FreeBSD/Linux Kernel Cross Reference
sys/arm/arm/fiq.c
1 /* $NetBSD: fiq.c,v 1.5 2002/04/03 23:33:27 thorpej Exp $ */
2
3 /*-
4 * Copyright (c) 2001, 2002 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed for the NetBSD Project by
20 * Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 * or promote products derived from this software without specific prior
23 * written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD: releng/10.2/sys/arm/arm/fiq.c 278613 2015-02-12 03:50:33Z ian $");
40
41 #include <sys/param.h>
42 #include <sys/systm.h>
43
44 #include <machine/armreg.h>
45 #include <machine/cpufunc.h>
46 #include <machine/fiq.h>
47 #include <vm/vm.h>
48 #include <machine/pcb.h>
49 #include <vm/pmap.h>
50 #include <machine/cpu.h>
51
52 TAILQ_HEAD(, fiqhandler) fiqhandler_stack =
53 TAILQ_HEAD_INITIALIZER(fiqhandler_stack);
54
55 extern char *fiq_nullhandler_code;
56 extern uint32_t fiq_nullhandler_size;
57
58 /*
59 * fiq_installhandler:
60 *
61 * Actually install the FIQ handler down at the FIQ vector.
62 *
63 * The FIQ vector is fixed by the hardware definition as the
64 * seventh 32-bit word in the vector page.
65 *
66 * Note: If the FIQ is invoked via an extra layer of
67 * indirection, the actual FIQ code store lives in the
68 * data segment, so there is no need to manipulate
69 * the vector page's protection.
70 */
71 static void
72 fiq_installhandler(void *func, size_t size)
73 {
74 const uint32_t fiqvector = 7 * sizeof(uint32_t);
75
76 #if !defined(__ARM_FIQ_INDIRECT)
77 vector_page_setprot(VM_PROT_READ|VM_PROT_WRITE);
78 #endif
79
80 memcpy((void *)(vector_page + fiqvector), func, size);
81
82 #if !defined(__ARM_FIQ_INDIRECT)
83 vector_page_setprot(VM_PROT_READ);
84 cpu_icache_sync_range((vm_offset_t) fiqvector, size);
85 #endif
86 }
87
88 /*
89 * fiq_claim:
90 *
91 * Claim the FIQ vector.
92 */
93 int
94 fiq_claim(struct fiqhandler *fh)
95 {
96 struct fiqhandler *ofh;
97 u_int oldirqstate;
98 int error = 0;
99
100 if (fh->fh_size > 0x100)
101 return (EFBIG);
102
103 oldirqstate = disable_interrupts(PSR_F);
104
105 if ((ofh = TAILQ_FIRST(&fiqhandler_stack)) != NULL) {
106 if ((ofh->fh_flags & FH_CANPUSH) == 0) {
107 error = EBUSY;
108 goto out;
109 }
110
111 /* Save the previous FIQ handler's registers. */
112 if (ofh->fh_regs != NULL)
113 fiq_getregs(ofh->fh_regs);
114 }
115
116 /* Set FIQ mode registers to ours. */
117 if (fh->fh_regs != NULL)
118 fiq_setregs(fh->fh_regs);
119
120 TAILQ_INSERT_HEAD(&fiqhandler_stack, fh, fh_list);
121
122 /* Now copy the actual handler into place. */
123 fiq_installhandler(fh->fh_func, fh->fh_size);
124
125 /* Make sure FIQs are enabled when we return. */
126 oldirqstate &= ~PSR_F;
127
128 out:
129 restore_interrupts(oldirqstate);
130 return (error);
131 }
132
133 /*
134 * fiq_release:
135 *
136 * Release the FIQ vector.
137 */
138 void
139 fiq_release(struct fiqhandler *fh)
140 {
141 u_int oldirqstate;
142 struct fiqhandler *ofh;
143
144 oldirqstate = disable_interrupts(PSR_F);
145
146 /*
147 * If we are the currently active FIQ handler, then we
148 * need to save our registers and pop the next one back
149 * into the vector.
150 */
151 if (fh == TAILQ_FIRST(&fiqhandler_stack)) {
152 if (fh->fh_regs != NULL)
153 fiq_getregs(fh->fh_regs);
154 TAILQ_REMOVE(&fiqhandler_stack, fh, fh_list);
155 if ((ofh = TAILQ_FIRST(&fiqhandler_stack)) != NULL) {
156 if (ofh->fh_regs != NULL)
157 fiq_setregs(ofh->fh_regs);
158 fiq_installhandler(ofh->fh_func, ofh->fh_size);
159 }
160 } else
161 TAILQ_REMOVE(&fiqhandler_stack, fh, fh_list);
162
163 if (TAILQ_FIRST(&fiqhandler_stack) == NULL) {
164 /* Copy the NULL handler back down into the vector. */
165 fiq_installhandler(fiq_nullhandler_code, fiq_nullhandler_size);
166
167 /* Make sure FIQs are disabled when we return. */
168 oldirqstate |= PSR_F;
169 }
170
171 restore_interrupts(oldirqstate);
172 }
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