| 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 | if (!references_shared_dsci(irq) && |
| 146 | has_multiple_inq_on_dsci(irq)) |
| 147 | xchg(irq->dsci, 0); |
| 148 | |
| 149 | for_each_input_queue(irq, q, i) { |
| 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 | inc_irq_stat(IRQIO_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 | } |