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 void *base
= vectors_page
;
88 unsigned offset
= FIQ_OFFSET
;
90 memcpy(base
+ offset
, start
, length
);
91 if (!cache_is_vipt_nonaliasing())
92 flush_icache_range((unsigned long)base
+ offset
, offset
+
94 flush_icache_range(0xffff0000 + offset
, 0xffff0000 + offset
+ length
);
97 int claim_fiq(struct fiq_handler
*f
)
104 if (current_fiq
->fiq_op
!= NULL
)
105 ret
= current_fiq
->fiq_op(current_fiq
->dev_id
, 1);
109 f
->next
= current_fiq
;
116 void release_fiq(struct fiq_handler
*f
)
118 if (current_fiq
!= f
) {
119 printk(KERN_ERR
"%s FIQ trying to release %s FIQ\n",
120 f
->name
, current_fiq
->name
);
126 current_fiq
= current_fiq
->next
;
127 while (current_fiq
->fiq_op(current_fiq
->dev_id
, 0));
130 static int fiq_start
;
132 void enable_fiq(int fiq
)
134 enable_irq(fiq
+ fiq_start
);
137 void disable_fiq(int fiq
)
139 disable_irq(fiq
+ fiq_start
);
142 EXPORT_SYMBOL(set_fiq_handler
);
143 EXPORT_SYMBOL(__set_fiq_regs
); /* defined in fiqasm.S */
144 EXPORT_SYMBOL(__get_fiq_regs
); /* defined in fiqasm.S */
145 EXPORT_SYMBOL(claim_fiq
);
146 EXPORT_SYMBOL(release_fiq
);
147 EXPORT_SYMBOL(enable_fiq
);
148 EXPORT_SYMBOL(disable_fiq
);
150 void __init
init_FIQ(int start
)
152 unsigned offset
= FIQ_OFFSET
;
153 no_fiq_insn
= *(unsigned long *)(0xffff0000 + offset
);