1 /* 2 * Copyright IBM Corp. 2000, 2009 3 * Author(s): Utz Bacher <utz.bacher@de.ibm.com> 4 * Cornelia Huck <cornelia.huck@de.ibm.com> 5 * Jan Glauber <jang@linux.vnet.ibm.com> 6 */ 7 #include <linux/io.h> 8 #include <linux/slab.h> 9 #include <linux/kernel_stat.h> 10 #include <linux/atomic.h> 11 #include <asm/debug.h> 12 #include <asm/qdio.h> 13 #include <asm/airq.h> 14 #include <asm/isc.h> 15 16 #include "cio.h" 17 #include "ioasm.h" 18 #include "qdio.h" 19 #include "qdio_debug.h" 20 21 /* 22 * Restriction: only 63 iqdio subchannels would have its own indicator, 23 * after that, subsequent subchannels share one indicator 24 */ 25 #define TIQDIO_NR_NONSHARED_IND 63 26 #define TIQDIO_NR_INDICATORS (TIQDIO_NR_NONSHARED_IND + 1) 27 #define TIQDIO_SHARED_IND 63 28 29 /* device state change indicators */ 30 struct indicator_t { 31 u32 ind; /* u32 because of compare-and-swap performance */ 32 atomic_t count; /* use count, 0 or 1 for non-shared indicators */ 33 }; 34 35 /* list of thin interrupt input queues */ 36 static LIST_HEAD(tiq_list); 37 static DEFINE_MUTEX(tiq_list_lock); 38 39 /* adapter local summary indicator */ 40 static u8 *tiqdio_alsi; 41 42 static struct indicator_t *q_indicators; 43 44 u64 last_ai_time; 45 46 /* returns addr for the device state change indicator */ 47 static u32 *get_indicator(void) 48 { 49 int i; 50 51 for (i = 0; i < TIQDIO_NR_NONSHARED_IND; i++) 52 if (!atomic_read(&q_indicators[i].count)) { 53 atomic_set(&q_indicators[i].count, 1); 54 return &q_indicators[i].ind; 55 } 56 57 /* use the shared indicator */ 58 atomic_inc(&q_indicators[TIQDIO_SHARED_IND].count); 59 return &q_indicators[TIQDIO_SHARED_IND].ind; 60 } 61 62 static void put_indicator(u32 *addr) 63 { 64 int i; 65 66 if (!addr) 67 return; 68 i = ((unsigned long)addr - (unsigned long)q_indicators) / 69 sizeof(struct indicator_t); 70 atomic_dec(&q_indicators[i].count); 71 } 72 73 void tiqdio_add_input_queues(struct qdio_irq *irq_ptr) 74 { 75 mutex_lock(&tiq_list_lock); 76 BUG_ON(irq_ptr->nr_input_qs < 1); 77 list_add_rcu(&irq_ptr->input_qs[0]->entry, &tiq_list); 78 mutex_unlock(&tiq_list_lock); 79 xchg(irq_ptr->dsci, 1 << 7); 80 } 81 82 void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr) 83 { 84 struct qdio_q *q; 85 86 BUG_ON(irq_ptr->nr_input_qs < 1); 87 q = irq_ptr->input_qs[0]; 88 /* if establish triggered an error */ 89 if (!q || !q->entry.prev || !q->entry.next) 90 return; 91 92 mutex_lock(&tiq_list_lock); 93 list_del_rcu(&q->entry); 94 mutex_unlock(&tiq_list_lock); 95 synchronize_rcu(); 96 } 97 98 static inline int has_multiple_inq_on_dsci(struct qdio_irq *irq_ptr) 99 { 100 return irq_ptr->nr_input_qs > 1; 101 } 102 103 static inline int references_shared_dsci(struct qdio_irq *irq_ptr) 104 { 105 return irq_ptr->dsci == &q_indicators[TIQDIO_SHARED_IND].ind; 106 } 107 108 static inline int shared_ind(struct qdio_irq *irq_ptr) 109 { 110 return references_shared_dsci(irq_ptr) || 111 has_multiple_inq_on_dsci(irq_ptr); 112 } 113 114 void clear_nonshared_ind(struct qdio_irq *irq_ptr) 115 { 116 if (!is_thinint_irq(irq_ptr)) 117 return; 118 if (shared_ind(irq_ptr)) 119 return; 120 xchg(irq_ptr->dsci, 0); 121 } 122 123 int test_nonshared_ind(struct qdio_irq *irq_ptr) 124 { 125 if (!is_thinint_irq(irq_ptr)) 126 return 0; 127 if (shared_ind(irq_ptr)) 128 return 0; 129 if (*irq_ptr->dsci) 130 return 1; 131 else 132 return 0; 133 } 134 135 static inline u32 clear_shared_ind(void) 136 { 137 if (!atomic_read(&q_indicators[TIQDIO_SHARED_IND].count)) 138 return 0; 139 return xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0); 140 } 141 142 static inline void tiqdio_call_inq_handlers(struct qdio_irq *irq) 143 { 144 struct qdio_q *q; 145 int i; 146 147 for_each_input_queue(irq, q, i) { 148 if (!references_shared_dsci(irq) && 149 has_multiple_inq_on_dsci(irq)) 150 xchg(q->irq_ptr->dsci, 0); 151 152 if (q->u.in.queue_start_poll) { 153 /* skip if polling is enabled or already in work */ 154 if (test_and_set_bit(QDIO_QUEUE_IRQS_DISABLED, 155 &q->u.in.queue_irq_state)) { 156 qperf_inc(q, int_discarded); 157 continue; 158 } 159 160 /* avoid dsci clear here, done after processing */ 161 q->u.in.queue_start_poll(q->irq_ptr->cdev, q->nr, 162 q->irq_ptr->int_parm); 163 } else { 164 if (!shared_ind(q->irq_ptr)) 165 xchg(q->irq_ptr->dsci, 0); 166 167 /* 168 * Call inbound processing but not directly 169 * since that could starve other thinint queues. 170 */ 171 tasklet_schedule(&q->tasklet); 172 } 173 } 174 } 175 176 /** 177 * tiqdio_thinint_handler - thin interrupt handler for qdio 178 * @alsi: pointer to adapter local summary indicator 179 * @data: NULL 180 */ 181 static void tiqdio_thinint_handler(void *alsi, void *data) 182 { 183 u32 si_used = clear_shared_ind(); 184 struct qdio_q *q; 185 186 last_ai_time = S390_lowcore.int_clock; 187 kstat_cpu(smp_processor_id()).irqs[IOINT_QAI]++; 188 189 /* protect tiq_list entries, only changed in activate or shutdown */ 190 rcu_read_lock(); 191 192 /* check for work on all inbound thinint queues */ 193 list_for_each_entry_rcu(q, &tiq_list, entry) { 194 struct qdio_irq *irq; 195 196 /* only process queues from changed sets */ 197 irq = q->irq_ptr; 198 if (unlikely(references_shared_dsci(irq))) { 199 if (!si_used) 200 continue; 201 } else if (!*irq->dsci) 202 continue; 203 204 tiqdio_call_inq_handlers(irq); 205 206 qperf_inc(q, adapter_int); 207 } 208 rcu_read_unlock(); 209 } 210 211 static int set_subchannel_ind(struct qdio_irq *irq_ptr, int reset) 212 { 213 struct scssc_area *scssc_area; 214 int rc; 215 216 scssc_area = (struct scssc_area *)irq_ptr->chsc_page; 217 memset(scssc_area, 0, PAGE_SIZE); 218 219 if (reset) { 220 scssc_area->summary_indicator_addr = 0; 221 scssc_area->subchannel_indicator_addr = 0; 222 } else { 223 scssc_area->summary_indicator_addr = virt_to_phys(tiqdio_alsi); 224 scssc_area->subchannel_indicator_addr = 225 virt_to_phys(irq_ptr->dsci); 226 } 227 228 scssc_area->request = (struct chsc_header) { 229 .length = 0x0fe0, 230 .code = 0x0021, 231 }; 232 scssc_area->operation_code = 0; 233 scssc_area->ks = PAGE_DEFAULT_KEY >> 4; 234 scssc_area->kc = PAGE_DEFAULT_KEY >> 4; 235 scssc_area->isc = QDIO_AIRQ_ISC; 236 scssc_area->schid = irq_ptr->schid; 237 238 /* enable the time delay disablement facility */ 239 if (css_general_characteristics.aif_tdd) 240 scssc_area->word_with_d_bit = 0x10000000; 241 242 rc = chsc(scssc_area); 243 if (rc) 244 return -EIO; 245 246 rc = chsc_error_from_response(scssc_area->response.code); 247 if (rc) { 248 DBF_ERROR("%4x SSI r:%4x", irq_ptr->schid.sch_no, 249 scssc_area->response.code); 250 DBF_ERROR_HEX(&scssc_area->response, sizeof(void *)); 251 return rc; 252 } 253 254 DBF_EVENT("setscind"); 255 DBF_HEX(&scssc_area->summary_indicator_addr, sizeof(unsigned long)); 256 DBF_HEX(&scssc_area->subchannel_indicator_addr, sizeof(unsigned long)); 257 return 0; 258 } 259 260 /* allocate non-shared indicators and shared indicator */ 261 int __init tiqdio_allocate_memory(void) 262 { 263 q_indicators = kzalloc(sizeof(struct indicator_t) * TIQDIO_NR_INDICATORS, 264 GFP_KERNEL); 265 if (!q_indicators) 266 return -ENOMEM; 267 return 0; 268 } 269 270 void tiqdio_free_memory(void) 271 { 272 kfree(q_indicators); 273 } 274 275 int __init tiqdio_register_thinints(void) 276 { 277 isc_register(QDIO_AIRQ_ISC); 278 tiqdio_alsi = s390_register_adapter_interrupt(&tiqdio_thinint_handler, 279 NULL, QDIO_AIRQ_ISC); 280 if (IS_ERR(tiqdio_alsi)) { 281 DBF_EVENT("RTI:%lx", PTR_ERR(tiqdio_alsi)); 282 tiqdio_alsi = NULL; 283 isc_unregister(QDIO_AIRQ_ISC); 284 return -ENOMEM; 285 } 286 return 0; 287 } 288 289 int qdio_establish_thinint(struct qdio_irq *irq_ptr) 290 { 291 if (!is_thinint_irq(irq_ptr)) 292 return 0; 293 return set_subchannel_ind(irq_ptr, 0); 294 } 295 296 void qdio_setup_thinint(struct qdio_irq *irq_ptr) 297 { 298 if (!is_thinint_irq(irq_ptr)) 299 return; 300 irq_ptr->dsci = get_indicator(); 301 DBF_HEX(&irq_ptr->dsci, sizeof(void *)); 302 } 303 304 void qdio_shutdown_thinint(struct qdio_irq *irq_ptr) 305 { 306 if (!is_thinint_irq(irq_ptr)) 307 return; 308 309 /* reset adapter interrupt indicators */ 310 set_subchannel_ind(irq_ptr, 1); 311 put_indicator(irq_ptr->dsci); 312 } 313 314 void __exit tiqdio_unregister_thinints(void) 315 { 316 WARN_ON(!list_empty(&tiq_list)); 317 318 if (tiqdio_alsi) { 319 s390_unregister_adapter_interrupt(tiqdio_alsi, QDIO_AIRQ_ISC); 320 isc_unregister(QDIO_AIRQ_ISC); 321 } 322 } 323