1/*	$NetBSD: userret.h,v 1.31 2020/07/06 09:34:17 rin Exp $	*/
2
3/*
4 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
5 * Copyright (C) 1995, 1996 TooLs GmbH.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by TooLs GmbH.
19 * 4. The name of TooLs GmbH may not be used to endorse or promote products
20 *    derived from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
28 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
30 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
31 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#ifdef _KERNEL_OPT
35#include "opt_altivec.h"
36#include "opt_ppcarch.h"
37#endif
38
39#include <sys/userret.h>
40#include <sys/ras.h>
41
42#include <powerpc/fpu.h>
43#include <powerpc/psl.h>
44
45#ifdef PPC_BOOKE
46#include <powerpc/spr.h>
47#include <powerpc/booke/spr.h>
48#endif
49
50/*
51 * Define the code needed before returning to user mode, for
52 * trap and syscall.
53 */
54static __inline void
55userret(struct lwp *l, struct trapframe *tf)
56{
57	KASSERTMSG((tf == trapframe(curlwp)),
58	   "tf=%p, trapframe(curlwp)=%p\n", tf, trapframe(curlwp));
59
60	/* Invoke MI userret code */
61	mi_userret(l);
62
63	KASSERTMSG((tf->tf_srr1 & PSL_PR) != 0,
64	    "tf=%p: srr1 (%#lx): PSL_PR isn't set!",
65	    tf, tf->tf_srr1);
66	KASSERTMSG((tf->tf_srr1 & PSL_FP) == 0
67	    || l->l_cpu->ci_data.cpu_pcu_curlwp[PCU_FPU] == l,
68	    "tf=%p: srr1 (%#lx): PSL_FP set but FPU curlwp %p is not curlwp %p!",
69	    tf, tf->tf_srr1, l->l_cpu->ci_data.cpu_pcu_curlwp[PCU_FPU], l);
70
71	/* clear SRR1 status bits */
72	tf->tf_srr1 &= (PSL_USERSRR1|PSL_FP|PSL_VEC);
73
74#ifdef ALTIVEC
75	/*
76	 * We need to manually restore PSL_VEC each time we return
77	 * to user mode since PSL_VEC isn't always preserved in SRR1.
78	 * We keep a copy of it in md_flags to make restoring easier.
79	 */
80	tf->tf_srr1 |= l->l_md.md_flags & PSL_VEC;
81#endif
82#ifdef PPC_BOOKE
83	/*
84	 * BookE doesn't have PSL_SE but it does have a debug instruction
85	 * completion exception but it needs PSL_DE to fire.  Instead we
86	 * use IAC1/IAC2 to match the next PC.
87	 */
88	if (__predict_false(tf->tf_srr1 & PSL_SE)) {
89		tf->tf_srr1 &= ~PSL_SE;
90		extern void booke_sstep(struct trapframe *); /* ugly */
91		booke_sstep(tf);
92	}
93#endif
94
95#ifdef __HAVE_RAS
96	/*
97	 * Check to see if a RAS was interrupted and restart it if it was.
98	 */
99	struct proc * const p = l->l_proc;
100	if (__predict_false(p->p_raslist != NULL)) {
101		void * const ras_pc = ras_lookup(p, (void *) tf->tf_srr0);
102		if (ras_pc != (void *) -1)
103			tf->tf_srr0 = (vaddr_t) ras_pc;
104	}
105#endif
106}
107