diff options
Diffstat (limited to 'arch/xtensa/kernel/irq.c')
| -rw-r--r-- | arch/xtensa/kernel/irq.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/irq.c b/arch/xtensa/kernel/irq.c new file mode 100644 index 000000000..3eee94f62 --- /dev/null +++ b/arch/xtensa/kernel/irq.c @@ -0,0 +1,188 @@ +/* + * linux/arch/xtensa/kernel/irq.c + * + * Xtensa built-in interrupt controller and some generic functions copied + * from i386. + * + * Copyright (C) 2002 - 2013 Tensilica, Inc. + * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar + * + * + * Chris Zankel <chris@zankel.net> + * Kevin Chea + * + */ + +#include <linux/module.h> +#include <linux/seq_file.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/kernel_stat.h> +#include <linux/irqchip.h> +#include <linux/irqchip/xtensa-mx.h> +#include <linux/irqchip/xtensa-pic.h> +#include <linux/irqdomain.h> +#include <linux/of.h> + +#include <asm/mxregs.h> +#include <asm/uaccess.h> +#include <asm/platform.h> + +atomic_t irq_err_count; + +asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs) +{ + int irq = irq_find_mapping(NULL, hwirq); + + if (hwirq >= NR_IRQS) { + printk(KERN_EMERG "%s: cannot handle IRQ %d\n", + __func__, hwirq); + } + +#ifdef CONFIG_DEBUG_STACKOVERFLOW + /* Debugging check for stack overflow: is there less than 1KB free? */ + { + unsigned long sp; + + __asm__ __volatile__ ("mov %0, a1\n" : "=a" (sp)); + sp &= THREAD_SIZE - 1; + + if (unlikely(sp < (sizeof(thread_info) + 1024))) + printk("Stack overflow in do_IRQ: %ld\n", + sp - sizeof(struct thread_info)); + } +#endif + generic_handle_irq(irq); +} + +int arch_show_interrupts(struct seq_file *p, int prec) +{ +#ifdef CONFIG_SMP + show_ipi_list(p, prec); +#endif + seq_printf(p, "%*s: ", prec, "ERR"); + seq_printf(p, "%10u\n", atomic_read(&irq_err_count)); + return 0; +} + +int xtensa_irq_domain_xlate(const u32 *intspec, unsigned int intsize, + unsigned long int_irq, unsigned long ext_irq, + unsigned long *out_hwirq, unsigned int *out_type) +{ + if (WARN_ON(intsize < 1 || intsize > 2)) + return -EINVAL; + if (intsize == 2 && intspec[1] == 1) { + int_irq = xtensa_map_ext_irq(ext_irq); + if (int_irq < XCHAL_NUM_INTERRUPTS) + *out_hwirq = int_irq; + else + return -EINVAL; + } else { + *out_hwirq = int_irq; + } + *out_type = IRQ_TYPE_NONE; + return 0; +} + +int xtensa_irq_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hw) +{ + struct irq_chip *irq_chip = d->host_data; + u32 mask = 1 << hw; + + if (mask & XCHAL_INTTYPE_MASK_SOFTWARE) { + irq_set_chip_and_handler_name(irq, irq_chip, + handle_simple_irq, "level"); + irq_set_status_flags(irq, IRQ_LEVEL); + } else if (mask & XCHAL_INTTYPE_MASK_EXTERN_EDGE) { + irq_set_chip_and_handler_name(irq, irq_chip, + handle_edge_irq, "edge"); + irq_clear_status_flags(irq, IRQ_LEVEL); + } else if (mask & XCHAL_INTTYPE_MASK_EXTERN_LEVEL) { + irq_set_chip_and_handler_name(irq, irq_chip, + handle_level_irq, "level"); + irq_set_status_flags(irq, IRQ_LEVEL); + } else if (mask & XCHAL_INTTYPE_MASK_TIMER) { + irq_set_chip_and_handler_name(irq, irq_chip, + handle_percpu_irq, "timer"); + irq_clear_status_flags(irq, IRQ_LEVEL); + } else {/* XCHAL_INTTYPE_MASK_WRITE_ERROR */ + /* XCHAL_INTTYPE_MASK_NMI */ + irq_set_chip_and_handler_name(irq, irq_chip, + handle_level_irq, "level"); + irq_set_status_flags(irq, IRQ_LEVEL); + } + return 0; +} + +unsigned xtensa_map_ext_irq(unsigned ext_irq) +{ + unsigned mask = XCHAL_INTTYPE_MASK_EXTERN_EDGE | + XCHAL_INTTYPE_MASK_EXTERN_LEVEL; + unsigned i; + + for (i = 0; mask; ++i, mask >>= 1) { + if ((mask & 1) && ext_irq-- == 0) + return i; + } + return XCHAL_NUM_INTERRUPTS; +} + +unsigned xtensa_get_ext_irq_no(unsigned irq) +{ + unsigned mask = (XCHAL_INTTYPE_MASK_EXTERN_EDGE | + XCHAL_INTTYPE_MASK_EXTERN_LEVEL) & + ((1u << irq) - 1); + return hweight32(mask); +} + +void __init init_IRQ(void) +{ +#ifdef CONFIG_OF + irqchip_init(); +#else +#ifdef CONFIG_HAVE_SMP + xtensa_mx_init_legacy(NULL); +#else + xtensa_pic_init_legacy(NULL); +#endif +#endif + +#ifdef CONFIG_SMP + ipi_init(); +#endif + variant_init_irq(); +} + +#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 i, cpu = smp_processor_id(); + + for_each_active_irq(i) { + struct irq_data *data = irq_get_irq_data(i); + unsigned int newcpu; + + if (irqd_is_per_cpu(data)) + continue; + + if (!cpumask_test_cpu(cpu, data->affinity)) + continue; + + 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", + i, cpu); + + cpumask_setall(data->affinity); + } + irq_set_affinity(i, data->affinity); + } +} +#endif /* CONFIG_HOTPLUG_CPU */ |