1 // SPDX-License-Identifier: GPL-2.0
3 * Support for adapter interruptions
5 * Copyright IBM Corp. 1999, 2007
6 * Author(s): Ingo Adlung <adlung@de.ibm.com>
7 * Cornelia Huck <cornelia.huck@de.ibm.com>
8 * Arnd Bergmann <arndb@de.ibm.com>
9 * Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
12 #include <linux/init.h>
13 #include <linux/irq.h>
14 #include <linux/kernel_stat.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/rculist.h>
18 #include <linux/slab.h>
19 #include <linux/dmapool.h>
26 #include "cio_debug.h"
29 static DEFINE_SPINLOCK(airq_lists_lock);
30 static struct hlist_head airq_lists[MAX_ISC+1];
32 static struct dma_pool *airq_iv_cache;
35 * register_adapter_interrupt() - register adapter interrupt handler
36 * @airq: pointer to adapter interrupt descriptor
38 * Returns 0 on success, or -EINVAL.
40 int register_adapter_interrupt(struct airq_struct *airq)
44 if (!airq->handler || airq->isc > MAX_ISC)
47 airq->lsi_ptr = cio_dma_zalloc(1);
50 airq->flags |= AIRQ_PTR_ALLOCATED;
52 snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%p", airq);
53 CIO_TRACE_EVENT(4, dbf_txt);
54 isc_register(airq->isc);
55 spin_lock(&airq_lists_lock);
56 hlist_add_head_rcu(&airq->list, &airq_lists[airq->isc]);
57 spin_unlock(&airq_lists_lock);
60 EXPORT_SYMBOL(register_adapter_interrupt);
63 * unregister_adapter_interrupt - unregister adapter interrupt handler
64 * @airq: pointer to adapter interrupt descriptor
66 void unregister_adapter_interrupt(struct airq_struct *airq)
70 if (hlist_unhashed(&airq->list))
72 snprintf(dbf_txt, sizeof(dbf_txt), "urairq:%p", airq);
73 CIO_TRACE_EVENT(4, dbf_txt);
74 spin_lock(&airq_lists_lock);
75 hlist_del_rcu(&airq->list);
76 spin_unlock(&airq_lists_lock);
78 isc_unregister(airq->isc);
79 if (airq->flags & AIRQ_PTR_ALLOCATED) {
80 cio_dma_free(airq->lsi_ptr, 1);
82 airq->flags &= ~AIRQ_PTR_ALLOCATED;
85 EXPORT_SYMBOL(unregister_adapter_interrupt);
87 static irqreturn_t do_airq_interrupt(int irq, void *dummy)
89 struct tpi_info *tpi_info;
90 struct airq_struct *airq;
91 struct hlist_head *head;
93 set_cpu_flag(CIF_NOHZ_DELAY);
94 tpi_info = &get_irq_regs()->tpi_info;
95 trace_s390_cio_adapter_int(tpi_info);
96 head = &airq_lists[tpi_info->isc];
98 hlist_for_each_entry_rcu(airq, head, list)
99 if (*airq->lsi_ptr != 0)
100 airq->handler(airq, tpi_info);
106 void __init init_airq_interrupts(void)
108 irq_set_chip_and_handler(THIN_INTERRUPT,
109 &dummy_irq_chip, handle_percpu_irq);
110 if (request_irq(THIN_INTERRUPT, do_airq_interrupt, 0, "AIO", NULL))
111 panic("Failed to register AIO interrupt\n");
114 static inline unsigned long iv_size(unsigned long bits)
116 return BITS_TO_LONGS(bits) * sizeof(unsigned long);
120 * airq_iv_create - create an interrupt vector
121 * @bits: number of bits in the interrupt vector
122 * @flags: allocation flags
123 * @vec: pointer to pinned guest memory if AIRQ_IV_GUESTVEC
125 * Returns a pointer to an interrupt vector structure
127 struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags,
133 iv = kzalloc(sizeof(*iv), GFP_KERNEL);
138 size = iv_size(bits);
140 if (flags & AIRQ_IV_CACHELINE) {
141 if ((cache_line_size() * BITS_PER_BYTE) < bits
145 iv->vector = dma_pool_zalloc(airq_iv_cache, GFP_KERNEL,
149 } else if (flags & AIRQ_IV_GUESTVEC) {
152 iv->vector = cio_dma_zalloc(size);
156 if (flags & AIRQ_IV_ALLOC) {
157 iv->avail = kmalloc(size, GFP_KERNEL);
160 memset(iv->avail, 0xff, size);
164 if (flags & AIRQ_IV_BITLOCK) {
165 iv->bitlock = kzalloc(size, GFP_KERNEL);
169 if (flags & AIRQ_IV_PTR) {
170 size = bits * sizeof(unsigned long);
171 iv->ptr = kzalloc(size, GFP_KERNEL);
175 if (flags & AIRQ_IV_DATA) {
176 size = bits * sizeof(unsigned int);
177 iv->data = kzalloc(size, GFP_KERNEL);
181 spin_lock_init(&iv->lock);
188 if (iv->flags & AIRQ_IV_CACHELINE && iv->vector)
189 dma_pool_free(airq_iv_cache, iv->vector, iv->vector_dma);
190 else if (!(iv->flags & AIRQ_IV_GUESTVEC))
191 cio_dma_free(iv->vector, size);
196 EXPORT_SYMBOL(airq_iv_create);
199 * airq_iv_release - release an interrupt vector
200 * @iv: pointer to interrupt vector structure
202 void airq_iv_release(struct airq_iv *iv)
207 if (iv->flags & AIRQ_IV_CACHELINE)
208 dma_pool_free(airq_iv_cache, iv->vector, iv->vector_dma);
209 else if (!(iv->flags & AIRQ_IV_GUESTVEC))
210 cio_dma_free(iv->vector, iv_size(iv->bits));
214 EXPORT_SYMBOL(airq_iv_release);
217 * airq_iv_alloc - allocate irq bits from an interrupt vector
218 * @iv: pointer to an interrupt vector structure
219 * @num: number of consecutive irq bits to allocate
221 * Returns the bit number of the first irq in the allocated block of irqs,
222 * or -1UL if no bit is available or the AIRQ_IV_ALLOC flag has not been
225 unsigned long airq_iv_alloc(struct airq_iv *iv, unsigned long num)
227 unsigned long bit, i, flags;
229 if (!iv->avail || num == 0)
231 spin_lock_irqsave(&iv->lock, flags);
232 bit = find_first_bit_inv(iv->avail, iv->bits);
233 while (bit + num <= iv->bits) {
234 for (i = 1; i < num; i++)
235 if (!test_bit_inv(bit + i, iv->avail))
238 /* Found a suitable block of irqs */
239 for (i = 0; i < num; i++)
240 clear_bit_inv(bit + i, iv->avail);
241 if (bit + num >= iv->end)
242 iv->end = bit + num + 1;
245 bit = find_next_bit_inv(iv->avail, iv->bits, bit + i + 1);
247 if (bit + num > iv->bits)
249 spin_unlock_irqrestore(&iv->lock, flags);
252 EXPORT_SYMBOL(airq_iv_alloc);
255 * airq_iv_free - free irq bits of an interrupt vector
256 * @iv: pointer to interrupt vector structure
257 * @bit: number of the first irq bit to free
258 * @num: number of consecutive irq bits to free
260 void airq_iv_free(struct airq_iv *iv, unsigned long bit, unsigned long num)
262 unsigned long i, flags;
264 if (!iv->avail || num == 0)
266 spin_lock_irqsave(&iv->lock, flags);
267 for (i = 0; i < num; i++) {
268 /* Clear (possibly left over) interrupt bit */
269 clear_bit_inv(bit + i, iv->vector);
270 /* Make the bit positions available again */
271 set_bit_inv(bit + i, iv->avail);
273 if (bit + num >= iv->end) {
274 /* Find new end of bit-field */
275 while (iv->end > 0 && !test_bit_inv(iv->end - 1, iv->avail))
278 spin_unlock_irqrestore(&iv->lock, flags);
280 EXPORT_SYMBOL(airq_iv_free);
283 * airq_iv_scan - scan interrupt vector for non-zero bits
284 * @iv: pointer to interrupt vector structure
285 * @start: bit number to start the search
286 * @end: bit number to end the search
288 * Returns the bit number of the next non-zero interrupt bit, or
289 * -1UL if the scan completed without finding any more any non-zero bits.
291 unsigned long airq_iv_scan(struct airq_iv *iv, unsigned long start,
296 /* Find non-zero bit starting from 'ivs->next'. */
297 bit = find_next_bit_inv(iv->vector, end, start);
300 clear_bit_inv(bit, iv->vector);
303 EXPORT_SYMBOL(airq_iv_scan);
305 int __init airq_init(void)
307 airq_iv_cache = dma_pool_create("airq_iv_cache", cio_get_dma_css_dev(),
309 cache_line_size(), PAGE_SIZE);