2 * linux/arch/arm/kernel/fiq.c
4 * Copyright (C) 1998 Russell King
5 * Copyright (C) 1998, 1999 Phil Blundell
7 * FIQ support written by Philip Blundell <philb@gnu.org>, 1998.
9 * FIQ support re-written by Russell King to be more generic
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.
15 * Operation is as follows:
16 * 1. Owner A claims FIQ:
17 * - default_fiq relinquishes control.
20 * - sets any registers,
22 * 3. Owner B claims FIQ:
23 * - if owner A has a relinquish function.
25 * - saves any registers.
29 * - sets any registers,
31 * 5. Owner B releases FIQ:
32 * - Owner A is asked to reacquire FIQ:
34 * - restores saved registers.
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>
44 #include <asm/cacheflush.h>
48 #include <asm/traps.h>
50 #define FIQ_OFFSET ({ \
51 extern void *vector_fiq_offset; \
52 (unsigned)&vector_fiq_offset; \
55 static unsigned long no_fiq_insn;
57 /* Default reacquire function
58 * - we always relinquish FIQ control
59 * - we always reacquire FIQ control
61 static int fiq_def_op(void *ref, int relinquish)
64 set_fiq_handler(&no_fiq_insn, sizeof(no_fiq_insn));
69 static struct fiq_handler default_owner = {
74 static struct fiq_handler *current_fiq = &default_owner;
76 int show_fiq_list(struct seq_file *p, int prec)
78 if (current_fiq != &default_owner)
79 seq_printf(p, "%*s: %s\n", prec, "FIQ",
85 void set_fiq_handler(void *start, unsigned int length)
87 #if defined(CONFIG_CPU_USE_DOMAINS)
88 void *base = (void *)0xffff0000;
90 void *base = vectors_page;
92 unsigned offset = FIQ_OFFSET;
94 memcpy(base + offset, start, length);
95 flush_icache_range(0xffff0000 + offset, 0xffff0000 + offset + length);
97 flush_icache_range(offset, offset + length);
100 int claim_fiq(struct fiq_handler *f)
107 if (current_fiq->fiq_op != NULL)
108 ret = current_fiq->fiq_op(current_fiq->dev_id, 1);
112 f->next = current_fiq;
119 void release_fiq(struct fiq_handler *f)
121 if (current_fiq != f) {
122 printk(KERN_ERR "%s FIQ trying to release %s FIQ\n",
123 f->name, current_fiq->name);
129 current_fiq = current_fiq->next;
130 while (current_fiq->fiq_op(current_fiq->dev_id, 0));
133 static int fiq_start;
135 void enable_fiq(int fiq)
137 enable_irq(fiq + fiq_start);
140 void disable_fiq(int fiq)
142 disable_irq(fiq + fiq_start);
145 EXPORT_SYMBOL(set_fiq_handler);
146 EXPORT_SYMBOL(__set_fiq_regs); /* defined in fiqasm.S */
147 EXPORT_SYMBOL(__get_fiq_regs); /* defined in fiqasm.S */
148 EXPORT_SYMBOL(claim_fiq);
149 EXPORT_SYMBOL(release_fiq);
150 EXPORT_SYMBOL(enable_fiq);
151 EXPORT_SYMBOL(disable_fiq);
153 void __init init_FIQ(int start)
155 unsigned offset = FIQ_OFFSET;
156 no_fiq_insn = *(unsigned long *)(0xffff0000 + offset);