[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 <linux/ftrace.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)
{
	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;
}

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;

	raw_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:
	raw_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 __irq_entry 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();
	irq = irq_demux(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] __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.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();

	/*
	 * Pin any of the legacy IRQ vectors that haven't already been
	 * grabbed by the platform
	 */
	reserve_irq_legacy();

	/* 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>
ba93483f	14	#include <linux/ftrace.h>
bf3a00f8	15	#include <asm/processor.h>
be782df5	16	#include <asm/machvec.h>
a6a31139 PM	17	#include <asm/uaccess.h>
a6a31139 PM	18	#include <asm/thread_info.h>
f15cbe6f	19	#include <cpu/mmu_context.h>
1da177e4	20
35f3c518 PM	21	atomic_t irq_err_count;
35f3c518 PM	22
1da177e4 LT	23	/*
	24	* 'what should we do if we get a hw irq event on an illegal vector'.
	25	* each architecture has to answer this themselves, it doesn't deserve
	26	* a generic callback i think.
	27	*/
	28	void ack_bad_irq(unsigned int irq)
	29	{
baf4326e	30	atomic_inc(&irq_err_count);
1da177e4 LT	31	printk("unexpected IRQ trap at vector %02x\n", irq);
	32	}
	33
	34	#if defined(CONFIG_PROC_FS)
fa1d43ab PM	35	/*
	36	* /proc/interrupts printing:
	37	*/
	38	static int show_other_interrupts(struct seq_file *p, int prec)
	39	{
731ba330 PM	40	int j;
	41
	42	seq_printf(p, "%*s: ", prec, "NMI");
	43	for_each_online_cpu(j)
	44	seq_printf(p, "%10u ", irq_stat[j].__nmi_count);
	45	seq_printf(p, " Non-maskable interrupts\n");
	46
fa1d43ab	47	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
731ba330	48
fa1d43ab PM	49	return 0;
	50	}
	51
1da177e4 LT	52	int show_interrupts(struct seq_file p, void v)
1da177e4 LT	53	{
fa1d43ab PM	54	unsigned long flags, any_count = 0;
	55	int i = (loff_t )v, j, prec;
	56	struct irqaction *action;
	57	struct irq_desc *desc;
	58
	59	if (i > nr_irqs)
	60	return 0;
	61
	62	for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
	63	j *= 10;
	64
	65	if (i == nr_irqs)
	66	return show_other_interrupts(p, prec);
1da177e4 LT	67
1da177e4 LT	68	if (i == 0) {
fa1d43ab	69	seq_printf(p, "%*s", prec + 8, "");
394e3902	70	for_each_online_cpu(j)
fa1d43ab	71	seq_printf(p, "CPU%-8d", j);
1da177e4 LT	72	seq_putc(p, '\n');
	73	}
	74
fa1d43ab PM	75	desc = irq_to_desc(i);
	76	if (!desc)
	77	return 0;
	78
239007b8	79	raw_spin_lock_irqsave(&desc->lock, flags);
fa1d43ab PM	80	for_each_online_cpu(j)
	81	any_count \|= kstat_irqs_cpu(i, j);
	82	action = desc->action;
	83	if (!action && !any_count)
	84	goto out;
1da177e4	85
fa1d43ab PM	86	seq_printf(p, "%*d: ", prec, i);
	87	for_each_online_cpu(j)
	88	seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
	89	seq_printf(p, " %14s", desc->chip->name);
	90	seq_printf(p, "-%-8s", desc->name);
	91
	92	if (action) {
	93	seq_printf(p, " %s", action->name);
	94	while ((action = action->next) != NULL)
1da177e4	95	seq_printf(p, ", %s", action->name);
fa1d43ab	96	}
35f3c518	97
fa1d43ab PM	98	seq_putc(p, '\n');
fa1d43ab PM	99	out:
239007b8	100	raw_spin_unlock_irqrestore(&desc->lock, flags);
1da177e4 LT	101	return 0;
	102	}
	103	#endif
	104
110ed282	105	#ifdef CONFIG_IRQSTACKS
a6a31139 PM	106	/*
	107	* per-CPU IRQ handling contexts (thread information and stack)
	108	*/
	109	union irq_ctx {
	110	struct thread_info tinfo;
	111	u32 stack[THREAD_SIZE/sizeof(u32)];
	112	};
	113
1dc41e58 PM	114	static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly;
1dc41e58 PM	115	static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
a6a31139 PM	116	#endif
a6a31139 PM	117
ba93483f	118	asmlinkage __irq_entry int do_IRQ(unsigned int irq, struct pt_regs *regs)
bf3a00f8	119	{
f0bc814c	120	struct pt_regs *old_regs = set_irq_regs(regs);
110ed282	121	#ifdef CONFIG_IRQSTACKS
a6a31139 PM	122	union irq_ctx curctx, irqctx;
a6a31139 PM	123	#endif
1da177e4 LT	124
1da177e4 LT	125	irq_enter();
1e1030dc	126	irq = irq_demux(irq);
a6a31139	127
110ed282	128	#ifdef CONFIG_IRQSTACKS
a6a31139 PM	129	curctx = (union irq_ctx *)current_thread_info();
	130	irqctx = hardirq_ctx[smp_processor_id()];
	131
	132	/*
	133	* this is where we switch to the IRQ stack. However, if we are
	134	* already using the IRQ stack (because we interrupted a hardirq
	135	* handler) we can't do that and just have to keep using the
	136	* current stack (which is the irq stack already after all)
	137	*/
	138	if (curctx != irqctx) {
	139	u32 *isp;
	140
	141	isp = (u32 )((char )irqctx + sizeof(*irqctx));
	142	irqctx->tinfo.task = curctx->tinfo.task;
	143	irqctx->tinfo.previous_sp = current_stack_pointer;
	144
1dc41e58 PM	145	/*
	146	* Copy the softirq bits in preempt_count so that the
	147	* softirq checks work in the hardirq context.
	148	*/
	149	irqctx->tinfo.preempt_count =
	150	(irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) \|
	151	(curctx->tinfo.preempt_count & SOFTIRQ_MASK);
	152
a6a31139 PM	153	__asm__ __volatile__ (
a6a31139 PM	154	"mov %0, r4 \n"
1dc41e58	155	"mov r15, r8 \n"
baf4326e	156	"jsr @%1 \n"
a6a31139	157	/* swith to the irq stack */
baf4326e	158	" mov %2, r15 \n"
a6a31139	159	/* restore the stack (ring zero) */
1dc41e58	160	"mov r8, r15 \n"
a6a31139	161	: /* no outputs */
35f3c518	162	: "r" (irq), "r" (generic_handle_irq), "r" (isp)
a6a31139 PM	163	: "memory", "r0", "r1", "r2", "r3", "r4",
	164	"r5", "r6", "r7", "r8", "t", "pr"
	165	);
	166	} else
	167	#endif
35f3c518	168	generic_handle_irq(irq);
a6a31139	169
1da177e4	170	irq_exit();
a6a31139	171
35f3c518	172	set_irq_regs(old_regs);
1da177e4 LT	173	return 1;
1da177e4 LT	174	}
a6a31139	175
110ed282	176	#ifdef CONFIG_IRQSTACKS
02b7da37	177	static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss;
a6a31139	178
02b7da37	179	static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss;
a6a31139 PM	180
	181	/*
	182	* allocate per-cpu stacks for hardirq and for softirq processing
	183	*/
	184	void irq_ctx_init(int cpu)
	185	{
	186	union irq_ctx *irqctx;
	187
	188	if (hardirq_ctx[cpu])
	189	return;
	190
	191	irqctx = (union irq_ctx )&hardirq_stack[cpu THREAD_SIZE];
	192	irqctx->tinfo.task = NULL;
	193	irqctx->tinfo.exec_domain = NULL;
	194	irqctx->tinfo.cpu = cpu;
	195	irqctx->tinfo.preempt_count = HARDIRQ_OFFSET;
	196	irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
	197
	198	hardirq_ctx[cpu] = irqctx;
	199
	200	irqctx = (union irq_ctx )&softirq_stack[cpu THREAD_SIZE];
	201	irqctx->tinfo.task = NULL;
	202	irqctx->tinfo.exec_domain = NULL;
	203	irqctx->tinfo.cpu = cpu;
1dc41e58	204	irqctx->tinfo.preempt_count = 0;
a6a31139 PM	205	irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
	206
	207	softirq_ctx[cpu] = irqctx;
	208
	209	printk("CPU %u irqstacks, hard=%p soft=%p\n",
	210	cpu, hardirq_ctx[cpu], softirq_ctx[cpu]);
	211	}
	212
	213	void irq_ctx_exit(int cpu)
	214	{
	215	hardirq_ctx[cpu] = NULL;
	216	}
	217
a6a31139 PM	218	asmlinkage void do_softirq(void)
	219	{
	220	unsigned long flags;
	221	struct thread_info *curctx;
	222	union irq_ctx *irqctx;
	223	u32 *isp;
	224
	225	if (in_interrupt())
	226	return;
	227
	228	local_irq_save(flags);
	229
	230	if (local_softirq_pending()) {
	231	curctx = current_thread_info();
	232	irqctx = softirq_ctx[smp_processor_id()];
	233	irqctx->tinfo.task = curctx->task;
	234	irqctx->tinfo.previous_sp = current_stack_pointer;
	235
	236	/* build the stack frame on the softirq stack */
	237	isp = (u32 )((char )irqctx + sizeof(*irqctx));
	238
	239	__asm__ __volatile__ (
	240	"mov r15, r9 \n"
	241	"jsr @%0 \n"
	242	/* switch to the softirq stack */
	243	" mov %1, r15 \n"
	244	/* restore the thread stack */
	245	"mov r9, r15 \n"
	246	: /* no outputs */
	247	: "r" (__do_softirq), "r" (isp)
a6a31139 PM	248	: "memory", "r0", "r1", "r2", "r3", "r4",
	249	"r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
	250	);
1dc41e58 PM	251
	252	/*
	253	* Shouldnt happen, we returned above if in_interrupt():
	254	*/
	255	WARN_ON_ONCE(softirq_count());
a6a31139 PM	256	}
	257
	258	local_irq_restore(flags);
	259	}
a6a31139	260	#endif
ea0f8fea JL	261
	262	void __init init_IRQ(void)
	263	{
90015c89	264	plat_irq_setup();
ea0f8fea	265
45b9deaf PM	266	/*
	267	* Pin any of the legacy IRQ vectors that haven't already been
	268	* grabbed by the platform
	269	*/
	270	reserve_irq_legacy();
	271
ea0f8fea JL	272	/* Perform the machine specific initialisation */
	273	if (sh_mv.mv_init_irq)
	274	sh_mv.mv_init_irq();
	275
	276	irq_ctx_init(smp_processor_id());
	277	}
d8586ba6 PM	278
	279	#ifdef CONFIG_SPARSE_IRQ
	280	int __init arch_probe_nr_irqs(void)
	281	{
	282	nr_irqs = sh_mv.mv_nr_irqs;
	283	return 0;
	284	}
	285	#endif