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 * Copyright (c) 2008 The DragonFly Project. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * the Systems Programming Group of the University of Utah Computer 10 * Science Department, and William Jolitz. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91 41 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$ 42 * $FreeBSD: src/sys/i386/i386/vm_machdep.c,v 1.132.2.9 2003/01/25 19:02:23 dillon Exp $ 43 */ 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/malloc.h> 48 #include <sys/proc.h> 49 #include <sys/buf.h> 50 #include <sys/interrupt.h> 51 #include <sys/vnode.h> 52 #include <sys/vmmeter.h> 53 #include <sys/kernel.h> 54 #include <sys/sysctl.h> 55 #include <sys/unistd.h> 56 #include <sys/dsched.h> 57 58 #include <machine/clock.h> 59 #include <machine/cpu.h> 60 #include <machine/md_var.h> 61 #include <machine/smp.h> 62 #include <machine/pcb.h> 63 #include <machine/pcb_ext.h> 64 #include <machine/segments.h> 65 #include <machine/globaldata.h> /* npxthread */ 66 67 #include <vm/vm.h> 68 #include <vm/vm_param.h> 69 #include <sys/lock.h> 70 #include <vm/vm_kern.h> 71 #include <vm/vm_page.h> 72 #include <vm/vm_map.h> 73 #include <vm/vm_extern.h> 74 75 #include <sys/thread2.h> 76 #include <sys/mplock2.h> 77 78 #include <bus/isa/isa.h> 79 80 static void cpu_reset_real (void); 81 /* 82 * Finish a fork operation, with lwp lp2 nearly set up. 83 * Copy and update the pcb, set up the stack so that the child 84 * ready to run and return to user mode. 85 */ 86 void 87 cpu_fork(struct lwp *lp1, struct lwp *lp2, int flags) 88 { 89 struct pcb *pcb2; 90 91 if ((flags & RFPROC) == 0) { 92 if ((flags & RFMEM) == 0) { 93 /* unshare user LDT */ 94 struct pcb *pcb1 = lp1->lwp_thread->td_pcb; 95 struct pcb_ldt *pcb_ldt = pcb1->pcb_ldt; 96 if (pcb_ldt && pcb_ldt->ldt_refcnt > 1) { 97 pcb_ldt = user_ldt_alloc(pcb1,pcb_ldt->ldt_len); 98 user_ldt_free(pcb1); 99 pcb1->pcb_ldt = pcb_ldt; 100 set_user_ldt(pcb1); 101 } 102 } 103 return; 104 } 105 106 /* Ensure that lp1's pcb is up to date. */ 107 if (mdcpu->gd_npxthread == lp1->lwp_thread) 108 npxsave(lp1->lwp_thread->td_savefpu); 109 110 /* 111 * Copy lp1's PCB. This really only applies to the 112 * debug registers and FP state, but its faster to just copy the 113 * whole thing. Because we only save the PCB at switchout time, 114 * the register state may not be current. 115 */ 116 pcb2 = lp2->lwp_thread->td_pcb; 117 *pcb2 = *lp1->lwp_thread->td_pcb; 118 119 /* 120 * Create a new fresh stack for the new process. 121 * Copy the trap frame for the return to user mode as if from a 122 * syscall. This copies the user mode register values. 123 * 124 * pcb_rsp must allocate an additional call-return pointer below 125 * the trap frame which will be restored by cpu_heavy_restore from 126 * PCB_RIP, and the thread's td_sp pointer must allocate an 127 * additonal two quadwords below the pcb_rsp call-return pointer to 128 * hold the LWKT restore function pointer and rflags. 129 * 130 * The LWKT restore function pointer must be set to cpu_heavy_restore, 131 * which is our standard heavy-weight process switch-in function. 132 * YYY eventually we should shortcut fork_return and fork_trampoline 133 * to use the LWKT restore function directly so we can get rid of 134 * all the extra crap we are setting up. 135 */ 136 lp2->lwp_md.md_regs = (struct trapframe *)pcb2 - 1; 137 bcopy(lp1->lwp_md.md_regs, lp2->lwp_md.md_regs, sizeof(*lp2->lwp_md.md_regs)); 138 139 /* 140 * Set registers for trampoline to user mode. Leave space for the 141 * return address on stack. These are the kernel mode register values. 142 */ 143 pcb2->pcb_cr3 = vtophys(vmspace_pmap(lp2->lwp_proc->p_vmspace)->pm_pml4); 144 pcb2->pcb_cr3 |= PG_RW | PG_U | PG_V; 145 pcb2->pcb_rbx = (unsigned long)fork_return; /* fork_trampoline argument */ 146 pcb2->pcb_rbp = 0; 147 pcb2->pcb_rsp = (unsigned long)lp2->lwp_md.md_regs - sizeof(void *); 148 pcb2->pcb_r12 = (unsigned long)lp2; /* fork_trampoline argument */ 149 pcb2->pcb_r13 = 0; 150 pcb2->pcb_r14 = 0; 151 pcb2->pcb_r15 = 0; 152 pcb2->pcb_rip = (unsigned long)fork_trampoline; 153 lp2->lwp_thread->td_sp = (char *)(pcb2->pcb_rsp - sizeof(void *)); 154 *(u_int64_t *)lp2->lwp_thread->td_sp = PSL_USER; 155 lp2->lwp_thread->td_sp -= sizeof(void *); 156 *(void **)lp2->lwp_thread->td_sp = (void *)cpu_heavy_restore; 157 158 /* 159 * pcb2->pcb_ldt: duplicated below, if necessary. 160 * pcb2->pcb_savefpu: cloned above. 161 * pcb2->pcb_flags: cloned above (always 0 here?). 162 * pcb2->pcb_onfault: cloned above (always NULL here?). 163 */ 164 165 /* 166 * XXX don't copy the i/o pages. this should probably be fixed. 167 */ 168 pcb2->pcb_ext = 0; 169 170 /* Copy the LDT, if necessary. */ 171 if (pcb2->pcb_ldt != 0) { 172 if (flags & RFMEM) { 173 pcb2->pcb_ldt->ldt_refcnt++; 174 } else { 175 pcb2->pcb_ldt = user_ldt_alloc(pcb2, 176 pcb2->pcb_ldt->ldt_len); 177 } 178 } 179 bcopy(&lp1->lwp_thread->td_tls, &lp2->lwp_thread->td_tls, 180 sizeof(lp2->lwp_thread->td_tls)); 181 /* 182 * Now, cpu_switch() can schedule the new lwp. 183 * pcb_rsp is loaded pointing to the cpu_switch() stack frame 184 * containing the return address when exiting cpu_switch. 185 * This will normally be to fork_trampoline(), which will have 186 * %rbx loaded with the new lwp's pointer. fork_trampoline() 187 * will set up a stack to call fork_return(lp, frame); to complete 188 * the return to user-mode. 189 */ 190 } 191 192 /* 193 * Prepare new lwp to return to the address specified in params. 194 */ 195 int 196 cpu_prepare_lwp(struct lwp *lp, struct lwp_params *params) 197 { 198 struct trapframe *regs = lp->lwp_md.md_regs; 199 void *bad_return = NULL; 200 int error; 201 202 regs->tf_rip = (long)params->func; 203 regs->tf_rsp = (long)params->stack; 204 /* Set up argument for function call */ 205 regs->tf_rdi = (long)params->arg; /* JG Can this be in userspace addresses? */ 206 /* 207 * Set up fake return address. As the lwp function may never return, 208 * we simply copy out a NULL pointer and force the lwp to receive 209 * a SIGSEGV if it returns anyways. 210 */ 211 regs->tf_rsp -= sizeof(void *); 212 error = copyout(&bad_return, (void *)regs->tf_rsp, sizeof(bad_return)); 213 if (error) 214 return (error); 215 216 cpu_set_fork_handler(lp, 217 (void (*)(void *, struct trapframe *))generic_lwp_return, lp); 218 return (0); 219 } 220 221 /* 222 * Intercept the return address from a freshly forked process that has NOT 223 * been scheduled yet. 224 * 225 * This is needed to make kernel threads stay in kernel mode. 226 */ 227 void 228 cpu_set_fork_handler(struct lwp *lp, void (*func)(void *, struct trapframe *), 229 void *arg) 230 { 231 /* 232 * Note that the trap frame follows the args, so the function 233 * is really called like this: func(arg, frame); 234 */ 235 lp->lwp_thread->td_pcb->pcb_rbx = (long)func; /* function */ 236 lp->lwp_thread->td_pcb->pcb_r12 = (long)arg; /* first arg */ 237 } 238 239 void 240 cpu_set_thread_handler(thread_t td, void (*rfunc)(void), void *func, void *arg) 241 { 242 td->td_pcb->pcb_rbx = (long)func; 243 td->td_pcb->pcb_r12 = (long)arg; 244 td->td_switch = cpu_lwkt_switch; 245 td->td_sp -= sizeof(void *); 246 *(void **)td->td_sp = rfunc; /* exit function on return */ 247 td->td_sp -= sizeof(void *); 248 *(void **)td->td_sp = cpu_kthread_restore; 249 } 250 251 void 252 cpu_lwp_exit(void) 253 { 254 struct thread *td = curthread; 255 struct pcb *pcb; 256 npxexit(); 257 pcb = td->td_pcb; 258 KKASSERT(pcb->pcb_ext == NULL); /* Some i386 functionality was dropped */ 259 if (pcb->pcb_flags & PCB_DBREGS) { 260 /* 261 * disable all hardware breakpoints 262 */ 263 reset_dbregs(); 264 pcb->pcb_flags &= ~PCB_DBREGS; 265 } 266 td->td_gd->gd_cnt.v_swtch++; 267 268 dsched_exit_thread(td); 269 crit_enter_quick(td); 270 if (td->td_flags & TDF_TSLEEPQ) 271 tsleep_remove(td); 272 lwkt_deschedule_self(td); 273 lwkt_remove_tdallq(td); 274 cpu_thread_exit(); 275 } 276 277 /* 278 * Terminate the current thread. The caller must have already acquired 279 * the thread's rwlock and placed it on a reap list or otherwise notified 280 * a reaper of its existance. We set a special assembly switch function which 281 * releases td_rwlock after it has cleaned up the MMU state and switched 282 * out the stack. 283 * 284 * Must be caller from a critical section and with the thread descheduled. 285 */ 286 void 287 cpu_thread_exit(void) 288 { 289 curthread->td_switch = cpu_exit_switch; 290 curthread->td_flags |= TDF_EXITING; 291 lwkt_switch(); 292 panic("cpu_thread_exit: lwkt_switch() unexpectedly returned"); 293 } 294 295 /* 296 * Process Reaper. Called after the caller has acquired the thread's 297 * rwlock and removed it from the reap list. 298 */ 299 void 300 cpu_proc_wait(struct proc *p) 301 { 302 /* drop per-process resources */ 303 pmap_dispose_proc(p); 304 } 305 306 void 307 cpu_reset(void) 308 { 309 cpu_reset_real(); 310 } 311 312 static void 313 cpu_reset_real(void) 314 { 315 /* 316 * Attempt to do a CPU reset via the keyboard controller, 317 * do not turn of the GateA20, as any machine that fails 318 * to do the reset here would then end up in no man's land. 319 */ 320 321 #if !defined(BROKEN_KEYBOARD_RESET) 322 outb(IO_KBD + 4, 0xFE); 323 DELAY(500000); /* wait 0.5 sec to see if that did it */ 324 kprintf("Keyboard reset did not work, attempting CPU shutdown\n"); 325 DELAY(1000000); /* wait 1 sec for kprintf to complete */ 326 #endif 327 #if JG 328 /* force a shutdown by unmapping entire address space ! */ 329 bzero((caddr_t) PTD, PAGE_SIZE); 330 #endif 331 332 /* "good night, sweet prince .... <THUNK!>" */ 333 cpu_invltlb(); 334 /* NOTREACHED */ 335 while(1); 336 } 337 338 /* 339 * Convert kernel VA to physical address 340 */ 341 vm_paddr_t 342 kvtop(void *addr) 343 { 344 vm_paddr_t pa; 345 346 pa = pmap_kextract((vm_offset_t)addr); 347 if (pa == 0) 348 panic("kvtop: zero page frame"); 349 return (pa); 350 } 351 352 /* 353 * Tell whether this address is in some physical memory region. 354 * Currently used by the kernel coredump code in order to avoid 355 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 356 * or other unpredictable behaviour. 357 */ 358 359 int 360 is_physical_memory(vm_offset_t addr) 361 { 362 #if NISA > 0 363 /* The ISA ``memory hole''. */ 364 if (addr >= 0xa0000 && addr < 0x100000) 365 return 0; 366 #endif 367 /* 368 * stuff other tests for known memory-mapped devices (PCI?) 369 * here 370 */ 371 372 return 1; 373 } 374 375 /* 376 * platform-specific vmspace initialization (nothing for x86_64) 377 */ 378 void 379 cpu_vmspace_alloc(struct vmspace *vm __unused) 380 { 381 } 382 383 void 384 cpu_vmspace_free(struct vmspace *vm __unused) 385 { 386 } 387 388 int 389 kvm_access_check(vm_offset_t saddr, vm_offset_t eaddr, int prot) 390 { 391 vm_offset_t addr; 392 393 if (saddr < KvaStart) 394 return EFAULT; 395 if (eaddr >= KvaEnd) 396 return EFAULT; 397 for (addr = saddr; addr < eaddr; addr += PAGE_SIZE) { 398 if (pmap_extract(&kernel_pmap, addr) == 0) 399 return EFAULT; 400 } 401 if (!kernacc((caddr_t)saddr, eaddr - saddr, prot)) 402 return EFAULT; 403 return 0; 404 } 405 406