/* * linux/arch/sh/kernel/irq.c * * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar * * * SuperH version: Copyright (C) 1999 Niibe Yutaka */ #include <linux/irq.h> #include <linux/interrupt.h> #include <linux/module.h> #include <linux/kernel_stat.h> #include <linux/seq_file.h> #include <asm/processor.h> #include <asm/machvec.h> #include <asm/uaccess.h> #include <asm/thread_info.h> #include <cpu/mmu_context.h> atomic_t irq_err_count; /* * 'what should we do if we get a hw irq event on an illegal vector'. * each architecture has to answer this themselves, it doesn't deserve * a generic callback i think. */ void ack_bad_irq(unsigned int irq) { atomic_inc(&irq_err_count); printk("unexpected IRQ trap at vector %02x\n", irq); } #if defined(CONFIG_PROC_FS) int show_interrupts(struct seq_file *p, void *v) { int i = *(loff_t *) v, j; struct irqaction * action; unsigned long flags; if (i == 0) { seq_puts(p, " "); for_each_online_cpu(j) seq_printf(p, "CPU%d ",j); seq_putc(p, '\n'); } if (i < sh_mv.mv_nr_irqs) { spin_lock_irqsave(&irq_desc[i].lock, flags); action = irq_desc[i].action; if (!action) goto unlock; seq_printf(p, "%3d: ",i); for_each_online_cpu(j) seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]); seq_printf(p, " %14s", irq_desc[i].chip->name); seq_printf(p, "-%-8s", irq_desc[i].name); seq_printf(p, " %s", action->name); for (action=action->next; action; action = action->next) seq_printf(p, ", %s", action->name); seq_putc(p, '\n'); unlock: spin_unlock_irqrestore(&irq_desc[i].lock, flags); } else if (i == sh_mv.mv_nr_irqs) seq_printf(p, "Err: %10u\n", atomic_read(&irq_err_count)); return 0; } #endif #ifdef CONFIG_IRQSTACKS /* * per-CPU IRQ handling contexts (thread information and stack) */ union irq_ctx { struct thread_info tinfo; u32 stack[THREAD_SIZE/sizeof(u32)]; }; static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly; static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly; #endif asmlinkage int do_IRQ(unsigned int irq, struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); #ifdef CONFIG_IRQSTACKS union irq_ctx *curctx, *irqctx; #endif irq_enter(); #ifdef CONFIG_DEBUG_STACKOVERFLOW /* Debugging check for stack overflow: is there less than 1KB free? */ { long sp; __asm__ __volatile__ ("and r15, %0" : "=r" (sp) : "0" (THREAD_SIZE - 1)); if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) { printk("do_IRQ: stack overflow: %ld\n", sp - sizeof(struct thread_info)); dump_stack(); } } #endif irq = irq_demux(evt2irq(irq)); #ifdef CONFIG_IRQSTACKS curctx = (union irq_ctx *)current_thread_info(); irqctx = hardirq_ctx[smp_processor_id()]; /* * this is where we switch to the IRQ stack. However, if we are * already using the IRQ stack (because we interrupted a hardirq * handler) we can't do that and just have to keep using the * current stack (which is the irq stack already after all) */ if (curctx != irqctx) { u32 *isp; isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); irqctx->tinfo.task = curctx->tinfo.task; irqctx->tinfo.previous_sp = current_stack_pointer; /* * Copy the softirq bits in preempt_count so that the * softirq checks work in the hardirq context. */ irqctx->tinfo.preempt_count = (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) | (curctx->tinfo.preempt_count & SOFTIRQ_MASK); __asm__ __volatile__ ( "mov %0, r4 \n" "mov r15, r8 \n" "jsr @%1 \n" /* swith to the irq stack */ " mov %2, r15 \n" /* restore the stack (ring zero) */ "mov r8, r15 \n" : /* no outputs */ : "r" (irq), "r" (generic_handle_irq), "r" (isp) : "memory", "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "t", "pr" ); } else #endif generic_handle_irq(irq); irq_exit(); set_irq_regs(old_regs); return 1; } #ifdef CONFIG_IRQSTACKS static char softirq_stack[NR_CPUS * THREAD_SIZE] __attribute__((__section__(".bss.page_aligned"))); static char hardirq_stack[NR_CPUS * THREAD_SIZE] __attribute__((__section__(".bss.page_aligned"))); /* * allocate per-cpu stacks for hardirq and for softirq processing */ void irq_ctx_init(int cpu) { union irq_ctx *irqctx; if (hardirq_ctx[cpu]) return; irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE]; irqctx->tinfo.task = NULL; irqctx->tinfo.exec_domain = NULL; irqctx->tinfo.cpu = cpu; irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); hardirq_ctx[cpu] = irqctx; irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE]; irqctx->tinfo.task = NULL; irqctx->tinfo.exec_domain = NULL; irqctx->tinfo.cpu = cpu; irqctx->tinfo.preempt_count = 0; irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); softirq_ctx[cpu] = irqctx; printk("CPU %u irqstacks, hard=%p soft=%p\n", cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); } void irq_ctx_exit(int cpu) { hardirq_ctx[cpu] = NULL; } asmlinkage void do_softirq(void) { unsigned long flags; struct thread_info *curctx; union irq_ctx *irqctx; u32 *isp; if (in_interrupt()) return; local_irq_save(flags); if (local_softirq_pending()) { curctx = current_thread_info(); irqctx = softirq_ctx[smp_processor_id()]; irqctx->tinfo.task = curctx->task; irqctx->tinfo.previous_sp = current_stack_pointer; /* build the stack frame on the softirq stack */ isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); __asm__ __volatile__ ( "mov r15, r9 \n" "jsr @%0 \n" /* switch to the softirq stack */ " mov %1, r15 \n" /* restore the thread stack */ "mov r9, r15 \n" : /* no outputs */ : "r" (__do_softirq), "r" (isp) : "memory", "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" ); /* * Shouldnt happen, we returned above if in_interrupt(): */ WARN_ON_ONCE(softirq_count()); } local_irq_restore(flags); } #endif void __init init_IRQ(void) { plat_irq_setup(); /* Perform the machine specific initialisation */ if (sh_mv.mv_init_irq) sh_mv.mv_init_irq(); irq_ctx_init(smp_processor_id()); }