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 = &get_irq_regs()->tpi_info; 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 void __init init_airq_interrupts(void) 109 { 110 irq_set_chip_and_handler(THIN_INTERRUPT, 111 &dummy_irq_chip, handle_percpu_irq); 112 if (request_irq(THIN_INTERRUPT, do_airq_interrupt, 0, "AIO", NULL)) 113 panic("Failed to register AIO interrupt\n"); 114 } 115 116 static inline unsigned long iv_size(unsigned long bits) 117 { 118 return BITS_TO_LONGS(bits) * sizeof(unsigned long); 119 } 120 121 /** 122 * airq_iv_create - create an interrupt vector 123 * @bits: number of bits in the interrupt vector 124 * @flags: allocation flags 125 * 126 * Returns a pointer to an interrupt vector structure 127 */ 128 struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags) 129 { 130 struct airq_iv *iv; 131 unsigned long size; 132 133 iv = kzalloc(sizeof(*iv), GFP_KERNEL); 134 if (!iv) 135 goto out; 136 iv->bits = bits; 137 iv->flags = flags; 138 size = iv_size(bits); 139 140 if (flags & AIRQ_IV_CACHELINE) { 141 if ((cache_line_size() * BITS_PER_BYTE) < bits 142 || !airq_iv_cache) 143 goto out_free; 144 145 iv->vector = dma_pool_zalloc(airq_iv_cache, GFP_KERNEL, 146 &iv->vector_dma); 147 if (!iv->vector) 148 goto out_free; 149 } else { 150 iv->vector = cio_dma_zalloc(size); 151 if (!iv->vector) 152 goto out_free; 153 } 154 if (flags & AIRQ_IV_ALLOC) { 155 iv->avail = kmalloc(size, GFP_KERNEL); 156 if (!iv->avail) 157 goto out_free; 158 memset(iv->avail, 0xff, size); 159 iv->end = 0; 160 } else 161 iv->end = bits; 162 if (flags & AIRQ_IV_BITLOCK) { 163 iv->bitlock = kzalloc(size, GFP_KERNEL); 164 if (!iv->bitlock) 165 goto out_free; 166 } 167 if (flags & AIRQ_IV_PTR) { 168 size = bits * sizeof(unsigned long); 169 iv->ptr = kzalloc(size, GFP_KERNEL); 170 if (!iv->ptr) 171 goto out_free; 172 } 173 if (flags & AIRQ_IV_DATA) { 174 size = bits * sizeof(unsigned int); 175 iv->data = kzalloc(size, GFP_KERNEL); 176 if (!iv->data) 177 goto out_free; 178 } 179 spin_lock_init(&iv->lock); 180 return iv; 181 182 out_free: 183 kfree(iv->ptr); 184 kfree(iv->bitlock); 185 kfree(iv->avail); 186 if (iv->flags & AIRQ_IV_CACHELINE && iv->vector) 187 dma_pool_free(airq_iv_cache, iv->vector, iv->vector_dma); 188 else 189 cio_dma_free(iv->vector, size); 190 kfree(iv); 191 out: 192 return NULL; 193 } 194 EXPORT_SYMBOL(airq_iv_create); 195 196 /** 197 * airq_iv_release - release an interrupt vector 198 * @iv: pointer to interrupt vector structure 199 */ 200 void airq_iv_release(struct airq_iv *iv) 201 { 202 kfree(iv->data); 203 kfree(iv->ptr); 204 kfree(iv->bitlock); 205 if (iv->flags & AIRQ_IV_CACHELINE) 206 dma_pool_free(airq_iv_cache, iv->vector, iv->vector_dma); 207 else 208 cio_dma_free(iv->vector, iv_size(iv->bits)); 209 kfree(iv->avail); 210 kfree(iv); 211 } 212 EXPORT_SYMBOL(airq_iv_release); 213 214 /** 215 * airq_iv_alloc - allocate irq bits from an interrupt vector 216 * @iv: pointer to an interrupt vector structure 217 * @num: number of consecutive irq bits to allocate 218 * 219 * Returns the bit number of the first irq in the allocated block of irqs, 220 * or -1UL if no bit is available or the AIRQ_IV_ALLOC flag has not been 221 * specified 222 */ 223 unsigned long airq_iv_alloc(struct airq_iv *iv, unsigned long num) 224 { 225 unsigned long bit, i, flags; 226 227 if (!iv->avail || num == 0) 228 return -1UL; 229 spin_lock_irqsave(&iv->lock, flags); 230 bit = find_first_bit_inv(iv->avail, iv->bits); 231 while (bit + num <= iv->bits) { 232 for (i = 1; i < num; i++) 233 if (!test_bit_inv(bit + i, iv->avail)) 234 break; 235 if (i >= num) { 236 /* Found a suitable block of irqs */ 237 for (i = 0; i < num; i++) 238 clear_bit_inv(bit + i, iv->avail); 239 if (bit + num >= iv->end) 240 iv->end = bit + num + 1; 241 break; 242 } 243 bit = find_next_bit_inv(iv->avail, iv->bits, bit + i + 1); 244 } 245 if (bit + num > iv->bits) 246 bit = -1UL; 247 spin_unlock_irqrestore(&iv->lock, flags); 248 return bit; 249 } 250 EXPORT_SYMBOL(airq_iv_alloc); 251 252 /** 253 * airq_iv_free - free irq bits of an interrupt vector 254 * @iv: pointer to interrupt vector structure 255 * @bit: number of the first irq bit to free 256 * @num: number of consecutive irq bits to free 257 */ 258 void airq_iv_free(struct airq_iv *iv, unsigned long bit, unsigned long num) 259 { 260 unsigned long i, flags; 261 262 if (!iv->avail || num == 0) 263 return; 264 spin_lock_irqsave(&iv->lock, flags); 265 for (i = 0; i < num; i++) { 266 /* Clear (possibly left over) interrupt bit */ 267 clear_bit_inv(bit + i, iv->vector); 268 /* Make the bit positions available again */ 269 set_bit_inv(bit + i, iv->avail); 270 } 271 if (bit + num >= iv->end) { 272 /* Find new end of bit-field */ 273 while (iv->end > 0 && !test_bit_inv(iv->end - 1, iv->avail)) 274 iv->end--; 275 } 276 spin_unlock_irqrestore(&iv->lock, flags); 277 } 278 EXPORT_SYMBOL(airq_iv_free); 279 280 /** 281 * airq_iv_scan - scan interrupt vector for non-zero bits 282 * @iv: pointer to interrupt vector structure 283 * @start: bit number to start the search 284 * @end: bit number to end the search 285 * 286 * Returns the bit number of the next non-zero interrupt bit, or 287 * -1UL if the scan completed without finding any more any non-zero bits. 288 */ 289 unsigned long airq_iv_scan(struct airq_iv *iv, unsigned long start, 290 unsigned long end) 291 { 292 unsigned long bit; 293 294 /* Find non-zero bit starting from 'ivs->next'. */ 295 bit = find_next_bit_inv(iv->vector, end, start); 296 if (bit >= end) 297 return -1UL; 298 clear_bit_inv(bit, iv->vector); 299 return bit; 300 } 301 EXPORT_SYMBOL(airq_iv_scan); 302 303 int __init airq_init(void) 304 { 305 airq_iv_cache = dma_pool_create("airq_iv_cache", cio_get_dma_css_dev(), 306 cache_line_size(), 307 cache_line_size(), PAGE_SIZE); 308 if (!airq_iv_cache) 309 return -ENOMEM; 310 return 0; 311 } 312