2 * File: arch/blackfin/kernel/irqchip.c
7 * Description: This file contains the simple DMA Implementation for Blackfin
10 * Copyright 2004-2006 Analog Devices Inc.
12 * Bugs: Enter bugs at http://blackfin.uclinux.org/
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, see the file COPYING, or write
26 * to the Free Software Foundation, Inc.,
27 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
30 #include <linux/kernel_stat.h>
31 #include <linux/module.h>
32 #include <linux/random.h>
33 #include <linux/seq_file.h>
34 #include <linux/kallsyms.h>
35 #include <linux/interrupt.h>
36 #include <linux/irq.h>
37 #include <asm/trace.h>
39 static atomic_t irq_err_count
;
40 static spinlock_t irq_controller_lock
;
43 * Dummy mask/unmask handler
45 void dummy_mask_unmask_irq(unsigned int irq
)
49 void ack_bad_irq(unsigned int irq
)
51 atomic_inc(&irq_err_count
);
52 printk(KERN_ERR
"IRQ: spurious interrupt %d\n", irq
);
55 static struct irq_chip bad_chip
= {
56 .ack
= dummy_mask_unmask_irq
,
57 .mask
= dummy_mask_unmask_irq
,
58 .unmask
= dummy_mask_unmask_irq
,
61 static struct irq_desc bad_irq_desc
= {
62 .status
= IRQ_DISABLED
,
64 .handle_irq
= handle_bad_irq
,
66 .lock
= __SPIN_LOCK_UNLOCKED(irq_desc
->lock
),
68 .affinity
= CPU_MASK_ALL
72 #ifdef CONFIG_CPUMASK_OFFSTACK
73 /* We are not allocating a variable-sized bad_irq_desc.affinity */
74 #error "Blackfin architecture does not support CONFIG_CPUMASK_OFFSTACK."
77 int show_interrupts(struct seq_file
*p
, void *v
)
79 int i
= *(loff_t
*) v
, j
;
80 struct irqaction
*action
;
84 spin_lock_irqsave(&irq_desc
[i
].lock
, flags
);
85 action
= irq_desc
[i
].action
;
88 seq_printf(p
, "%3d: ", i
);
89 for_each_online_cpu(j
)
90 seq_printf(p
, "%10u ", kstat_cpu(j
).irqs
[i
]);
91 seq_printf(p
, " %8s", irq_desc
[i
].chip
->name
);
92 seq_printf(p
, " %s", action
->name
);
93 for (action
= action
->next
; action
; action
= action
->next
)
94 seq_printf(p
, " %s", action
->name
);
98 spin_unlock_irqrestore(&irq_desc
[i
].lock
, flags
);
99 } else if (i
== NR_IRQS
)
100 seq_printf(p
, "Err: %10u\n", atomic_read(&irq_err_count
));
105 * do_IRQ handles all hardware IRQs. Decoded IRQs should not
106 * come via this function. Instead, they should provide their
109 #ifdef CONFIG_DO_IRQ_L1
110 __attribute__((l1_text
))
112 asmlinkage
void asm_do_IRQ(unsigned int irq
, struct pt_regs
*regs
)
114 struct pt_regs
*old_regs
;
115 struct irq_desc
*desc
= irq_desc
+ irq
;
117 unsigned short pending
, other_ints
;
119 old_regs
= set_irq_regs(regs
);
122 * Some hardware gives randomly wrong interrupts. Rather
123 * than crashing, do something sensible.
126 desc
= &bad_irq_desc
;
129 #ifdef CONFIG_DEBUG_STACKOVERFLOW
130 /* Debugging check for stack overflow: is there less than STACK_WARN free? */
134 sp
= __get_SP() & (THREAD_SIZE
-1);
136 if (unlikely(sp
< (sizeof(struct thread_info
) + STACK_WARN
))) {
138 printk(KERN_EMERG
"%s: possible stack overflow while handling irq %i "
139 " only %ld bytes free\n",
140 __func__
, irq
, sp
- sizeof(struct thread_info
));
144 generic_handle_irq(irq
);
146 #ifndef CONFIG_IPIPE /* Useless and bugous over the I-pipe: IRQs are threaded. */
147 /* If we're the only interrupt running (ignoring IRQ15 which is for
148 syscalls), lower our priority to IRQ14 so that softirqs run at
149 that level. If there's another, lower-level interrupt, irq_exit
150 will defer softirqs to that. */
152 pending
= bfin_read_IPEND() & ~0x8000;
153 other_ints
= pending
& (pending
- 1);
156 #endif /* !CONFIG_IPIPE */
159 set_irq_regs(old_regs
);
162 void __init
init_IRQ(void)
164 struct irq_desc
*desc
;
167 spin_lock_init(&irq_controller_lock
);
168 for (irq
= 0, desc
= irq_desc
; irq
< NR_IRQS
; irq
++, desc
++) {
169 *desc
= bad_irq_desc
;
174 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
175 /* Now that evt_ivhw is set up, turn this on */
176 trace_buff_offset
= 0;
177 bfin_write_TBUFCTL(BFIN_TRACE_ON
);
178 printk(KERN_INFO
"Hardware Trace expanded to %ik\n",
179 1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN
);