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
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.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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.
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
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: src/sys/i386/i386/vm_machdep.c,v 1.132.2.9 2003/01/25 19:02:23 dillon Exp $
42 * $DragonFly: src/sys/platform/vkernel/i386/vm_machdep.c,v 1.3 2007/01/08 03:33:43 dillon Exp $
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/malloc.h>
53 #include <sys/interrupt.h>
54 #include <sys/vnode.h>
55 #include <sys/vmmeter.h>
56 #include <sys/kernel.h>
57 #include <sys/sysctl.h>
58 #include <sys/unistd.h>
60 #include <machine/clock.h>
61 #include <machine/cpu.h>
62 #include <machine/md_var.h>
63 #include <machine/smp.h>
64 #include <machine/pcb.h>
65 #include <machine/pcb_ext.h>
66 #include <machine/vm86.h>
67 #include <machine/segments.h>
68 #include <machine/globaldata.h> /* npxthread */
71 #include <vm/vm_param.h>
73 #include <vm/vm_kern.h>
74 #include <vm/vm_page.h>
75 #include <vm/vm_map.h>
76 #include <vm/vm_extern.h>
79 #include <sys/thread2.h>
81 #include <bus/isa/i386/isa.h>
86 char machine[] = MACHINE_CPU;
87 SYSCTL_STRING(_hw, HW_MACHINE, machine, CTLFLAG_RD,
88 machine, 0, "Machine class");
90 char cpu_vendor[] = "DragonFly"; /* XXX */
91 u_int cpu_id = 0x80000000; /* XXX */
94 * Finish a fork operation, with lwp lp2 nearly set up.
95 * Copy and update the pcb, set up the stack so that the child
96 * ready to run and return to user mode.
99 cpu_fork(struct lwp *lp1, struct lwp *lp2, int flags)
103 if ((flags & RFPROC) == 0) {
104 if ((flags & RFMEM) == 0) {
105 /* unshare user LDT */
106 struct pcb *pcb1 = lp1->lwp_thread->td_pcb;
107 struct pcb_ldt *pcb_ldt = pcb1->pcb_ldt;
108 if (pcb_ldt && pcb_ldt->ldt_refcnt > 1) {
109 pcb_ldt = user_ldt_alloc(pcb1,pcb_ldt->ldt_len);
111 pcb1->pcb_ldt = pcb_ldt;
119 /* Ensure that lp1's pcb is up to date. */
120 if (mdcpu->gd_npxthread == lp1->lwp_thread)
121 npxsave(lp1->lwp_thread->td_savefpu);
125 * Copy lp1's PCB. This really only applies to the
126 * debug registers and FP state, but its faster to just copy the
127 * whole thing. Because we only save the PCB at switchout time,
128 * the register state may not be current.
130 pcb2 = lp2->lwp_thread->td_pcb;
131 *pcb2 = *lp1->lwp_thread->td_pcb;
134 * Create a new fresh stack for the new process.
135 * Copy the trap frame for the return to user mode as if from a
136 * syscall. This copies the user mode register values. The
137 * 16 byte offset saves space for vm86, and must match
138 * common_tss.esp0 (kernel stack pointer on entry from user mode)
140 * pcb_esp must allocate an additional call-return pointer below
141 * the trap frame which will be restored by cpu_restore from
142 * PCB_EIP, and the thread's td_sp pointer must allocate an
143 * additonal two worsd below the pcb_esp call-return pointer to
144 * hold the LWKT restore function pointer and eflags.
146 * The LWKT restore function pointer must be set to cpu_restore,
147 * which is our standard heavy weight process switch-in function.
148 * YYY eventually we should shortcut fork_return and fork_trampoline
149 * to use the LWKT restore function directly so we can get rid of
150 * all the extra crap we are setting up.
152 lp2->lwp_md.md_regs = (struct trapframe *)((char *)pcb2 - 16) - 1;
153 bcopy(lp1->lwp_md.md_regs, lp2->lwp_md.md_regs, sizeof(*lp2->lwp_md.md_regs));
156 * Set registers for trampoline to user mode. Leave space for the
157 * return address on stack. These are the kernel mode register values.
159 pcb2->pcb_cr3 = vtophys(vmspace_pmap(lp2->lwp_proc->p_vmspace)->pm_pdir);
161 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */
163 pcb2->pcb_esp = (int)lp2->lwp_md.md_regs - sizeof(void *);
164 pcb2->pcb_ebx = (int)lp2; /* fork_trampoline argument */
165 pcb2->pcb_eip = (int)fork_trampoline;
166 lp2->lwp_thread->td_sp = (char *)(pcb2->pcb_esp - sizeof(void *));
167 *(u_int32_t *)lp2->lwp_thread->td_sp = PSL_USER;
168 lp2->lwp_thread->td_sp -= sizeof(void *);
169 *(void **)lp2->lwp_thread->td_sp = (void *)cpu_heavy_restore;
172 * pcb2->pcb_ldt: duplicated below, if necessary.
173 * pcb2->pcb_savefpu: cloned above.
174 * pcb2->pcb_flags: cloned above (always 0 here?).
175 * pcb2->pcb_onfault: cloned above (always NULL here?).
179 * XXX don't copy the i/o pages. this should probably be fixed.
183 /* Copy the LDT, if necessary. */
184 if (pcb2->pcb_ldt != 0) {
186 pcb2->pcb_ldt->ldt_refcnt++;
188 pcb2->pcb_ldt = user_ldt_alloc(pcb2,
189 pcb2->pcb_ldt->ldt_len);
192 bcopy(&lp1->lwp_thread->td_tls, &lp2->lwp_thread->td_tls,
193 sizeof(lp2->lwp_thread->td_tls));
195 * Now, cpu_switch() can schedule the new process.
196 * pcb_esp is loaded pointing to the cpu_switch() stack frame
197 * containing the return address when exiting cpu_switch.
198 * This will normally be to fork_trampoline(), which will have
199 * %ebx loaded with the new proc's pointer. fork_trampoline()
200 * will set up a stack to call fork_return(p, frame); to complete
201 * the return to user-mode.
206 * Intercept the return address from a freshly forked process that has NOT
207 * been scheduled yet.
209 * This is needed to make kernel threads stay in kernel mode.
212 cpu_set_fork_handler(struct lwp *lp, void (*func)(void *), void *arg)
215 * Note that the trap frame follows the args, so the function
216 * is really called like this: func(arg, frame);
218 lp->lwp_thread->td_pcb->pcb_esi = (int) func; /* function */
219 lp->lwp_thread->td_pcb->pcb_ebx = (int) arg; /* first arg */
223 cpu_set_thread_handler(thread_t td, void (*rfunc)(void), void *func, void *arg)
225 td->td_pcb->pcb_esi = (int)func;
226 td->td_pcb->pcb_ebx = (int) arg;
227 td->td_switch = cpu_lwkt_switch;
228 td->td_sp -= sizeof(void *);
229 *(void **)td->td_sp = rfunc; /* exit function on return */
230 td->td_sp -= sizeof(void *);
231 *(void **)td->td_sp = cpu_kthread_restore;
237 struct thread *td = curthread;
246 * If we were using a private TSS do a forced-switch to ourselves
247 * to switch back to the common TSS before freeing it.
250 if ((ext = pcb->pcb_ext) != NULL) {
255 kmem_free(&kernel_map, (vm_offset_t)ext, ctob(IOPAGES + 1));
258 if (pcb->pcb_flags & PCB_DBREGS) {
260 * disable all hardware breakpoints
263 pcb->pcb_flags &= ~PCB_DBREGS;
265 td->td_gd->gd_cnt.v_swtch++;
267 crit_enter_quick(td);
268 lwkt_deschedule_self(td);
269 lwkt_remove_tdallq(td);
274 * Terminate the current thread. The caller must have already acquired
275 * the thread's rwlock and placed it on a reap list or otherwise notified
276 * a reaper of its existance. We set a special assembly switch function which
277 * releases td_rwlock after it has cleaned up the MMU state and switched
280 * Must be caller from a critical section and with the thread descheduled.
283 cpu_thread_exit(void)
285 curthread->td_switch = cpu_exit_switch;
286 curthread->td_flags |= TDF_EXITING;
292 * Process Reaper. Called after the caller has acquired the thread's
293 * rwlock and removed it from the reap list.
296 cpu_proc_wait(struct proc *p)
300 /* drop per-process resources */
301 td = pmap_dispose_proc(p);
303 lwkt_free_thread(td);
307 * Dump the machine specific header information at the start of a core dump.
310 cpu_coredump(struct thread *td, struct vnode *vp, struct ucred *cred)
312 struct proc *p = td->td_proc;
317 tempuser = kmalloc(ctob(UPAGES), M_TEMP, M_WAITOK);
321 bzero(tempuser, ctob(UPAGES));
322 bcopy(p->p_addr, tempuser, sizeof(struct user));
323 bcopy(p->p_md.md_regs,
324 tempuser + ((caddr_t) p->p_md.md_regs - (caddr_t) p->p_addr),
325 sizeof(struct trapframe));
326 bcopy(p->p_thread->td_pcb, tempuser + ((char *)p->p_thread->td_pcb - (char *)p->p_addr), sizeof(struct pcb));
328 error = vn_rdwr(UIO_WRITE, vp, (caddr_t) tempuser, ctob(UPAGES),
329 (off_t)0, UIO_SYSSPACE, IO_UNIT, cred, (int *)NULL);
331 kfree(tempuser, M_TEMP);
338 setredzone(u_short *pte, caddr_t vaddr)
340 /* eventually do this by setting up an expand-down stack segment
341 for ss0: selector, allowing stack access down to top of u.
342 this means though that protection violations need to be handled
343 thru a double fault exception that must do an integral task
344 switch to a known good context, within which a dump can be
345 taken. a sensible scheme might be to save the initial context
346 used by sched (that has physical memory mapped 1:1 at bottom)
347 and take the dump while still in mapped mode */
352 * Convert kernel VA to physical address
359 pa = pmap_kextract((vm_offset_t)addr);
361 panic("kvtop: zero page frame");
366 grow_stack(struct proc *p, u_int sp)
370 rv = vm_map_growstack (p, sp);
371 if (rv != KERN_SUCCESS)
377 SYSCTL_DECL(_vm_stats_misc);
379 static int cnt_prezero;
381 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
382 cnt_prezero, CTLFLAG_RD, &cnt_prezero, 0, "");
385 * Tell whether this address is in some physical memory region.
386 * Currently used by the kernel coredump code in order to avoid
387 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
388 * or other unpredictable behaviour.
392 is_physical_memory(vm_offset_t addr)