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>
40 static atomic_t irq_err_count
;
41 static spinlock_t irq_controller_lock
;
44 * Dummy mask/unmask handler
46 void dummy_mask_unmask_irq(unsigned int irq
)
50 void ack_bad_irq(unsigned int irq
)
52 atomic_inc(&irq_err_count
);
53 printk(KERN_ERR
"IRQ: spurious interrupt %d\n", irq
);
56 static struct irq_chip bad_chip
= {
57 .ack
= dummy_mask_unmask_irq
,
58 .mask
= dummy_mask_unmask_irq
,
59 .unmask
= dummy_mask_unmask_irq
,
62 static struct irq_desc bad_irq_desc
= {
63 .status
= IRQ_DISABLED
,
65 .handle_irq
= handle_bad_irq
,
67 .lock
= __SPIN_LOCK_UNLOCKED(irq_desc
->lock
),
69 .affinity
= CPU_MASK_ALL
73 int show_interrupts(struct seq_file
*p
, void *v
)
75 int i
= *(loff_t
*) v
, j
;
76 struct irqaction
*action
;
80 spin_lock_irqsave(&irq_desc
[i
].lock
, flags
);
81 action
= irq_desc
[i
].action
;
84 seq_printf(p
, "%3d: ", i
);
85 for_each_online_cpu(j
)
86 seq_printf(p
, "%10u ", kstat_irqs_cpu(i
, j
));
87 seq_printf(p
, " %8s", irq_desc
[i
].chip
->name
);
88 seq_printf(p
, " %s", action
->name
);
89 for (action
= action
->next
; action
; action
= action
->next
)
90 seq_printf(p
, " %s", action
->name
);
94 spin_unlock_irqrestore(&irq_desc
[i
].lock
, flags
);
95 } else if (i
== NR_IRQS
) {
96 seq_printf(p
, "NMI: ");
97 for_each_online_cpu(j
)
98 seq_printf(p
, "%10u ", cpu_pda
[j
].__nmi_count
);
99 seq_printf(p
, " CORE Non Maskable Interrupt\n");
100 seq_printf(p
, "Err: %10u\n", atomic_read(&irq_err_count
));
106 * do_IRQ handles all hardware IRQs. Decoded IRQs should not
107 * come via this function. Instead, they should provide their
110 #ifdef CONFIG_DO_IRQ_L1
111 __attribute__((l1_text
))
113 asmlinkage
void asm_do_IRQ(unsigned int irq
, struct pt_regs
*regs
)
115 struct pt_regs
*old_regs
;
116 struct irq_desc
*desc
= irq_desc
+ irq
;
118 unsigned short pending
, other_ints
;
120 old_regs
= set_irq_regs(regs
);
123 * Some hardware gives randomly wrong interrupts. Rather
124 * than crashing, do something sensible.
127 desc
= &bad_irq_desc
;
130 #ifdef CONFIG_DEBUG_STACKOVERFLOW
131 /* Debugging check for stack overflow: is there less than STACK_WARN free? */
135 sp
= __get_SP() & (THREAD_SIZE
-1);
137 if (unlikely(sp
< (sizeof(struct thread_info
) + STACK_WARN
))) {
139 printk(KERN_EMERG
"%s: possible stack overflow while handling irq %i "
140 " only %ld bytes free\n",
141 __func__
, irq
, sp
- sizeof(struct thread_info
));
145 generic_handle_irq(irq
);
147 #ifndef CONFIG_IPIPE /* Useless and bugous over the I-pipe: IRQs are threaded. */
148 /* If we're the only interrupt running (ignoring IRQ15 which is for
149 syscalls), lower our priority to IRQ14 so that softirqs run at
150 that level. If there's another, lower-level interrupt, irq_exit
151 will defer softirqs to that. */
153 pending
= bfin_read_IPEND() & ~0x8000;
154 other_ints
= pending
& (pending
- 1);
157 #endif /* !CONFIG_IPIPE */
160 set_irq_regs(old_regs
);
163 void __init
init_IRQ(void)
165 struct irq_desc
*desc
;
168 spin_lock_init(&irq_controller_lock
);
169 for (irq
= 0, desc
= irq_desc
; irq
< NR_IRQS
; irq
++, desc
++) {
170 *desc
= bad_irq_desc
;
175 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
176 /* Now that evt_ivhw is set up, turn this on */
177 trace_buff_offset
= 0;
178 bfin_write_TBUFCTL(BFIN_TRACE_ON
);
179 printk(KERN_INFO
"Hardware Trace expanded to %ik\n",
180 1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN
);