aboutsummaryrefslogtreecommitdiffstats
path: root/arch/s390/kernel/irq.c
blob: 3514420f0259930f74d8b75fd624d49e5eedda43 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
// SPDX-License-Identifier: GPL-2.0
/*
 *    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/export.h>
#include <linux/kernel.h>
#include <linux/ftrace.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/irq.h>
#include <asm/irq_regs.h>
#include <asm/cputime.h>
#include <asm/lowcore.h>
#include <asm/irq.h>
#include <asm/hw_irq.h>
#include <asm/stacktrace.h>
#include "entry.h"

DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat);
EXPORT_PER_CPU_SYMBOL_GPL(irq_stat);

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

/*
 * The list of "main" irq classes on s390. This is the list of interrupts
 * that appear both in /proc/stat ("intr" line) and /proc/interrupts.
 * Historically only external and I/O interrupts have been part of /proc/stat.
 * We can't add the split external and I/O sub classes since the first field
 * in the "intr" line in /proc/stat is supposed to be the sum of all other
 * fields.
 * Since the external and I/O interrupt fields are already sums we would end
 * up with having a sum which accounts each interrupt twice.
 */
static const struct irq_class irqclass_main_desc[NR_IRQS_BASE] = {
	{.irq = EXT_INTERRUPT,	.name = "EXT"},
	{.irq = IO_INTERRUPT,	.name = "I/O"},
	{.irq = THIN_INTERRUPT, .name = "AIO"},
};

/*
 * The list of split external and I/O interrupts that appear only in
 * /proc/interrupts.
 * In addition this list contains non external / I/O events like NMIs.
 */
static const struct irq_class irqclass_sub_desc[] = {
	{.irq = IRQEXT_CLK, .name = "CLK", .desc = "[EXT] Clock Comparator"},
	{.irq = IRQEXT_EXC, .name = "EXC", .desc = "[EXT] External Call"},
	{.irq = IRQEXT_EMS, .name = "EMS", .desc = "[EXT] Emergency Signal"},
	{.irq = IRQEXT_TMR, .name = "TMR", .desc = "[EXT] CPU Timer"},
	{.irq = IRQEXT_TLA, .name = "TAL", .desc = "[EXT] Timing Alert"},
	{.irq = IRQEXT_PFL, .name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
	{.irq = IRQEXT_DSD, .name = "DSD", .desc = "[EXT] DASD Diag"},
	{.irq = IRQEXT_VRT, .name = "VRT", .desc = "[EXT] Virtio"},
	{.irq = IRQEXT_SCP, .name = "SCP", .desc = "[EXT] Service Call"},
	{.irq = IRQEXT_IUC, .name = "IUC", .desc = "[EXT] IUCV"},
	{.irq = IRQEXT_CMS, .name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
	{.irq = IRQEXT_CMC, .name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
	{.irq = IRQEXT_FTP, .name = "FTP", .desc = "[EXT] HMC FTP Service"},
	{.irq = IRQIO_CIO,  .name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
	{.irq = IRQIO_DAS,  .name = "DAS", .desc = "[I/O] DASD"},
	{.irq = IRQIO_C15,  .name = "C15", .desc = "[I/O] 3215"},
	{.irq = IRQIO_C70,  .name = "C70", .desc = "[I/O] 3270"},
	{.irq = IRQIO_TAP,  .name = "TAP", .desc = "[I/O] Tape"},
	{.irq = IRQIO_VMR,  .name = "VMR", .desc = "[I/O] Unit Record Devices"},
	{.irq = IRQIO_LCS,  .name = "LCS", .desc = "[I/O] LCS"},
	{.irq = IRQIO_CTC,  .name = "CTC", .desc = "[I/O] CTC"},
	{.irq = IRQIO_ADM,  .name = "ADM", .desc = "[I/O] EADM Subchannel"},
	{.irq = IRQIO_CSC,  .name = "CSC", .desc = "[I/O] CHSC Subchannel"},
	{.irq = IRQIO_VIR,  .name = "VIR", .desc = "[I/O] Virtual I/O Devices"},
	{.irq = IRQIO_QAI,  .name = "QAI", .desc = "[AIO] QDIO Adapter Interrupt"},
	{.irq = IRQIO_APB,  .name = "APB", .desc = "[AIO] AP Bus"},
	{.irq = IRQIO_PCF,  .name = "PCF", .desc = "[AIO] PCI Floating Interrupt"},
	{.irq = IRQIO_PCD,  .name = "PCD", .desc = "[AIO] PCI Directed Interrupt"},
	{.irq = IRQIO_MSI,  .name = "MSI", .desc = "[AIO] MSI Interrupt"},
	{.irq = IRQIO_VAI,  .name = "VAI", .desc = "[AIO] Virtual I/O Devices AI"},
	{.irq = IRQIO_GAL,  .name = "GAL", .desc = "[AIO] GIB Alert"},
	{.irq = NMI_NMI,    .name = "NMI", .desc = "[NMI] Machine Check"},
	{.irq = CPU_RST,    .name = "RST", .desc = "[CPU] CPU Restart"},
};

void do_IRQ(struct pt_regs *regs, int irq)
{
	struct pt_regs *old_regs;

	old_regs = set_irq_regs(regs);
	irq_enter();
	if (tod_after_eq(S390_lowcore.int_clock,
			 S390_lowcore.clock_comparator))
		/* Serve timer interrupts first. */
		clock_comparator_work();
	generic_handle_irq(irq);
	irq_exit();
	set_irq_regs(old_regs);
}

static void show_msi_interrupt(struct seq_file *p, int irq)
{
	struct irq_desc *desc;
	unsigned long flags;
	int cpu;

	irq_lock_sparse();
	desc = irq_to_desc(irq);
	if (!desc)
		goto out;

	raw_spin_lock_irqsave(&desc->lock, flags);
	seq_printf(p, "%3d: ", irq);
	for_each_online_cpu(cpu)
		seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));

	if (desc->irq_data.chip)
		seq_printf(p, " %8s", desc->irq_data.chip->name);

	if (desc->action)
		seq_printf(p, "  %s", desc->action->name);

	seq_putc(p, '\n');
	raw_spin_unlock_irqrestore(&desc->lock, flags);
out:
	irq_unlock_sparse();
}

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

	get_online_cpus();
	if (index == 0) {
		seq_puts(p, "           ");
		for_each_online_cpu(cpu)
			seq_printf(p, "CPU%-8d", cpu);
		seq_putc(p, '\n');
	}
	if (index < NR_IRQS_BASE) {
		seq_printf(p, "%s: ", irqclass_main_desc[index].name);
		irq = irqclass_main_desc[index].irq;
		for_each_online_cpu(cpu)
			seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
		seq_putc(p, '\n');
		goto out;
	}
	if (index < nr_irqs) {
		show_msi_interrupt(p, index);
		goto out;
	}
	for (index = 0; index < NR_ARCH_IRQS; index++) {
		seq_printf(p, "%s: ", irqclass_sub_desc[index].name);
		irq = irqclass_sub_desc[index].irq;
		for_each_online_cpu(cpu)
			seq_printf(p, "%10u ",
				   per_cpu(irq_stat, cpu).irqs[irq]);
		if (irqclass_sub_desc[index].desc)
			seq_printf(p, "  %s", irqclass_sub_desc[index].desc);
		seq_putc(p, '\n');
	}
out:
	put_online_cpus();
	return 0;
}

unsigned int arch_dynirq_lower_bound(unsigned int from)
{
	return from < NR_IRQS_BASE ? NR_IRQS_BASE : from;
}

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

	old = current_stack_pointer();
	/* Check against async. stack address range. */
	new = S390_lowcore.async_stack;
	if (((new - old) >> (PAGE_SHIFT + THREAD_SIZE_ORDER)) != 0) {
		CALL_ON_STACK(__do_softirq, new, 0);
	} else {
		/* We are already on the async stack. */
		__do_softirq();
	}
}

/*
 * ext_int_hash[index] is the list head for all external interrupts that hash
 * to this index.
 */
static struct hlist_head ext_int_hash[32] ____cacheline_aligned;

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

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

static inline int ext_hash(u16 code)
{
	BUILD_BUG_ON(!is_power_of_2(ARRAY_SIZE(ext_int_hash)));

	return (code + (code >> 9)) & (ARRAY_SIZE(ext_int_hash) - 1);
}

int register_external_irq(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);
	hlist_add_head_rcu(&p->entry, &ext_int_hash[index]);
	spin_unlock_irqrestore(&ext_int_hash_lock, flags);
	return 0;
}
EXPORT_SYMBOL(register_external_irq);

int unregister_external_irq(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);
	hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
		if (p->code == code && p->handler == handler) {
			hlist_del_rcu(&p->entry);
			kfree_rcu(p, rcu);
		}
	}
	spin_unlock_irqrestore(&ext_int_hash_lock, flags);
	return 0;
}
EXPORT_SYMBOL(unregister_external_irq);

static irqreturn_t do_ext_interrupt(int irq, void *dummy)
{
	struct pt_regs *regs = get_irq_regs();
	struct ext_code ext_code;
	struct ext_int_info *p;
	int index;

	ext_code = *(struct ext_code *) &regs->int_code;
	if (ext_code.code != EXT_IRQ_CLK_COMP)
		set_cpu_flag(CIF_NOHZ_DELAY);

	index = ext_hash(ext_code.code);
	rcu_read_lock();
	hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
		if (unlikely(p->code != ext_code.code))
			continue;
		p->handler(ext_code, regs->int_parm, regs->int_parm_long);
	}
	rcu_read_unlock();
	return IRQ_HANDLED;
}

static void __init init_ext_interrupts(void)
{
	int idx;

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

	irq_set_chip_and_handler(EXT_INTERRUPT,
				 &dummy_irq_chip, handle_percpu_irq);
	if (request_irq(EXT_INTERRUPT, do_ext_interrupt, 0, "EXT", NULL))
		panic("Failed to register EXT interrupt\n");
}

void __init init_IRQ(void)
{
	BUILD_BUG_ON(ARRAY_SIZE(irqclass_sub_desc) != NR_ARCH_IRQS);
	init_cio_interrupts();
	init_airq_interrupts();
	init_ext_interrupts();
}

static DEFINE_SPINLOCK(irq_subclass_lock);
static unsigned char irq_subclass_refcount[64];

void irq_subclass_register(enum irq_subclass subclass)
{
	spin_lock(&irq_subclass_lock);
	if (!irq_subclass_refcount[subclass])
		ctl_set_bit(0, subclass);
	irq_subclass_refcount[subclass]++;
	spin_unlock(&irq_subclass_lock);
}
EXPORT_SYMBOL(irq_subclass_register);

void irq_subclass_unregister(enum irq_subclass subclass)
{
	spin_lock(&irq_subclass_lock);
	irq_subclass_refcount[subclass]--;
	if (!irq_subclass_refcount[subclass])
		ctl_clear_bit(0, subclass);
	spin_unlock(&irq_subclass_lock);
}
EXPORT_SYMBOL(irq_subclass_unregister);

Privacy Policy