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1/*
2 * linux/arch/arm/kernel/fiq.c
3 *
4 * Copyright (C) 1998 Russell King
5 * Copyright (C) 1998, 1999 Phil Blundell
6 *
7 * FIQ support written by Philip Blundell <philb@gnu.org>, 1998.
8 *
9 * FIQ support re-written by Russell King to be more generic
10 *
11 * We now properly support a method by which the FIQ handlers can
12 * be stacked onto the vector. We still do not support sharing
13 * the FIQ vector itself.
14 *
15 * Operation is as follows:
16 * 1. Owner A claims FIQ:
17 * - default_fiq relinquishes control.
18 * 2. Owner A:
19 * - inserts code.
20 * - sets any registers,
21 * - enables FIQ.
22 * 3. Owner B claims FIQ:
23 * - if owner A has a relinquish function.
24 * - disable FIQs.
25 * - saves any registers.
26 * - returns zero.
27 * 4. Owner B:
28 * - inserts code.
29 * - sets any registers,
30 * - enables FIQ.
31 * 5. Owner B releases FIQ:
32 * - Owner A is asked to reacquire FIQ:
33 * - inserts code.
34 * - restores saved registers.
35 * - enables FIQ.
36 * 6. Goto 3
37 */
38#include <linux/module.h>
39#include <linux/kernel.h>
40#include <linux/init.h>
41#include <linux/interrupt.h>
42#include <linux/seq_file.h>
43
44#include <asm/cacheflush.h>
45#include <asm/fiq.h>
46#include <asm/irq.h>
47#include <asm/system.h>
48#include <asm/traps.h>
49
50static unsigned long no_fiq_insn;
51
52/* Default reacquire function
53 * - we always relinquish FIQ control
54 * - we always reacquire FIQ control
55 */
56static int fiq_def_op(void *ref, int relinquish)
57{
58 if (!relinquish)
59 set_fiq_handler(&no_fiq_insn, sizeof(no_fiq_insn));
60
61 return 0;
62}
63
64static struct fiq_handler default_owner = {
65 .name = "default",
66 .fiq_op = fiq_def_op,
67};
68
69static struct fiq_handler *current_fiq = &default_owner;
70
71int show_fiq_list(struct seq_file *p, int prec)
72{
73 if (current_fiq != &default_owner)
74 seq_printf(p, "%*s: %s\n", prec, "FIQ",
75 current_fiq->name);
76
77 return 0;
78}
79
80void set_fiq_handler(void *start, unsigned int length)
81{
82#if defined(CONFIG_CPU_USE_DOMAINS)
83 memcpy((void *)0xffff001c, start, length);
84#else
85 memcpy(vectors_page + 0x1c, start, length);
86#endif
87 flush_icache_range(0xffff001c, 0xffff001c + length);
88 if (!vectors_high())
89 flush_icache_range(0x1c, 0x1c + length);
90}
91
92int claim_fiq(struct fiq_handler *f)
93{
94 int ret = 0;
95
96 if (current_fiq) {
97 ret = -EBUSY;
98
99 if (current_fiq->fiq_op != NULL)
100 ret = current_fiq->fiq_op(current_fiq->dev_id, 1);
101 }
102
103 if (!ret) {
104 f->next = current_fiq;
105 current_fiq = f;
106 }
107
108 return ret;
109}
110
111void release_fiq(struct fiq_handler *f)
112{
113 if (current_fiq != f) {
114 printk(KERN_ERR "%s FIQ trying to release %s FIQ\n",
115 f->name, current_fiq->name);
116 dump_stack();
117 return;
118 }
119
120 do
121 current_fiq = current_fiq->next;
122 while (current_fiq->fiq_op(current_fiq->dev_id, 0));
123}
124
125void enable_fiq(int fiq)
126{
127 enable_irq(fiq + FIQ_START);
128}
129
130void disable_fiq(int fiq)
131{
132 disable_irq(fiq + FIQ_START);
133}
134
135EXPORT_SYMBOL(set_fiq_handler);
136EXPORT_SYMBOL(__set_fiq_regs); /* defined in fiqasm.S */
137EXPORT_SYMBOL(__get_fiq_regs); /* defined in fiqasm.S */
138EXPORT_SYMBOL(claim_fiq);
139EXPORT_SYMBOL(release_fiq);
140EXPORT_SYMBOL(enable_fiq);
141EXPORT_SYMBOL(disable_fiq);
142
143void __init init_FIQ(void)
144{
145 no_fiq_insn = *(unsigned long *)0xffff001c;
146}
1/*
2 * linux/arch/arm/kernel/fiq.c
3 *
4 * Copyright (C) 1998 Russell King
5 * Copyright (C) 1998, 1999 Phil Blundell
6 *
7 * FIQ support written by Philip Blundell <philb@gnu.org>, 1998.
8 *
9 * FIQ support re-written by Russell King to be more generic
10 *
11 * We now properly support a method by which the FIQ handlers can
12 * be stacked onto the vector. We still do not support sharing
13 * the FIQ vector itself.
14 *
15 * Operation is as follows:
16 * 1. Owner A claims FIQ:
17 * - default_fiq relinquishes control.
18 * 2. Owner A:
19 * - inserts code.
20 * - sets any registers,
21 * - enables FIQ.
22 * 3. Owner B claims FIQ:
23 * - if owner A has a relinquish function.
24 * - disable FIQs.
25 * - saves any registers.
26 * - returns zero.
27 * 4. Owner B:
28 * - inserts code.
29 * - sets any registers,
30 * - enables FIQ.
31 * 5. Owner B releases FIQ:
32 * - Owner A is asked to reacquire FIQ:
33 * - inserts code.
34 * - restores saved registers.
35 * - enables FIQ.
36 * 6. Goto 3
37 */
38#include <linux/module.h>
39#include <linux/kernel.h>
40#include <linux/init.h>
41#include <linux/interrupt.h>
42#include <linux/seq_file.h>
43
44#include <asm/cacheflush.h>
45#include <asm/cp15.h>
46#include <asm/fiq.h>
47#include <asm/irq.h>
48#include <asm/traps.h>
49
50#define FIQ_OFFSET ({ \
51 extern void *vector_fiq_offset; \
52 (unsigned)&vector_fiq_offset; \
53 })
54
55static unsigned long dfl_fiq_insn;
56static struct pt_regs dfl_fiq_regs;
57
58/* Default reacquire function
59 * - we always relinquish FIQ control
60 * - we always reacquire FIQ control
61 */
62static int fiq_def_op(void *ref, int relinquish)
63{
64 if (!relinquish) {
65 /* Restore default handler and registers */
66 local_fiq_disable();
67 set_fiq_regs(&dfl_fiq_regs);
68 set_fiq_handler(&dfl_fiq_insn, sizeof(dfl_fiq_insn));
69 local_fiq_enable();
70
71 /* FIXME: notify irq controller to standard enable FIQs */
72 }
73
74 return 0;
75}
76
77static struct fiq_handler default_owner = {
78 .name = "default",
79 .fiq_op = fiq_def_op,
80};
81
82static struct fiq_handler *current_fiq = &default_owner;
83
84int show_fiq_list(struct seq_file *p, int prec)
85{
86 if (current_fiq != &default_owner)
87 seq_printf(p, "%*s: %s\n", prec, "FIQ",
88 current_fiq->name);
89
90 return 0;
91}
92
93void set_fiq_handler(void *start, unsigned int length)
94{
95 void *base = vectors_page;
96 unsigned offset = FIQ_OFFSET;
97
98 memcpy(base + offset, start, length);
99 if (!cache_is_vipt_nonaliasing())
100 flush_icache_range((unsigned long)base + offset, offset +
101 length);
102 flush_icache_range(0xffff0000 + offset, 0xffff0000 + offset + length);
103}
104
105int claim_fiq(struct fiq_handler *f)
106{
107 int ret = 0;
108
109 if (current_fiq) {
110 ret = -EBUSY;
111
112 if (current_fiq->fiq_op != NULL)
113 ret = current_fiq->fiq_op(current_fiq->dev_id, 1);
114 }
115
116 if (!ret) {
117 f->next = current_fiq;
118 current_fiq = f;
119 }
120
121 return ret;
122}
123
124void release_fiq(struct fiq_handler *f)
125{
126 if (current_fiq != f) {
127 pr_err("%s FIQ trying to release %s FIQ\n",
128 f->name, current_fiq->name);
129 dump_stack();
130 return;
131 }
132
133 do
134 current_fiq = current_fiq->next;
135 while (current_fiq->fiq_op(current_fiq->dev_id, 0));
136}
137
138static int fiq_start;
139
140void enable_fiq(int fiq)
141{
142 enable_irq(fiq + fiq_start);
143}
144
145void disable_fiq(int fiq)
146{
147 disable_irq(fiq + fiq_start);
148}
149
150EXPORT_SYMBOL(set_fiq_handler);
151EXPORT_SYMBOL(__set_fiq_regs); /* defined in fiqasm.S */
152EXPORT_SYMBOL(__get_fiq_regs); /* defined in fiqasm.S */
153EXPORT_SYMBOL(claim_fiq);
154EXPORT_SYMBOL(release_fiq);
155EXPORT_SYMBOL(enable_fiq);
156EXPORT_SYMBOL(disable_fiq);
157
158void __init init_FIQ(int start)
159{
160 unsigned offset = FIQ_OFFSET;
161 dfl_fiq_insn = *(unsigned long *)(0xffff0000 + offset);
162 get_fiq_regs(&dfl_fiq_regs);
163 fiq_start = start;
164}