drivers/s390/cio/airq.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *    Support for adapter interruptions
   4  *
   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>
  10  */
  11
  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>
  20
  21 #include <asm/airq.h>
  22 #include <asm/isc.h>
  23 #include <asm/cio.h>
  24
  25 #include "cio.h"
  26 #include "cio_debug.h"
  27 #include "ioasm.h"
  28
  29 static DEFINE_SPINLOCK(airq_lists_lock);
  30 static struct hlist_head airq_lists[MAX_ISC+1];
  31
  32 static struct dma_pool *airq_iv_cache;
  33
  34 /**
  35  * register_adapter_interrupt() - register adapter interrupt handler
  36  * @airq: pointer to adapter interrupt descriptor
  37  *
  38  * Returns 0 on success, or -EINVAL.
  39  */
  40 int register_adapter_interrupt(struct airq_struct *airq)
  41 {
  42         char dbf_txt[32];
  43
  44         if (!airq->handler || airq->isc > MAX_ISC)
  45                 return -EINVAL;
  46         if (!airq->lsi_ptr) {
  47                 airq->lsi_ptr = kzalloc(1, GFP_KERNEL);
  48                 if (!airq->lsi_ptr)
  49                         return -ENOMEM;
  50                 airq->flags |= AIRQ_PTR_ALLOCATED;
  51         }
  52         if (!airq->lsi_mask)
  53                 airq->lsi_mask = 0xff;
  54         snprintf(dbf_txt, sizeof(dbf_txt), "rairq:%p", airq);
  55         CIO_TRACE_EVENT(4, dbf_txt);
  56         isc_register(airq->isc);
  57         spin_lock(&airq_lists_lock);
  58         hlist_add_head_rcu(&airq->list, &airq_lists[airq->isc]);
  59         spin_unlock(&airq_lists_lock);
  60         return 0;
  61 }
  62 EXPORT_SYMBOL(register_adapter_interrupt);
  63
  64 /**
  65  * unregister_adapter_interrupt - unregister adapter interrupt handler
  66  * @airq: pointer to adapter interrupt descriptor
  67  */
  68 void unregister_adapter_interrupt(struct airq_struct *airq)
  69 {
  70         char dbf_txt[32];
  71
  72         if (hlist_unhashed(&airq->list))
  73                 return;
  74         snprintf(dbf_txt, sizeof(dbf_txt), "urairq:%p", airq);
  75         CIO_TRACE_EVENT(4, dbf_txt);
  76         spin_lock(&airq_lists_lock);
  77         hlist_del_rcu(&airq->list);
  78         spin_unlock(&airq_lists_lock);
  79         synchronize_rcu();
  80         isc_unregister(airq->isc);
  81         if (airq->flags & AIRQ_PTR_ALLOCATED) {
  82                 kfree(airq->lsi_ptr);
  83                 airq->lsi_ptr = NULL;
  84                 airq->flags &= ~AIRQ_PTR_ALLOCATED;
  85         }
  86 }
  87 EXPORT_SYMBOL(unregister_adapter_interrupt);
  88
  89 static irqreturn_t do_airq_interrupt(int irq, void *dummy)
  90 {
  91         struct tpi_info *tpi_info;
  92         struct airq_struct *airq;
  93         struct hlist_head *head;
  94
  95         set_cpu_flag(CIF_NOHZ_DELAY);
  96         tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
  97         trace_s390_cio_adapter_int(tpi_info);
  98         head = &airq_lists[tpi_info->isc];
  99         rcu_read_lock();
 100         hlist_for_each_entry_rcu(airq, head, list)
 101                 if ((*airq->lsi_ptr & airq->lsi_mask) != 0)
 102                         airq->handler(airq, !tpi_info->directed_irq);
 103         rcu_read_unlock();
 104
 105         return IRQ_HANDLED;
 106 }
 107
 108 static struct irqaction airq_interrupt = {
 109         .name    = "AIO",
 110         .handler = do_airq_interrupt,
 111 };
 112
 113 void __init init_airq_interrupts(void)
 114 {
 115         irq_set_chip_and_handler(THIN_INTERRUPT,
 116                                  &dummy_irq_chip, handle_percpu_irq);
 117         setup_irq(THIN_INTERRUPT, &airq_interrupt);
 118 }
 119
 120 static inline unsigned long iv_size(unsigned long bits)
 121 {
 122         return BITS_TO_LONGS(bits) * sizeof(unsigned long);
 123 }
 124
 125 /**
 126  * airq_iv_create - create an interrupt vector
 127  * @bits: number of bits in the interrupt vector
 128  * @flags: allocation flags
 129  *
 130  * Returns a pointer to an interrupt vector structure
 131  */
 132 struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags)
 133 {
 134         struct airq_iv *iv;
 135         unsigned long size;
 136
 137         iv = kzalloc(sizeof(*iv), GFP_KERNEL);
 138         if (!iv)
 139                 goto out;
 140         iv->bits = bits;
 141         iv->flags = flags;
 142         size = iv_size(bits);
 143
 144         if (flags & AIRQ_IV_CACHELINE) {
 145                 if ((cache_line_size() * BITS_PER_BYTE) < bits
 146                                 || !airq_iv_cache)
 147                         goto out_free;
 148
 149                 iv->vector = dma_pool_zalloc(airq_iv_cache, GFP_KERNEL,
 150                                              &iv->vector_dma);
 151                 if (!iv->vector)
 152                         goto out_free;
 153         } else {
 154                 iv->vector = cio_dma_zalloc(size);
 155                 if (!iv->vector)
 156                         goto out_free;
 157         }
 158         if (flags & AIRQ_IV_ALLOC) {
 159                 iv->avail = kmalloc(size, GFP_KERNEL);
 160                 if (!iv->avail)
 161                         goto out_free;
 162                 memset(iv->avail, 0xff, size);
 163                 iv->end = 0;
 164         } else
 165                 iv->end = bits;
 166         if (flags & AIRQ_IV_BITLOCK) {
 167                 iv->bitlock = kzalloc(size, GFP_KERNEL);
 168                 if (!iv->bitlock)
 169                         goto out_free;
 170         }
 171         if (flags & AIRQ_IV_PTR) {
 172                 size = bits * sizeof(unsigned long);
 173                 iv->ptr = kzalloc(size, GFP_KERNEL);
 174                 if (!iv->ptr)
 175                         goto out_free;
 176         }
 177         if (flags & AIRQ_IV_DATA) {
 178                 size = bits * sizeof(unsigned int);
 179                 iv->data = kzalloc(size, GFP_KERNEL);
 180                 if (!iv->data)
 181                         goto out_free;
 182         }
 183         spin_lock_init(&iv->lock);
 184         return iv;
 185
 186 out_free:
 187         kfree(iv->ptr);
 188         kfree(iv->bitlock);
 189         kfree(iv->avail);
 190         if (iv->flags & AIRQ_IV_CACHELINE && iv->vector)
 191                 dma_pool_free(airq_iv_cache, iv->vector, iv->vector_dma);
 192         else
 193                 cio_dma_free(iv->vector, size);
 194         kfree(iv);
 195 out:
 196         return NULL;
 197 }
 198 EXPORT_SYMBOL(airq_iv_create);
 199
 200 /**
 201  * airq_iv_release - release an interrupt vector
 202  * @iv: pointer to interrupt vector structure
 203  */
 204 void airq_iv_release(struct airq_iv *iv)
 205 {
 206         kfree(iv->data);
 207         kfree(iv->ptr);
 208         kfree(iv->bitlock);
 209         if (iv->flags & AIRQ_IV_CACHELINE)
 210                 dma_pool_free(airq_iv_cache, iv->vector, iv->vector_dma);
 211         else
 212                 cio_dma_free(iv->vector, iv_size(iv->bits));
 213         kfree(iv->avail);
 214         kfree(iv);
 215 }
 216 EXPORT_SYMBOL(airq_iv_release);
 217
 218 /**
 219  * airq_iv_alloc - allocate irq bits from an interrupt vector
 220  * @iv: pointer to an interrupt vector structure
 221  * @num: number of consecutive irq bits to allocate
 222  *
 223  * Returns the bit number of the first irq in the allocated block of irqs,
 224  * or -1UL if no bit is available or the AIRQ_IV_ALLOC flag has not been
 225  * specified
 226  */
 227 unsigned long airq_iv_alloc(struct airq_iv *iv, unsigned long num)
 228 {
 229         unsigned long bit, i, flags;
 230
 231         if (!iv->avail || num == 0)
 232                 return -1UL;
 233         spin_lock_irqsave(&iv->lock, flags);
 234         bit = find_first_bit_inv(iv->avail, iv->bits);
 235         while (bit + num <= iv->bits) {
 236                 for (i = 1; i < num; i++)
 237                         if (!test_bit_inv(bit + i, iv->avail))
 238                                 break;
 239                 if (i >= num) {
 240                         /* Found a suitable block of irqs */
 241                         for (i = 0; i < num; i++)
 242                                 clear_bit_inv(bit + i, iv->avail);
 243                         if (bit + num >= iv->end)
 244                                 iv->end = bit + num + 1;
 245                         break;
 246                 }
 247                 bit = find_next_bit_inv(iv->avail, iv->bits, bit + i + 1);
 248         }
 249         if (bit + num > iv->bits)
 250                 bit = -1UL;
 251         spin_unlock_irqrestore(&iv->lock, flags);
 252         return bit;
 253 }
 254 EXPORT_SYMBOL(airq_iv_alloc);
 255
 256 /**
 257  * airq_iv_free - free irq bits of an interrupt vector
 258  * @iv: pointer to interrupt vector structure
 259  * @bit: number of the first irq bit to free
 260  * @num: number of consecutive irq bits to free
 261  */
 262 void airq_iv_free(struct airq_iv *iv, unsigned long bit, unsigned long num)
 263 {
 264         unsigned long i, flags;
 265
 266         if (!iv->avail || num == 0)
 267                 return;
 268         spin_lock_irqsave(&iv->lock, flags);
 269         for (i = 0; i < num; i++) {
 270                 /* Clear (possibly left over) interrupt bit */
 271                 clear_bit_inv(bit + i, iv->vector);
 272                 /* Make the bit positions available again */
 273                 set_bit_inv(bit + i, iv->avail);
 274         }
 275         if (bit + num >= iv->end) {
 276                 /* Find new end of bit-field */
 277                 while (iv->end > 0 && !test_bit_inv(iv->end - 1, iv->avail))
 278                         iv->end--;
 279         }
 280         spin_unlock_irqrestore(&iv->lock, flags);
 281 }
 282 EXPORT_SYMBOL(airq_iv_free);
 283
 284 /**
 285  * airq_iv_scan - scan interrupt vector for non-zero bits
 286  * @iv: pointer to interrupt vector structure
 287  * @start: bit number to start the search
 288  * @end: bit number to end the search
 289  *
 290  * Returns the bit number of the next non-zero interrupt bit, or
 291  * -1UL if the scan completed without finding any more any non-zero bits.
 292  */
 293 unsigned long airq_iv_scan(struct airq_iv *iv, unsigned long start,
 294                            unsigned long end)
 295 {
 296         unsigned long bit;
 297
 298         /* Find non-zero bit starting from 'ivs->next'. */
 299         bit = find_next_bit_inv(iv->vector, end, start);
 300         if (bit >= end)
 301                 return -1UL;
 302         clear_bit_inv(bit, iv->vector);
 303         return bit;
 304 }
 305 EXPORT_SYMBOL(airq_iv_scan);
 306
 307 int __init airq_init(void)
 308 {
 309         airq_iv_cache = dma_pool_create("airq_iv_cache", cio_get_dma_css_dev(),
 310                                         cache_line_size(),
 311                                         cache_line_size(), PAGE_SIZE);
 312         if (!airq_iv_cache)
 313                 return -ENOMEM;
 314         return 0;
 315 }