1 /* $NetBSD: ast.c,v 1.32 2021/02/01 19:31:34 skrll Exp $ */
2
3 /*
4 * Copyright (c) 1994,1995 Mark Brinicombe
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the RiscBSD team.
18 * 4. The name of the company nor the name of the author may be used to
19 * endorse or promote products derived from this software without specific
20 * prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTERS BE LIABLE FOR ANY DIRECT,
26 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
27 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
28 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * RiscBSD kernel project
35 *
36 * ast.c
37 *
38 * Code to handle ast's and returns to user mode
39 *
40 * Created : 11/10/94
41 */
42
43 #include <sys/cdefs.h>
44 __KERNEL_RCSID(0, "$NetBSD: ast.c,v 1.32 2021/02/01 19:31:34 skrll Exp $");
45
46 #include "opt_ddb.h"
47
48 #include <sys/param.h>
49 #include <sys/cpu.h>
50 #include <sys/proc.h>
51 #include <sys/acct.h>
52 #include <sys/systm.h>
53 #include <sys/atomic.h>
54 #include <sys/kernel.h>
55 #include <sys/signal.h>
56 #include <sys/userret.h>
57 #include <sys/vmmeter.h>
58
59 #include <arm/locore.h>
60
61 #include <uvm/uvm_extern.h>
62
63 /*
64 * Prototypes
65 */
66 void ast(struct trapframe *);
67
68 void
userret(struct lwp * l)69 userret(struct lwp *l)
70 {
71 #if defined(ARM_MMU_EXTENDED)
72 /*
73 * If our ASID got released, access via TTBR0 will have been disabled.
74 * So if it is disabled, activate the lwp again to get a new ASID.
75 */
76 #ifdef __HAVE_PREEMPTION
77 kpreempt_disable();
78 #endif
79 KASSERTMSG(curcpu()->ci_pmap_cur == l->l_proc->p_vmspace->vm_map.pmap,
80 "%p vs %p", curcpu()->ci_pmap_cur,
81 l->l_proc->p_vmspace->vm_map.pmap);
82 if (__predict_false(armreg_ttbcr_read() & TTBCR_S_PD0)) {
83 pmap_activate(l);
84 }
85 KASSERT(!(armreg_ttbcr_read() & TTBCR_S_PD0));
86 #ifdef __HAVE_PREEMPTION
87 kpreempt_enable();
88 #endif
89 #endif
90
91 /* Invoke MI userret code */
92 mi_userret(l);
93
94 KASSERT(VALID_PSR(lwp_trapframe(l)->tf_spsr));
95 }
96
97
98 /*
99 * Handle asynchronous system traps.
100 * This is called from the irq handler to deliver signals
101 * and switch processes if required.
102 */
103
104 void
ast(struct trapframe * tf)105 ast(struct trapframe *tf)
106 {
107 struct lwp * const l = curlwp;
108
109 /* Interrupts were restored by exception_exit. */
110
111 KASSERT(VALID_PSR(tf->tf_spsr));
112
113 #ifdef __HAVE_PREEMPTION
114 kpreempt_disable();
115 #endif
116 struct cpu_info * const ci = curcpu();
117
118 ci->ci_data.cpu_ntrap++;
119
120 KDASSERT(ci->ci_cpl == IPL_NONE);
121 #ifdef __HAVE_PREEMPTION
122 kpreempt_enable();
123 #endif
124
125 if (l->l_pflag & LP_OWEUPC) {
126 l->l_pflag &= ~LP_OWEUPC;
127 ADDUPROF(l);
128 }
129
130 userret(l);
131 }
132