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 = cio_dma_zalloc(1); 48 if (!airq->lsi_ptr) 49 return -ENOMEM; 50 airq->flags |= AIRQ_PTR_ALLOCATED; 51 } 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); 58 return 0; 59 } 60 EXPORT_SYMBOL(register_adapter_interrupt); 61 62 /** 63 * unregister_adapter_interrupt - unregister adapter interrupt handler 64 * @airq: pointer to adapter interrupt descriptor 65 */ 66 void unregister_adapter_interrupt(struct airq_struct *airq) 67 { 68 char dbf_txt[32]; 69 70 if (hlist_unhashed(&airq->list)) 71 return; 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); 77 synchronize_rcu(); 78 isc_unregister(airq->isc); 79 if (airq->flags & AIRQ_PTR_ALLOCATED) { 80 cio_dma_free(airq->lsi_ptr, 1); 81 airq->lsi_ptr = NULL; 82 airq->flags &= ~AIRQ_PTR_ALLOCATED; 83 } 84 } 85 EXPORT_SYMBOL(unregister_adapter_interrupt); 86 87 static irqreturn_t do_airq_interrupt(int irq, void *dummy) 88 { 89 struct tpi_info *tpi_info; 90 struct airq_struct *airq; 91 struct hlist_head *head; 92 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]; 97 rcu_read_lock(); 98 hlist_for_each_entry_rcu(airq, head, list) 99 if (*airq->lsi_ptr != 0) 100 airq->handler(airq, tpi_info); 101 rcu_read_unlock(); 102 103 return IRQ_HANDLED; 104 } 105 106 void __init init_airq_interrupts(void) 107 { 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"); 112 } 113 114 static inline unsigned long iv_size(unsigned long bits) 115 { 116 return BITS_TO_LONGS(bits) * sizeof(unsigned long); 117 } 118 119 /** 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 124 * 125 * Returns a pointer to an interrupt vector structure 126 */ 127 struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags, 128 unsigned long *vec) 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 if (flags & AIRQ_IV_GUESTVEC) { 150 iv->vector = vec; 151 } else { 152 iv->vector = cio_dma_zalloc(size); 153 if (!iv->vector) 154 goto out_free; 155 } 156 if (flags & AIRQ_IV_ALLOC) { 157 iv->avail = kmalloc(size, GFP_KERNEL); 158 if (!iv->avail) 159 goto out_free; 160 memset(iv->avail, 0xff, size); 161 iv->end = 0; 162 } else 163 iv->end = bits; 164 if (flags & AIRQ_IV_BITLOCK) { 165 iv->bitlock = kzalloc(size, GFP_KERNEL); 166 if (!iv->bitlock) 167 goto out_free; 168 } 169 if (flags & AIRQ_IV_PTR) { 170 size = bits * sizeof(unsigned long); 171 iv->ptr = kzalloc(size, GFP_KERNEL); 172 if (!iv->ptr) 173 goto out_free; 174 } 175 if (flags & AIRQ_IV_DATA) { 176 size = bits * sizeof(unsigned int); 177 iv->data = kzalloc(size, GFP_KERNEL); 178 if (!iv->data) 179 goto out_free; 180 } 181 spin_lock_init(&iv->lock); 182 return iv; 183 184 out_free: 185 kfree(iv->ptr); 186 kfree(iv->bitlock); 187 kfree(iv->avail); 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); 192 kfree(iv); 193 out: 194 return NULL; 195 } 196 EXPORT_SYMBOL(airq_iv_create); 197 198 /** 199 * airq_iv_release - release an interrupt vector 200 * @iv: pointer to interrupt vector structure 201 */ 202 void airq_iv_release(struct airq_iv *iv) 203 { 204 kfree(iv->data); 205 kfree(iv->ptr); 206 kfree(iv->bitlock); 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)); 211 kfree(iv->avail); 212 kfree(iv); 213 } 214 EXPORT_SYMBOL(airq_iv_release); 215 216 /** 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 220 * 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 223 * specified 224 */ 225 unsigned long airq_iv_alloc(struct airq_iv *iv, unsigned long num) 226 { 227 unsigned long bit, i, flags; 228 229 if (!iv->avail || num == 0) 230 return -1UL; 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)) 236 break; 237 if (i >= num) { 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; 243 break; 244 } 245 bit = find_next_bit_inv(iv->avail, iv->bits, bit + i + 1); 246 } 247 if (bit + num > iv->bits) 248 bit = -1UL; 249 spin_unlock_irqrestore(&iv->lock, flags); 250 return bit; 251 } 252 EXPORT_SYMBOL(airq_iv_alloc); 253 254 /** 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 259 */ 260 void airq_iv_free(struct airq_iv *iv, unsigned long bit, unsigned long num) 261 { 262 unsigned long i, flags; 263 264 if (!iv->avail || num == 0) 265 return; 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); 272 } 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)) 276 iv->end--; 277 } 278 spin_unlock_irqrestore(&iv->lock, flags); 279 } 280 EXPORT_SYMBOL(airq_iv_free); 281 282 /** 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 287 * 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. 290 */ 291 unsigned long airq_iv_scan(struct airq_iv *iv, unsigned long start, 292 unsigned long end) 293 { 294 unsigned long bit; 295 296 /* Find non-zero bit starting from 'ivs->next'. */ 297 bit = find_next_bit_inv(iv->vector, end, start); 298 if (bit >= end) 299 return -1UL; 300 clear_bit_inv(bit, iv->vector); 301 return bit; 302 } 303 EXPORT_SYMBOL(airq_iv_scan); 304 305 int __init airq_init(void) 306 { 307 airq_iv_cache = dma_pool_create("airq_iv_cache", cio_get_dma_css_dev(), 308 cache_line_size(), 309 cache_line_size(), PAGE_SIZE); 310 if (!airq_iv_cache) 311 return -ENOMEM; 312 return 0; 313 } 314