED */ 519 } else { 520 521 u_int map; 522 int cnt; 523 printf("cpu_reset called on cpu#%d\n", PCPU_GET(cpuid)); 524 525 map = PCPU_GET(other_cpus) & ~ stopped_cpus; 526 527 if (map != 0) { 528 printf("cpu_reset: Stopping other CPUs\n"); 529 stop_cpus(map); /* Stop all other CPUs */ 530 } 531 532 if (PCPU_GET(cpuid) == 0) { 533 DELAY(1000000); 534 cpu_reset_real(); 535 /* NOTREACHED */ 536 } else { 537 /* We are not BSP (CPU #0) */ 538 539 cpu_reset_proxyid = PCPU_GET(cpuid); 540 cpustop_restartfunc = cpu_reset_proxy; 541 cpu_reset_proxy_active = 0; 542 printf("cpu_reset: Restarting BSP\n"); 543 started_cpus = (1<<0); /* Restart CPU #0 */ 544 545 cnt = 0; 546 while (cpu_reset_proxy_active == 0 && cnt < 10000000) 547 cnt++; /* Wait for BSP to announce restart */ 548 if (cpu_reset_proxy_active == 0) 549 printf("cpu_reset: Failed to restart BSP\n"); 550 enable_intr(); 551 cpu_reset_proxy_active = 2; 552 553 while (1); 554 /* NOTREACHED */ 555 } 556 } 557 #else 558 cpu_reset_real(); 559 #endif 560 } 561 562 static void 563 cpu_reset_real() 564 { 565 566 #ifdef PC98 567 /* 568 * Attempt to do a CPU reset via CPU reset port. 569 */ 570 disable_intr(); 571 if ((inb(0x35) & 0xa0) != 0xa0) { 572 outb(0x37, 0x0f); /* SHUT0 = 0. */ 573 outb(0x37, 0x0b); /* SHUT1 = 0. */ 574 } 575 outb(0xf0, 0x00); /* Reset. */ 576 #else 577 /* 578 * Attempt to do a CPU reset via the keyboard controller, 579 * do not turn of the GateA20, as any machine that fails 580 * to do the reset here would then end up in no man's land. 581 */ 582 583 #if !defined(BROKEN_KEYBOARD_RESET) 584 outb(IO_KBD + 4, 0xFE); 585 DELAY(500000); /* wait 0.5 sec to see if that did it */ 586 printf("Keyboard reset did not work, attempting CPU shutdown\n"); 587 DELAY(1000000); /* wait 1 sec for printf to complete */ 588 #endif 589 #endif /* PC98 */ 590 /* force a shutdown by unmapping entire address space ! */ 591 bzero((caddr_t) PTD, PAGE_SIZE); 592 593 /* "good night, sweet prince .... <THUNK!>" */ 594 invltlb(); 595 /* NOTREACHED */ 596 while(1); 597 } 598 599 /* 600 * Software interrupt handler for queued VM system processing. 601 */ 602 void 603 swi_vm(void *dummy) 604 { 605 if (busdma_swi_pending != 0) 606 busdma_swi(); 607 } 608 609 /* 610 * Tell whether this address is in some physical memory region. 611 * Currently used by the kernel coredump code in order to avoid 612 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 613 * or other unpredictable behaviour. 614 */ 615 616 int 617 is_physical_memory(addr) 618 vm_offset_t addr; 619 { 620 621 #ifdef DEV_ISA 622 /* The ISA ``memory hole''. */ 623 if (addr >= 0xa0000 && addr < 0x100000) 624 return 0; 625 #endif 626 627 /* 628 * stuff other tests for known memory-mapped devices (PCI?) 629 * here 630 */ 631 632 return 1; 633 } 634