arch/sh/kernel/irq.c - maze/linux - Git at Google

 /*
  * 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.exec_domain	= 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.exec_domain	= 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;
 }

 asmlinkage void do_softirq(void)
 {
 	unsigned long flags;
 	struct thread_info *curctx;
 	union irq_ctx *irqctx;
 	u32 *isp;

 	if (in_interrupt())
 		return;

 	local_irq_save(flags);

 	if (local_softirq_pending()) {
 		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"
 		);

 		/*
 		 * Shouldn't happen, we returned above if in_interrupt():
 		 */
 		WARN_ON_ONCE(softirq_count());
 	}

 	local_irq_restore(flags);
 }
 #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
 static void route_irq(struct irq_data *data, unsigned int irq, unsigned int cpu)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	struct irq_chip *chip = irq_data_get_irq_chip(data);

 	printk(KERN_INFO "IRQ%u: moving from cpu%u to cpu%u\n",
 	       irq, data->node, cpu);

 	raw_spin_lock_irq(&desc->lock);
 	chip->irq_set_affinity(data, cpumask_of(cpu), false);
 	raw_spin_unlock_irq(&desc->lock);
 }

 /*
  * 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);
 				newcpu = cpumask_any_and(data->affinity,
 							 cpu_online_mask);
 			}

 			route_irq(data, irq, newcpu);
 		}
 	}
 }
 #endif
	/*
	* 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.exec_domain = 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.exec_domain = 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;
	}

	asmlinkage void do_softirq(void)
	{
	unsigned long flags;
	struct thread_info *curctx;
	union irq_ctx *irqctx;
	u32 *isp;

	if (in_interrupt())
	return;

	local_irq_save(flags);

	if (local_softirq_pending()) {
	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"
	);

	/*
	* Shouldn't happen, we returned above if in_interrupt():
	*/
	WARN_ON_ONCE(softirq_count());
	}

	local_irq_restore(flags);
	}
	#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
	static void route_irq(struct irq_data *data, unsigned int irq, unsigned int cpu)
	{
	struct irq_desc *desc = irq_to_desc(irq);
	struct irq_chip *chip = irq_data_get_irq_chip(data);

	printk(KERN_INFO "IRQ%u: moving from cpu%u to cpu%u\n",
	irq, data->node, cpu);

	raw_spin_lock_irq(&desc->lock);
	chip->irq_set_affinity(data, cpumask_of(cpu), false);
	raw_spin_unlock_irq(&desc->lock);
	}

	/*
	* 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);
	newcpu = cpumask_any_and(data->affinity,
	cpu_online_mask);
	}

	route_irq(data, irq, newcpu);
	}
	}
	}
	#endif