// SPDX-License-Identifier: GPL-2.0
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/*
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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/ftrace.h>
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#include <linux/delay.h>
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#include <linux/ratelimit.h>
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#include <asm/processor.h>
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#include <asm/machvec.h>
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#include <linux/uaccess.h>
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#include <asm/thread_info.h>
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#include <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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/*
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* /proc/interrupts printing for arch specific interrupts
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*/
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int arch_show_interrupts(struct seq_file *p, int prec)
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{
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int j;
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seq_printf(p, "%*s: ", prec, "NMI");
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", nmi_count(j));
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seq_printf(p, " Non-maskable interrupts\n");
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seq_printf(p, "%*s: %10u\n", prec, "ERR", 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_IRQSTACKS
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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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static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss;
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static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss;
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static inline void handle_one_irq(unsigned int irq)
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{
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union irq_ctx *curctx, *irqctx;
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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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/* switch 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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generic_handle_irq(irq);
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}
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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.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.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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void do_softirq_own_stack(void)
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{
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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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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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#else
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static inline void handle_one_irq(unsigned int irq)
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{
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generic_handle_irq(irq);
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}
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#endif
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asmlinkage __irq_entry 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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irq_enter();
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irq = irq_demux(irq_lookup(irq));
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if (irq != NO_IRQ_IGNORE) {
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handle_one_irq(irq);
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irq_finish(irq);
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}
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irq_exit();
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set_irq_regs(old_regs);
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return IRQ_HANDLED;
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}
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void __init init_IRQ(void)
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{
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plat_irq_setup();
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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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intc_finalize();
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irq_ctx_init(smp_processor_id());
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}
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#ifdef CONFIG_HOTPLUG_CPU
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/*
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* The CPU has been marked offline. Migrate IRQs off this CPU. If
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* the affinity settings do not allow other CPUs, force them onto any
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* available CPU.
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*/
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void migrate_irqs(void)
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{
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unsigned int irq, cpu = smp_processor_id();
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for_each_active_irq(irq) {
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struct irq_data *data = irq_get_irq_data(irq);
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if (irq_data_get_node(data) == cpu) {
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struct cpumask *mask = irq_data_get_affinity_mask(data);
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unsigned int newcpu = cpumask_any_and(mask,
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cpu_online_mask);
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if (newcpu >= nr_cpu_ids) {
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pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n",
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irq, cpu);
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cpumask_setall(mask);
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}
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irq_set_affinity(irq, mask);
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}
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}
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}
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#endif
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