1 /* $NetBSD: fiq.c,v 1.5 2002/04/03 23:33:27 thorpej Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-4-Clause
5 *
6 * Copyright (c) 2001, 2002 Wasabi Systems, Inc.
7 * All rights reserved.
8 *
9 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
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 for the NetBSD Project by
22 * Wasabi Systems, Inc.
23 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
24 * or promote products derived from this software without specific prior
25 * written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45
46 #include <machine/armreg.h>
47 #include <machine/cpufunc.h>
48 #include <machine/fiq.h>
49 #include <vm/vm.h>
50 #include <machine/pcb.h>
51 #include <vm/pmap.h>
52 #include <machine/cpu.h>
53
54 TAILQ_HEAD(, fiqhandler) fiqhandler_stack =
55 TAILQ_HEAD_INITIALIZER(fiqhandler_stack);
56
57 extern char *fiq_nullhandler_code;
58 extern uint32_t fiq_nullhandler_size;
59
60 /*
61 * fiq_installhandler:
62 *
63 * Actually install the FIQ handler down at the FIQ vector.
64 *
65 * The FIQ vector is fixed by the hardware definition as the
66 * seventh 32-bit word in the vector page.
67 *
68 * Note: If the FIQ is invoked via an extra layer of
69 * indirection, the actual FIQ code store lives in the
70 * data segment, so there is no need to manipulate
71 * the vector page's protection.
72 */
73 static void
fiq_installhandler(void * func,size_t size)74 fiq_installhandler(void *func, size_t size)
75 {
76 const uint32_t fiqvector = 7 * sizeof(uint32_t);
77
78 memcpy((void *)(vector_page + fiqvector), func, size);
79 icache_sync((vm_offset_t) fiqvector, size);
80 }
81
82 /*
83 * fiq_claim:
84 *
85 * Claim the FIQ vector.
86 */
87 int
fiq_claim(struct fiqhandler * fh)88 fiq_claim(struct fiqhandler *fh)
89 {
90 struct fiqhandler *ofh;
91 u_int oldirqstate;
92 int error = 0;
93
94 if (fh->fh_size > 0x100)
95 return (EFBIG);
96
97 oldirqstate = disable_interrupts(PSR_F);
98
99 if ((ofh = TAILQ_FIRST(&fiqhandler_stack)) != NULL) {
100 if ((ofh->fh_flags & FH_CANPUSH) == 0) {
101 error = EBUSY;
102 goto out;
103 }
104
105 /* Save the previous FIQ handler's registers. */
106 if (ofh->fh_regs != NULL)
107 fiq_getregs(ofh->fh_regs);
108 }
109
110 /* Set FIQ mode registers to ours. */
111 if (fh->fh_regs != NULL)
112 fiq_setregs(fh->fh_regs);
113
114 TAILQ_INSERT_HEAD(&fiqhandler_stack, fh, fh_list);
115
116 /* Now copy the actual handler into place. */
117 fiq_installhandler(fh->fh_func, fh->fh_size);
118
119 /* Make sure FIQs are enabled when we return. */
120 oldirqstate &= ~PSR_F;
121
122 out:
123 restore_interrupts(oldirqstate);
124 return (error);
125 }
126
127 /*
128 * fiq_release:
129 *
130 * Release the FIQ vector.
131 */
132 void
fiq_release(struct fiqhandler * fh)133 fiq_release(struct fiqhandler *fh)
134 {
135 u_int oldirqstate;
136 struct fiqhandler *ofh;
137
138 oldirqstate = disable_interrupts(PSR_F);
139
140 /*
141 * If we are the currently active FIQ handler, then we
142 * need to save our registers and pop the next one back
143 * into the vector.
144 */
145 if (fh == TAILQ_FIRST(&fiqhandler_stack)) {
146 if (fh->fh_regs != NULL)
147 fiq_getregs(fh->fh_regs);
148 TAILQ_REMOVE(&fiqhandler_stack, fh, fh_list);
149 if ((ofh = TAILQ_FIRST(&fiqhandler_stack)) != NULL) {
150 if (ofh->fh_regs != NULL)
151 fiq_setregs(ofh->fh_regs);
152 fiq_installhandler(ofh->fh_func, ofh->fh_size);
153 }
154 } else
155 TAILQ_REMOVE(&fiqhandler_stack, fh, fh_list);
156
157 if (TAILQ_FIRST(&fiqhandler_stack) == NULL) {
158 /* Copy the NULL handler back down into the vector. */
159 fiq_installhandler(fiq_nullhandler_code, fiq_nullhandler_size);
160
161 /* Make sure FIQs are disabled when we return. */
162 oldirqstate |= PSR_F;
163 }
164
165 restore_interrupts(oldirqstate);
166 }
167