1 // SPDX-License-Identifier: GPL-2.0 2 #define KMSG_COMPONENT "zpci" 3 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 4 5 #include <linux/kernel.h> 6 #include <linux/irq.h> 7 #include <linux/kernel_stat.h> 8 #include <linux/pci.h> 9 #include <linux/msi.h> 10 #include <linux/smp.h> 11 12 #include <asm/isc.h> 13 #include <asm/airq.h> 14 15 static enum {FLOATING, DIRECTED} irq_delivery; 16 17 #define SIC_IRQ_MODE_ALL 0 18 #define SIC_IRQ_MODE_SINGLE 1 19 #define SIC_IRQ_MODE_DIRECT 4 20 #define SIC_IRQ_MODE_D_ALL 16 21 #define SIC_IRQ_MODE_D_SINGLE 17 22 #define SIC_IRQ_MODE_SET_CPU 18 23 24 /* 25 * summary bit vector 26 * FLOATING - summary bit per function 27 * DIRECTED - summary bit per cpu (only used in fallback path) 28 */ 29 static struct airq_iv *zpci_sbv; 30 31 /* 32 * interrupt bit vectors 33 * FLOATING - interrupt bit vector per function 34 * DIRECTED - interrupt bit vector per cpu 35 */ 36 static struct airq_iv **zpci_ibv; 37 38 /* Modify PCI: Register floating adapter interruptions */ 39 static int zpci_set_airq(struct zpci_dev *zdev) 40 { 41 u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT); 42 struct zpci_fib fib = {0}; 43 u8 status; 44 45 fib.fmt0.isc = PCI_ISC; 46 fib.fmt0.sum = 1; /* enable summary notifications */ 47 fib.fmt0.noi = airq_iv_end(zdev->aibv); 48 fib.fmt0.aibv = virt_to_phys(zdev->aibv->vector); 49 fib.fmt0.aibvo = 0; /* each zdev has its own interrupt vector */ 50 fib.fmt0.aisb = virt_to_phys(zpci_sbv->vector) + (zdev->aisb / 64) * 8; 51 fib.fmt0.aisbo = zdev->aisb & 63; 52 53 return zpci_mod_fc(req, &fib, &status) ? -EIO : 0; 54 } 55 56 /* Modify PCI: Unregister floating adapter interruptions */ 57 static int zpci_clear_airq(struct zpci_dev *zdev) 58 { 59 u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_DEREG_INT); 60 struct zpci_fib fib = {0}; 61 u8 cc, status; 62 63 cc = zpci_mod_fc(req, &fib, &status); 64 if (cc == 3 || (cc == 1 && status == 24)) 65 /* Function already gone or IRQs already deregistered. */ 66 cc = 0; 67 68 return cc ? -EIO : 0; 69 } 70 71 /* Modify PCI: Register CPU directed interruptions */ 72 static int zpci_set_directed_irq(struct zpci_dev *zdev) 73 { 74 u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT_D); 75 struct zpci_fib fib = {0}; 76 u8 status; 77 78 fib.fmt = 1; 79 fib.fmt1.noi = zdev->msi_nr_irqs; 80 fib.fmt1.dibvo = zdev->msi_first_bit; 81 82 return zpci_mod_fc(req, &fib, &status) ? -EIO : 0; 83 } 84 85 /* Modify PCI: Unregister CPU directed interruptions */ 86 static int zpci_clear_directed_irq(struct zpci_dev *zdev) 87 { 88 u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_DEREG_INT_D); 89 struct zpci_fib fib = {0}; 90 u8 cc, status; 91 92 fib.fmt = 1; 93 cc = zpci_mod_fc(req, &fib, &status); 94 if (cc == 3 || (cc == 1 && status == 24)) 95 /* Function already gone or IRQs already deregistered. */ 96 cc = 0; 97 98 return cc ? -EIO : 0; 99 } 100 101 /* Register adapter interruptions */ 102 static int zpci_set_irq(struct zpci_dev *zdev) 103 { 104 int rc; 105 106 if (irq_delivery == DIRECTED) 107 rc = zpci_set_directed_irq(zdev); 108 else 109 rc = zpci_set_airq(zdev); 110 111 if (!rc) 112 zdev->irqs_registered = 1; 113 114 return rc; 115 } 116 117 /* Clear adapter interruptions */ 118 static int zpci_clear_irq(struct zpci_dev *zdev) 119 { 120 int rc; 121 122 if (irq_delivery == DIRECTED) 123 rc = zpci_clear_directed_irq(zdev); 124 else 125 rc = zpci_clear_airq(zdev); 126 127 if (!rc) 128 zdev->irqs_registered = 0; 129 130 return rc; 131 } 132 133 static int zpci_set_irq_affinity(struct irq_data *data, const struct cpumask *dest, 134 bool force) 135 { 136 struct msi_desc *entry = irq_get_msi_desc(data->irq); 137 struct msi_msg msg = entry->msg; 138 int cpu_addr = smp_cpu_get_cpu_address(cpumask_first(dest)); 139 140 msg.address_lo &= 0xff0000ff; 141 msg.address_lo |= (cpu_addr << 8); 142 pci_write_msi_msg(data->irq, &msg); 143 144 return IRQ_SET_MASK_OK; 145 } 146 147 static struct irq_chip zpci_irq_chip = { 148 .name = "PCI-MSI", 149 .irq_unmask = pci_msi_unmask_irq, 150 .irq_mask = pci_msi_mask_irq, 151 }; 152 153 static void zpci_handle_cpu_local_irq(bool rescan) 154 { 155 struct airq_iv *dibv = zpci_ibv[smp_processor_id()]; 156 unsigned long bit; 157 int irqs_on = 0; 158 159 for (bit = 0;;) { 160 /* Scan the directed IRQ bit vector */ 161 bit = airq_iv_scan(dibv, bit, airq_iv_end(dibv)); 162 if (bit == -1UL) { 163 if (!rescan || irqs_on++) 164 /* End of second scan with interrupts on. */ 165 break; 166 /* First scan complete, reenable interrupts. */ 167 if (zpci_set_irq_ctrl(SIC_IRQ_MODE_D_SINGLE, PCI_ISC)) 168 break; 169 bit = 0; 170 continue; 171 } 172 inc_irq_stat(IRQIO_MSI); 173 generic_handle_irq(airq_iv_get_data(dibv, bit)); 174 } 175 } 176 177 struct cpu_irq_data { 178 call_single_data_t csd; 179 atomic_t scheduled; 180 }; 181 static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_irq_data, irq_data); 182 183 static void zpci_handle_remote_irq(void *data) 184 { 185 atomic_t *scheduled = data; 186 187 do { 188 zpci_handle_cpu_local_irq(false); 189 } while (atomic_dec_return(scheduled)); 190 } 191 192 static void zpci_handle_fallback_irq(void) 193 { 194 struct cpu_irq_data *cpu_data; 195 unsigned long cpu; 196 int irqs_on = 0; 197 198 for (cpu = 0;;) { 199 cpu = airq_iv_scan(zpci_sbv, cpu, airq_iv_end(zpci_sbv)); 200 if (cpu == -1UL) { 201 if (irqs_on++) 202 /* End of second scan with interrupts on. */ 203 break; 204 /* First scan complete, reenable interrupts. */ 205 if (zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC)) 206 break; 207 cpu = 0; 208 continue; 209 } 210 cpu_data = &per_cpu(irq_data, cpu); 211 if (atomic_inc_return(&cpu_data->scheduled) > 1) 212 continue; 213 214 INIT_CSD(&cpu_data->csd, zpci_handle_remote_irq, &cpu_data->scheduled); 215 smp_call_function_single_async(cpu, &cpu_data->csd); 216 } 217 } 218 219 static void zpci_directed_irq_handler(struct airq_struct *airq, bool floating) 220 { 221 if (floating) { 222 inc_irq_stat(IRQIO_PCF); 223 zpci_handle_fallback_irq(); 224 } else { 225 inc_irq_stat(IRQIO_PCD); 226 zpci_handle_cpu_local_irq(true); 227 } 228 } 229 230 static void zpci_floating_irq_handler(struct airq_struct *airq, bool floating) 231 { 232 unsigned long si, ai; 233 struct airq_iv *aibv; 234 int irqs_on = 0; 235 236 inc_irq_stat(IRQIO_PCF); 237 for (si = 0;;) { 238 /* Scan adapter summary indicator bit vector */ 239 si = airq_iv_scan(zpci_sbv, si, airq_iv_end(zpci_sbv)); 240 if (si == -1UL) { 241 if (irqs_on++) 242 /* End of second scan with interrupts on. */ 243 break; 244 /* First scan complete, reenable interrupts. */ 245 if (zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC)) 246 break; 247 si = 0; 248 continue; 249 } 250 251 /* Scan the adapter interrupt vector for this device. */ 252 aibv = zpci_ibv[si]; 253 for (ai = 0;;) { 254 ai = airq_iv_scan(aibv, ai, airq_iv_end(aibv)); 255 if (ai == -1UL) 256 break; 257 inc_irq_stat(IRQIO_MSI); 258 airq_iv_lock(aibv, ai); 259 generic_handle_irq(airq_iv_get_data(aibv, ai)); 260 airq_iv_unlock(aibv, ai); 261 } 262 } 263 } 264 265 int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type) 266 { 267 struct zpci_dev *zdev = to_zpci(pdev); 268 unsigned int hwirq, msi_vecs, cpu; 269 unsigned long bit; 270 struct msi_desc *msi; 271 struct msi_msg msg; 272 int cpu_addr; 273 int rc, irq; 274 275 zdev->aisb = -1UL; 276 zdev->msi_first_bit = -1U; 277 if (type == PCI_CAP_ID_MSI && nvec > 1) 278 return 1; 279 msi_vecs = min_t(unsigned int, nvec, zdev->max_msi); 280 281 if (irq_delivery == DIRECTED) { 282 /* Allocate cpu vector bits */ 283 bit = airq_iv_alloc(zpci_ibv[0], msi_vecs); 284 if (bit == -1UL) 285 return -EIO; 286 } else { 287 /* Allocate adapter summary indicator bit */ 288 bit = airq_iv_alloc_bit(zpci_sbv); 289 if (bit == -1UL) 290 return -EIO; 291 zdev->aisb = bit; 292 293 /* Create adapter interrupt vector */ 294 zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA | AIRQ_IV_BITLOCK); 295 if (!zdev->aibv) 296 return -ENOMEM; 297 298 /* Wire up shortcut pointer */ 299 zpci_ibv[bit] = zdev->aibv; 300 /* Each function has its own interrupt vector */ 301 bit = 0; 302 } 303 304 /* Request MSI interrupts */ 305 hwirq = bit; 306 msi_for_each_desc(msi, &pdev->dev, MSI_DESC_NOTASSOCIATED) { 307 rc = -EIO; 308 if (hwirq - bit >= msi_vecs) 309 break; 310 irq = __irq_alloc_descs(-1, 0, 1, 0, THIS_MODULE, 311 (irq_delivery == DIRECTED) ? 312 msi->affinity : NULL); 313 if (irq < 0) 314 return -ENOMEM; 315 rc = irq_set_msi_desc(irq, msi); 316 if (rc) 317 return rc; 318 irq_set_chip_and_handler(irq, &zpci_irq_chip, 319 handle_percpu_irq); 320 msg.data = hwirq - bit; 321 if (irq_delivery == DIRECTED) { 322 if (msi->affinity) 323 cpu = cpumask_first(&msi->affinity->mask); 324 else 325 cpu = 0; 326 cpu_addr = smp_cpu_get_cpu_address(cpu); 327 328 msg.address_lo = zdev->msi_addr & 0xff0000ff; 329 msg.address_lo |= (cpu_addr << 8); 330 331 for_each_possible_cpu(cpu) { 332 airq_iv_set_data(zpci_ibv[cpu], hwirq, irq); 333 } 334 } else { 335 msg.address_lo = zdev->msi_addr & 0xffffffff; 336 airq_iv_set_data(zdev->aibv, hwirq, irq); 337 } 338 msg.address_hi = zdev->msi_addr >> 32; 339 pci_write_msi_msg(irq, &msg); 340 hwirq++; 341 } 342 343 zdev->msi_first_bit = bit; 344 zdev->msi_nr_irqs = msi_vecs; 345 346 rc = zpci_set_irq(zdev); 347 if (rc) 348 return rc; 349 350 return (msi_vecs == nvec) ? 0 : msi_vecs; 351 } 352 353 void arch_teardown_msi_irqs(struct pci_dev *pdev) 354 { 355 struct zpci_dev *zdev = to_zpci(pdev); 356 struct msi_desc *msi; 357 int rc; 358 359 /* Disable interrupts */ 360 rc = zpci_clear_irq(zdev); 361 if (rc) 362 return; 363 364 /* Release MSI interrupts */ 365 msi_for_each_desc(msi, &pdev->dev, MSI_DESC_ASSOCIATED) { 366 irq_set_msi_desc(msi->irq, NULL); 367 irq_free_desc(msi->irq); 368 msi->msg.address_lo = 0; 369 msi->msg.address_hi = 0; 370 msi->msg.data = 0; 371 msi->irq = 0; 372 } 373 374 if (zdev->aisb != -1UL) { 375 zpci_ibv[zdev->aisb] = NULL; 376 airq_iv_free_bit(zpci_sbv, zdev->aisb); 377 zdev->aisb = -1UL; 378 } 379 if (zdev->aibv) { 380 airq_iv_release(zdev->aibv); 381 zdev->aibv = NULL; 382 } 383 384 if ((irq_delivery == DIRECTED) && zdev->msi_first_bit != -1U) 385 airq_iv_free(zpci_ibv[0], zdev->msi_first_bit, zdev->msi_nr_irqs); 386 } 387 388 bool arch_restore_msi_irqs(struct pci_dev *pdev) 389 { 390 struct zpci_dev *zdev = to_zpci(pdev); 391 392 if (!zdev->irqs_registered) 393 zpci_set_irq(zdev); 394 return true; 395 } 396 397 static struct airq_struct zpci_airq = { 398 .handler = zpci_floating_irq_handler, 399 .isc = PCI_ISC, 400 }; 401 402 static void __init cpu_enable_directed_irq(void *unused) 403 { 404 union zpci_sic_iib iib = {{0}}; 405 406 iib.cdiib.dibv_addr = (u64) zpci_ibv[smp_processor_id()]->vector; 407 408 __zpci_set_irq_ctrl(SIC_IRQ_MODE_SET_CPU, 0, &iib); 409 zpci_set_irq_ctrl(SIC_IRQ_MODE_D_SINGLE, PCI_ISC); 410 } 411 412 static int __init zpci_directed_irq_init(void) 413 { 414 union zpci_sic_iib iib = {{0}}; 415 unsigned int cpu; 416 417 zpci_sbv = airq_iv_create(num_possible_cpus(), 0); 418 if (!zpci_sbv) 419 return -ENOMEM; 420 421 iib.diib.isc = PCI_ISC; 422 iib.diib.nr_cpus = num_possible_cpus(); 423 iib.diib.disb_addr = virt_to_phys(zpci_sbv->vector); 424 __zpci_set_irq_ctrl(SIC_IRQ_MODE_DIRECT, 0, &iib); 425 426 zpci_ibv = kcalloc(num_possible_cpus(), sizeof(*zpci_ibv), 427 GFP_KERNEL); 428 if (!zpci_ibv) 429 return -ENOMEM; 430 431 for_each_possible_cpu(cpu) { 432 /* 433 * Per CPU IRQ vectors look the same but bit-allocation 434 * is only done on the first vector. 435 */ 436 zpci_ibv[cpu] = airq_iv_create(cache_line_size() * BITS_PER_BYTE, 437 AIRQ_IV_DATA | 438 AIRQ_IV_CACHELINE | 439 (!cpu ? AIRQ_IV_ALLOC : 0)); 440 if (!zpci_ibv[cpu]) 441 return -ENOMEM; 442 } 443 on_each_cpu(cpu_enable_directed_irq, NULL, 1); 444 445 zpci_irq_chip.irq_set_affinity = zpci_set_irq_affinity; 446 447 return 0; 448 } 449 450 static int __init zpci_floating_irq_init(void) 451 { 452 zpci_ibv = kcalloc(ZPCI_NR_DEVICES, sizeof(*zpci_ibv), GFP_KERNEL); 453 if (!zpci_ibv) 454 return -ENOMEM; 455 456 zpci_sbv = airq_iv_create(ZPCI_NR_DEVICES, AIRQ_IV_ALLOC); 457 if (!zpci_sbv) 458 goto out_free; 459 460 return 0; 461 462 out_free: 463 kfree(zpci_ibv); 464 return -ENOMEM; 465 } 466 467 int __init zpci_irq_init(void) 468 { 469 int rc; 470 471 irq_delivery = sclp.has_dirq ? DIRECTED : FLOATING; 472 if (s390_pci_force_floating) 473 irq_delivery = FLOATING; 474 475 if (irq_delivery == DIRECTED) 476 zpci_airq.handler = zpci_directed_irq_handler; 477 478 rc = register_adapter_interrupt(&zpci_airq); 479 if (rc) 480 goto out; 481 /* Set summary to 1 to be called every time for the ISC. */ 482 *zpci_airq.lsi_ptr = 1; 483 484 switch (irq_delivery) { 485 case FLOATING: 486 rc = zpci_floating_irq_init(); 487 break; 488 case DIRECTED: 489 rc = zpci_directed_irq_init(); 490 break; 491 } 492 493 if (rc) 494 goto out_airq; 495 496 /* 497 * Enable floating IRQs (with suppression after one IRQ). When using 498 * directed IRQs this enables the fallback path. 499 */ 500 zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC); 501 502 return 0; 503 out_airq: 504 unregister_adapter_interrupt(&zpci_airq); 505 out: 506 return rc; 507 } 508 509 void __init zpci_irq_exit(void) 510 { 511 unsigned int cpu; 512 513 if (irq_delivery == DIRECTED) { 514 for_each_possible_cpu(cpu) { 515 airq_iv_release(zpci_ibv[cpu]); 516 } 517 } 518 kfree(zpci_ibv); 519 if (zpci_sbv) 520 airq_iv_release(zpci_sbv); 521 unregister_adapter_interrupt(&zpci_airq); 522 } 523