2 * linux/arch/sh/kernel/irq.c
4 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
7 * SuperH version: Copyright (C) 1999 Niibe Yutaka
10 #include <linux/interrupt.h>
11 #include <linux/module.h>
12 #include <linux/kernel_stat.h>
13 #include <linux/seq_file.h>
16 #include <asm/processor.h>
17 #include <asm/uaccess.h>
18 #include <asm/thread_info.h>
19 #include <asm/cpu/mmu_context.h>
21 atomic_t irq_err_count;
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.
28 void ack_bad_irq(unsigned int irq)
30 atomic_inc(&irq_err_count);
31 printk("unexpected IRQ trap at vector %02x\n", irq);
34 #if defined(CONFIG_PROC_FS)
35 int show_interrupts(struct seq_file *p, void *v)
37 int i = *(loff_t *) v, j;
38 struct irqaction * action;
43 for_each_online_cpu(j)
44 seq_printf(p, "CPU%d ",j);
49 spin_lock_irqsave(&irq_desc[i].lock, flags);
50 action = irq_desc[i].action;
53 seq_printf(p, "%3d: ",i);
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);
57 seq_printf(p, "-%-8s", irq_desc[i].name);
58 seq_printf(p, " %s", action->name);
60 for (action=action->next; action; action = action->next)
61 seq_printf(p, ", %s", action->name);
64 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
65 } else if (i == NR_IRQS)
66 seq_printf(p, "Err: %10u\n", atomic_read(&irq_err_count));
72 #ifdef CONFIG_4KSTACKS
74 * per-CPU IRQ handling contexts (thread information and stack)
77 struct thread_info tinfo;
78 u32 stack[THREAD_SIZE/sizeof(u32)];
81 static union irq_ctx *hardirq_ctx[NR_CPUS];
82 static union irq_ctx *softirq_ctx[NR_CPUS];
85 asmlinkage int do_IRQ(unsigned long r4, unsigned long r5,
86 unsigned long r6, unsigned long r7,
87 struct pt_regs __regs)
89 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
90 struct pt_regs *old_regs = set_irq_regs(regs);
92 #ifdef CONFIG_4KSTACKS
93 union irq_ctx *curctx, *irqctx;
98 #ifdef CONFIG_DEBUG_STACKOVERFLOW
99 /* Debugging check for stack overflow: is there less than 1KB free? */
103 __asm__ __volatile__ ("and r15, %0" :
104 "=r" (sp) : "0" (THREAD_SIZE - 1));
106 if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
107 printk("do_IRQ: stack overflow: %ld\n",
108 sp - sizeof(struct thread_info));
114 #ifdef CONFIG_CPU_HAS_INTEVT
115 irq = (ctrl_inl(INTEVT) >> 5) - 16;
120 irq = irq_demux(irq);
122 #ifdef CONFIG_4KSTACKS
123 curctx = (union irq_ctx *)current_thread_info();
124 irqctx = hardirq_ctx[smp_processor_id()];
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)
132 if (curctx != irqctx) {
135 isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
136 irqctx->tinfo.task = curctx->tinfo.task;
137 irqctx->tinfo.previous_sp = current_stack_pointer;
139 __asm__ __volatile__ (
143 /* swith to the irq stack */
145 /* restore the stack (ring zero) */
148 : "r" (irq), "r" (generic_handle_irq), "r" (isp)
149 /* XXX: A somewhat excessive clobber list? -PFM */
150 : "memory", "r0", "r1", "r2", "r3", "r4",
151 "r5", "r6", "r7", "r8", "t", "pr"
155 generic_handle_irq(irq);
159 set_irq_regs(old_regs);
163 #ifdef CONFIG_4KSTACKS
165 * These should really be __section__(".bss.page_aligned") as well, but
166 * gcc's 3.0 and earlier don't handle that correctly.
168 static char softirq_stack[NR_CPUS * THREAD_SIZE]
169 __attribute__((__aligned__(THREAD_SIZE)));
171 static char hardirq_stack[NR_CPUS * THREAD_SIZE]
172 __attribute__((__aligned__(THREAD_SIZE)));
175 * allocate per-cpu stacks for hardirq and for softirq processing
177 void irq_ctx_init(int cpu)
179 union irq_ctx *irqctx;
181 if (hardirq_ctx[cpu])
184 irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE];
185 irqctx->tinfo.task = NULL;
186 irqctx->tinfo.exec_domain = NULL;
187 irqctx->tinfo.cpu = cpu;
188 irqctx->tinfo.preempt_count = HARDIRQ_OFFSET;
189 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
191 hardirq_ctx[cpu] = irqctx;
193 irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE];
194 irqctx->tinfo.task = NULL;
195 irqctx->tinfo.exec_domain = NULL;
196 irqctx->tinfo.cpu = cpu;
197 irqctx->tinfo.preempt_count = SOFTIRQ_OFFSET;
198 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
200 softirq_ctx[cpu] = irqctx;
202 printk("CPU %u irqstacks, hard=%p soft=%p\n",
203 cpu, hardirq_ctx[cpu], softirq_ctx[cpu]);
206 void irq_ctx_exit(int cpu)
208 hardirq_ctx[cpu] = NULL;
211 extern asmlinkage void __do_softirq(void);
213 asmlinkage void do_softirq(void)
216 struct thread_info *curctx;
217 union irq_ctx *irqctx;
223 local_irq_save(flags);
225 if (local_softirq_pending()) {
226 curctx = current_thread_info();
227 irqctx = softirq_ctx[smp_processor_id()];
228 irqctx->tinfo.task = curctx->task;
229 irqctx->tinfo.previous_sp = current_stack_pointer;
231 /* build the stack frame on the softirq stack */
232 isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
234 __asm__ __volatile__ (
237 /* switch to the softirq stack */
239 /* restore the thread stack */
242 : "r" (__do_softirq), "r" (isp)
243 /* XXX: A somewhat excessive clobber list? -PFM */
244 : "memory", "r0", "r1", "r2", "r3", "r4",
245 "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
249 local_irq_restore(flags);
251 EXPORT_SYMBOL(do_softirq);