sh: irq: Convert from irq_desc[] to irq_to_desc().
[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 <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 /*
35  * /proc/interrupts printing:
36  */
37 static int show_other_interrupts(struct seq_file *p, int prec)
38 {
39         seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
40         return 0;
41 }
42
43 int show_interrupts(struct seq_file *p, void *v)
44 {
45         unsigned long flags, any_count = 0;
46         int i = *(loff_t *)v, j, prec;
47         struct irqaction *action;
48         struct irq_desc *desc;
49
50         if (i > nr_irqs)
51                 return 0;
52
53         for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
54                 j *= 10;
55
56         if (i == nr_irqs)
57                 return show_other_interrupts(p, prec);
58
59         if (i == 0) {
60                 seq_printf(p, "%*s", prec + 8, "");
61                 for_each_online_cpu(j)
62                         seq_printf(p, "CPU%-8d", j);
63                 seq_putc(p, '\n');
64         }
65
66         desc = irq_to_desc(i);
67         if (!desc)
68                 return 0;
69
70         spin_lock_irqsave(&desc->lock, flags);
71         for_each_online_cpu(j)
72                 any_count |= kstat_irqs_cpu(i, j);
73         action = desc->action;
74         if (!action && !any_count)
75                 goto out;
76
77         seq_printf(p, "%*d: ", prec, i);
78         for_each_online_cpu(j)
79                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
80         seq_printf(p, " %14s", desc->chip->name);
81         seq_printf(p, "-%-8s", desc->name);
82
83         if (action) {
84                 seq_printf(p, "  %s", action->name);
85                 while ((action = action->next) != NULL)
86                         seq_printf(p, ", %s", action->name);
87         }
88
89         seq_putc(p, '\n');
90 out:
91         spin_unlock_irqrestore(&desc->lock, flags);
92         return 0;
93 }
94 #endif
95
96 #ifdef CONFIG_IRQSTACKS
97 /*
98  * per-CPU IRQ handling contexts (thread information and stack)
99  */
100 union irq_ctx {
101         struct thread_info      tinfo;
102         u32                     stack[THREAD_SIZE/sizeof(u32)];
103 };
104
105 static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly;
106 static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
107 #endif
108
109 asmlinkage int do_IRQ(unsigned int irq, struct pt_regs *regs)
110 {
111         struct pt_regs *old_regs = set_irq_regs(regs);
112 #ifdef CONFIG_IRQSTACKS
113         union irq_ctx *curctx, *irqctx;
114 #endif
115
116         irq_enter();
117
118 #ifdef CONFIG_DEBUG_STACKOVERFLOW
119         /* Debugging check for stack overflow: is there less than 1KB free? */
120         {
121                 long sp;
122
123                 __asm__ __volatile__ ("and r15, %0" :
124                                         "=r" (sp) : "0" (THREAD_SIZE - 1));
125
126                 if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
127                         printk("do_IRQ: stack overflow: %ld\n",
128                                sp - sizeof(struct thread_info));
129                         dump_stack();
130                 }
131         }
132 #endif
133
134         irq = irq_demux(intc_evt2irq(irq));
135
136 #ifdef CONFIG_IRQSTACKS
137         curctx = (union irq_ctx *)current_thread_info();
138         irqctx = hardirq_ctx[smp_processor_id()];
139
140         /*
141          * this is where we switch to the IRQ stack. However, if we are
142          * already using the IRQ stack (because we interrupted a hardirq
143          * handler) we can't do that and just have to keep using the
144          * current stack (which is the irq stack already after all)
145          */
146         if (curctx != irqctx) {
147                 u32 *isp;
148
149                 isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
150                 irqctx->tinfo.task = curctx->tinfo.task;
151                 irqctx->tinfo.previous_sp = current_stack_pointer;
152
153                 /*
154                  * Copy the softirq bits in preempt_count so that the
155                  * softirq checks work in the hardirq context.
156                  */
157                 irqctx->tinfo.preempt_count =
158                         (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
159                         (curctx->tinfo.preempt_count & SOFTIRQ_MASK);
160
161                 __asm__ __volatile__ (
162                         "mov    %0, r4          \n"
163                         "mov    r15, r8         \n"
164                         "jsr    @%1             \n"
165                         /* swith to the irq stack */
166                         " mov   %2, r15         \n"
167                         /* restore the stack (ring zero) */
168                         "mov    r8, r15         \n"
169                         : /* no outputs */
170                         : "r" (irq), "r" (generic_handle_irq), "r" (isp)
171                         : "memory", "r0", "r1", "r2", "r3", "r4",
172                           "r5", "r6", "r7", "r8", "t", "pr"
173                 );
174         } else
175 #endif
176                 generic_handle_irq(irq);
177
178         irq_exit();
179
180         set_irq_regs(old_regs);
181         return 1;
182 }
183
184 #ifdef CONFIG_IRQSTACKS
185 static char softirq_stack[NR_CPUS * THREAD_SIZE]
186                 __attribute__((__section__(".bss.page_aligned")));
187
188 static char hardirq_stack[NR_CPUS * THREAD_SIZE]
189                 __attribute__((__section__(".bss.page_aligned")));
190
191 /*
192  * allocate per-cpu stacks for hardirq and for softirq processing
193  */
194 void irq_ctx_init(int cpu)
195 {
196         union irq_ctx *irqctx;
197
198         if (hardirq_ctx[cpu])
199                 return;
200
201         irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE];
202         irqctx->tinfo.task              = NULL;
203         irqctx->tinfo.exec_domain       = NULL;
204         irqctx->tinfo.cpu               = cpu;
205         irqctx->tinfo.preempt_count     = HARDIRQ_OFFSET;
206         irqctx->tinfo.addr_limit        = MAKE_MM_SEG(0);
207
208         hardirq_ctx[cpu] = irqctx;
209
210         irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE];
211         irqctx->tinfo.task              = NULL;
212         irqctx->tinfo.exec_domain       = NULL;
213         irqctx->tinfo.cpu               = cpu;
214         irqctx->tinfo.preempt_count     = 0;
215         irqctx->tinfo.addr_limit        = MAKE_MM_SEG(0);
216
217         softirq_ctx[cpu] = irqctx;
218
219         printk("CPU %u irqstacks, hard=%p soft=%p\n",
220                 cpu, hardirq_ctx[cpu], softirq_ctx[cpu]);
221 }
222
223 void irq_ctx_exit(int cpu)
224 {
225         hardirq_ctx[cpu] = NULL;
226 }
227
228 asmlinkage void do_softirq(void)
229 {
230         unsigned long flags;
231         struct thread_info *curctx;
232         union irq_ctx *irqctx;
233         u32 *isp;
234
235         if (in_interrupt())
236                 return;
237
238         local_irq_save(flags);
239
240         if (local_softirq_pending()) {
241                 curctx = current_thread_info();
242                 irqctx = softirq_ctx[smp_processor_id()];
243                 irqctx->tinfo.task = curctx->task;
244                 irqctx->tinfo.previous_sp = current_stack_pointer;
245
246                 /* build the stack frame on the softirq stack */
247                 isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
248
249                 __asm__ __volatile__ (
250                         "mov    r15, r9         \n"
251                         "jsr    @%0             \n"
252                         /* switch to the softirq stack */
253                         " mov   %1, r15         \n"
254                         /* restore the thread stack */
255                         "mov    r9, r15         \n"
256                         : /* no outputs */
257                         : "r" (__do_softirq), "r" (isp)
258                         : "memory", "r0", "r1", "r2", "r3", "r4",
259                           "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
260                 );
261
262                 /*
263                  * Shouldnt happen, we returned above if in_interrupt():
264                  */
265                 WARN_ON_ONCE(softirq_count());
266         }
267
268         local_irq_restore(flags);
269 }
270 #endif
271
272 void __init init_IRQ(void)
273 {
274         plat_irq_setup();
275
276         /* Perform the machine specific initialisation */
277         if (sh_mv.mv_init_irq)
278                 sh_mv.mv_init_irq();
279
280         irq_ctx_init(smp_processor_id());
281 }