![Paul Mundt](/assets/img/avatar_default.png)
Each board sets the total number of IRQs that it's interested in via the machvec. Previously we cared about the off vs on-chip IRQ range, but any code relying on that is long dead. Set NR_IRQS to something sensible given the vector range, and allow boards to cap it if they really care. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
275 lines
6.3 KiB
C
275 lines
6.3 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/irq.h>
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#include <asm/processor.h>
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#include <asm/machvec.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 < sh_mv.mv_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, "-%-8s", irq_desc[i].name);
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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 == sh_mv.mv_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] __read_mostly;
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static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
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#endif
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asmlinkage int do_IRQ(unsigned int irq, struct pt_regs *regs)
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{
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struct pt_regs *old_regs = set_irq_regs(regs);
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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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irq = irq_demux(evt2irq(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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/*
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* Copy the softirq bits in preempt_count so that the
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* softirq checks work in the hardirq context.
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*/
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irqctx->tinfo.preempt_count =
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(irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
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(curctx->tinfo.preempt_count & SOFTIRQ_MASK);
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__asm__ __volatile__ (
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"mov %0, r4 \n"
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"mov r15, r8 \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 r8, r15 \n"
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: /* no outputs */
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: "r" (irq), "r" (generic_handle_irq), "r" (isp)
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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 = 0;
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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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: "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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* Shouldnt happen, we returned above if in_interrupt():
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*/
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WARN_ON_ONCE(softirq_count());
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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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void __init init_IRQ(void)
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{
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#ifdef CONFIG_CPU_HAS_PINT_IRQ
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init_IRQ_pint();
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#endif
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#ifdef CONFIG_CPU_HAS_INTC2_IRQ
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init_IRQ_intc2();
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#endif
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#ifdef CONFIG_CPU_HAS_IPR_IRQ
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init_IRQ_ipr();
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#endif
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/* Perform the machine specific initialisation */
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if (sh_mv.mv_init_irq)
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sh_mv.mv_init_irq();
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irq_ctx_init(smp_processor_id());
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}
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