baf4326e49
Kill off interrupt_table for all of the CPU subtypes, we now default in to stepping in to do_IRQ() for _all_ IRQ exceptions and counting the spurious ones, rather than simply flipping on the ones we cared about. This and enabling the IRQ by default automatically has already uncovered a couple of bugs and IRQs that weren't being caught, as well as some that are being generated far too often (SCI Tx Data Empty, for example). The general rationale is to use a marker for interrupt exceptions, test for it in the handle_exception() path, and skip out to do_IRQ() if it's found. Everything else follows the same behaviour of finding the cached EXPEVT value in r2/r2_bank, we just rip out the INTEVT read from entry.S entirely (except for in the kGDB NMI case, which is another matter). Note that while this changes the do_IRQ() semantics regarding r4 handling, they were fundamentally broken anyways (relying entirely on r2_bank for the cached code). With this, we do the INTEVT read from do_IRQ() itself (in the CONFIG_CPU_HAS_INTEVT case), or fall back on r4 for the muxed IRQ number, which should also be closer to what SH-2 and SH-2A want anyways. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
251 lines
5.9 KiB
C
251 lines
5.9 KiB
C
/*
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* linux/arch/sh/kernel/irq.c
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*
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* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
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*
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*
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* SuperH version: Copyright (C) 1999 Niibe Yutaka
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*/
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#include <linux/irq.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/kernel_stat.h>
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#include <linux/seq_file.h>
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#include <linux/io.h>
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#include <asm/irq.h>
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#include <asm/processor.h>
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#include <asm/uaccess.h>
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#include <asm/thread_info.h>
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#include <asm/cpu/mmu_context.h>
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atomic_t irq_err_count;
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/*
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* 'what should we do if we get a hw irq event on an illegal vector'.
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* each architecture has to answer this themselves, it doesn't deserve
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* a generic callback i think.
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*/
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void ack_bad_irq(unsigned int irq)
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{
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atomic_inc(&irq_err_count);
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printk("unexpected IRQ trap at vector %02x\n", irq);
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}
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#if defined(CONFIG_PROC_FS)
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int show_interrupts(struct seq_file *p, void *v)
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{
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int i = *(loff_t *) v, j;
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struct irqaction * action;
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unsigned long flags;
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if (i == 0) {
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seq_puts(p, " ");
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for_each_online_cpu(j)
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seq_printf(p, "CPU%d ",j);
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seq_putc(p, '\n');
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}
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if (i < NR_IRQS) {
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spin_lock_irqsave(&irq_desc[i].lock, flags);
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action = irq_desc[i].action;
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if (!action)
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goto unlock;
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seq_printf(p, "%3d: ",i);
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
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seq_printf(p, " %14s", irq_desc[i].chip->name);
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seq_printf(p, "-%s", handle_irq_name(irq_desc[i].handle_irq));
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seq_printf(p, " %s", action->name);
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for (action=action->next; action; action = action->next)
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seq_printf(p, ", %s", action->name);
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seq_putc(p, '\n');
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unlock:
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spin_unlock_irqrestore(&irq_desc[i].lock, flags);
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} else if (i == NR_IRQS)
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seq_printf(p, "Err: %10u\n", atomic_read(&irq_err_count));
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return 0;
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}
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#endif
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#ifdef CONFIG_4KSTACKS
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/*
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* per-CPU IRQ handling contexts (thread information and stack)
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*/
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union irq_ctx {
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struct thread_info tinfo;
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u32 stack[THREAD_SIZE/sizeof(u32)];
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};
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static union irq_ctx *hardirq_ctx[NR_CPUS];
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static union irq_ctx *softirq_ctx[NR_CPUS];
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#endif
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asmlinkage int do_IRQ(unsigned long r4, unsigned long r5,
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unsigned long r6, unsigned long r7,
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struct pt_regs regs)
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{
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struct pt_regs *old_regs = set_irq_regs(®s);
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int irq;
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#ifdef CONFIG_4KSTACKS
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union irq_ctx *curctx, *irqctx;
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#endif
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irq_enter();
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#ifdef CONFIG_DEBUG_STACKOVERFLOW
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/* Debugging check for stack overflow: is there less than 1KB free? */
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{
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long sp;
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__asm__ __volatile__ ("and r15, %0" :
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"=r" (sp) : "0" (THREAD_SIZE - 1));
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if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
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printk("do_IRQ: stack overflow: %ld\n",
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sp - sizeof(struct thread_info));
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dump_stack();
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}
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}
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#endif
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#ifdef CONFIG_CPU_HAS_INTEVT
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irq = (ctrl_inl(INTEVT) >> 5) - 16;
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#else
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irq = r4;
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#endif
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irq = irq_demux(irq);
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#ifdef CONFIG_4KSTACKS
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curctx = (union irq_ctx *)current_thread_info();
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irqctx = hardirq_ctx[smp_processor_id()];
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/*
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* this is where we switch to the IRQ stack. However, if we are
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* already using the IRQ stack (because we interrupted a hardirq
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* handler) we can't do that and just have to keep using the
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* current stack (which is the irq stack already after all)
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*/
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if (curctx != irqctx) {
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u32 *isp;
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isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
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irqctx->tinfo.task = curctx->tinfo.task;
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irqctx->tinfo.previous_sp = current_stack_pointer;
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__asm__ __volatile__ (
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"mov %0, r4 \n"
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"mov r15, r9 \n"
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"jsr @%1 \n"
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/* swith to the irq stack */
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" mov %2, r15 \n"
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/* restore the stack (ring zero) */
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"mov r9, r15 \n"
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: /* no outputs */
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: "r" (irq), "r" (generic_handle_irq), "r" (isp)
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/* XXX: A somewhat excessive clobber list? -PFM */
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: "memory", "r0", "r1", "r2", "r3", "r4",
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"r5", "r6", "r7", "r8", "t", "pr"
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);
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} else
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#endif
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generic_handle_irq(irq);
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irq_exit();
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set_irq_regs(old_regs);
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return 1;
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}
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#ifdef CONFIG_4KSTACKS
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/*
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* These should really be __section__(".bss.page_aligned") as well, but
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* gcc's 3.0 and earlier don't handle that correctly.
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*/
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static char softirq_stack[NR_CPUS * THREAD_SIZE]
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__attribute__((__aligned__(THREAD_SIZE)));
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static char hardirq_stack[NR_CPUS * THREAD_SIZE]
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__attribute__((__aligned__(THREAD_SIZE)));
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/*
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* allocate per-cpu stacks for hardirq and for softirq processing
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*/
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void irq_ctx_init(int cpu)
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{
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union irq_ctx *irqctx;
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if (hardirq_ctx[cpu])
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return;
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irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE];
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irqctx->tinfo.task = NULL;
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irqctx->tinfo.exec_domain = NULL;
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irqctx->tinfo.cpu = cpu;
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irqctx->tinfo.preempt_count = HARDIRQ_OFFSET;
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irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
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hardirq_ctx[cpu] = irqctx;
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irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE];
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irqctx->tinfo.task = NULL;
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irqctx->tinfo.exec_domain = NULL;
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irqctx->tinfo.cpu = cpu;
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irqctx->tinfo.preempt_count = SOFTIRQ_OFFSET;
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irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
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softirq_ctx[cpu] = irqctx;
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printk("CPU %u irqstacks, hard=%p soft=%p\n",
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cpu, hardirq_ctx[cpu], softirq_ctx[cpu]);
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}
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void irq_ctx_exit(int cpu)
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{
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hardirq_ctx[cpu] = NULL;
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}
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extern asmlinkage void __do_softirq(void);
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asmlinkage void do_softirq(void)
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{
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unsigned long flags;
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struct thread_info *curctx;
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union irq_ctx *irqctx;
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u32 *isp;
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if (in_interrupt())
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return;
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local_irq_save(flags);
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if (local_softirq_pending()) {
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curctx = current_thread_info();
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irqctx = softirq_ctx[smp_processor_id()];
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irqctx->tinfo.task = curctx->task;
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irqctx->tinfo.previous_sp = current_stack_pointer;
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/* build the stack frame on the softirq stack */
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isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
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__asm__ __volatile__ (
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"mov r15, r9 \n"
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"jsr @%0 \n"
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/* switch to the softirq stack */
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" mov %1, r15 \n"
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/* restore the thread stack */
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"mov r9, r15 \n"
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: /* no outputs */
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: "r" (__do_softirq), "r" (isp)
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/* XXX: A somewhat excessive clobber list? -PFM */
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: "memory", "r0", "r1", "r2", "r3", "r4",
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"r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
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);
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}
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local_irq_restore(flags);
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}
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EXPORT_SYMBOL(do_softirq);
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#endif
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