[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 3
[linux-2.6.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 (j=0; j<NR_CPUS; j++)
87                         if (cpu_online(j))
88                                 seq_printf(p, "CPU%d       ",j);
89                 seq_putc(p, '\n');
90         }
91
92         if (i < NR_IRQS) {
93                 spin_lock_irqsave(&irq_desc[i].lock, flags);
94                 action = irq_desc[i].action;
95                 if (!action)
96                         goto skip;
97                 seq_printf(p, "%3d: ",i);
98 #ifndef CONFIG_SMP
99                 seq_printf(p, "%10u ", kstat_irqs(i));
100 #else
101                 for (j = 0; j < NR_CPUS; j++)
102                         if (cpu_online(j))
103                                 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
104 #endif
105                 seq_printf(p, " %14s", irq_desc[i].handler->typename);
106                 seq_printf(p, "  %s", action->name);
107
108                 for (action=action->next; action; action = action->next)
109                         seq_printf(p, ", %s", action->name);
110
111                 seq_putc(p, '\n');
112 skip:
113                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
114         } else if (i == NR_IRQS) {
115                 seq_printf(p, "NMI: ");
116                 for (j = 0; j < NR_CPUS; j++)
117                         if (cpu_online(j))
118                                 seq_printf(p, "%10u ", nmi_count(j));
119                 seq_putc(p, '\n');
120                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
121         }
122         return 0;
123 }
124 /* shutdown is same as "disable" */
125 #define shutdown_xtensa_irq disable_xtensa_irq
126
127 static unsigned int startup_xtensa_irq(unsigned int irq)
128 {
129         enable_xtensa_irq(irq);
130         return 0;               /* never anything pending */
131 }
132
133 static struct hw_interrupt_type xtensa_irq_type = {
134         "Xtensa-IRQ",
135         startup_xtensa_irq,
136         shutdown_xtensa_irq,
137         enable_xtensa_irq,
138         disable_xtensa_irq,
139         mask_and_ack_xtensa,
140         end_xtensa_irq
141 };
142
143 static inline void mask_irq(unsigned int irq)
144 {
145         cached_irq_mask &= ~(1 << irq);
146         set_sr (cached_irq_mask, INTENABLE);
147 }
148
149 static inline void unmask_irq(unsigned int irq)
150 {
151         cached_irq_mask |= 1 << irq;
152         set_sr (cached_irq_mask, INTENABLE);
153 }
154
155 static void disable_xtensa_irq(unsigned int irq)
156 {
157         unsigned long flags;
158         local_save_flags(flags);
159         mask_irq(irq);
160         local_irq_restore(flags);
161 }
162
163 static void enable_xtensa_irq(unsigned int irq)
164 {
165         unsigned long flags;
166         local_save_flags(flags);
167         unmask_irq(irq);
168         local_irq_restore(flags);
169 }
170
171 static void mask_and_ack_xtensa(unsigned int irq)
172 {
173         disable_xtensa_irq(irq);
174 }
175
176 static void end_xtensa_irq(unsigned int irq)
177 {
178         enable_xtensa_irq(irq);
179 }
180
181
182 void __init init_IRQ(void)
183 {
184         int i;
185
186         for (i=0; i < XTENSA_NR_IRQS; i++)
187                 irq_desc[i].handler = &xtensa_irq_type;
188
189         cached_irq_mask = 0;
190
191         platform_init_irq();
192 }