[mirror_ubuntu-artful-kernel.git] / arch / s390 / kernel / irq.c

/*
 *    Copyright IBM Corp. 2004, 2011
 *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
 *		 Holger Smolinski <Holger.Smolinski@de.ibm.com>,
 *		 Thomas Spatzier <tspat@de.ibm.com>,
 *
 * This file contains interrupt related functions.
 */

#include <linux/kernel_stat.h>
#include <linux/interrupt.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#include <linux/profile.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/ftrace.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/cpu.h>
#include <asm/irq_regs.h>
#include <asm/cputime.h>
#include <asm/lowcore.h>
#include <asm/irq.h>
#include "entry.h"

struct irq_class {
	char *name;
	char *desc;
};

static const struct irq_class intrclass_names[] = {
	{.name = "EXT" },
	{.name = "I/O" },
	{.name = "CLK", .desc = "[EXT] Clock Comparator" },
	{.name = "EXC", .desc = "[EXT] External Call" },
	{.name = "EMS", .desc = "[EXT] Emergency Signal" },
	{.name = "TMR", .desc = "[EXT] CPU Timer" },
	{.name = "TAL", .desc = "[EXT] Timing Alert" },
	{.name = "PFL", .desc = "[EXT] Pseudo Page Fault" },
	{.name = "DSD", .desc = "[EXT] DASD Diag" },
	{.name = "VRT", .desc = "[EXT] Virtio" },
	{.name = "SCP", .desc = "[EXT] Service Call" },
	{.name = "IUC", .desc = "[EXT] IUCV" },
	{.name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling" },
	{.name = "CMC", .desc = "[EXT] CPU-Measurement: Counter" },
	{.name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt" },
	{.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt" },
	{.name = "DAS", .desc = "[I/O] DASD" },
	{.name = "C15", .desc = "[I/O] 3215" },
	{.name = "C70", .desc = "[I/O] 3270" },
	{.name = "TAP", .desc = "[I/O] Tape" },
	{.name = "VMR", .desc = "[I/O] Unit Record Devices" },
	{.name = "LCS", .desc = "[I/O] LCS" },
	{.name = "CLW", .desc = "[I/O] CLAW" },
	{.name = "CTC", .desc = "[I/O] CTC" },
	{.name = "APB", .desc = "[I/O] AP Bus" },
	{.name = "CSC", .desc = "[I/O] CHSC Subchannel" },
	{.name = "NMI", .desc = "[NMI] Machine Check" },
};

/*
 * show_interrupts is needed by /proc/interrupts.
 */
int show_interrupts(struct seq_file *p, void *v)
{
	int i = *(loff_t *) v, j;

	get_online_cpus();
	if (i == 0) {
		seq_puts(p, "           ");
		for_each_online_cpu(j)
			seq_printf(p, "CPU%d       ",j);
		seq_putc(p, '\n');
	}

	if (i < NR_IRQS) {
		seq_printf(p, "%s: ", intrclass_names[i].name);
#ifndef CONFIG_SMP
		seq_printf(p, "%10u ", kstat_irqs(i));
#else
		for_each_online_cpu(j)
			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
#endif
		if (intrclass_names[i].desc)
			seq_printf(p, "  %s", intrclass_names[i].desc);
                seq_putc(p, '\n');
        }
	put_online_cpus();
        return 0;
}

/*
 * Switch to the asynchronous interrupt stack for softirq execution.
 */
asmlinkage void do_softirq(void)
{
	unsigned long flags, old, new;

	if (in_interrupt())
		return;

	local_irq_save(flags);

	if (local_softirq_pending()) {
		/* Get current stack pointer. */
		asm volatile("la %0,0(15)" : "=a" (old));
		/* Check against async. stack address range. */
		new = S390_lowcore.async_stack;
		if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
			/* Need to switch to the async. stack. */
			new -= STACK_FRAME_OVERHEAD;
			((struct stack_frame *) new)->back_chain = old;

			asm volatile("   la    15,0(%0)\n"
				     "   basr  14,%2\n"
				     "   la    15,0(%1)\n"
				     : : "a" (new), "a" (old),
				         "a" (__do_softirq)
				     : "0", "1", "2", "3", "4", "5", "14",
				       "cc", "memory" );
		} else {
			/* We are already on the async stack. */
			__do_softirq();
		}
	}

	local_irq_restore(flags);
}

#ifdef CONFIG_PROC_FS
void init_irq_proc(void)
{
	struct proc_dir_entry *root_irq_dir;

	root_irq_dir = proc_mkdir("irq", NULL);
	create_prof_cpu_mask(root_irq_dir);
}
#endif

/*
 * ext_int_hash[index] is the list head for all external interrupts that hash
 * to this index.
 */
static struct list_head ext_int_hash[256];

struct ext_int_info {
	ext_int_handler_t handler;
	u16 code;
	struct list_head entry;
	struct rcu_head rcu;
};

/* ext_int_hash_lock protects the handler lists for external interrupts */
DEFINE_SPINLOCK(ext_int_hash_lock);

static void __init init_external_interrupts(void)
{
	int idx;

	for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
		INIT_LIST_HEAD(&ext_int_hash[idx]);
}

static inline int ext_hash(u16 code)
{
	return (code + (code >> 9)) & 0xff;
}

int register_external_interrupt(u16 code, ext_int_handler_t handler)
{
	struct ext_int_info *p;
	unsigned long flags;
	int index;

	p = kmalloc(sizeof(*p), GFP_ATOMIC);
	if (!p)
		return -ENOMEM;
	p->code = code;
	p->handler = handler;
	index = ext_hash(code);

	spin_lock_irqsave(&ext_int_hash_lock, flags);
	list_add_rcu(&p->entry, &ext_int_hash[index]);
	spin_unlock_irqrestore(&ext_int_hash_lock, flags);
	return 0;
}
EXPORT_SYMBOL(register_external_interrupt);

int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
{
	struct ext_int_info *p;
	unsigned long flags;
	int index = ext_hash(code);

	spin_lock_irqsave(&ext_int_hash_lock, flags);
	list_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
		if (p->code == code && p->handler == handler) {
			list_del_rcu(&p->entry);
			kfree_rcu(p, rcu);
		}
	}
	spin_unlock_irqrestore(&ext_int_hash_lock, flags);
	return 0;
}
EXPORT_SYMBOL(unregister_external_interrupt);

void __irq_entry do_extint(struct pt_regs *regs, struct ext_code ext_code,
			   unsigned int param32, unsigned long param64)
{
	struct pt_regs *old_regs;
	struct ext_int_info *p;
	int index;

	old_regs = set_irq_regs(regs);
	irq_enter();
	if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator) {
		/* Serve timer interrupts first. */
		clock_comparator_work();
	}
	kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
	if (ext_code.code != 0x1004)
		__get_cpu_var(s390_idle).nohz_delay = 1;

	index = ext_hash(ext_code.code);
	rcu_read_lock();
	list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
		if (likely(p->code == ext_code.code))
			p->handler(ext_code, param32, param64);
	rcu_read_unlock();
	irq_exit();
	set_irq_regs(old_regs);
}

void __init init_IRQ(void)
{
	init_external_interrupts();
}

static DEFINE_SPINLOCK(sc_irq_lock);
static int sc_irq_refcount;

void service_subclass_irq_register(void)
{
	spin_lock(&sc_irq_lock);
	if (!sc_irq_refcount)
		ctl_set_bit(0, 9);
	sc_irq_refcount++;
	spin_unlock(&sc_irq_lock);
}
EXPORT_SYMBOL(service_subclass_irq_register);

void service_subclass_irq_unregister(void)
{
	spin_lock(&sc_irq_lock);
	sc_irq_refcount--;
	if (!sc_irq_refcount)
		ctl_clear_bit(0, 9);
	spin_unlock(&sc_irq_lock);
}
EXPORT_SYMBOL(service_subclass_irq_unregister);

static DEFINE_SPINLOCK(ma_subclass_lock);
static int ma_subclass_refcount;

void measurement_alert_subclass_register(void)
{
	spin_lock(&ma_subclass_lock);
	if (!ma_subclass_refcount)
		ctl_set_bit(0, 5);
	ma_subclass_refcount++;
	spin_unlock(&ma_subclass_lock);
}
EXPORT_SYMBOL(measurement_alert_subclass_register);

void measurement_alert_subclass_unregister(void)
{
	spin_lock(&ma_subclass_lock);
	ma_subclass_refcount--;
	if (!ma_subclass_refcount)
		ctl_clear_bit(0, 5);
	spin_unlock(&ma_subclass_lock);
}
EXPORT_SYMBOL(measurement_alert_subclass_unregister);
Commit	Line	Data
1da177e4	1	/*
a53c8fab	2	* Copyright IBM Corp. 2004, 2011
d7b250e2 HC	3	* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
	4	* Holger Smolinski <Holger.Smolinski@de.ibm.com>,
	5	* Thomas Spatzier <tspat@de.ibm.com>,
1da177e4 LT	6	*
	7	* This file contains interrupt related functions.
	8	*/
	9
1da177e4 LT	10	#include <linux/kernel_stat.h>
	11	#include <linux/interrupt.h>
	12	#include <linux/seq_file.h>
55dff522 HC	13	#include <linux/proc_fs.h>
55dff522 HC	14	#include <linux/profile.h>
d7b250e2 HC	15	#include <linux/module.h>
	16	#include <linux/kernel.h>
	17	#include <linux/ftrace.h>
	18	#include <linux/errno.h>
	19	#include <linux/slab.h>
	20	#include <linux/cpu.h>
	21	#include <asm/irq_regs.h>
	22	#include <asm/cputime.h>
	23	#include <asm/lowcore.h>
	24	#include <asm/irq.h>
	25	#include "entry.h"
1da177e4	26
052ff461 HC	27	struct irq_class {
	28	char *name;
	29	char *desc;
	30	};
	31
	32	static const struct irq_class intrclass_names[] = {
	33	{.name = "EXT" },
	34	{.name = "I/O" },
	35	{.name = "CLK", .desc = "[EXT] Clock Comparator" },
2a3a2d66 HC	36	{.name = "EXC", .desc = "[EXT] External Call" },
2a3a2d66 HC	37	{.name = "EMS", .desc = "[EXT] Emergency Signal" },
052ff461 HC	38	{.name = "TMR", .desc = "[EXT] CPU Timer" },
	39	{.name = "TAL", .desc = "[EXT] Timing Alert" },
	40	{.name = "PFL", .desc = "[EXT] Pseudo Page Fault" },
	41	{.name = "DSD", .desc = "[EXT] DASD Diag" },
	42	{.name = "VRT", .desc = "[EXT] Virtio" },
	43	{.name = "SCP", .desc = "[EXT] Service Call" },
	44	{.name = "IUC", .desc = "[EXT] IUCV" },
02456169 HB	45	{.name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling" },
02456169 HB	46	{.name = "CMC", .desc = "[EXT] CPU-Measurement: Counter" },
de400d6b	47	{.name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt" },
30d77c3e	48	{.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt" },
3283942b	49	{.name = "DAS", .desc = "[I/O] DASD" },
12fae585	50	{.name = "C15", .desc = "[I/O] 3215" },
3fe22f6b	51	{.name = "C70", .desc = "[I/O] 3270" },
b8665172	52	{.name = "TAP", .desc = "[I/O] Tape" },
f48198d5	53	{.name = "VMR", .desc = "[I/O] Unit Record Devices" },
096a6168	54	{.name = "LCS", .desc = "[I/O] LCS" },
355eb402	55	{.name = "CLW", .desc = "[I/O] CLAW" },
85b81cdd	56	{.name = "CTC", .desc = "[I/O] CTC" },
62d146ff	57	{.name = "APB", .desc = "[I/O] AP Bus" },
65b4e403	58	{.name = "CSC", .desc = "[I/O] CHSC Subchannel" },
052ff461 HC	59	{.name = "NMI", .desc = "[NMI] Machine Check" },
	60	};
	61
1da177e4 LT	62	/*
	63	* show_interrupts is needed by /proc/interrupts.
	64	*/
	65	int show_interrupts(struct seq_file p, void v)
	66	{
1da177e4 LT	67	int i = (loff_t ) v, j;
1da177e4 LT	68
8dd79cb1	69	get_online_cpus();
1da177e4 LT	70	if (i == 0) {
	71	seq_puts(p, " ");
	72	for_each_online_cpu(j)
	73	seq_printf(p, "CPU%d ",j);
	74	seq_putc(p, '\n');
	75	}
	76
	77	if (i < NR_IRQS) {
052ff461	78	seq_printf(p, "%s: ", intrclass_names[i].name);
1da177e4 LT	79	#ifndef CONFIG_SMP
	80	seq_printf(p, "%10u ", kstat_irqs(i));
	81	#else
	82	for_each_online_cpu(j)
	83	seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
	84	#endif
052ff461 HC	85	if (intrclass_names[i].desc)
052ff461 HC	86	seq_printf(p, " %s", intrclass_names[i].desc);
1da177e4	87	seq_putc(p, '\n');
1da177e4	88	}
8dd79cb1	89	put_online_cpus();
1da177e4 LT	90	return 0;
	91	}
	92
1da177e4 LT	93	/*
	94	* Switch to the asynchronous interrupt stack for softirq execution.
	95	*/
1da177e4 LT	96	asmlinkage void do_softirq(void)
	97	{
	98	unsigned long flags, old, new;
	99
	100	if (in_interrupt())
	101	return;
	102
	103	local_irq_save(flags);
	104
1da177e4 LT	105	if (local_softirq_pending()) {
	106	/* Get current stack pointer. */
	107	asm volatile("la %0,0(15)" : "=a" (old));
	108	/* Check against async. stack address range. */
	109	new = S390_lowcore.async_stack;
	110	if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
	111	/* Need to switch to the async. stack. */
	112	new -= STACK_FRAME_OVERHEAD;
	113	((struct stack_frame *) new)->back_chain = old;
	114
	115	asm volatile(" la 15,0(%0)\n"
	116	" basr 14,%2\n"
	117	" la 15,0(%1)\n"
	118	: : "a" (new), "a" (old),
	119	"a" (__do_softirq)
	120	: "0", "1", "2", "3", "4", "5", "14",
	121	"cc", "memory" );
7968ca81	122	} else {
1da177e4 LT	123	/* We are already on the async stack. */
1da177e4 LT	124	__do_softirq();
7968ca81	125	}
1da177e4 LT	126	}
1da177e4 LT	127
1da177e4 LT	128	local_irq_restore(flags);
1da177e4 LT	129	}
55dff522	130
0addff81	131	#ifdef CONFIG_PROC_FS
55dff522 HC	132	void init_irq_proc(void)
	133	{
	134	struct proc_dir_entry *root_irq_dir;
	135
	136	root_irq_dir = proc_mkdir("irq", NULL);
	137	create_prof_cpu_mask(root_irq_dir);
	138	}
0addff81	139	#endif
d7b250e2 HC	140
d7b250e2 HC	141	/*
89c9b66b JG	142	* ext_int_hash[index] is the list head for all external interrupts that hash
89c9b66b JG	143	* to this index.
d7b250e2	144	*/
89c9b66b	145	static struct list_head ext_int_hash[256];
d7b250e2 HC	146
d7b250e2 HC	147	struct ext_int_info {
d7b250e2 HC	148	ext_int_handler_t handler;
d7b250e2 HC	149	u16 code;
89c9b66b JG	150	struct list_head entry;
89c9b66b JG	151	struct rcu_head rcu;
d7b250e2 HC	152	};
d7b250e2 HC	153
89c9b66b JG	154	/* ext_int_hash_lock protects the handler lists for external interrupts */
	155	DEFINE_SPINLOCK(ext_int_hash_lock);
	156
	157	static void __init init_external_interrupts(void)
	158	{
	159	int idx;
	160
	161	for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
	162	INIT_LIST_HEAD(&ext_int_hash[idx]);
	163	}
d7b250e2 HC	164
	165	static inline int ext_hash(u16 code)
	166	{
	167	return (code + (code >> 9)) & 0xff;
	168	}
	169
	170	int register_external_interrupt(u16 code, ext_int_handler_t handler)
	171	{
	172	struct ext_int_info *p;
89c9b66b	173	unsigned long flags;
d7b250e2 HC	174	int index;
	175
	176	p = kmalloc(sizeof(*p), GFP_ATOMIC);
	177	if (!p)
	178	return -ENOMEM;
	179	p->code = code;
	180	p->handler = handler;
	181	index = ext_hash(code);
89c9b66b JG	182
	183	spin_lock_irqsave(&ext_int_hash_lock, flags);
	184	list_add_rcu(&p->entry, &ext_int_hash[index]);
	185	spin_unlock_irqrestore(&ext_int_hash_lock, flags);
d7b250e2 HC	186	return 0;
	187	}
	188	EXPORT_SYMBOL(register_external_interrupt);
	189
	190	int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
	191	{
89c9b66b JG	192	struct ext_int_info *p;
	193	unsigned long flags;
	194	int index = ext_hash(code);
d7b250e2	195
89c9b66b	196	spin_lock_irqsave(&ext_int_hash_lock, flags);
7968ca81	197	list_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
89c9b66b JG	198	if (p->code == code && p->handler == handler) {
89c9b66b JG	199	list_del_rcu(&p->entry);
bc399d6e	200	kfree_rcu(p, rcu);
89c9b66b	201	}
7968ca81	202	}
89c9b66b	203	spin_unlock_irqrestore(&ext_int_hash_lock, flags);
d7b250e2 HC	204	return 0;
	205	}
	206	EXPORT_SYMBOL(unregister_external_interrupt);
	207
fde15c3a	208	void __irq_entry do_extint(struct pt_regs *regs, struct ext_code ext_code,
d7b250e2 HC	209	unsigned int param32, unsigned long param64)
	210	{
	211	struct pt_regs *old_regs;
d7b250e2 HC	212	struct ext_int_info *p;
	213	int index;
	214
d7b250e2	215	old_regs = set_irq_regs(regs);
d7b250e2	216	irq_enter();
7968ca81	217	if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator) {
d7b250e2 HC	218	/* Serve timer interrupts first. */
d7b250e2 HC	219	clock_comparator_work();
7968ca81	220	}
d7b250e2	221	kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
fde15c3a	222	if (ext_code.code != 0x1004)
d7b250e2	223	__get_cpu_var(s390_idle).nohz_delay = 1;
89c9b66b	224
fde15c3a	225	index = ext_hash(ext_code.code);
89c9b66b JG	226	rcu_read_lock();
89c9b66b JG	227	list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
fde15c3a HC	228	if (likely(p->code == ext_code.code))
fde15c3a HC	229	p->handler(ext_code, param32, param64);
89c9b66b	230	rcu_read_unlock();
d7b250e2 HC	231	irq_exit();
	232	set_irq_regs(old_regs);
	233	}
	234
89c9b66b JG	235	void __init init_IRQ(void)
	236	{
	237	init_external_interrupts();
	238	}
	239
d7b250e2 HC	240	static DEFINE_SPINLOCK(sc_irq_lock);
	241	static int sc_irq_refcount;
	242
	243	void service_subclass_irq_register(void)
	244	{
	245	spin_lock(&sc_irq_lock);
	246	if (!sc_irq_refcount)
	247	ctl_set_bit(0, 9);
	248	sc_irq_refcount++;
	249	spin_unlock(&sc_irq_lock);
	250	}
	251	EXPORT_SYMBOL(service_subclass_irq_register);
	252
	253	void service_subclass_irq_unregister(void)
	254	{
	255	spin_lock(&sc_irq_lock);
	256	sc_irq_refcount--;
	257	if (!sc_irq_refcount)
	258	ctl_clear_bit(0, 9);
	259	spin_unlock(&sc_irq_lock);
	260	}
	261	EXPORT_SYMBOL(service_subclass_irq_unregister);
b03d541a JG	262
	263	static DEFINE_SPINLOCK(ma_subclass_lock);
	264	static int ma_subclass_refcount;
	265
	266	void measurement_alert_subclass_register(void)
	267	{
	268	spin_lock(&ma_subclass_lock);
	269	if (!ma_subclass_refcount)
	270	ctl_set_bit(0, 5);
	271	ma_subclass_refcount++;
	272	spin_unlock(&ma_subclass_lock);
	273	}
	274	EXPORT_SYMBOL(measurement_alert_subclass_register);
	275
	276	void measurement_alert_subclass_unregister(void)
	277	{
	278	spin_lock(&ma_subclass_lock);
	279	ma_subclass_refcount--;
	280	if (!ma_subclass_refcount)
	281	ctl_clear_bit(0, 5);
	282	spin_unlock(&ma_subclass_lock);
	283	}
	284	EXPORT_SYMBOL(measurement_alert_subclass_unregister);