Commit | Line | Data |
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a6a31139 | 1 | /* |
1da177e4 LT |
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 | */ | |
bf3a00f8 | 9 | #include <linux/irq.h> |
1da177e4 | 10 | #include <linux/interrupt.h> |
a6a31139 | 11 | #include <linux/module.h> |
bf3a00f8 | 12 | #include <linux/kernel_stat.h> |
1da177e4 | 13 | #include <linux/seq_file.h> |
baf4326e | 14 | #include <linux/io.h> |
1da177e4 | 15 | #include <asm/irq.h> |
bf3a00f8 | 16 | #include <asm/processor.h> |
a6a31139 PM |
17 | #include <asm/uaccess.h> |
18 | #include <asm/thread_info.h> | |
bf3a00f8 | 19 | #include <asm/cpu/mmu_context.h> |
1da177e4 | 20 | |
35f3c518 PM |
21 | atomic_t irq_err_count; |
22 | ||
1da177e4 LT |
23 | /* |
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. | |
27 | */ | |
28 | void ack_bad_irq(unsigned int irq) | |
29 | { | |
baf4326e | 30 | atomic_inc(&irq_err_count); |
1da177e4 LT |
31 | printk("unexpected IRQ trap at vector %02x\n", irq); |
32 | } | |
33 | ||
34 | #if defined(CONFIG_PROC_FS) | |
35 | int show_interrupts(struct seq_file *p, void *v) | |
36 | { | |
37 | int i = *(loff_t *) v, j; | |
38 | struct irqaction * action; | |
39 | unsigned long flags; | |
40 | ||
41 | if (i == 0) { | |
42 | seq_puts(p, " "); | |
394e3902 AM |
43 | for_each_online_cpu(j) |
44 | seq_printf(p, "CPU%d ",j); | |
1da177e4 LT |
45 | seq_putc(p, '\n'); |
46 | } | |
47 | ||
bf3a00f8 | 48 | if (i < NR_IRQS) { |
1da177e4 LT |
49 | spin_lock_irqsave(&irq_desc[i].lock, flags); |
50 | action = irq_desc[i].action; | |
51 | if (!action) | |
52 | goto unlock; | |
53 | seq_printf(p, "%3d: ",i); | |
35f3c518 PM |
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); | |
709bc44c | 57 | seq_printf(p, "-%-8s", irq_desc[i].name); |
1da177e4 LT |
58 | seq_printf(p, " %s", action->name); |
59 | ||
60 | for (action=action->next; action; action = action->next) | |
61 | seq_printf(p, ", %s", action->name); | |
62 | seq_putc(p, '\n'); | |
63 | unlock: | |
64 | spin_unlock_irqrestore(&irq_desc[i].lock, flags); | |
35f3c518 PM |
65 | } else if (i == NR_IRQS) |
66 | seq_printf(p, "Err: %10u\n", atomic_read(&irq_err_count)); | |
67 | ||
1da177e4 LT |
68 | return 0; |
69 | } | |
70 | #endif | |
71 | ||
a6a31139 PM |
72 | #ifdef CONFIG_4KSTACKS |
73 | /* | |
74 | * per-CPU IRQ handling contexts (thread information and stack) | |
75 | */ | |
76 | union irq_ctx { | |
77 | struct thread_info tinfo; | |
78 | u32 stack[THREAD_SIZE/sizeof(u32)]; | |
79 | }; | |
80 | ||
1dc41e58 PM |
81 | static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly; |
82 | static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly; | |
a6a31139 PM |
83 | #endif |
84 | ||
1da177e4 LT |
85 | asmlinkage int do_IRQ(unsigned long r4, unsigned long r5, |
86 | unsigned long r6, unsigned long r7, | |
f0bc814c | 87 | struct pt_regs __regs) |
bf3a00f8 | 88 | { |
f0bc814c SM |
89 | struct pt_regs *regs = RELOC_HIDE(&__regs, 0); |
90 | struct pt_regs *old_regs = set_irq_regs(regs); | |
baf4326e | 91 | int irq; |
a6a31139 PM |
92 | #ifdef CONFIG_4KSTACKS |
93 | union irq_ctx *curctx, *irqctx; | |
94 | #endif | |
1da177e4 LT |
95 | |
96 | irq_enter(); | |
bf3a00f8 | 97 | |
d153ea88 PM |
98 | #ifdef CONFIG_DEBUG_STACKOVERFLOW |
99 | /* Debugging check for stack overflow: is there less than 1KB free? */ | |
100 | { | |
101 | long sp; | |
102 | ||
103 | __asm__ __volatile__ ("and r15, %0" : | |
104 | "=r" (sp) : "0" (THREAD_SIZE - 1)); | |
105 | ||
106 | if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) { | |
107 | printk("do_IRQ: stack overflow: %ld\n", | |
108 | sp - sizeof(struct thread_info)); | |
109 | dump_stack(); | |
110 | } | |
111 | } | |
112 | #endif | |
113 | ||
bf3a00f8 | 114 | #ifdef CONFIG_CPU_HAS_INTEVT |
baf4326e | 115 | irq = (ctrl_inl(INTEVT) >> 5) - 16; |
bf3a00f8 | 116 | #else |
baf4326e | 117 | irq = r4; |
bf3a00f8 PM |
118 | #endif |
119 | ||
1da177e4 | 120 | irq = irq_demux(irq); |
a6a31139 PM |
121 | |
122 | #ifdef CONFIG_4KSTACKS | |
123 | curctx = (union irq_ctx *)current_thread_info(); | |
124 | irqctx = hardirq_ctx[smp_processor_id()]; | |
125 | ||
126 | /* | |
127 | * this is where we switch to the IRQ stack. However, if we are | |
128 | * already using the IRQ stack (because we interrupted a hardirq | |
129 | * handler) we can't do that and just have to keep using the | |
130 | * current stack (which is the irq stack already after all) | |
131 | */ | |
132 | if (curctx != irqctx) { | |
133 | u32 *isp; | |
134 | ||
135 | isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); | |
136 | irqctx->tinfo.task = curctx->tinfo.task; | |
137 | irqctx->tinfo.previous_sp = current_stack_pointer; | |
138 | ||
1dc41e58 PM |
139 | /* |
140 | * Copy the softirq bits in preempt_count so that the | |
141 | * softirq checks work in the hardirq context. | |
142 | */ | |
143 | irqctx->tinfo.preempt_count = | |
144 | (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) | | |
145 | (curctx->tinfo.preempt_count & SOFTIRQ_MASK); | |
146 | ||
a6a31139 PM |
147 | __asm__ __volatile__ ( |
148 | "mov %0, r4 \n" | |
1dc41e58 | 149 | "mov r15, r8 \n" |
baf4326e | 150 | "jsr @%1 \n" |
a6a31139 | 151 | /* swith to the irq stack */ |
baf4326e | 152 | " mov %2, r15 \n" |
a6a31139 | 153 | /* restore the stack (ring zero) */ |
1dc41e58 | 154 | "mov r8, r15 \n" |
a6a31139 | 155 | : /* no outputs */ |
35f3c518 | 156 | : "r" (irq), "r" (generic_handle_irq), "r" (isp) |
a6a31139 PM |
157 | : "memory", "r0", "r1", "r2", "r3", "r4", |
158 | "r5", "r6", "r7", "r8", "t", "pr" | |
159 | ); | |
160 | } else | |
161 | #endif | |
35f3c518 | 162 | generic_handle_irq(irq); |
a6a31139 | 163 | |
1da177e4 | 164 | irq_exit(); |
a6a31139 | 165 | |
35f3c518 | 166 | set_irq_regs(old_regs); |
1da177e4 LT |
167 | return 1; |
168 | } | |
a6a31139 PM |
169 | |
170 | #ifdef CONFIG_4KSTACKS | |
171 | /* | |
172 | * These should really be __section__(".bss.page_aligned") as well, but | |
173 | * gcc's 3.0 and earlier don't handle that correctly. | |
174 | */ | |
175 | static char softirq_stack[NR_CPUS * THREAD_SIZE] | |
176 | __attribute__((__aligned__(THREAD_SIZE))); | |
177 | ||
178 | static char hardirq_stack[NR_CPUS * THREAD_SIZE] | |
179 | __attribute__((__aligned__(THREAD_SIZE))); | |
180 | ||
181 | /* | |
182 | * allocate per-cpu stacks for hardirq and for softirq processing | |
183 | */ | |
184 | void irq_ctx_init(int cpu) | |
185 | { | |
186 | union irq_ctx *irqctx; | |
187 | ||
188 | if (hardirq_ctx[cpu]) | |
189 | return; | |
190 | ||
191 | irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE]; | |
192 | irqctx->tinfo.task = NULL; | |
193 | irqctx->tinfo.exec_domain = NULL; | |
194 | irqctx->tinfo.cpu = cpu; | |
195 | irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; | |
196 | irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); | |
197 | ||
198 | hardirq_ctx[cpu] = irqctx; | |
199 | ||
200 | irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE]; | |
201 | irqctx->tinfo.task = NULL; | |
202 | irqctx->tinfo.exec_domain = NULL; | |
203 | irqctx->tinfo.cpu = cpu; | |
1dc41e58 | 204 | irqctx->tinfo.preempt_count = 0; |
a6a31139 PM |
205 | irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); |
206 | ||
207 | softirq_ctx[cpu] = irqctx; | |
208 | ||
209 | printk("CPU %u irqstacks, hard=%p soft=%p\n", | |
210 | cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); | |
211 | } | |
212 | ||
213 | void irq_ctx_exit(int cpu) | |
214 | { | |
215 | hardirq_ctx[cpu] = NULL; | |
216 | } | |
217 | ||
218 | extern asmlinkage void __do_softirq(void); | |
219 | ||
220 | asmlinkage void do_softirq(void) | |
221 | { | |
222 | unsigned long flags; | |
223 | struct thread_info *curctx; | |
224 | union irq_ctx *irqctx; | |
225 | u32 *isp; | |
226 | ||
227 | if (in_interrupt()) | |
228 | return; | |
229 | ||
230 | local_irq_save(flags); | |
231 | ||
232 | if (local_softirq_pending()) { | |
233 | curctx = current_thread_info(); | |
234 | irqctx = softirq_ctx[smp_processor_id()]; | |
235 | irqctx->tinfo.task = curctx->task; | |
236 | irqctx->tinfo.previous_sp = current_stack_pointer; | |
237 | ||
238 | /* build the stack frame on the softirq stack */ | |
239 | isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); | |
240 | ||
241 | __asm__ __volatile__ ( | |
242 | "mov r15, r9 \n" | |
243 | "jsr @%0 \n" | |
244 | /* switch to the softirq stack */ | |
245 | " mov %1, r15 \n" | |
246 | /* restore the thread stack */ | |
247 | "mov r9, r15 \n" | |
248 | : /* no outputs */ | |
249 | : "r" (__do_softirq), "r" (isp) | |
a6a31139 PM |
250 | : "memory", "r0", "r1", "r2", "r3", "r4", |
251 | "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" | |
252 | ); | |
1dc41e58 PM |
253 | |
254 | /* | |
255 | * Shouldnt happen, we returned above if in_interrupt(): | |
256 | */ | |
257 | WARN_ON_ONCE(softirq_count()); | |
a6a31139 PM |
258 | } |
259 | ||
260 | local_irq_restore(flags); | |
261 | } | |
262 | EXPORT_SYMBOL(do_softirq); | |
263 | #endif |