1 files changed, 249 insertions, 0 deletions
diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
new file mode 100644
index 000000000..4e6835de5
--- /dev/null
+++ b/arch/sh/kernel/irq.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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 <linux/uaccess.h>
+#include <asm/thread_info.h>
+#include <cpu/mmu_context.h>
+#include <asm/softirq_stack.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 ", per_cpu(irq_stat.__nmi_count, j));
+	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"
+			/* switch 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;
+}
+
+#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
+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"
+	);
+}
+#endif
+#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 (irq_data_get_node(data) == cpu) {
+			const struct cpumask *mask = irq_data_get_affinity_mask(data);
+			unsigned int 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",
+						    irq, cpu);
+
+				irq_set_affinity(irq, cpu_all_mask);
+			} else {
+				irq_set_affinity(irq, mask);
+			}
+		}
+	}
+}
+#endif