1 /* $OpenBSD: fiq.c,v 1.7 2016/01/31 00:14:50 jsg Exp $ */
2 /* $NetBSD: fiq.c,v 1.5 2002/04/03 23:33:27 thorpej Exp $ */
3
4 /*
5 * Copyright (c) 2001, 2002 Wasabi Systems, Inc.
6 * All rights reserved.
7 *
8 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed for the NetBSD Project by
21 * Wasabi Systems, Inc.
22 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
23 * or promote products derived from this software without specific prior
24 * written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41
42 #include <arm/cpufunc.h>
43 #include <arm/fiq.h>
44
45 TAILQ_HEAD(, fiqhandler) fiqhandler_stack =
46 TAILQ_HEAD_INITIALIZER(fiqhandler_stack);
47
48 extern char fiqvector[];
49 extern char fiq_nullhandler[], fiq_nullhandler_end[];
50
51 #define IRQ_BIT PSR_I
52 #define FIQ_BIT PSR_F
53
54 /*
55 * fiq_installhandler:
56 *
57 * Actually install the FIQ handler down at the FIQ vector.
58 *
59 * Note: If the FIQ is invoked via an extra layer of
60 * indirection, the actual FIQ code store lives in the
61 * data segment, so there is no need to manipulate
62 * the vector page's protection.
63 */
64 static void
fiq_installhandler(void * func,size_t size)65 fiq_installhandler(void *func, size_t size)
66 {
67 #if !defined(__ARM_FIQ_INDIRECT)
68 vector_page_setprot(PROT_READ | PROT_WRITE | PROT_EXEC);
69 #endif
70
71 memcpy(fiqvector, func, size);
72
73 #if !defined(__ARM_FIQ_INDIRECT)
74 vector_page_setprot(PROT_READ | PROT_EXEC);
75 #endif
76 cpu_icache_sync_range((vaddr_t) fiqvector, size);
77 }
78
79 /*
80 * fiq_claim:
81 *
82 * Claim the FIQ vector.
83 */
84 int
fiq_claim(struct fiqhandler * fh)85 fiq_claim(struct fiqhandler *fh)
86 {
87 struct fiqhandler *ofh;
88 u_int oldirqstate;
89 int error = 0;
90
91 if (fh->fh_size > 0x100)
92 return (EFBIG);
93
94 oldirqstate = disable_interrupts(FIQ_BIT);
95
96 if ((ofh = TAILQ_FIRST(&fiqhandler_stack)) != NULL) {
97 if ((ofh->fh_flags & FH_CANPUSH) == 0) {
98 error = EBUSY;
99 goto out;
100 }
101
102 /* Save the previous FIQ handler's registers. */
103 if (ofh->fh_regs != NULL)
104 fiq_getregs(ofh->fh_regs);
105 }
106
107 /* Set FIQ mode registers to ours. */
108 if (fh->fh_regs != NULL)
109 fiq_setregs(fh->fh_regs);
110
111 TAILQ_INSERT_HEAD(&fiqhandler_stack, fh, fh_list);
112
113 /* Now copy the actual handler into place. */
114 fiq_installhandler(fh->fh_func, fh->fh_size);
115
116 /* Make sure FIQs are enabled when we return. */
117 oldirqstate &= ~FIQ_BIT;
118
119 out:
120 restore_interrupts(oldirqstate);
121 return (error);
122 }
123
124 /*
125 * fiq_release:
126 *
127 * Release the FIQ vector.
128 */
129 void
fiq_release(struct fiqhandler * fh)130 fiq_release(struct fiqhandler *fh)
131 {
132 u_int oldirqstate;
133 struct fiqhandler *ofh;
134
135 oldirqstate = disable_interrupts(FIQ_BIT);
136
137 /*
138 * If we are the currently active FIQ handler, then we
139 * need to save our registers and pop the next one back
140 * into the vector.
141 */
142 if (fh == TAILQ_FIRST(&fiqhandler_stack)) {
143 if (fh->fh_regs != NULL)
144 fiq_getregs(fh->fh_regs);
145 TAILQ_REMOVE(&fiqhandler_stack, fh, fh_list);
146 if ((ofh = TAILQ_FIRST(&fiqhandler_stack)) != NULL) {
147 if (ofh->fh_regs != NULL)
148 fiq_setregs(ofh->fh_regs);
149 fiq_installhandler(ofh->fh_func, ofh->fh_size);
150 }
151 } else
152 TAILQ_REMOVE(&fiqhandler_stack, fh, fh_list);
153
154 if (TAILQ_FIRST(&fiqhandler_stack) == NULL) {
155 /* Copy the NULL handler back down into the vector. */
156 fiq_installhandler(fiq_nullhandler,
157 (size_t)(fiq_nullhandler_end - fiq_nullhandler));
158
159 /* Make sure FIQs are disabled when we return. */
160 oldirqstate |= FIQ_BIT;
161 }
162
163 restore_interrupts(oldirqstate);
164 }
165