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 list_add_rcu(&irq_ptr->input_qs[0]->entry, &tiq_list); 77 mutex_unlock(&tiq_list_lock); 78 xchg(irq_ptr->dsci, 1 << 7); 79 } 80 81 void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr) 82 { 83 struct qdio_q *q; 84 85 q = irq_ptr->input_qs[0]; 86 /* if establish triggered an error */ 87 if (!q || !q->entry.prev || !q->entry.next) 88 return; 89 90 mutex_lock(&tiq_list_lock); 91 list_del_rcu(&q->entry); 92 mutex_unlock(&tiq_list_lock); 93 synchronize_rcu(); 94 } 95 96 static inline int has_multiple_inq_on_dsci(struct qdio_irq *irq_ptr) 97 { 98 return irq_ptr->nr_input_qs > 1; 99 } 100 101 static inline int references_shared_dsci(struct qdio_irq *irq_ptr) 102 { 103 return irq_ptr->dsci == &q_indicators[TIQDIO_SHARED_IND].ind; 104 } 105 106 static inline int shared_ind(struct qdio_irq *irq_ptr) 107 { 108 return references_shared_dsci(irq_ptr) || 109 has_multiple_inq_on_dsci(irq_ptr); 110 } 111 112 void clear_nonshared_ind(struct qdio_irq *irq_ptr) 113 { 114 if (!is_thinint_irq(irq_ptr)) 115 return; 116 if (shared_ind(irq_ptr)) 117 return; 118 xchg(irq_ptr->dsci, 0); 119 } 120 121 int test_nonshared_ind(struct qdio_irq *irq_ptr) 122 { 123 if (!is_thinint_irq(irq_ptr)) 124 return 0; 125 if (shared_ind(irq_ptr)) 126 return 0; 127 if (*irq_ptr->dsci) 128 return 1; 129 else 130 return 0; 131 } 132 133 static inline u32 clear_shared_ind(void) 134 { 135 if (!atomic_read(&q_indicators[TIQDIO_SHARED_IND].count)) 136 return 0; 137 return xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0); 138 } 139 140 static inline void tiqdio_call_inq_handlers(struct qdio_irq *irq) 141 { 142 struct qdio_q *q; 143 int i; 144 145 for_each_input_queue(irq, q, i) { 146 if (!references_shared_dsci(irq) && 147 has_multiple_inq_on_dsci(irq)) 148 xchg(q->irq_ptr->dsci, 0); 149 150 if (q->u.in.queue_start_poll) { 151 /* skip if polling is enabled or already in work */ 152 if (test_and_set_bit(QDIO_QUEUE_IRQS_DISABLED, 153 &q->u.in.queue_irq_state)) { 154 qperf_inc(q, int_discarded); 155 continue; 156 } 157 158 /* avoid dsci clear here, done after processing */ 159 q->u.in.queue_start_poll(q->irq_ptr->cdev, q->nr, 160 q->irq_ptr->int_parm); 161 } else { 162 if (!shared_ind(q->irq_ptr)) 163 xchg(q->irq_ptr->dsci, 0); 164 165 /* 166 * Call inbound processing but not directly 167 * since that could starve other thinint queues. 168 */ 169 tasklet_schedule(&q->tasklet); 170 } 171 } 172 } 173 174 /** 175 * tiqdio_thinint_handler - thin interrupt handler for qdio 176 * @alsi: pointer to adapter local summary indicator 177 * @data: NULL 178 */ 179 static void tiqdio_thinint_handler(void *alsi, void *data) 180 { 181 u32 si_used = clear_shared_ind(); 182 struct qdio_q *q; 183 184 last_ai_time = S390_lowcore.int_clock; 185 kstat_cpu(smp_processor_id()).irqs[IOINT_QAI]++; 186 187 /* protect tiq_list entries, only changed in activate or shutdown */ 188 rcu_read_lock(); 189 190 /* check for work on all inbound thinint queues */ 191 list_for_each_entry_rcu(q, &tiq_list, entry) { 192 struct qdio_irq *irq; 193 194 /* only process queues from changed sets */ 195 irq = q->irq_ptr; 196 if (unlikely(references_shared_dsci(irq))) { 197 if (!si_used) 198 continue; 199 } else if (!*irq->dsci) 200 continue; 201 202 tiqdio_call_inq_handlers(irq); 203 204 qperf_inc(q, adapter_int); 205 } 206 rcu_read_unlock(); 207 } 208 209 static int set_subchannel_ind(struct qdio_irq *irq_ptr, int reset) 210 { 211 struct scssc_area *scssc_area; 212 int rc; 213 214 scssc_area = (struct scssc_area *)irq_ptr->chsc_page; 215 memset(scssc_area, 0, PAGE_SIZE); 216 217 if (reset) { 218 scssc_area->summary_indicator_addr = 0; 219 scssc_area->subchannel_indicator_addr = 0; 220 } else { 221 scssc_area->summary_indicator_addr = virt_to_phys(tiqdio_alsi); 222 scssc_area->subchannel_indicator_addr = 223 virt_to_phys(irq_ptr->dsci); 224 } 225 226 scssc_area->request = (struct chsc_header) { 227 .length = 0x0fe0, 228 .code = 0x0021, 229 }; 230 scssc_area->operation_code = 0; 231 scssc_area->ks = PAGE_DEFAULT_KEY >> 4; 232 scssc_area->kc = PAGE_DEFAULT_KEY >> 4; 233 scssc_area->isc = QDIO_AIRQ_ISC; 234 scssc_area->schid = irq_ptr->schid; 235 236 /* enable the time delay disablement facility */ 237 if (css_general_characteristics.aif_tdd) 238 scssc_area->word_with_d_bit = 0x10000000; 239 240 rc = chsc(scssc_area); 241 if (rc) 242 return -EIO; 243 244 rc = chsc_error_from_response(scssc_area->response.code); 245 if (rc) { 246 DBF_ERROR("%4x SSI r:%4x", irq_ptr->schid.sch_no, 247 scssc_area->response.code); 248 DBF_ERROR_HEX(&scssc_area->response, sizeof(void *)); 249 return rc; 250 } 251 252 DBF_EVENT("setscind"); 253 DBF_HEX(&scssc_area->summary_indicator_addr, sizeof(unsigned long)); 254 DBF_HEX(&scssc_area->subchannel_indicator_addr, sizeof(unsigned long)); 255 return 0; 256 } 257 258 /* allocate non-shared indicators and shared indicator */ 259 int __init tiqdio_allocate_memory(void) 260 { 261 q_indicators = kzalloc(sizeof(struct indicator_t) * TIQDIO_NR_INDICATORS, 262 GFP_KERNEL); 263 if (!q_indicators) 264 return -ENOMEM; 265 return 0; 266 } 267 268 void tiqdio_free_memory(void) 269 { 270 kfree(q_indicators); 271 } 272 273 int __init tiqdio_register_thinints(void) 274 { 275 isc_register(QDIO_AIRQ_ISC); 276 tiqdio_alsi = s390_register_adapter_interrupt(&tiqdio_thinint_handler, 277 NULL, QDIO_AIRQ_ISC); 278 if (IS_ERR(tiqdio_alsi)) { 279 DBF_EVENT("RTI:%lx", PTR_ERR(tiqdio_alsi)); 280 tiqdio_alsi = NULL; 281 isc_unregister(QDIO_AIRQ_ISC); 282 return -ENOMEM; 283 } 284 return 0; 285 } 286 287 int qdio_establish_thinint(struct qdio_irq *irq_ptr) 288 { 289 if (!is_thinint_irq(irq_ptr)) 290 return 0; 291 return set_subchannel_ind(irq_ptr, 0); 292 } 293 294 void qdio_setup_thinint(struct qdio_irq *irq_ptr) 295 { 296 if (!is_thinint_irq(irq_ptr)) 297 return; 298 irq_ptr->dsci = get_indicator(); 299 DBF_HEX(&irq_ptr->dsci, sizeof(void *)); 300 } 301 302 void qdio_shutdown_thinint(struct qdio_irq *irq_ptr) 303 { 304 if (!is_thinint_irq(irq_ptr)) 305 return; 306 307 /* reset adapter interrupt indicators */ 308 set_subchannel_ind(irq_ptr, 1); 309 put_indicator(irq_ptr->dsci); 310 } 311 312 void __exit tiqdio_unregister_thinints(void) 313 { 314 WARN_ON(!list_empty(&tiq_list)); 315 316 if (tiqdio_alsi) { 317 s390_unregister_adapter_interrupt(tiqdio_alsi, QDIO_AIRQ_ISC); 318 isc_unregister(QDIO_AIRQ_ISC); 319 } 320 } 321