diff options
Diffstat (limited to 'arch/sh/kernel/irq.c')
| -rw-r--r-- | arch/sh/kernel/irq.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c new file mode 100644 index 000000000..eb10ff840 --- /dev/null +++ b/arch/sh/kernel/irq.c @@ -0,0 +1,243 @@ +/* + * 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 <linux/ftrace.h> +#include <linux/delay.h> +#include <linux/ratelimit.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) +/* + * /proc/interrupts printing for arch specific interrupts + */ +int arch_show_interrupts(struct seq_file *p, int prec) +{ + int j; + + seq_printf(p, "%*s: ", prec, "NMI"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", irq_stat[j].__nmi_count); + seq_printf(p, " Non-maskable interrupts\n"); + + seq_printf(p, "%*s: %10u\n", prec, "ERR", 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; + +static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; +static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; + +static inline void handle_one_irq(unsigned int irq) +{ + union irq_ctx *curctx, *irqctx; + + 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 + generic_handle_irq(irq); +} + +/* + * 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.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.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; +} + +void do_softirq_own_stack(void) +{ + struct thread_info *curctx; + union irq_ctx *irqctx; + u32 *isp; + + 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" + ); +} +#else +static inline void handle_one_irq(unsigned int irq) +{ + generic_handle_irq(irq); +} +#endif + +asmlinkage __irq_entry int do_IRQ(unsigned int irq, struct pt_regs *regs) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + + irq_enter(); + + irq = irq_demux(irq_lookup(irq)); + + if (irq != NO_IRQ_IGNORE) { + handle_one_irq(irq); + irq_finish(irq); + } + + irq_exit(); + + set_irq_regs(old_regs); + + return IRQ_HANDLED; +} + +void __init init_IRQ(void) +{ + plat_irq_setup(); + + /* Perform the machine specific initialisation */ + if (sh_mv.mv_init_irq) + sh_mv.mv_init_irq(); + + intc_finalize(); + + irq_ctx_init(smp_processor_id()); +} + +#ifdef CONFIG_HOTPLUG_CPU +/* + * The CPU has been marked offline. Migrate IRQs off this CPU. If + * the affinity settings do not allow other CPUs, force them onto any + * available CPU. + */ +void migrate_irqs(void) +{ + unsigned int irq, cpu = smp_processor_id(); + + for_each_active_irq(irq) { + struct irq_data *data = irq_get_irq_data(irq); + + if (data->node == cpu) { + unsigned int newcpu = cpumask_any_and(data->affinity, + cpu_online_mask); + if (newcpu >= nr_cpu_ids) { + pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n", + irq, cpu); + + cpumask_setall(data->affinity); + } + irq_set_affinity(irq, data->affinity); + } + } +} +#endif |