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 "opt_compat.h"
44
45#include <sys/cdefs.h>
46__FBSDID("$FreeBSD: stable/11/sys/arm/arm/vm_machdep.c 331722 2018-03-29 02:50:57Z eadler $");
47
48#include <sys/param.h>
49#include <sys/systm.h>
50#include <sys/kernel.h>
51#include <sys/malloc.h>
52#include <sys/mbuf.h>
53#include <sys/proc.h>
54#include <sys/socketvar.h>
55#include <sys/syscall.h>
56#include <sys/sysctl.h>
57#include <sys/sysent.h>
58#include <sys/unistd.h>
59
60#include <machine/cpu.h>
61#include <machine/frame.h>
62#include <machine/pcb.h>
63#include <machine/sysarch.h>
64#include <sys/lock.h>
65#include <sys/mutex.h>
66
67#include <vm/vm.h>
68#include <vm/pmap.h>
69#include <vm/vm_extern.h>
70#include <vm/vm_kern.h>
71#include <vm/vm_page.h>
72#include <vm/vm_map.h>
73#include <vm/vm_param.h>
74#include <vm/vm_pageout.h>
75#include <vm/uma.h>
76#include <vm/uma_int.h>
77
78#include <machine/md_var.h>
79#include <machine/vfp.h>
80
81/*
82 * struct switchframe and trapframe must both be a multiple of 8
83 * for correct stack alignment.
84 */
85_Static_assert((sizeof(struct switchframe) % 8) == 0, "Bad alignment");
86_Static_assert((sizeof(struct trapframe) % 8) == 0, "Bad alignment");
87
88uint32_t initial_fpscr = VFPSCR_DN | VFPSCR_FZ;
89
90/*
91 * Finish a fork operation, with process p2 nearly set up.
92 * Copy and update the pcb, set up the stack so that the child
93 * ready to run and return to user mode.
94 */
95void
96cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
97{
98	struct pcb *pcb2;
99	struct trapframe *tf;
100	struct mdproc *mdp2;
101
102	if ((flags & RFPROC) == 0)
103		return;
104
105	/* Point the pcb to the top of the stack */
106	pcb2 = (struct pcb *)
107	    (td2->td_kstack + td2->td_kstack_pages * PAGE_SIZE) - 1;
108#ifdef __XSCALE__
109#ifndef CPU_XSCALE_CORE3
110	pmap_use_minicache(td2->td_kstack, td2->td_kstack_pages * PAGE_SIZE);
111#endif
112#endif
113#ifdef VFP
114	/* Store actual state of VFP */
115	if (curthread == td1) {
116		critical_enter();
117		vfp_store(&td1->td_pcb->pcb_vfpstate, false);
118		critical_exit();
119	}
120#endif
121	td2->td_pcb = pcb2;
122
123	/* Clone td1's pcb */
124	bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
125
126	/* Point to mdproc and then copy over td1's contents */
127	mdp2 = &p2->p_md;
128	bcopy(&td1->td_proc->p_md, mdp2, sizeof(*mdp2));
129
130	/* Point the frame to the stack in front of pcb and copy td1's frame */
131	td2->td_frame = (struct trapframe *)pcb2 - 1;
132	*td2->td_frame = *td1->td_frame;
133
134	/*
135	 * Create a new fresh stack for the new process.
136	 * Copy the trap frame for the return to user mode as if from a
137	 * syscall.  This copies most of the user mode register values.
138	 */
139	pmap_set_pcb_pagedir(vmspace_pmap(p2->p_vmspace), pcb2);
140	pcb2->pcb_regs.sf_r4 = (register_t)fork_return;
141	pcb2->pcb_regs.sf_r5 = (register_t)td2;
142	pcb2->pcb_regs.sf_lr = (register_t)fork_trampoline;
143	pcb2->pcb_regs.sf_sp = STACKALIGN(td2->td_frame);
144#if __ARM_ARCH >= 6
145	pcb2->pcb_regs.sf_tpidrurw = (register_t)get_tls();
146#endif
147
148	pcb2->pcb_vfpcpu = -1;
149	pcb2->pcb_vfpstate.fpscr = initial_fpscr;
150
151	tf = td2->td_frame;
152	tf->tf_spsr &= ~PSR_C;
153	tf->tf_r0 = 0;
154	tf->tf_r1 = 0;
155
156
157	/* Setup to release spin count in fork_exit(). */
158	td2->td_md.md_spinlock_count = 1;
159	td2->td_md.md_saved_cspr = PSR_SVC32_MODE;
160#if __ARM_ARCH < 6
161	td2->td_md.md_tp = *(register_t *)ARM_TP_ADDRESS;
162#endif
163}
164
165void
166cpu_thread_swapin(struct thread *td)
167{
168}
169
170void
171cpu_thread_swapout(struct thread *td)
172{
173}
174
175void
176cpu_set_syscall_retval(struct thread *td, int error)
177{
178	struct trapframe *frame;
179	int fixup;
180#ifdef __ARMEB__
181	u_int call;
182#endif
183
184	frame = td->td_frame;
185	fixup = 0;
186
187#ifdef __ARMEB__
188	/*
189	 * __syscall returns an off_t while most other syscalls return an
190	 * int. As an off_t is 64-bits and an int is 32-bits we need to
191	 * place the returned data into r1. As the lseek and freebsd6_lseek
192	 * syscalls also return an off_t they do not need this fixup.
193	 */
194	call = frame->tf_r7;
195	if (call == SYS___syscall) {
196		register_t *ap = &frame->tf_r0;
197		register_t code = ap[_QUAD_LOWWORD];
198		if (td->td_proc->p_sysent->sv_mask)
199			code &= td->td_proc->p_sysent->sv_mask;
200		fixup = (code != SYS_lseek);
201	}
202#endif
203
204	switch (error) {
205	case 0:
206		if (fixup) {
207			frame->tf_r0 = 0;
208			frame->tf_r1 = td->td_retval[0];
209		} else {
210			frame->tf_r0 = td->td_retval[0];
211			frame->tf_r1 = td->td_retval[1];
212		}
213		frame->tf_spsr &= ~PSR_C;   /* carry bit */
214		break;
215	case ERESTART:
216		/*
217		 * Reconstruct the pc to point at the swi.
218		 */
219#if __ARM_ARCH >= 7
220		if ((frame->tf_spsr & PSR_T) != 0)
221			frame->tf_pc -= THUMB_INSN_SIZE;
222		else
223#endif
224			frame->tf_pc -= INSN_SIZE;
225		break;
226	case EJUSTRETURN:
227		/* nothing to do */
228		break;
229	default:
230		frame->tf_r0 = error;
231		frame->tf_spsr |= PSR_C;    /* carry bit */
232		break;
233	}
234}
235
236/*
237 * Initialize machine state, mostly pcb and trap frame for a new
238 * thread, about to return to userspace.  Put enough state in the new
239 * thread's PCB to get it to go back to the fork_return(), which
240 * finalizes the thread state and handles peculiarities of the first
241 * return to userspace for the new thread.
242 */
243void
244cpu_copy_thread(struct thread *td, struct thread *td0)
245{
246
247	bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
248	bcopy(td0->td_pcb, td->td_pcb, sizeof(struct pcb));
249
250	td->td_pcb->pcb_regs.sf_r4 = (register_t)fork_return;
251	td->td_pcb->pcb_regs.sf_r5 = (register_t)td;
252	td->td_pcb->pcb_regs.sf_lr = (register_t)fork_trampoline;
253	td->td_pcb->pcb_regs.sf_sp = STACKALIGN(td->td_frame);
254
255	td->td_frame->tf_spsr &= ~PSR_C;
256	td->td_frame->tf_r0 = 0;
257
258	/* Setup to release spin count in fork_exit(). */
259	td->td_md.md_spinlock_count = 1;
260	td->td_md.md_saved_cspr = PSR_SVC32_MODE;
261}
262
263/*
264 * Set that machine state for performing an upcall that starts
265 * the entry function with the given argument.
266 */
267void
268cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg,
269	stack_t *stack)
270{
271	struct trapframe *tf = td->td_frame;
272
273	tf->tf_usr_sp = STACKALIGN((int)stack->ss_sp + stack->ss_size);
274	tf->tf_pc = (int)entry;
275	tf->tf_r0 = (int)arg;
276	tf->tf_spsr = PSR_USR32_MODE;
277}
278
279int
280cpu_set_user_tls(struct thread *td, void *tls_base)
281{
282
283#if __ARM_ARCH >= 6
284	td->td_pcb->pcb_regs.sf_tpidrurw = (register_t)tls_base;
285	if (td == curthread)
286		set_tls(tls_base);
287#else
288	td->td_md.md_tp = (register_t)tls_base;
289	if (td == curthread) {
290		critical_enter();
291		*(register_t *)ARM_TP_ADDRESS = (register_t)tls_base;
292		critical_exit();
293	}
294#endif
295	return (0);
296}
297
298void
299cpu_thread_exit(struct thread *td)
300{
301}
302
303void
304cpu_thread_alloc(struct thread *td)
305{
306	td->td_pcb = (struct pcb *)(td->td_kstack + td->td_kstack_pages *
307	    PAGE_SIZE) - 1;
308	/*
309	 * Ensure td_frame is aligned to an 8 byte boundary as it will be
310	 * placed into the stack pointer which must be 8 byte aligned in
311	 * the ARM EABI.
312	 */
313	td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb) - 1;
314
315#ifdef __XSCALE__
316#ifndef CPU_XSCALE_CORE3
317	pmap_use_minicache(td->td_kstack, td->td_kstack_pages * PAGE_SIZE);
318#endif
319#endif
320}
321
322void
323cpu_thread_free(struct thread *td)
324{
325}
326
327void
328cpu_thread_clean(struct thread *td)
329{
330}
331
332/*
333 * Intercept the return address from a freshly forked process that has NOT
334 * been scheduled yet.
335 *
336 * This is needed to make kernel threads stay in kernel mode.
337 */
338void
339cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg)
340{
341	td->td_pcb->pcb_regs.sf_r4 = (register_t)func;	/* function */
342	td->td_pcb->pcb_regs.sf_r5 = (register_t)arg;	/* first arg */
343}
344
345/*
346 * Software interrupt handler for queued VM system processing.
347 */
348void
349swi_vm(void *dummy)
350{
351
352	if (busdma_swi_pending)
353		busdma_swi();
354}
355
356void
357cpu_exit(struct thread *td)
358{
359}
360
361