2 * Copyright (C) 2010 Google, Inc.
4 * This software is licensed under the terms of the GNU General Public
5 * License version 2, as published by the Free Software Foundation, and
6 * may be copied, distributed, and modified under those terms.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
14 #include <linux/kernel.h>
15 #include <linux/percpu.h>
16 #include <linux/slab.h>
18 #include <asm/fiq_glue.h>
20 extern unsigned char fiq_glue
, fiq_glue_end
;
21 extern void fiq_glue_setup(void *func
, void *data
, void *sp
,
22 fiq_return_handler_t fiq_return_handler
);
24 static struct fiq_handler fiq_debbuger_fiq_handler
= {
27 DEFINE_PER_CPU(void *, fiq_stack
);
28 static struct fiq_glue_handler
*current_handler
;
29 static fiq_return_handler_t fiq_return_handler
;
30 static DEFINE_MUTEX(fiq_glue_lock
);
32 static void fiq_glue_setup_helper(void *info
)
34 struct fiq_glue_handler
*handler
= info
;
35 fiq_glue_setup(handler
->fiq
, handler
,
36 __get_cpu_var(fiq_stack
) + THREAD_START_SP
,
40 int fiq_glue_register_handler(struct fiq_glue_handler
*handler
)
45 if (!handler
|| !handler
->fiq
)
48 mutex_lock(&fiq_glue_lock
);
54 for_each_possible_cpu(cpu
) {
56 stack
= (void *)__get_free_pages(GFP_KERNEL
, THREAD_SIZE_ORDER
);
57 if (WARN_ON(!stack
)) {
59 goto err_alloc_fiq_stack
;
61 per_cpu(fiq_stack
, cpu
) = stack
;
64 ret
= claim_fiq(&fiq_debbuger_fiq_handler
);
68 current_handler
= handler
;
69 on_each_cpu(fiq_glue_setup_helper
, handler
, true);
70 set_fiq_handler(&fiq_glue
, &fiq_glue_end
- &fiq_glue
);
72 mutex_unlock(&fiq_glue_lock
);
77 for_each_possible_cpu(cpu
) {
78 __free_pages(per_cpu(fiq_stack
, cpu
), THREAD_SIZE_ORDER
);
79 per_cpu(fiq_stack
, cpu
) = NULL
;
82 mutex_unlock(&fiq_glue_lock
);
86 static void fiq_glue_update_return_handler(void (*fiq_return
)(void))
88 fiq_return_handler
= fiq_return
;
90 on_each_cpu(fiq_glue_setup_helper
, current_handler
, true);
93 int fiq_glue_set_return_handler(void (*fiq_return
)(void))
97 mutex_lock(&fiq_glue_lock
);
98 if (fiq_return_handler
) {
102 fiq_glue_update_return_handler(fiq_return
);
105 mutex_unlock(&fiq_glue_lock
);
109 EXPORT_SYMBOL(fiq_glue_set_return_handler
);
111 int fiq_glue_clear_return_handler(void (*fiq_return
)(void))
115 mutex_lock(&fiq_glue_lock
);
116 if (WARN_ON(fiq_return_handler
!= fiq_return
)) {
120 fiq_glue_update_return_handler(NULL
);
123 mutex_unlock(&fiq_glue_lock
);
127 EXPORT_SYMBOL(fiq_glue_clear_return_handler
);
130 * fiq_glue_resume - Restore fiqs after suspend or low power idle states
132 * This must be called before calling local_fiq_enable after returning from a
133 * power state where the fiq mode registers were lost. If a driver provided
134 * a resume hook when it registered the handler it will be called.
137 void fiq_glue_resume(void)
139 if (!current_handler
)
141 fiq_glue_setup(current_handler
->fiq
, current_handler
,
142 __get_cpu_var(fiq_stack
) + THREAD_START_SP
,
144 if (current_handler
->resume
)
145 current_handler
->resume(current_handler
);