Merge branch 'upstream'
[platform/adaptation/renesas_rcar/renesas_kernel.git] / arch / xtensa / kernel / irq.c
1 /*
2  * linux/arch/xtensa/kernel/irq.c
3  *
4  * Xtensa built-in interrupt controller and some generic functions copied
5  * from i386.
6  *
7  * Copyright (C) 2002 - 2005 Tensilica, Inc.
8  * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
9  *
10  *
11  * Chris Zankel <chris@zankel.net>
12  * Kevin Chea
13  *
14  */
15
16 #include <linux/module.h>
17 #include <linux/seq_file.h>
18 #include <linux/interrupt.h>
19 #include <linux/irq.h>
20 #include <linux/kernel_stat.h>
21
22 #include <asm/uaccess.h>
23 #include <asm/platform.h>
24
25 static void enable_xtensa_irq(unsigned int irq);
26 static void disable_xtensa_irq(unsigned int irq);
27 static void mask_and_ack_xtensa(unsigned int irq);
28 static void end_xtensa_irq(unsigned int irq);
29
30 static unsigned int cached_irq_mask;
31
32 atomic_t irq_err_count;
33
34 /*
35  * 'what should we do if we get a hw irq event on an illegal vector'.
36  * each architecture has to answer this themselves.
37  */
38 void ack_bad_irq(unsigned int irq)
39 {
40           printk("unexpected IRQ trap at vector %02x\n", irq);
41 }
42
43 /*
44  * do_IRQ handles all normal device IRQ's (the special
45  * SMP cross-CPU interrupts have their own specific
46  * handlers).
47  */
48
49 unsigned int  do_IRQ(int irq, struct pt_regs *regs)
50 {
51         irq_enter();
52
53 #ifdef CONFIG_DEBUG_STACKOVERFLOW
54         /* Debugging check for stack overflow: is there less than 1KB free? */
55         {
56                 unsigned long sp;
57
58                 __asm__ __volatile__ ("mov %0, a1\n" : "=a" (sp));
59                 sp &= THREAD_SIZE - 1;
60
61                 if (unlikely(sp < (sizeof(thread_info) + 1024)))
62                         printk("Stack overflow in do_IRQ: %ld\n",
63                                sp - sizeof(struct thread_info));
64         }
65 #endif
66
67         __do_IRQ(irq, regs);
68
69         irq_exit();
70
71         return 1;
72 }
73
74 /*
75  * Generic, controller-independent functions:
76  */
77
78 int show_interrupts(struct seq_file *p, void *v)
79 {
80         int i = *(loff_t *) v, j;
81         struct irqaction * action;
82         unsigned long flags;
83
84         if (i == 0) {
85                 seq_printf(p, "           ");
86                 for_each_online_cpu(j)
87                         seq_printf(p, "CPU%d       ",j);
88                 seq_putc(p, '\n');
89         }
90
91         if (i < NR_IRQS) {
92                 spin_lock_irqsave(&irq_desc[i].lock, flags);
93                 action = irq_desc[i].action;
94                 if (!action)
95                         goto skip;
96                 seq_printf(p, "%3d: ",i);
97 #ifndef CONFIG_SMP
98                 seq_printf(p, "%10u ", kstat_irqs(i));
99 #else
100                 for_each_online_cpu(j)
101                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
102 #endif
103                 seq_printf(p, " %14s", irq_desc[i].handler->typename);
104                 seq_printf(p, "  %s", action->name);
105
106                 for (action=action->next; action; action = action->next)
107                         seq_printf(p, ", %s", action->name);
108
109                 seq_putc(p, '\n');
110 skip:
111                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
112         } else if (i == NR_IRQS) {
113                 seq_printf(p, "NMI: ");
114                 for_each_online_cpu(j)
115                         seq_printf(p, "%10u ", nmi_count(j));
116                 seq_putc(p, '\n');
117                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
118         }
119         return 0;
120 }
121 /* shutdown is same as "disable" */
122 #define shutdown_xtensa_irq disable_xtensa_irq
123
124 static unsigned int startup_xtensa_irq(unsigned int irq)
125 {
126         enable_xtensa_irq(irq);
127         return 0;               /* never anything pending */
128 }
129
130 static struct hw_interrupt_type xtensa_irq_type = {
131         "Xtensa-IRQ",
132         startup_xtensa_irq,
133         shutdown_xtensa_irq,
134         enable_xtensa_irq,
135         disable_xtensa_irq,
136         mask_and_ack_xtensa,
137         end_xtensa_irq
138 };
139
140 static inline void mask_irq(unsigned int irq)
141 {
142         cached_irq_mask &= ~(1 << irq);
143         set_sr (cached_irq_mask, INTENABLE);
144 }
145
146 static inline void unmask_irq(unsigned int irq)
147 {
148         cached_irq_mask |= 1 << irq;
149         set_sr (cached_irq_mask, INTENABLE);
150 }
151
152 static void disable_xtensa_irq(unsigned int irq)
153 {
154         unsigned long flags;
155         local_save_flags(flags);
156         mask_irq(irq);
157         local_irq_restore(flags);
158 }
159
160 static void enable_xtensa_irq(unsigned int irq)
161 {
162         unsigned long flags;
163         local_save_flags(flags);
164         unmask_irq(irq);
165         local_irq_restore(flags);
166 }
167
168 static void mask_and_ack_xtensa(unsigned int irq)
169 {
170         disable_xtensa_irq(irq);
171 }
172
173 static void end_xtensa_irq(unsigned int irq)
174 {
175         enable_xtensa_irq(irq);
176 }
177
178
179 void __init init_IRQ(void)
180 {
181         int i;
182
183         for (i=0; i < XTENSA_NR_IRQS; i++)
184                 irq_desc[i].handler = &xtensa_irq_type;
185
186         cached_irq_mask = 0;
187
188         platform_init_irq();
189 }