/* * Linux/Meta general interrupt handling code * */ #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_4KSTACKS 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 static struct irq_domain *root_domain; static unsigned int startup_meta_irq(struct irq_data *data) { tbi_startup_interrupt(data->hwirq); return 0; } static void shutdown_meta_irq(struct irq_data *data) { tbi_shutdown_interrupt(data->hwirq); } void do_IRQ(int irq, struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); #ifdef CONFIG_4KSTACKS struct irq_desc *desc; union irq_ctx *curctx, *irqctx; u32 *isp; #endif irq_enter(); irq = irq_linear_revmap(root_domain, irq); #ifdef CONFIG_DEBUG_STACKOVERFLOW /* Debugging check for stack overflow: is there less than 1KB free? */ { unsigned long sp; sp = __core_reg_get(A0StP); sp &= THREAD_SIZE - 1; if (unlikely(sp > (THREAD_SIZE - 1024))) pr_err("Stack overflow in do_IRQ: %ld\n", sp); } #endif #ifdef CONFIG_4KSTACKS 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) { /* build the stack frame on the IRQ stack */ isp = (u32 *) ((char *)irqctx + sizeof(struct thread_info)); irqctx->tinfo.task = curctx->tinfo.task; /* * 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); desc = irq_to_desc(irq); asm volatile ( "MOV D0.5,%0\n" "MOV D1Ar1,%1\n" "MOV D1RtP,%2\n" "MOV D0Ar2,%3\n" "SWAP A0StP,D0.5\n" "SWAP PC,D1RtP\n" "MOV A0StP,D0.5\n" : : "r" (isp), "r" (irq), "r" (desc->handle_irq), "r" (desc) : "memory", "cc", "D1Ar1", "D0Ar2", "D1Ar3", "D0Ar4", "D1Ar5", "D0Ar6", "D0Re0", "D1Re0", "D0.4", "D1RtP", "D0.5" ); } else #endif generic_handle_irq(irq); irq_exit(); set_irq_regs(old_regs); } #ifdef CONFIG_4KSTACKS static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; /* * 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; pr_info("CPU %u irqstacks, hard=%p soft=%p\n", cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); } void irq_ctx_exit(int cpu) { hardirq_ctx[smp_processor_id()] = NULL; } extern asmlinkage void __do_softirq(void); 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; /* build the stack frame on the softirq stack */ isp = (u32 *) ((char *)irqctx + sizeof(struct thread_info)); asm volatile ( "MOV D0.5,%0\n" "SWAP A0StP,D0.5\n" "CALLR D1RtP,___do_softirq\n" "MOV A0StP,D0.5\n" : : "r" (isp) : "memory", "cc", "D1Ar1", "D0Ar2", "D1Ar3", "D0Ar4", "D1Ar5", "D0Ar6", "D0Re0", "D1Re0", "D0.4", "D1RtP", "D0.5" ); } #endif static struct irq_chip meta_irq_type = { .name = "META-IRQ", .irq_startup = startup_meta_irq, .irq_shutdown = shutdown_meta_irq, }; /** * tbisig_map() - Map a TBI signal number to a virtual IRQ number. * @hw: Number of the TBI signal. Must be in range. * * Returns: The virtual IRQ number of the TBI signal number IRQ specified by * @hw. */ int tbisig_map(unsigned int hw) { return irq_create_mapping(root_domain, hw); } /** * metag_tbisig_map() - map a tbi signal to a Linux virtual IRQ number * @d: root irq domain * @irq: virtual irq number * @hw: hardware irq number (TBI signal number) * * This sets up a virtual irq for a specified TBI signal number. */ static int metag_tbisig_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) { #ifdef CONFIG_SMP irq_set_chip_and_handler(irq, &meta_irq_type, handle_percpu_irq); #else irq_set_chip_and_handler(irq, &meta_irq_type, handle_simple_irq); #endif return 0; } static const struct irq_domain_ops metag_tbisig_domain_ops = { .map = metag_tbisig_map, }; /* * void init_IRQ(void) * * Parameters: None * * Returns: Nothing * * This function should be called during kernel startup to initialize * the IRQ handling routines. */ void __init init_IRQ(void) { root_domain = irq_domain_add_linear(NULL, 32, &metag_tbisig_domain_ops, NULL); if (unlikely(!root_domain)) panic("init_IRQ: cannot add root IRQ domain"); irq_ctx_init(smp_processor_id()); init_internal_IRQ(); init_external_IRQ(); if (machine_desc->init_irq) machine_desc->init_irq(); } int __init arch_probe_nr_irqs(void) { if (machine_desc->nr_irqs) nr_irqs = machine_desc->nr_irqs; return 0; } #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); struct cpumask *mask; unsigned int newcpu; if (irqd_is_per_cpu(data)) continue; mask = irq_data_get_affinity_mask(data); if (!cpumask_test_cpu(cpu, mask)) continue; newcpu = cpumask_any_and(mask, cpu_online_mask); if (newcpu >= nr_cpu_ids) { pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n", i, cpu); cpumask_setall(mask); } irq_set_affinity(i, mask); } } #endif /* CONFIG_HOTPLUG_CPU */