2 * linux/arch/sh/kernel/irq.c
4 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
7 * SuperH version: Copyright (C) 1999 Niibe Yutaka
10 #include <linux/interrupt.h>
11 #include <linux/module.h>
12 #include <linux/kernel_stat.h>
13 #include <linux/seq_file.h>
14 #include <linux/irq.h>
15 #include <asm/processor.h>
16 #include <asm/machvec.h>
17 #include <asm/uaccess.h>
18 #include <asm/thread_info.h>
19 #include <asm/cpu/mmu_context.h>
21 atomic_t irq_err_count
;
24 * 'what should we do if we get a hw irq event on an illegal vector'.
25 * each architecture has to answer this themselves, it doesn't deserve
26 * a generic callback i think.
28 void ack_bad_irq(unsigned int irq
)
30 atomic_inc(&irq_err_count
);
31 printk("unexpected IRQ trap at vector %02x\n", irq
);
34 #if defined(CONFIG_PROC_FS)
35 int show_interrupts(struct seq_file
*p
, void *v
)
37 int i
= *(loff_t
*) v
, j
;
38 struct irqaction
* action
;
43 for_each_online_cpu(j
)
44 seq_printf(p
, "CPU%d ",j
);
48 if (i
< sh_mv
.mv_nr_irqs
) {
49 spin_lock_irqsave(&irq_desc
[i
].lock
, flags
);
50 action
= irq_desc
[i
].action
;
53 seq_printf(p
, "%3d: ",i
);
54 for_each_online_cpu(j
)
55 seq_printf(p
, "%10u ", kstat_cpu(j
).irqs
[i
]);
56 seq_printf(p
, " %14s", irq_desc
[i
].chip
->name
);
57 seq_printf(p
, "-%-8s", irq_desc
[i
].name
);
58 seq_printf(p
, " %s", action
->name
);
60 for (action
=action
->next
; action
; action
= action
->next
)
61 seq_printf(p
, ", %s", action
->name
);
64 spin_unlock_irqrestore(&irq_desc
[i
].lock
, flags
);
65 } else if (i
== sh_mv
.mv_nr_irqs
)
66 seq_printf(p
, "Err: %10u\n", atomic_read(&irq_err_count
));
72 #ifdef CONFIG_4KSTACKS
74 * per-CPU IRQ handling contexts (thread information and stack)
77 struct thread_info tinfo
;
78 u32 stack
[THREAD_SIZE
/sizeof(u32
)];
81 static union irq_ctx
*hardirq_ctx
[NR_CPUS
] __read_mostly
;
82 static union irq_ctx
*softirq_ctx
[NR_CPUS
] __read_mostly
;
85 asmlinkage
int do_IRQ(unsigned int irq
, struct pt_regs
*regs
)
87 struct pt_regs
*old_regs
= set_irq_regs(regs
);
88 #ifdef CONFIG_4KSTACKS
89 union irq_ctx
*curctx
, *irqctx
;
94 #ifdef CONFIG_DEBUG_STACKOVERFLOW
95 /* Debugging check for stack overflow: is there less than 1KB free? */
99 __asm__
__volatile__ ("and r15, %0" :
100 "=r" (sp
) : "0" (THREAD_SIZE
- 1));
102 if (unlikely(sp
< (sizeof(struct thread_info
) + STACK_WARN
))) {
103 printk("do_IRQ: stack overflow: %ld\n",
104 sp
- sizeof(struct thread_info
));
110 irq
= irq_demux(evt2irq(irq
));
112 #ifdef CONFIG_4KSTACKS
113 curctx
= (union irq_ctx
*)current_thread_info();
114 irqctx
= hardirq_ctx
[smp_processor_id()];
117 * this is where we switch to the IRQ stack. However, if we are
118 * already using the IRQ stack (because we interrupted a hardirq
119 * handler) we can't do that and just have to keep using the
120 * current stack (which is the irq stack already after all)
122 if (curctx
!= irqctx
) {
125 isp
= (u32
*)((char *)irqctx
+ sizeof(*irqctx
));
126 irqctx
->tinfo
.task
= curctx
->tinfo
.task
;
127 irqctx
->tinfo
.previous_sp
= current_stack_pointer
;
130 * Copy the softirq bits in preempt_count so that the
131 * softirq checks work in the hardirq context.
133 irqctx
->tinfo
.preempt_count
=
134 (irqctx
->tinfo
.preempt_count
& ~SOFTIRQ_MASK
) |
135 (curctx
->tinfo
.preempt_count
& SOFTIRQ_MASK
);
137 __asm__
__volatile__ (
141 /* swith to the irq stack */
143 /* restore the stack (ring zero) */
146 : "r" (irq
), "r" (generic_handle_irq
), "r" (isp
)
147 : "memory", "r0", "r1", "r2", "r3", "r4",
148 "r5", "r6", "r7", "r8", "t", "pr"
152 generic_handle_irq(irq
);
156 set_irq_regs(old_regs
);
160 #ifdef CONFIG_4KSTACKS
161 static char softirq_stack
[NR_CPUS
* THREAD_SIZE
]
162 __attribute__((__section__(".bss.page_aligned")));
164 static char hardirq_stack
[NR_CPUS
* THREAD_SIZE
]
165 __attribute__((__section__(".bss.page_aligned")));
168 * allocate per-cpu stacks for hardirq and for softirq processing
170 void irq_ctx_init(int cpu
)
172 union irq_ctx
*irqctx
;
174 if (hardirq_ctx
[cpu
])
177 irqctx
= (union irq_ctx
*)&hardirq_stack
[cpu
* THREAD_SIZE
];
178 irqctx
->tinfo
.task
= NULL
;
179 irqctx
->tinfo
.exec_domain
= NULL
;
180 irqctx
->tinfo
.cpu
= cpu
;
181 irqctx
->tinfo
.preempt_count
= HARDIRQ_OFFSET
;
182 irqctx
->tinfo
.addr_limit
= MAKE_MM_SEG(0);
184 hardirq_ctx
[cpu
] = irqctx
;
186 irqctx
= (union irq_ctx
*)&softirq_stack
[cpu
* THREAD_SIZE
];
187 irqctx
->tinfo
.task
= NULL
;
188 irqctx
->tinfo
.exec_domain
= NULL
;
189 irqctx
->tinfo
.cpu
= cpu
;
190 irqctx
->tinfo
.preempt_count
= 0;
191 irqctx
->tinfo
.addr_limit
= MAKE_MM_SEG(0);
193 softirq_ctx
[cpu
] = irqctx
;
195 printk("CPU %u irqstacks, hard=%p soft=%p\n",
196 cpu
, hardirq_ctx
[cpu
], softirq_ctx
[cpu
]);
199 void irq_ctx_exit(int cpu
)
201 hardirq_ctx
[cpu
] = NULL
;
204 extern asmlinkage
void __do_softirq(void);
206 asmlinkage
void do_softirq(void)
209 struct thread_info
*curctx
;
210 union irq_ctx
*irqctx
;
216 local_irq_save(flags
);
218 if (local_softirq_pending()) {
219 curctx
= current_thread_info();
220 irqctx
= softirq_ctx
[smp_processor_id()];
221 irqctx
->tinfo
.task
= curctx
->task
;
222 irqctx
->tinfo
.previous_sp
= current_stack_pointer
;
224 /* build the stack frame on the softirq stack */
225 isp
= (u32
*)((char *)irqctx
+ sizeof(*irqctx
));
227 __asm__
__volatile__ (
230 /* switch to the softirq stack */
232 /* restore the thread stack */
235 : "r" (__do_softirq
), "r" (isp
)
236 : "memory", "r0", "r1", "r2", "r3", "r4",
237 "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
241 * Shouldnt happen, we returned above if in_interrupt():
243 WARN_ON_ONCE(softirq_count());
246 local_irq_restore(flags
);
248 EXPORT_SYMBOL(do_softirq
);
251 void __init
init_IRQ(void)
253 #ifdef CONFIG_CPU_HAS_PINT_IRQ
257 #ifdef CONFIG_CPU_HAS_INTC2_IRQ
261 #ifdef CONFIG_CPU_HAS_IPR_IRQ
265 /* Perform the machine specific initialisation */
266 if (sh_mv
.mv_init_irq
)
269 irq_ctx_init(smp_processor_id());