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.
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.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
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.
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
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 $
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/malloc.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>
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 */
68 #include <vm/vm_param.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>
75 #include <sys/thread2.h>
77 #include <bus/isa/isa.h>
79 char machine
[] = MACHINE
;
80 SYSCTL_STRING(_hw
, HW_MACHINE
, machine
, CTLFLAG_RD
,
81 machine
, 0, "Machine class");
83 u_int cpu_vendor_id
= 0; /* XXX */
86 * Finish a fork operation, with lwp lp2 nearly set up.
87 * Copy and update the pcb, set up the stack so that the child
88 * ready to run and return to user mode.
91 cpu_fork(struct lwp
*lp1
, struct lwp
*lp2
, int flags
)
95 if ((flags
& RFPROC
) == 0) {
96 if ((flags
& RFMEM
) == 0) {
97 /* unshare user LDT */
98 struct pcb
*pcb1
= lp1
->lwp_thread
->td_pcb
;
99 struct pcb_ldt
*pcb_ldt
= pcb1
->pcb_ldt
;
100 if (pcb_ldt
&& pcb_ldt
->ldt_refcnt
> 1) {
101 pcb_ldt
= user_ldt_alloc(pcb1
,pcb_ldt
->ldt_len
);
103 pcb1
->pcb_ldt
= pcb_ldt
;
110 /* Ensure that lp1's pcb is up to date. */
111 if (mdcpu
->gd_npxthread
== lp1
->lwp_thread
)
112 npxsave(lp1
->lwp_thread
->td_savefpu
);
115 * Copy lp1's PCB. This really only applies to the
116 * debug registers and FP state, but its faster to just copy the
117 * whole thing. Because we only save the PCB at switchout time,
118 * the register state may not be current.
120 pcb2
= lp2
->lwp_thread
->td_pcb
;
121 *pcb2
= *lp1
->lwp_thread
->td_pcb
;
124 * Create a new fresh stack for the new process.
125 * Copy the trap frame for the return to user mode as if from a
126 * syscall. This copies the user mode register values.
128 * pcb_rsp must allocate an additional call-return pointer below
129 * the trap frame which will be restored by cpu_heavy_restore from
130 * PCB_RIP, and the thread's td_sp pointer must allocate an
131 * additonal two quadwords below the pcb_rsp call-return pointer to
132 * hold the LWKT restore function pointer and rflags.
134 * The LWKT restore function pointer must be set to cpu_heavy_restore,
135 * which is our standard heavy-weight process switch-in function.
136 * YYY eventually we should shortcut fork_return and fork_trampoline
137 * to use the LWKT restore function directly so we can get rid of
138 * all the extra crap we are setting up.
140 lp2
->lwp_md
.md_regs
= (struct trapframe
*)pcb2
- 1;
141 bcopy(lp1
->lwp_md
.md_regs
, lp2
->lwp_md
.md_regs
, sizeof(*lp2
->lwp_md
.md_regs
));
144 * Set registers for trampoline to user mode. Leave space for the
145 * return address on stack. These are the kernel mode register values.
147 pcb2
->pcb_unused01
= 0;
148 pcb2
->pcb_rbx
= (unsigned long)fork_return
; /* fork_trampoline argument */
150 pcb2
->pcb_rsp
= (unsigned long)lp2
->lwp_md
.md_regs
- sizeof(void *);
151 pcb2
->pcb_r12
= (unsigned long)lp2
; /* fork_trampoline argument */
155 pcb2
->pcb_rip
= (unsigned long)fork_trampoline
;
156 lp2
->lwp_thread
->td_sp
= (char *)(pcb2
->pcb_rsp
- sizeof(void *));
157 *(u_int64_t
*)lp2
->lwp_thread
->td_sp
= PSL_USER
;
158 lp2
->lwp_thread
->td_sp
-= sizeof(void *);
159 *(void **)lp2
->lwp_thread
->td_sp
= (void *)cpu_heavy_restore
;
162 * pcb2->pcb_ldt: duplicated below, if necessary.
163 * pcb2->pcb_savefpu: cloned above.
164 * pcb2->pcb_flags: cloned above (always 0 here?).
165 * pcb2->pcb_onfault: cloned above (always NULL here?).
169 * XXX don't copy the i/o pages. this should probably be fixed.
171 pcb2
->pcb_ext
= NULL
;
173 /* Copy the LDT, if necessary. */
174 if (pcb2
->pcb_ldt
!= NULL
) {
176 atomic_add_int(&pcb2
->pcb_ldt
->ldt_refcnt
, 1);
178 pcb2
->pcb_ldt
= user_ldt_alloc(pcb2
,
179 pcb2
->pcb_ldt
->ldt_len
);
182 bcopy(&lp1
->lwp_thread
->td_tls
, &lp2
->lwp_thread
->td_tls
,
183 sizeof(lp2
->lwp_thread
->td_tls
));
185 * Now, cpu_switch() can schedule the new lwp.
186 * pcb_rsp is loaded pointing to the cpu_switch() stack frame
187 * containing the return address when exiting cpu_switch.
188 * This will normally be to fork_trampoline(), which will have
189 * %rbx loaded with the new lwp's pointer. fork_trampoline()
190 * will set up a stack to call fork_return(lp, frame); to complete
191 * the return to user-mode.
196 * Prepare new lwp to return to the address specified in params.
199 cpu_prepare_lwp(struct lwp
*lp
, struct lwp_params
*params
)
201 struct trapframe
*regs
= lp
->lwp_md
.md_regs
;
202 void *bad_return
= NULL
;
205 regs
->tf_rip
= (long)params
->lwp_func
;
206 regs
->tf_rsp
= (long)params
->lwp_stack
;
207 /* Set up argument for function call */
208 regs
->tf_rdi
= (long)params
->lwp_arg
; /* JG Can this be in userspace addresses? */
210 * Set up fake return address. As the lwp function may never return,
211 * we simply copy out a NULL pointer and force the lwp to receive
212 * a SIGSEGV if it returns anyways.
214 regs
->tf_rsp
-= sizeof(void *);
215 error
= copyout(&bad_return
, (void *)regs
->tf_rsp
, sizeof(bad_return
));
219 cpu_set_fork_handler(lp
,
220 (void (*)(void *, struct trapframe
*))generic_lwp_return
, lp
);
225 * Intercept the return address from a freshly forked process that has NOT
226 * been scheduled yet.
228 * This is needed to make kernel threads stay in kernel mode.
231 cpu_set_fork_handler(struct lwp
*lp
, void (*func
)(void *, struct trapframe
*),
235 * Note that the trap frame follows the args, so the function
236 * is really called like this: func(arg, frame);
238 lp
->lwp_thread
->td_pcb
->pcb_rbx
= (long)func
; /* function */
239 lp
->lwp_thread
->td_pcb
->pcb_r12
= (long)arg
; /* first arg */
243 cpu_set_thread_handler(thread_t td
, void (*rfunc
)(void), void *func
, void *arg
)
245 td
->td_pcb
->pcb_rbx
= (long)func
;
246 td
->td_pcb
->pcb_r12
= (long)arg
;
247 td
->td_switch
= cpu_lwkt_switch
;
248 td
->td_sp
-= sizeof(void *);
249 *(void **)td
->td_sp
= rfunc
; /* exit function on return */
250 td
->td_sp
-= sizeof(void *);
251 *(void **)td
->td_sp
= cpu_kthread_restore
;
257 struct thread
*td
= curthread
;
262 /* Some x86 functionality was dropped */
263 KKASSERT(pcb
->pcb_ext
== NULL
);
266 * disable all hardware breakpoints
268 if (pcb
->pcb_flags
& PCB_DBREGS
) {
270 pcb
->pcb_flags
&= ~PCB_DBREGS
;
272 td
->td_gd
->gd_cnt
.v_swtch
++;
274 crit_enter_quick(td
);
275 if (td
->td_flags
& TDF_TSLEEPQ
)
277 lwkt_deschedule_self(td
);
278 lwkt_remove_tdallq(td
);
283 * Terminate the current thread. The caller must have already acquired
284 * the thread's rwlock and placed it on a reap list or otherwise notified
285 * a reaper of its existance. We set a special assembly switch function which
286 * releases td_rwlock after it has cleaned up the MMU state and switched
289 * Must be caller from a critical section and with the thread descheduled.
292 cpu_thread_exit(void)
295 curthread
->td_switch
= cpu_exit_switch
;
296 curthread
->td_flags
|= TDF_EXITING
;
298 panic("cpu_thread_exit: lwkt_switch() unexpectedly returned");
302 * Used by /dev/kmem to determine if we can safely read or write
303 * the requested KVA range. Some portions of kernel memory are
304 * not governed by our virtual page table.
307 extern void _start(void);
310 kvm_access_check(vm_offset_t saddr
, vm_offset_t eaddr
, int prot
)
314 if (saddr
>= trunc_page((vm_offset_t
)&_start
) &&
315 eaddr
<= round_page((vm_offset_t
)&_end
)) {
318 if (saddr
< KvaStart
)
322 for (addr
= saddr
; addr
< eaddr
; addr
+= PAGE_SIZE
) {
323 if (pmap_kextract(addr
) == 0)
326 if (!kernacc((caddr_t
)saddr
, eaddr
- saddr
, prot
))