Jan Glauber | 779e6e1 | 2008-07-17 17:16:48 +0200 | [diff] [blame] | 1 | /* |
| 2 | * linux/drivers/s390/cio/thinint_qdio.c |
| 3 | * |
| 4 | * thin interrupt support for qdio |
| 5 | * |
| 6 | * Copyright 2000-2008 IBM Corp. |
| 7 | * Author(s): Utz Bacher <utz.bacher@de.ibm.com> |
| 8 | * Cornelia Huck <cornelia.huck@de.ibm.com> |
| 9 | * Jan Glauber <jang@linux.vnet.ibm.com> |
| 10 | */ |
| 11 | #include <linux/io.h> |
| 12 | #include <asm/atomic.h> |
| 13 | #include <asm/debug.h> |
| 14 | #include <asm/qdio.h> |
| 15 | #include <asm/airq.h> |
| 16 | #include <asm/isc.h> |
| 17 | |
| 18 | #include "cio.h" |
| 19 | #include "ioasm.h" |
| 20 | #include "qdio.h" |
| 21 | #include "qdio_debug.h" |
| 22 | #include "qdio_perf.h" |
| 23 | |
| 24 | /* |
| 25 | * Restriction: only 63 iqdio subchannels would have its own indicator, |
| 26 | * after that, subsequent subchannels share one indicator |
| 27 | */ |
| 28 | #define TIQDIO_NR_NONSHARED_IND 63 |
| 29 | #define TIQDIO_NR_INDICATORS (TIQDIO_NR_NONSHARED_IND + 1) |
| 30 | #define TIQDIO_SHARED_IND 63 |
| 31 | |
| 32 | /* list of thin interrupt input queues */ |
| 33 | static LIST_HEAD(tiq_list); |
| 34 | |
| 35 | /* adapter local summary indicator */ |
| 36 | static unsigned char *tiqdio_alsi; |
| 37 | |
| 38 | /* device state change indicators */ |
| 39 | struct indicator_t { |
| 40 | u32 ind; /* u32 because of compare-and-swap performance */ |
| 41 | atomic_t count; /* use count, 0 or 1 for non-shared indicators */ |
| 42 | }; |
| 43 | static struct indicator_t *q_indicators; |
| 44 | |
| 45 | static void tiqdio_tasklet_fn(unsigned long data); |
| 46 | static DECLARE_TASKLET(tiqdio_tasklet, tiqdio_tasklet_fn, 0); |
| 47 | |
| 48 | static int css_qdio_omit_svs; |
| 49 | |
| 50 | static inline unsigned long do_clear_global_summary(void) |
| 51 | { |
| 52 | register unsigned long __fn asm("1") = 3; |
| 53 | register unsigned long __tmp asm("2"); |
| 54 | register unsigned long __time asm("3"); |
| 55 | |
| 56 | asm volatile( |
| 57 | " .insn rre,0xb2650000,2,0" |
| 58 | : "+d" (__fn), "=d" (__tmp), "=d" (__time)); |
| 59 | return __time; |
| 60 | } |
| 61 | |
| 62 | /* returns addr for the device state change indicator */ |
| 63 | static u32 *get_indicator(void) |
| 64 | { |
| 65 | int i; |
| 66 | |
| 67 | for (i = 0; i < TIQDIO_NR_NONSHARED_IND; i++) |
| 68 | if (!atomic_read(&q_indicators[i].count)) { |
| 69 | atomic_set(&q_indicators[i].count, 1); |
| 70 | return &q_indicators[i].ind; |
| 71 | } |
| 72 | |
| 73 | /* use the shared indicator */ |
| 74 | atomic_inc(&q_indicators[TIQDIO_SHARED_IND].count); |
| 75 | return &q_indicators[TIQDIO_SHARED_IND].ind; |
| 76 | } |
| 77 | |
| 78 | static void put_indicator(u32 *addr) |
| 79 | { |
| 80 | int i; |
| 81 | |
| 82 | if (!addr) |
| 83 | return; |
| 84 | i = ((unsigned long)addr - (unsigned long)q_indicators) / |
| 85 | sizeof(struct indicator_t); |
| 86 | atomic_dec(&q_indicators[i].count); |
| 87 | } |
| 88 | |
| 89 | void tiqdio_add_input_queues(struct qdio_irq *irq_ptr) |
| 90 | { |
| 91 | struct qdio_q *q; |
| 92 | int i; |
| 93 | |
| 94 | /* No TDD facility? If we must use SIGA-s we can also omit SVS. */ |
| 95 | if (!css_qdio_omit_svs && irq_ptr->siga_flag.sync) |
| 96 | css_qdio_omit_svs = 1; |
| 97 | |
| 98 | for_each_input_queue(irq_ptr, q, i) { |
| 99 | list_add_rcu(&q->entry, &tiq_list); |
| 100 | synchronize_rcu(); |
| 101 | } |
| 102 | xchg(irq_ptr->dsci, 1); |
| 103 | tasklet_schedule(&tiqdio_tasklet); |
| 104 | } |
| 105 | |
| 106 | /* |
| 107 | * we cannot stop the tiqdio tasklet here since it is for all |
| 108 | * thinint qdio devices and it must run as long as there is a |
| 109 | * thinint device left |
| 110 | */ |
| 111 | void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr) |
| 112 | { |
| 113 | struct qdio_q *q; |
| 114 | int i; |
| 115 | |
Jan Glauber | 53b41ba | 2008-08-21 19:46:33 +0200 | [diff] [blame] | 116 | for (i = 0; i < irq_ptr->nr_input_qs; i++) { |
| 117 | q = irq_ptr->input_qs[i]; |
| 118 | /* if establish triggered an error */ |
| 119 | if (!q || !q->entry.prev || !q->entry.next) |
| 120 | continue; |
Jan Glauber | 779e6e1 | 2008-07-17 17:16:48 +0200 | [diff] [blame] | 121 | list_del_rcu(&q->entry); |
| 122 | synchronize_rcu(); |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | static inline int tiqdio_inbound_q_done(struct qdio_q *q) |
| 127 | { |
Jan Glauber | 9a1ce28 | 2008-12-25 13:38:45 +0100 | [diff] [blame] | 128 | unsigned char state = 0; |
Jan Glauber | 779e6e1 | 2008-07-17 17:16:48 +0200 | [diff] [blame] | 129 | |
| 130 | if (!atomic_read(&q->nr_buf_used)) |
| 131 | return 1; |
| 132 | |
| 133 | qdio_siga_sync_q(q); |
| 134 | get_buf_state(q, q->first_to_check, &state); |
| 135 | |
| 136 | if (state == SLSB_P_INPUT_PRIMED) |
| 137 | /* more work coming */ |
| 138 | return 0; |
| 139 | return 1; |
| 140 | } |
| 141 | |
| 142 | static inline int shared_ind(struct qdio_irq *irq_ptr) |
| 143 | { |
| 144 | return irq_ptr->dsci == &q_indicators[TIQDIO_SHARED_IND].ind; |
| 145 | } |
| 146 | |
| 147 | static void __tiqdio_inbound_processing(struct qdio_q *q) |
| 148 | { |
| 149 | qdio_perf_stat_inc(&perf_stats.thinint_inbound); |
| 150 | qdio_sync_after_thinint(q); |
| 151 | |
| 152 | /* |
| 153 | * Maybe we have work on our outbound queues... at least |
| 154 | * we have to check the PCI capable queues. |
| 155 | */ |
| 156 | qdio_check_outbound_after_thinint(q); |
| 157 | |
| 158 | again: |
| 159 | if (!qdio_inbound_q_moved(q)) |
| 160 | return; |
| 161 | |
| 162 | qdio_kick_inbound_handler(q); |
| 163 | |
| 164 | if (!tiqdio_inbound_q_done(q)) { |
| 165 | qdio_perf_stat_inc(&perf_stats.thinint_inbound_loop); |
| 166 | goto again; |
| 167 | } |
| 168 | |
| 169 | qdio_stop_polling(q); |
| 170 | /* |
| 171 | * We need to check again to not lose initiative after |
| 172 | * resetting the ACK state. |
| 173 | */ |
| 174 | if (!tiqdio_inbound_q_done(q)) { |
| 175 | qdio_perf_stat_inc(&perf_stats.thinint_inbound_loop2); |
| 176 | goto again; |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | void tiqdio_inbound_processing(unsigned long data) |
| 181 | { |
| 182 | struct qdio_q *q = (struct qdio_q *)data; |
| 183 | |
| 184 | __tiqdio_inbound_processing(q); |
| 185 | } |
| 186 | |
| 187 | /* check for work on all inbound thinint queues */ |
| 188 | static void tiqdio_tasklet_fn(unsigned long data) |
| 189 | { |
| 190 | struct qdio_q *q; |
| 191 | |
| 192 | qdio_perf_stat_inc(&perf_stats.tasklet_thinint); |
| 193 | again: |
| 194 | |
| 195 | /* protect tiq_list entries, only changed in activate or shutdown */ |
| 196 | rcu_read_lock(); |
| 197 | |
| 198 | list_for_each_entry_rcu(q, &tiq_list, entry) |
| 199 | /* only process queues from changed sets */ |
| 200 | if (*q->irq_ptr->dsci) { |
| 201 | |
| 202 | /* only clear it if the indicator is non-shared */ |
| 203 | if (!shared_ind(q->irq_ptr)) |
| 204 | xchg(q->irq_ptr->dsci, 0); |
| 205 | /* |
| 206 | * don't call inbound processing directly since |
| 207 | * that could starve other thinint queues |
| 208 | */ |
| 209 | tasklet_schedule(&q->tasklet); |
| 210 | } |
| 211 | |
| 212 | rcu_read_unlock(); |
| 213 | |
| 214 | /* |
| 215 | * if we used the shared indicator clear it now after all queues |
| 216 | * were processed |
| 217 | */ |
| 218 | if (atomic_read(&q_indicators[TIQDIO_SHARED_IND].count)) { |
| 219 | xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 0); |
| 220 | |
| 221 | /* prevent racing */ |
| 222 | if (*tiqdio_alsi) |
| 223 | xchg(&q_indicators[TIQDIO_SHARED_IND].ind, 1); |
| 224 | } |
| 225 | |
| 226 | /* check for more work */ |
| 227 | if (*tiqdio_alsi) { |
| 228 | xchg(tiqdio_alsi, 0); |
| 229 | qdio_perf_stat_inc(&perf_stats.tasklet_thinint_loop); |
| 230 | goto again; |
| 231 | } |
| 232 | } |
| 233 | |
| 234 | /** |
| 235 | * tiqdio_thinint_handler - thin interrupt handler for qdio |
| 236 | * @ind: pointer to adapter local summary indicator |
| 237 | * @drv_data: NULL |
| 238 | */ |
| 239 | static void tiqdio_thinint_handler(void *ind, void *drv_data) |
| 240 | { |
| 241 | qdio_perf_stat_inc(&perf_stats.thin_int); |
| 242 | |
| 243 | /* |
| 244 | * SVS only when needed: issue SVS to benefit from iqdio interrupt |
| 245 | * avoidance (SVS clears adapter interrupt suppression overwrite) |
| 246 | */ |
| 247 | if (!css_qdio_omit_svs) |
| 248 | do_clear_global_summary(); |
| 249 | |
| 250 | /* |
| 251 | * reset local summary indicator (tiqdio_alsi) to stop adapter |
| 252 | * interrupts for now, the tasklet will clean all dsci's |
| 253 | */ |
| 254 | xchg((u8 *)ind, 0); |
| 255 | tasklet_hi_schedule(&tiqdio_tasklet); |
| 256 | } |
| 257 | |
| 258 | static int set_subchannel_ind(struct qdio_irq *irq_ptr, int reset) |
| 259 | { |
| 260 | struct scssc_area *scssc_area; |
Jan Glauber | 779e6e1 | 2008-07-17 17:16:48 +0200 | [diff] [blame] | 261 | int rc; |
| 262 | |
| 263 | scssc_area = (struct scssc_area *)irq_ptr->chsc_page; |
| 264 | memset(scssc_area, 0, PAGE_SIZE); |
| 265 | |
| 266 | if (reset) { |
| 267 | scssc_area->summary_indicator_addr = 0; |
| 268 | scssc_area->subchannel_indicator_addr = 0; |
| 269 | } else { |
| 270 | scssc_area->summary_indicator_addr = virt_to_phys(tiqdio_alsi); |
| 271 | scssc_area->subchannel_indicator_addr = |
| 272 | virt_to_phys(irq_ptr->dsci); |
| 273 | } |
| 274 | |
| 275 | scssc_area->request = (struct chsc_header) { |
| 276 | .length = 0x0fe0, |
| 277 | .code = 0x0021, |
| 278 | }; |
| 279 | scssc_area->operation_code = 0; |
| 280 | scssc_area->ks = PAGE_DEFAULT_KEY; |
| 281 | scssc_area->kc = PAGE_DEFAULT_KEY; |
| 282 | scssc_area->isc = QDIO_AIRQ_ISC; |
| 283 | scssc_area->schid = irq_ptr->schid; |
| 284 | |
| 285 | /* enable the time delay disablement facility */ |
| 286 | if (css_general_characteristics.aif_tdd) |
| 287 | scssc_area->word_with_d_bit = 0x10000000; |
| 288 | |
| 289 | rc = chsc(scssc_area); |
| 290 | if (rc) |
| 291 | return -EIO; |
| 292 | |
| 293 | rc = chsc_error_from_response(scssc_area->response.code); |
| 294 | if (rc) { |
Jan Glauber | 22f9934 | 2008-12-25 13:38:46 +0100 | [diff] [blame^] | 295 | DBF_ERROR("%4x SSI r:%4x", irq_ptr->schid.sch_no, |
| 296 | scssc_area->response.code); |
| 297 | DBF_ERROR_HEX(&scssc_area->response, sizeof(void *)); |
Jan Glauber | 779e6e1 | 2008-07-17 17:16:48 +0200 | [diff] [blame] | 298 | return rc; |
| 299 | } |
| 300 | |
Jan Glauber | 22f9934 | 2008-12-25 13:38:46 +0100 | [diff] [blame^] | 301 | DBF_EVENT("setscind"); |
| 302 | DBF_HEX(&scssc_area->summary_indicator_addr, sizeof(unsigned long)); |
| 303 | DBF_HEX(&scssc_area->subchannel_indicator_addr, sizeof(unsigned long)); |
Jan Glauber | 779e6e1 | 2008-07-17 17:16:48 +0200 | [diff] [blame] | 304 | return 0; |
| 305 | } |
| 306 | |
| 307 | /* allocate non-shared indicators and shared indicator */ |
| 308 | int __init tiqdio_allocate_memory(void) |
| 309 | { |
| 310 | q_indicators = kzalloc(sizeof(struct indicator_t) * TIQDIO_NR_INDICATORS, |
| 311 | GFP_KERNEL); |
| 312 | if (!q_indicators) |
| 313 | return -ENOMEM; |
| 314 | return 0; |
| 315 | } |
| 316 | |
| 317 | void tiqdio_free_memory(void) |
| 318 | { |
| 319 | kfree(q_indicators); |
| 320 | } |
| 321 | |
| 322 | int __init tiqdio_register_thinints(void) |
| 323 | { |
Jan Glauber | 779e6e1 | 2008-07-17 17:16:48 +0200 | [diff] [blame] | 324 | isc_register(QDIO_AIRQ_ISC); |
| 325 | tiqdio_alsi = s390_register_adapter_interrupt(&tiqdio_thinint_handler, |
| 326 | NULL, QDIO_AIRQ_ISC); |
| 327 | if (IS_ERR(tiqdio_alsi)) { |
Jan Glauber | 22f9934 | 2008-12-25 13:38:46 +0100 | [diff] [blame^] | 328 | DBF_EVENT("RTI:%lx", PTR_ERR(tiqdio_alsi)); |
Jan Glauber | 779e6e1 | 2008-07-17 17:16:48 +0200 | [diff] [blame] | 329 | tiqdio_alsi = NULL; |
| 330 | isc_unregister(QDIO_AIRQ_ISC); |
| 331 | return -ENOMEM; |
| 332 | } |
| 333 | return 0; |
| 334 | } |
| 335 | |
| 336 | int qdio_establish_thinint(struct qdio_irq *irq_ptr) |
| 337 | { |
| 338 | if (!is_thinint_irq(irq_ptr)) |
| 339 | return 0; |
| 340 | |
| 341 | /* Check for aif time delay disablement. If installed, |
| 342 | * omit SVS even under LPAR |
| 343 | */ |
| 344 | if (css_general_characteristics.aif_tdd) |
| 345 | css_qdio_omit_svs = 1; |
| 346 | return set_subchannel_ind(irq_ptr, 0); |
| 347 | } |
| 348 | |
| 349 | void qdio_setup_thinint(struct qdio_irq *irq_ptr) |
| 350 | { |
| 351 | if (!is_thinint_irq(irq_ptr)) |
| 352 | return; |
| 353 | irq_ptr->dsci = get_indicator(); |
Jan Glauber | 22f9934 | 2008-12-25 13:38:46 +0100 | [diff] [blame^] | 354 | DBF_HEX(&irq_ptr->dsci, sizeof(void *)); |
Jan Glauber | 779e6e1 | 2008-07-17 17:16:48 +0200 | [diff] [blame] | 355 | } |
| 356 | |
| 357 | void qdio_shutdown_thinint(struct qdio_irq *irq_ptr) |
| 358 | { |
| 359 | if (!is_thinint_irq(irq_ptr)) |
| 360 | return; |
| 361 | |
| 362 | /* reset adapter interrupt indicators */ |
| 363 | put_indicator(irq_ptr->dsci); |
| 364 | set_subchannel_ind(irq_ptr, 1); |
| 365 | } |
| 366 | |
| 367 | void __exit tiqdio_unregister_thinints(void) |
| 368 | { |
| 369 | tasklet_disable(&tiqdio_tasklet); |
| 370 | |
| 371 | if (tiqdio_alsi) { |
| 372 | s390_unregister_adapter_interrupt(tiqdio_alsi, QDIO_AIRQ_ISC); |
| 373 | isc_unregister(QDIO_AIRQ_ISC); |
| 374 | } |
| 375 | } |