summaryrefslogtreecommitdiffstats
path: root/drivers/s390/cio/airq.c
blob: d028fd800c9c6afd7f5b5627475c4bfe6552f04b (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
/*
 *    Support for adapter interruptions
 *
 *    Copyright IBM Corp. 1999, 2007
 *    Author(s): Ingo Adlung <adlung@de.ibm.com>
 *		 Cornelia Huck <cornelia.huck@de.ibm.com>
 *		 Arnd Bergmann <arndb@de.ibm.com>
 *		 Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
 */

#include <linux/init.h>
#include <linux/irq.h>
#include <linux/kernel_stat.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/rculist.h>
#include <linux/slab.h>

#include <asm/airq.h>
#include <asm/isc.h>

#include "cio.h"
#include "cio_debug.h"
#include "ioasm.h"

static DEFINE_SPINLOCK(airq_lists_lock);
static struct hlist_head airq_lists[MAX_ISC+1];

/**
 * register_adapter_interrupt() - register adapter interrupt handler
 * @airq: pointer to adapter interrupt descriptor
 *
 * Returns 0 on success, or -EINVAL.
 */
int register_adapter_interrupt(struct airq_struct *airq)
{
	char dbf_txt[32];

	if (!airq->handler || airq->isc > MAX_ISC)
		return -EINVAL;
	if (!airq->lsi_ptr) {
		airq->lsi_ptr = kzalloc(1, GFP_KERNEL);
		if (!airq->lsi_ptr)
			return -ENOMEM;
		airq->flags |= AIRQ_PTR_ALLOCATED;
	}
	if (!airq->lsi_mask)
		airq->lsi_mask = 0xff;
	snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%p", airq);
	CIO_TRACE_EVENT(4, dbf_txt);
	isc_register(airq->isc);
	spin_lock(&airq_lists_lock);
	hlist_add_head_rcu(&airq->list, &airq_lists[airq->isc]);
	spin_unlock(&airq_lists_lock);
	return 0;
}
EXPORT_SYMBOL(register_adapter_interrupt);

/**
 * unregister_adapter_interrupt - unregister adapter interrupt handler
 * @airq: pointer to adapter interrupt descriptor
 */
void unregister_adapter_interrupt(struct airq_struct *airq)
{
	char dbf_txt[32];

	if (hlist_unhashed(&airq->list))
		return;
	snprintf(dbf_txt, sizeof(dbf_txt), "urairq:%p", airq);
	CIO_TRACE_EVENT(4, dbf_txt);
	spin_lock(&airq_lists_lock);
	hlist_del_rcu(&airq->list);
	spin_unlock(&airq_lists_lock);
	synchronize_rcu();
	isc_unregister(airq->isc);
	if (airq->flags & AIRQ_PTR_ALLOCATED) {
		kfree(airq->lsi_ptr);
		airq->lsi_ptr = NULL;
		airq->flags &= ~AIRQ_PTR_ALLOCATED;
	}
}
EXPORT_SYMBOL(unregister_adapter_interrupt);

static irqreturn_t do_airq_interrupt(int irq, void *dummy)
{
	struct tpi_info *tpi_info;
	struct airq_struct *airq;
	struct hlist_head *head;

	__this_cpu_write(s390_idle.nohz_delay, 1);
	tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
	head = &airq_lists[tpi_info->isc];
	rcu_read_lock();
	hlist_for_each_entry_rcu(airq, head, list)
		if ((*airq->lsi_ptr & airq->lsi_mask) != 0)
			airq->handler(airq);
	rcu_read_unlock();

	return IRQ_HANDLED;
}

static struct irqaction airq_interrupt = {
	.name	 = "AIO",
	.handler = do_airq_interrupt,
};

void __init init_airq_interrupts(void)
{
	irq_set_chip_and_handler(THIN_INTERRUPT,
				 &dummy_irq_chip, handle_percpu_irq);
	setup_irq(THIN_INTERRUPT, &airq_interrupt);
}

/**
 * airq_iv_create - create an interrupt vector
 * @bits: number of bits in the interrupt vector
 * @flags: allocation flags
 *
 * Returns a pointer to an interrupt vector structure
 */
struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags)
{
	struct airq_iv *iv;
	unsigned long size;

	iv = kzalloc(sizeof(*iv), GFP_KERNEL);
	if (!iv)
		goto out;
	iv->bits = bits;
	size = BITS_TO_LONGS(bits) * sizeof(unsigned long);
	iv->vector = kzalloc(size, GFP_KERNEL);
	if (!iv->vector)
		goto out_free;
	if (flags & AIRQ_IV_ALLOC) {
		iv->avail = kmalloc(size, GFP_KERNEL);
		if (!iv->avail)
			goto out_free;
		memset(iv->avail, 0xff, size);
		iv->end = 0;
	} else
		iv->end = bits;
	if (flags & AIRQ_IV_BITLOCK) {
		iv->bitlock = kzalloc(size, GFP_KERNEL);
		if (!iv->bitlock)
			goto out_free;
	}
	if (flags & AIRQ_IV_PTR) {
		size = bits * sizeof(unsigned long);
		iv->ptr = kzalloc(size, GFP_KERNEL);
		if (!iv->ptr)
			goto out_free;
	}
	if (flags & AIRQ_IV_DATA) {
		size = bits * sizeof(unsigned int);
		iv->data = kzalloc(size, GFP_KERNEL);
		if (!iv->data)
			goto out_free;
	}
	spin_lock_init(&iv->lock);
	return iv;

out_free:
	kfree(iv->ptr);
	kfree(iv->bitlock);
	kfree(iv->avail);
	kfree(iv->vector);
	kfree(iv);
out:
	return NULL;
}
EXPORT_SYMBOL(airq_iv_create);

/**
 * airq_iv_release - release an interrupt vector
 * @iv: pointer to interrupt vector structure
 */
void airq_iv_release(struct airq_iv *iv)
{
	kfree(iv->data);
	kfree(iv->ptr);
	kfree(iv->bitlock);
	kfree(iv->vector);
	kfree(iv->avail);
	kfree(iv);
}
EXPORT_SYMBOL(airq_iv_release);

/**
 * airq_iv_alloc_bit - allocate an irq bit from an interrupt vector
 * @iv: pointer to an interrupt vector structure
 *
 * Returns the bit number of the allocated irq, or -1UL if no bit
 * is available or the AIRQ_IV_ALLOC flag has not been specified
 */
unsigned long airq_iv_alloc_bit(struct airq_iv *iv)
{
	const unsigned long be_to_le = BITS_PER_LONG - 1;
	unsigned long bit;

	if (!iv->avail)
		return -1UL;
	spin_lock(&iv->lock);
	bit = find_first_bit_left(iv->avail, iv->bits);
	if (bit < iv->bits) {
		clear_bit(bit ^ be_to_le, iv->avail);
		if (bit >= iv->end)
			iv->end = bit + 1;
	} else
		bit = -1UL;
	spin_unlock(&iv->lock);
	return bit;

}
EXPORT_SYMBOL(airq_iv_alloc_bit);

/**
 * airq_iv_free_bit - free an irq bit of an interrupt vector
 * @iv: pointer to interrupt vector structure
 * @bit: number of the irq bit to free
 */
void airq_iv_free_bit(struct airq_iv *iv, unsigned long bit)
{
	const unsigned long be_to_le = BITS_PER_LONG - 1;

	if (!iv->avail)
		return;
	spin_lock(&iv->lock);
	/* Clear (possibly left over) interrupt bit */
	clear_bit(bit ^ be_to_le, iv->vector);
	/* Make the bit position available again */
	set_bit(bit ^ be_to_le, iv->avail);
	if (bit == iv->end - 1) {
		/* Find new end of bit-field */
		while (--iv->end > 0)
			if (!test_bit((iv->end - 1) ^ be_to_le, iv->avail))
				break;
	}
	spin_unlock(&iv->lock);
}
EXPORT_SYMBOL(airq_iv_free_bit);

/**
 * airq_iv_scan - scan interrupt vector for non-zero bits
 * @iv: pointer to interrupt vector structure
 * @start: bit number to start the search
 * @end: bit number to end the search
 *
 * Returns the bit number of the next non-zero interrupt bit, or
 * -1UL if the scan completed without finding any more any non-zero bits.
 */
unsigned long airq_iv_scan(struct airq_iv *iv, unsigned long start,
			   unsigned long end)
{
	const unsigned long be_to_le = BITS_PER_LONG - 1;
	unsigned long bit;

	/* Find non-zero bit starting from 'ivs->next'. */
	bit = find_next_bit_left(iv->vector, end, start);
	if (bit >= end)
		return -1UL;
	/* Clear interrupt bit (find left uses big-endian bit numbers) */
	clear_bit(bit ^ be_to_le, iv->vector);
	return bit;
}
EXPORT_SYMBOL(airq_iv_scan);