[linux-2.6-block.git] / arch / sh / kernel / irq.c

/*
 * 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 <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:
 */
static int show_other_interrupts(struct seq_file *p, int prec)
{
	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
	return 0;
}

int show_interrupts(struct seq_file *p, void *v)
{
	unsigned long flags, any_count = 0;
	int i = *(loff_t *)v, j, prec;
	struct irqaction *action;
	struct irq_desc *desc;

	if (i > nr_irqs)
		return 0;

	for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
		j *= 10;

	if (i == nr_irqs)
		return show_other_interrupts(p, prec);

	if (i == 0) {
		seq_printf(p, "%*s", prec + 8, "");
		for_each_online_cpu(j)
			seq_printf(p, "CPU%-8d", j);
		seq_putc(p, '\n');
	}

	desc = irq_to_desc(i);
	if (!desc)
		return 0;

	spin_lock_irqsave(&desc->lock, flags);
	for_each_online_cpu(j)
		any_count |= kstat_irqs_cpu(i, j);
	action = desc->action;
	if (!action && !any_count)
		goto out;

	seq_printf(p, "%*d: ", prec, i);
	for_each_online_cpu(j)
		seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
	seq_printf(p, " %14s", desc->chip->name);
	seq_printf(p, "-%-8s", desc->name);

	if (action) {
		seq_printf(p, "  %s", action->name);
		while ((action = action->next) != NULL)
			seq_printf(p, ", %s", action->name);
	}

	seq_putc(p, '\n');
out:
	spin_unlock_irqrestore(&desc->lock, flags);
	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;
#endif

asmlinkage int do_IRQ(unsigned int irq, struct pt_regs *regs)
{
	struct pt_regs *old_regs = set_irq_regs(regs);
#ifdef CONFIG_IRQSTACKS
	union irq_ctx *curctx, *irqctx;
#endif

	irq_enter();

#ifdef CONFIG_DEBUG_STACKOVERFLOW
	/* Debugging check for stack overflow: is there less than 1KB free? */
	{
		long sp;

		__asm__ __volatile__ ("and r15, %0" :
					"=r" (sp) : "0" (THREAD_SIZE - 1));

		if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
			printk("do_IRQ: stack overflow: %ld\n",
			       sp - sizeof(struct thread_info));
			dump_stack();
		}
	}
#endif

	irq = irq_demux(intc_evt2irq(irq));

#ifdef CONFIG_IRQSTACKS
	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
#endif
		generic_handle_irq(irq);

	irq_exit();

	set_irq_regs(old_regs);
	return 1;
}

#ifdef CONFIG_IRQSTACKS
static char softirq_stack[NR_CPUS * THREAD_SIZE]
		__attribute__((__section__(".bss.page_aligned")));

static char hardirq_stack[NR_CPUS * THREAD_SIZE]
		__attribute__((__section__(".bss.page_aligned")));

/*
 * 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"
		);

		/*
		 * Shouldnt happen, we returned above if in_interrupt():
		 */
		WARN_ON_ONCE(softirq_count());
	}

	local_irq_restore(flags);
}
#endif

void __init init_IRQ(void)
{
	plat_irq_setup();

	/* Perform the machine specific initialisation */
	if (sh_mv.mv_init_irq)
		sh_mv.mv_init_irq();

	irq_ctx_init(smp_processor_id());
}

#ifdef CONFIG_SPARSE_IRQ
int __init arch_probe_nr_irqs(void)
{
	nr_irqs = sh_mv.mv_nr_irqs;
	return 0;
}
#endif
Commit	Line	Data
a6a31139	1	/*
1da177e4 LT	2	* linux/arch/sh/kernel/irq.c
	3	*
	4	* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
	5	*
	6	*
	7	* SuperH version: Copyright (C) 1999 Niibe Yutaka
	8	*/
bf3a00f8	9	#include <linux/irq.h>
1da177e4	10	#include <linux/interrupt.h>
a6a31139	11	#include <linux/module.h>
bf3a00f8	12	#include <linux/kernel_stat.h>
1da177e4	13	#include <linux/seq_file.h>
bf3a00f8	14	#include <asm/processor.h>
be782df5	15	#include <asm/machvec.h>
a6a31139 PM	16	#include <asm/uaccess.h>
a6a31139 PM	17	#include <asm/thread_info.h>
f15cbe6f	18	#include <cpu/mmu_context.h>
1da177e4	19
35f3c518 PM	20	atomic_t irq_err_count;
35f3c518 PM	21
1da177e4 LT	22	/*
	23	* 'what should we do if we get a hw irq event on an illegal vector'.
	24	* each architecture has to answer this themselves, it doesn't deserve
	25	* a generic callback i think.
	26	*/
	27	void ack_bad_irq(unsigned int irq)
	28	{
baf4326e	29	atomic_inc(&irq_err_count);
1da177e4 LT	30	printk("unexpected IRQ trap at vector %02x\n", irq);
	31	}
	32
	33	#if defined(CONFIG_PROC_FS)
fa1d43ab PM	34	/*
	35	* /proc/interrupts printing:
	36	*/
	37	static int show_other_interrupts(struct seq_file *p, int prec)
	38	{
	39	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
	40	return 0;
	41	}
	42
1da177e4 LT	43	int show_interrupts(struct seq_file p, void v)
1da177e4 LT	44	{
fa1d43ab PM	45	unsigned long flags, any_count = 0;
	46	int i = (loff_t )v, j, prec;
	47	struct irqaction *action;
	48	struct irq_desc *desc;
	49
	50	if (i > nr_irqs)
	51	return 0;
	52
	53	for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
	54	j *= 10;
	55
	56	if (i == nr_irqs)
	57	return show_other_interrupts(p, prec);
1da177e4 LT	58
1da177e4 LT	59	if (i == 0) {
fa1d43ab	60	seq_printf(p, "%*s", prec + 8, "");
394e3902	61	for_each_online_cpu(j)
fa1d43ab	62	seq_printf(p, "CPU%-8d", j);
1da177e4 LT	63	seq_putc(p, '\n');
	64	}
	65
fa1d43ab PM	66	desc = irq_to_desc(i);
	67	if (!desc)
	68	return 0;
	69
	70	spin_lock_irqsave(&desc->lock, flags);
	71	for_each_online_cpu(j)
	72	any_count \|= kstat_irqs_cpu(i, j);
	73	action = desc->action;
	74	if (!action && !any_count)
	75	goto out;
1da177e4	76
fa1d43ab PM	77	seq_printf(p, "%*d: ", prec, i);
	78	for_each_online_cpu(j)
	79	seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
	80	seq_printf(p, " %14s", desc->chip->name);
	81	seq_printf(p, "-%-8s", desc->name);
	82
	83	if (action) {
	84	seq_printf(p, " %s", action->name);
	85	while ((action = action->next) != NULL)
1da177e4	86	seq_printf(p, ", %s", action->name);
fa1d43ab	87	}
35f3c518	88
fa1d43ab PM	89	seq_putc(p, '\n');
	90	out:
	91	spin_unlock_irqrestore(&desc->lock, flags);
1da177e4 LT	92	return 0;
	93	}
	94	#endif
	95
110ed282	96	#ifdef CONFIG_IRQSTACKS
a6a31139 PM	97	/*
	98	* per-CPU IRQ handling contexts (thread information and stack)
	99	*/
	100	union irq_ctx {
	101	struct thread_info tinfo;
	102	u32 stack[THREAD_SIZE/sizeof(u32)];
	103	};
	104
1dc41e58 PM	105	static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly;
1dc41e58 PM	106	static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
a6a31139 PM	107	#endif
a6a31139 PM	108
3afb209a	109	asmlinkage int do_IRQ(unsigned int irq, struct pt_regs *regs)
bf3a00f8	110	{
f0bc814c	111	struct pt_regs *old_regs = set_irq_regs(regs);
110ed282	112	#ifdef CONFIG_IRQSTACKS
a6a31139 PM	113	union irq_ctx curctx, irqctx;
a6a31139 PM	114	#endif
1da177e4 LT	115
1da177e4 LT	116	irq_enter();
bf3a00f8	117
d153ea88 PM	118	#ifdef CONFIG_DEBUG_STACKOVERFLOW
	119	/* Debugging check for stack overflow: is there less than 1KB free? */
	120	{
	121	long sp;
	122
	123	__asm__ __volatile__ ("and r15, %0" :
	124	"=r" (sp) : "0" (THREAD_SIZE - 1));
	125
	126	if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
	127	printk("do_IRQ: stack overflow: %ld\n",
	128	sp - sizeof(struct thread_info));
	129	dump_stack();
	130	}
	131	}
	132	#endif
	133
bdaa6e80	134	irq = irq_demux(intc_evt2irq(irq));
a6a31139	135
110ed282	136	#ifdef CONFIG_IRQSTACKS
a6a31139 PM	137	curctx = (union irq_ctx *)current_thread_info();
	138	irqctx = hardirq_ctx[smp_processor_id()];
	139
	140	/*
	141	* this is where we switch to the IRQ stack. However, if we are
	142	* already using the IRQ stack (because we interrupted a hardirq
	143	* handler) we can't do that and just have to keep using the
	144	* current stack (which is the irq stack already after all)
	145	*/
	146	if (curctx != irqctx) {
	147	u32 *isp;
	148
	149	isp = (u32 )((char )irqctx + sizeof(*irqctx));
	150	irqctx->tinfo.task = curctx->tinfo.task;
	151	irqctx->tinfo.previous_sp = current_stack_pointer;
	152
1dc41e58 PM	153	/*
	154	* Copy the softirq bits in preempt_count so that the
	155	* softirq checks work in the hardirq context.
	156	*/
	157	irqctx->tinfo.preempt_count =
	158	(irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) \|
	159	(curctx->tinfo.preempt_count & SOFTIRQ_MASK);
	160
a6a31139 PM	161	__asm__ __volatile__ (
a6a31139 PM	162	"mov %0, r4 \n"
1dc41e58	163	"mov r15, r8 \n"
baf4326e	164	"jsr @%1 \n"
a6a31139	165	/* swith to the irq stack */
baf4326e	166	" mov %2, r15 \n"
a6a31139	167	/* restore the stack (ring zero) */
1dc41e58	168	"mov r8, r15 \n"
a6a31139	169	: /* no outputs */
35f3c518	170	: "r" (irq), "r" (generic_handle_irq), "r" (isp)
a6a31139 PM	171	: "memory", "r0", "r1", "r2", "r3", "r4",
	172	"r5", "r6", "r7", "r8", "t", "pr"
	173	);
	174	} else
	175	#endif
35f3c518	176	generic_handle_irq(irq);
a6a31139	177
1da177e4	178	irq_exit();
a6a31139	179
35f3c518	180	set_irq_regs(old_regs);
1da177e4 LT	181	return 1;
1da177e4 LT	182	}
a6a31139	183
110ed282	184	#ifdef CONFIG_IRQSTACKS
a6a31139	185	static char softirq_stack[NR_CPUS * THREAD_SIZE]
bdf4fa53	186	__attribute__((__section__(".bss.page_aligned")));
a6a31139 PM	187
a6a31139 PM	188	static char hardirq_stack[NR_CPUS * THREAD_SIZE]
bdf4fa53	189	__attribute__((__section__(".bss.page_aligned")));
a6a31139 PM	190
	191	/*
	192	* allocate per-cpu stacks for hardirq and for softirq processing
	193	*/
	194	void irq_ctx_init(int cpu)
	195	{
	196	union irq_ctx *irqctx;
	197
	198	if (hardirq_ctx[cpu])
	199	return;
	200
	201	irqctx = (union irq_ctx )&hardirq_stack[cpu THREAD_SIZE];
	202	irqctx->tinfo.task = NULL;
	203	irqctx->tinfo.exec_domain = NULL;
	204	irqctx->tinfo.cpu = cpu;
	205	irqctx->tinfo.preempt_count = HARDIRQ_OFFSET;
	206	irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
	207
	208	hardirq_ctx[cpu] = irqctx;
	209
	210	irqctx = (union irq_ctx )&softirq_stack[cpu THREAD_SIZE];
	211	irqctx->tinfo.task = NULL;
	212	irqctx->tinfo.exec_domain = NULL;
	213	irqctx->tinfo.cpu = cpu;
1dc41e58	214	irqctx->tinfo.preempt_count = 0;
a6a31139 PM	215	irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
	216
	217	softirq_ctx[cpu] = irqctx;
	218
	219	printk("CPU %u irqstacks, hard=%p soft=%p\n",
	220	cpu, hardirq_ctx[cpu], softirq_ctx[cpu]);
	221	}
	222
	223	void irq_ctx_exit(int cpu)
	224	{
	225	hardirq_ctx[cpu] = NULL;
	226	}
	227
a6a31139 PM	228	asmlinkage void do_softirq(void)
	229	{
	230	unsigned long flags;
	231	struct thread_info *curctx;
	232	union irq_ctx *irqctx;
	233	u32 *isp;
	234
	235	if (in_interrupt())
	236	return;
	237
	238	local_irq_save(flags);
	239
	240	if (local_softirq_pending()) {
	241	curctx = current_thread_info();
	242	irqctx = softirq_ctx[smp_processor_id()];
	243	irqctx->tinfo.task = curctx->task;
	244	irqctx->tinfo.previous_sp = current_stack_pointer;
	245
	246	/* build the stack frame on the softirq stack */
	247	isp = (u32 )((char )irqctx + sizeof(*irqctx));
	248
	249	__asm__ __volatile__ (
	250	"mov r15, r9 \n"
	251	"jsr @%0 \n"
	252	/* switch to the softirq stack */
	253	" mov %1, r15 \n"
	254	/* restore the thread stack */
	255	"mov r9, r15 \n"
	256	: /* no outputs */
	257	: "r" (__do_softirq), "r" (isp)
a6a31139 PM	258	: "memory", "r0", "r1", "r2", "r3", "r4",
	259	"r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
	260	);
1dc41e58 PM	261
	262	/*
	263	* Shouldnt happen, we returned above if in_interrupt():
	264	*/
	265	WARN_ON_ONCE(softirq_count());
a6a31139 PM	266	}
	267
	268	local_irq_restore(flags);
	269	}
a6a31139	270	#endif
ea0f8fea JL	271
	272	void __init init_IRQ(void)
	273	{
90015c89	274	plat_irq_setup();
ea0f8fea JL	275
	276	/* Perform the machine specific initialisation */
	277	if (sh_mv.mv_init_irq)
	278	sh_mv.mv_init_irq();
	279
	280	irq_ctx_init(smp_processor_id());
	281	}
d8586ba6 PM	282
	283	#ifdef CONFIG_SPARSE_IRQ
	284	int __init arch_probe_nr_irqs(void)
	285	{
	286	nr_irqs = sh_mv.mv_nr_irqs;
	287	return 0;
	288	}
	289	#endif