sh: Kill off more dead symbols.
[linux-2.6.git] / arch / sh / kernel / irq.c
1 /*
2  * linux/arch/sh/kernel/irq.c
3  *
4  *      Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
5  *
6  *
7  * SuperH version:  Copyright (C) 1999  Niibe Yutaka
8  */
9 #include <linux/irq.h>
10 #include <linux/interrupt.h>
11 #include <linux/module.h>
12 #include <linux/kernel_stat.h>
13 #include <linux/seq_file.h>
14 #include <asm/processor.h>
15 #include <asm/machvec.h>
16 #include <asm/uaccess.h>
17 #include <asm/thread_info.h>
18 #include <asm/cpu/mmu_context.h>
19
20 atomic_t irq_err_count;
21
22 /*
23  * 'what should we do if we get a hw irq event on an illegal vector'.
24  * each architecture has to answer this themselves, it doesn't deserve
25  * a generic callback i think.
26  */
27 void ack_bad_irq(unsigned int irq)
28 {
29         atomic_inc(&irq_err_count);
30         printk("unexpected IRQ trap at vector %02x\n", irq);
31 }
32
33 #if defined(CONFIG_PROC_FS)
34 int show_interrupts(struct seq_file *p, void *v)
35 {
36         int i = *(loff_t *) v, j;
37         struct irqaction * action;
38         unsigned long flags;
39
40         if (i == 0) {
41                 seq_puts(p, "           ");
42                 for_each_online_cpu(j)
43                         seq_printf(p, "CPU%d       ",j);
44                 seq_putc(p, '\n');
45         }
46
47         if (i < sh_mv.mv_nr_irqs) {
48                 spin_lock_irqsave(&irq_desc[i].lock, flags);
49                 action = irq_desc[i].action;
50                 if (!action)
51                         goto unlock;
52                 seq_printf(p, "%3d: ",i);
53                 for_each_online_cpu(j)
54                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
55                 seq_printf(p, " %14s", irq_desc[i].chip->name);
56                 seq_printf(p, "-%-8s", irq_desc[i].name);
57                 seq_printf(p, "  %s", action->name);
58
59                 for (action=action->next; action; action = action->next)
60                         seq_printf(p, ", %s", action->name);
61                 seq_putc(p, '\n');
62 unlock:
63                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
64         } else if (i == sh_mv.mv_nr_irqs)
65                 seq_printf(p, "Err: %10u\n", atomic_read(&irq_err_count));
66
67         return 0;
68 }
69 #endif
70
71 #ifdef CONFIG_IRQSTACKS
72 /*
73  * per-CPU IRQ handling contexts (thread information and stack)
74  */
75 union irq_ctx {
76         struct thread_info      tinfo;
77         u32                     stack[THREAD_SIZE/sizeof(u32)];
78 };
79
80 static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly;
81 static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
82 #endif
83
84 asmlinkage int do_IRQ(unsigned int irq, struct pt_regs *regs)
85 {
86         struct pt_regs *old_regs = set_irq_regs(regs);
87 #ifdef CONFIG_IRQSTACKS
88         union irq_ctx *curctx, *irqctx;
89 #endif
90
91         irq_enter();
92
93 #ifdef CONFIG_DEBUG_STACKOVERFLOW
94         /* Debugging check for stack overflow: is there less than 1KB free? */
95         {
96                 long sp;
97
98                 __asm__ __volatile__ ("and r15, %0" :
99                                         "=r" (sp) : "0" (THREAD_SIZE - 1));
100
101                 if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
102                         printk("do_IRQ: stack overflow: %ld\n",
103                                sp - sizeof(struct thread_info));
104                         dump_stack();
105                 }
106         }
107 #endif
108
109         irq = irq_demux(evt2irq(irq));
110
111 #ifdef CONFIG_IRQSTACKS
112         curctx = (union irq_ctx *)current_thread_info();
113         irqctx = hardirq_ctx[smp_processor_id()];
114
115         /*
116          * this is where we switch to the IRQ stack. However, if we are
117          * already using the IRQ stack (because we interrupted a hardirq
118          * handler) we can't do that and just have to keep using the
119          * current stack (which is the irq stack already after all)
120          */
121         if (curctx != irqctx) {
122                 u32 *isp;
123
124                 isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
125                 irqctx->tinfo.task = curctx->tinfo.task;
126                 irqctx->tinfo.previous_sp = current_stack_pointer;
127
128                 /*
129                  * Copy the softirq bits in preempt_count so that the
130                  * softirq checks work in the hardirq context.
131                  */
132                 irqctx->tinfo.preempt_count =
133                         (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
134                         (curctx->tinfo.preempt_count & SOFTIRQ_MASK);
135
136                 __asm__ __volatile__ (
137                         "mov    %0, r4          \n"
138                         "mov    r15, r8         \n"
139                         "jsr    @%1             \n"
140                         /* swith to the irq stack */
141                         " mov   %2, r15         \n"
142                         /* restore the stack (ring zero) */
143                         "mov    r8, r15         \n"
144                         : /* no outputs */
145                         : "r" (irq), "r" (generic_handle_irq), "r" (isp)
146                         : "memory", "r0", "r1", "r2", "r3", "r4",
147                           "r5", "r6", "r7", "r8", "t", "pr"
148                 );
149         } else
150 #endif
151                 generic_handle_irq(irq);
152
153         irq_exit();
154
155         set_irq_regs(old_regs);
156         return 1;
157 }
158
159 #ifdef CONFIG_IRQSTACKS
160 static char softirq_stack[NR_CPUS * THREAD_SIZE]
161                 __attribute__((__section__(".bss.page_aligned")));
162
163 static char hardirq_stack[NR_CPUS * THREAD_SIZE]
164                 __attribute__((__section__(".bss.page_aligned")));
165
166 /*
167  * allocate per-cpu stacks for hardirq and for softirq processing
168  */
169 void irq_ctx_init(int cpu)
170 {
171         union irq_ctx *irqctx;
172
173         if (hardirq_ctx[cpu])
174                 return;
175
176         irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE];
177         irqctx->tinfo.task              = NULL;
178         irqctx->tinfo.exec_domain       = NULL;
179         irqctx->tinfo.cpu               = cpu;
180         irqctx->tinfo.preempt_count     = HARDIRQ_OFFSET;
181         irqctx->tinfo.addr_limit        = MAKE_MM_SEG(0);
182
183         hardirq_ctx[cpu] = irqctx;
184
185         irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE];
186         irqctx->tinfo.task              = NULL;
187         irqctx->tinfo.exec_domain       = NULL;
188         irqctx->tinfo.cpu               = cpu;
189         irqctx->tinfo.preempt_count     = 0;
190         irqctx->tinfo.addr_limit        = MAKE_MM_SEG(0);
191
192         softirq_ctx[cpu] = irqctx;
193
194         printk("CPU %u irqstacks, hard=%p soft=%p\n",
195                 cpu, hardirq_ctx[cpu], softirq_ctx[cpu]);
196 }
197
198 void irq_ctx_exit(int cpu)
199 {
200         hardirq_ctx[cpu] = NULL;
201 }
202
203 extern asmlinkage void __do_softirq(void);
204
205 asmlinkage void do_softirq(void)
206 {
207         unsigned long flags;
208         struct thread_info *curctx;
209         union irq_ctx *irqctx;
210         u32 *isp;
211
212         if (in_interrupt())
213                 return;
214
215         local_irq_save(flags);
216
217         if (local_softirq_pending()) {
218                 curctx = current_thread_info();
219                 irqctx = softirq_ctx[smp_processor_id()];
220                 irqctx->tinfo.task = curctx->task;
221                 irqctx->tinfo.previous_sp = current_stack_pointer;
222
223                 /* build the stack frame on the softirq stack */
224                 isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
225
226                 __asm__ __volatile__ (
227                         "mov    r15, r9         \n"
228                         "jsr    @%0             \n"
229                         /* switch to the softirq stack */
230                         " mov   %1, r15         \n"
231                         /* restore the thread stack */
232                         "mov    r9, r15         \n"
233                         : /* no outputs */
234                         : "r" (__do_softirq), "r" (isp)
235                         : "memory", "r0", "r1", "r2", "r3", "r4",
236                           "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
237                 );
238
239                 /*
240                  * Shouldnt happen, we returned above if in_interrupt():
241                  */
242                 WARN_ON_ONCE(softirq_count());
243         }
244
245         local_irq_restore(flags);
246 }
247 #endif
248
249 void __init init_IRQ(void)
250 {
251         plat_irq_setup();
252
253         /* Perform the machine specific initialisation */
254         if (sh_mv.mv_init_irq)
255                 sh_mv.mv_init_irq();
256
257         irq_ctx_init(smp_processor_id());
258 }