1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2021 Western Digital Corporation or its affiliates. 4 * Copyright (C) 2022 Ventana Micro Systems Inc. 5 * 6 * Authors: 7 * Anup Patel <apatel@ventanamicro.com> 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/bitops.h> 12 #include <linux/irq.h> 13 #include <linux/irqdomain.h> 14 #include <linux/kvm_host.h> 15 #include <linux/percpu.h> 16 #include <linux/spinlock.h> 17 #include <asm/hwcap.h> 18 #include <asm/kvm_aia_imsic.h> 19 20 struct aia_hgei_control { 21 raw_spinlock_t lock; 22 unsigned long free_bitmap; 23 struct kvm_vcpu *owners[BITS_PER_LONG]; 24 }; 25 static DEFINE_PER_CPU(struct aia_hgei_control, aia_hgei); 26 static int hgei_parent_irq; 27 28 unsigned int kvm_riscv_aia_nr_hgei; 29 unsigned int kvm_riscv_aia_max_ids; 30 DEFINE_STATIC_KEY_FALSE(kvm_riscv_aia_available); 31 32 static int aia_find_hgei(struct kvm_vcpu *owner) 33 { 34 int i, hgei; 35 unsigned long flags; 36 struct aia_hgei_control *hgctrl = get_cpu_ptr(&aia_hgei); 37 38 raw_spin_lock_irqsave(&hgctrl->lock, flags); 39 40 hgei = -1; 41 for (i = 1; i <= kvm_riscv_aia_nr_hgei; i++) { 42 if (hgctrl->owners[i] == owner) { 43 hgei = i; 44 break; 45 } 46 } 47 48 raw_spin_unlock_irqrestore(&hgctrl->lock, flags); 49 50 put_cpu_ptr(&aia_hgei); 51 return hgei; 52 } 53 54 static void aia_set_hvictl(bool ext_irq_pending) 55 { 56 unsigned long hvictl; 57 58 /* 59 * HVICTL.IID == 9 and HVICTL.IPRIO == 0 represents 60 * no interrupt in HVICTL. 61 */ 62 63 hvictl = (IRQ_S_EXT << HVICTL_IID_SHIFT) & HVICTL_IID; 64 hvictl |= ext_irq_pending; 65 csr_write(CSR_HVICTL, hvictl); 66 } 67 68 #ifdef CONFIG_32BIT 69 void kvm_riscv_vcpu_aia_flush_interrupts(struct kvm_vcpu *vcpu) 70 { 71 struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr; 72 unsigned long mask, val; 73 74 if (!kvm_riscv_aia_available()) 75 return; 76 77 if (READ_ONCE(vcpu->arch.irqs_pending_mask[1])) { 78 mask = xchg_acquire(&vcpu->arch.irqs_pending_mask[1], 0); 79 val = READ_ONCE(vcpu->arch.irqs_pending[1]) & mask; 80 81 csr->hviph &= ~mask; 82 csr->hviph |= val; 83 } 84 } 85 86 void kvm_riscv_vcpu_aia_sync_interrupts(struct kvm_vcpu *vcpu) 87 { 88 struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr; 89 90 if (kvm_riscv_aia_available()) 91 csr->vsieh = csr_read(CSR_VSIEH); 92 } 93 #endif 94 95 bool kvm_riscv_vcpu_aia_has_interrupts(struct kvm_vcpu *vcpu, u64 mask) 96 { 97 int hgei; 98 unsigned long seip; 99 100 if (!kvm_riscv_aia_available()) 101 return false; 102 103 #ifdef CONFIG_32BIT 104 if (READ_ONCE(vcpu->arch.irqs_pending[1]) & 105 (vcpu->arch.aia_context.guest_csr.vsieh & upper_32_bits(mask))) 106 return true; 107 #endif 108 109 seip = vcpu->arch.guest_csr.vsie; 110 seip &= (unsigned long)mask; 111 seip &= BIT(IRQ_S_EXT); 112 113 if (!kvm_riscv_aia_initialized(vcpu->kvm) || !seip) 114 return false; 115 116 hgei = aia_find_hgei(vcpu); 117 if (hgei > 0) 118 return !!(csr_read(CSR_HGEIP) & BIT(hgei)); 119 120 return false; 121 } 122 123 void kvm_riscv_vcpu_aia_update_hvip(struct kvm_vcpu *vcpu) 124 { 125 struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; 126 127 if (!kvm_riscv_aia_available()) 128 return; 129 130 #ifdef CONFIG_32BIT 131 csr_write(CSR_HVIPH, vcpu->arch.aia_context.guest_csr.hviph); 132 #endif 133 aia_set_hvictl(!!(csr->hvip & BIT(IRQ_VS_EXT))); 134 } 135 136 void kvm_riscv_vcpu_aia_load(struct kvm_vcpu *vcpu, int cpu) 137 { 138 struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr; 139 140 if (!kvm_riscv_aia_available()) 141 return; 142 143 csr_write(CSR_VSISELECT, csr->vsiselect); 144 csr_write(CSR_HVIPRIO1, csr->hviprio1); 145 csr_write(CSR_HVIPRIO2, csr->hviprio2); 146 #ifdef CONFIG_32BIT 147 csr_write(CSR_VSIEH, csr->vsieh); 148 csr_write(CSR_HVIPH, csr->hviph); 149 csr_write(CSR_HVIPRIO1H, csr->hviprio1h); 150 csr_write(CSR_HVIPRIO2H, csr->hviprio2h); 151 #endif 152 } 153 154 void kvm_riscv_vcpu_aia_put(struct kvm_vcpu *vcpu) 155 { 156 struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr; 157 158 if (!kvm_riscv_aia_available()) 159 return; 160 161 csr->vsiselect = csr_read(CSR_VSISELECT); 162 csr->hviprio1 = csr_read(CSR_HVIPRIO1); 163 csr->hviprio2 = csr_read(CSR_HVIPRIO2); 164 #ifdef CONFIG_32BIT 165 csr->vsieh = csr_read(CSR_VSIEH); 166 csr->hviph = csr_read(CSR_HVIPH); 167 csr->hviprio1h = csr_read(CSR_HVIPRIO1H); 168 csr->hviprio2h = csr_read(CSR_HVIPRIO2H); 169 #endif 170 } 171 172 int kvm_riscv_vcpu_aia_get_csr(struct kvm_vcpu *vcpu, 173 unsigned long reg_num, 174 unsigned long *out_val) 175 { 176 struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr; 177 178 if (reg_num >= sizeof(struct kvm_riscv_aia_csr) / sizeof(unsigned long)) 179 return -ENOENT; 180 181 *out_val = 0; 182 if (kvm_riscv_aia_available()) 183 *out_val = ((unsigned long *)csr)[reg_num]; 184 185 return 0; 186 } 187 188 int kvm_riscv_vcpu_aia_set_csr(struct kvm_vcpu *vcpu, 189 unsigned long reg_num, 190 unsigned long val) 191 { 192 struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr; 193 194 if (reg_num >= sizeof(struct kvm_riscv_aia_csr) / sizeof(unsigned long)) 195 return -ENOENT; 196 197 if (kvm_riscv_aia_available()) { 198 ((unsigned long *)csr)[reg_num] = val; 199 200 #ifdef CONFIG_32BIT 201 if (reg_num == KVM_REG_RISCV_CSR_AIA_REG(siph)) 202 WRITE_ONCE(vcpu->arch.irqs_pending_mask[1], 0); 203 #endif 204 } 205 206 return 0; 207 } 208 209 int kvm_riscv_vcpu_aia_rmw_topei(struct kvm_vcpu *vcpu, 210 unsigned int csr_num, 211 unsigned long *val, 212 unsigned long new_val, 213 unsigned long wr_mask) 214 { 215 /* If AIA not available then redirect trap */ 216 if (!kvm_riscv_aia_available()) 217 return KVM_INSN_ILLEGAL_TRAP; 218 219 /* If AIA not initialized then forward to user space */ 220 if (!kvm_riscv_aia_initialized(vcpu->kvm)) 221 return KVM_INSN_EXIT_TO_USER_SPACE; 222 223 return kvm_riscv_vcpu_aia_imsic_rmw(vcpu, KVM_RISCV_AIA_IMSIC_TOPEI, 224 val, new_val, wr_mask); 225 } 226 227 /* 228 * External IRQ priority always read-only zero. This means default 229 * priority order is always preferred for external IRQs unless 230 * HVICTL.IID == 9 and HVICTL.IPRIO != 0 231 */ 232 static int aia_irq2bitpos[] = { 233 0, 8, -1, -1, 16, 24, -1, -1, /* 0 - 7 */ 234 32, -1, -1, -1, -1, 40, 48, 56, /* 8 - 15 */ 235 64, 72, 80, 88, 96, 104, 112, 120, /* 16 - 23 */ 236 -1, -1, -1, -1, -1, -1, -1, -1, /* 24 - 31 */ 237 -1, -1, -1, -1, -1, -1, -1, -1, /* 32 - 39 */ 238 -1, -1, -1, -1, -1, -1, -1, -1, /* 40 - 47 */ 239 -1, -1, -1, -1, -1, -1, -1, -1, /* 48 - 55 */ 240 -1, -1, -1, -1, -1, -1, -1, -1, /* 56 - 63 */ 241 }; 242 243 static u8 aia_get_iprio8(struct kvm_vcpu *vcpu, unsigned int irq) 244 { 245 unsigned long hviprio; 246 int bitpos = aia_irq2bitpos[irq]; 247 248 if (bitpos < 0) 249 return 0; 250 251 switch (bitpos / BITS_PER_LONG) { 252 case 0: 253 hviprio = csr_read(CSR_HVIPRIO1); 254 break; 255 case 1: 256 #ifndef CONFIG_32BIT 257 hviprio = csr_read(CSR_HVIPRIO2); 258 break; 259 #else 260 hviprio = csr_read(CSR_HVIPRIO1H); 261 break; 262 case 2: 263 hviprio = csr_read(CSR_HVIPRIO2); 264 break; 265 case 3: 266 hviprio = csr_read(CSR_HVIPRIO2H); 267 break; 268 #endif 269 default: 270 return 0; 271 } 272 273 return (hviprio >> (bitpos % BITS_PER_LONG)) & TOPI_IPRIO_MASK; 274 } 275 276 static void aia_set_iprio8(struct kvm_vcpu *vcpu, unsigned int irq, u8 prio) 277 { 278 unsigned long hviprio; 279 int bitpos = aia_irq2bitpos[irq]; 280 281 if (bitpos < 0) 282 return; 283 284 switch (bitpos / BITS_PER_LONG) { 285 case 0: 286 hviprio = csr_read(CSR_HVIPRIO1); 287 break; 288 case 1: 289 #ifndef CONFIG_32BIT 290 hviprio = csr_read(CSR_HVIPRIO2); 291 break; 292 #else 293 hviprio = csr_read(CSR_HVIPRIO1H); 294 break; 295 case 2: 296 hviprio = csr_read(CSR_HVIPRIO2); 297 break; 298 case 3: 299 hviprio = csr_read(CSR_HVIPRIO2H); 300 break; 301 #endif 302 default: 303 return; 304 } 305 306 hviprio &= ~(TOPI_IPRIO_MASK << (bitpos % BITS_PER_LONG)); 307 hviprio |= (unsigned long)prio << (bitpos % BITS_PER_LONG); 308 309 switch (bitpos / BITS_PER_LONG) { 310 case 0: 311 csr_write(CSR_HVIPRIO1, hviprio); 312 break; 313 case 1: 314 #ifndef CONFIG_32BIT 315 csr_write(CSR_HVIPRIO2, hviprio); 316 break; 317 #else 318 csr_write(CSR_HVIPRIO1H, hviprio); 319 break; 320 case 2: 321 csr_write(CSR_HVIPRIO2, hviprio); 322 break; 323 case 3: 324 csr_write(CSR_HVIPRIO2H, hviprio); 325 break; 326 #endif 327 default: 328 return; 329 } 330 } 331 332 static int aia_rmw_iprio(struct kvm_vcpu *vcpu, unsigned int isel, 333 unsigned long *val, unsigned long new_val, 334 unsigned long wr_mask) 335 { 336 int i, first_irq, nirqs; 337 unsigned long old_val; 338 u8 prio; 339 340 #ifndef CONFIG_32BIT 341 if (isel & 0x1) 342 return KVM_INSN_ILLEGAL_TRAP; 343 #endif 344 345 nirqs = 4 * (BITS_PER_LONG / 32); 346 first_irq = (isel - ISELECT_IPRIO0) * 4; 347 348 old_val = 0; 349 for (i = 0; i < nirqs; i++) { 350 prio = aia_get_iprio8(vcpu, first_irq + i); 351 old_val |= (unsigned long)prio << (TOPI_IPRIO_BITS * i); 352 } 353 354 if (val) 355 *val = old_val; 356 357 if (wr_mask) { 358 new_val = (old_val & ~wr_mask) | (new_val & wr_mask); 359 for (i = 0; i < nirqs; i++) { 360 prio = (new_val >> (TOPI_IPRIO_BITS * i)) & 361 TOPI_IPRIO_MASK; 362 aia_set_iprio8(vcpu, first_irq + i, prio); 363 } 364 } 365 366 return KVM_INSN_CONTINUE_NEXT_SEPC; 367 } 368 369 int kvm_riscv_vcpu_aia_rmw_ireg(struct kvm_vcpu *vcpu, unsigned int csr_num, 370 unsigned long *val, unsigned long new_val, 371 unsigned long wr_mask) 372 { 373 unsigned int isel; 374 375 /* If AIA not available then redirect trap */ 376 if (!kvm_riscv_aia_available()) 377 return KVM_INSN_ILLEGAL_TRAP; 378 379 /* First try to emulate in kernel space */ 380 isel = csr_read(CSR_VSISELECT) & ISELECT_MASK; 381 if (isel >= ISELECT_IPRIO0 && isel <= ISELECT_IPRIO15) 382 return aia_rmw_iprio(vcpu, isel, val, new_val, wr_mask); 383 else if (isel >= IMSIC_FIRST && isel <= IMSIC_LAST && 384 kvm_riscv_aia_initialized(vcpu->kvm)) 385 return kvm_riscv_vcpu_aia_imsic_rmw(vcpu, isel, val, new_val, 386 wr_mask); 387 388 /* We can't handle it here so redirect to user space */ 389 return KVM_INSN_EXIT_TO_USER_SPACE; 390 } 391 392 int kvm_riscv_aia_alloc_hgei(int cpu, struct kvm_vcpu *owner, 393 void __iomem **hgei_va, phys_addr_t *hgei_pa) 394 { 395 int ret = -ENOENT; 396 unsigned long flags; 397 struct aia_hgei_control *hgctrl = per_cpu_ptr(&aia_hgei, cpu); 398 399 if (!kvm_riscv_aia_available() || !hgctrl) 400 return -ENODEV; 401 402 raw_spin_lock_irqsave(&hgctrl->lock, flags); 403 404 if (hgctrl->free_bitmap) { 405 ret = __ffs(hgctrl->free_bitmap); 406 hgctrl->free_bitmap &= ~BIT(ret); 407 hgctrl->owners[ret] = owner; 408 } 409 410 raw_spin_unlock_irqrestore(&hgctrl->lock, flags); 411 412 /* TODO: To be updated later by AIA IMSIC HW guest file support */ 413 if (hgei_va) 414 *hgei_va = NULL; 415 if (hgei_pa) 416 *hgei_pa = 0; 417 418 return ret; 419 } 420 421 void kvm_riscv_aia_free_hgei(int cpu, int hgei) 422 { 423 unsigned long flags; 424 struct aia_hgei_control *hgctrl = per_cpu_ptr(&aia_hgei, cpu); 425 426 if (!kvm_riscv_aia_available() || !hgctrl) 427 return; 428 429 raw_spin_lock_irqsave(&hgctrl->lock, flags); 430 431 if (hgei > 0 && hgei <= kvm_riscv_aia_nr_hgei) { 432 if (!(hgctrl->free_bitmap & BIT(hgei))) { 433 hgctrl->free_bitmap |= BIT(hgei); 434 hgctrl->owners[hgei] = NULL; 435 } 436 } 437 438 raw_spin_unlock_irqrestore(&hgctrl->lock, flags); 439 } 440 441 void kvm_riscv_aia_wakeon_hgei(struct kvm_vcpu *owner, bool enable) 442 { 443 int hgei; 444 445 if (!kvm_riscv_aia_available()) 446 return; 447 448 hgei = aia_find_hgei(owner); 449 if (hgei > 0) { 450 if (enable) 451 csr_set(CSR_HGEIE, BIT(hgei)); 452 else 453 csr_clear(CSR_HGEIE, BIT(hgei)); 454 } 455 } 456 457 static irqreturn_t hgei_interrupt(int irq, void *dev_id) 458 { 459 int i; 460 unsigned long hgei_mask, flags; 461 struct aia_hgei_control *hgctrl = get_cpu_ptr(&aia_hgei); 462 463 hgei_mask = csr_read(CSR_HGEIP) & csr_read(CSR_HGEIE); 464 csr_clear(CSR_HGEIE, hgei_mask); 465 466 raw_spin_lock_irqsave(&hgctrl->lock, flags); 467 468 for_each_set_bit(i, &hgei_mask, BITS_PER_LONG) { 469 if (hgctrl->owners[i]) 470 kvm_vcpu_kick(hgctrl->owners[i]); 471 } 472 473 raw_spin_unlock_irqrestore(&hgctrl->lock, flags); 474 475 put_cpu_ptr(&aia_hgei); 476 return IRQ_HANDLED; 477 } 478 479 static int aia_hgei_init(void) 480 { 481 int cpu, rc; 482 struct irq_domain *domain; 483 struct aia_hgei_control *hgctrl; 484 485 /* Initialize per-CPU guest external interrupt line management */ 486 for_each_possible_cpu(cpu) { 487 hgctrl = per_cpu_ptr(&aia_hgei, cpu); 488 raw_spin_lock_init(&hgctrl->lock); 489 if (kvm_riscv_aia_nr_hgei) { 490 hgctrl->free_bitmap = 491 BIT(kvm_riscv_aia_nr_hgei + 1) - 1; 492 hgctrl->free_bitmap &= ~BIT(0); 493 } else 494 hgctrl->free_bitmap = 0; 495 } 496 497 /* Find INTC irq domain */ 498 domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(), 499 DOMAIN_BUS_ANY); 500 if (!domain) { 501 kvm_err("unable to find INTC domain\n"); 502 return -ENOENT; 503 } 504 505 /* Map per-CPU SGEI interrupt from INTC domain */ 506 hgei_parent_irq = irq_create_mapping(domain, IRQ_S_GEXT); 507 if (!hgei_parent_irq) { 508 kvm_err("unable to map SGEI IRQ\n"); 509 return -ENOMEM; 510 } 511 512 /* Request per-CPU SGEI interrupt */ 513 rc = request_percpu_irq(hgei_parent_irq, hgei_interrupt, 514 "riscv-kvm", &aia_hgei); 515 if (rc) { 516 kvm_err("failed to request SGEI IRQ\n"); 517 return rc; 518 } 519 520 return 0; 521 } 522 523 static void aia_hgei_exit(void) 524 { 525 /* Free per-CPU SGEI interrupt */ 526 free_percpu_irq(hgei_parent_irq, &aia_hgei); 527 } 528 529 void kvm_riscv_aia_enable(void) 530 { 531 if (!kvm_riscv_aia_available()) 532 return; 533 534 aia_set_hvictl(false); 535 csr_write(CSR_HVIPRIO1, 0x0); 536 csr_write(CSR_HVIPRIO2, 0x0); 537 #ifdef CONFIG_32BIT 538 csr_write(CSR_HVIPH, 0x0); 539 csr_write(CSR_HIDELEGH, 0x0); 540 csr_write(CSR_HVIPRIO1H, 0x0); 541 csr_write(CSR_HVIPRIO2H, 0x0); 542 #endif 543 544 /* Enable per-CPU SGEI interrupt */ 545 enable_percpu_irq(hgei_parent_irq, 546 irq_get_trigger_type(hgei_parent_irq)); 547 csr_set(CSR_HIE, BIT(IRQ_S_GEXT)); 548 } 549 550 void kvm_riscv_aia_disable(void) 551 { 552 int i; 553 unsigned long flags; 554 struct kvm_vcpu *vcpu; 555 struct aia_hgei_control *hgctrl; 556 557 if (!kvm_riscv_aia_available()) 558 return; 559 hgctrl = get_cpu_ptr(&aia_hgei); 560 561 /* Disable per-CPU SGEI interrupt */ 562 csr_clear(CSR_HIE, BIT(IRQ_S_GEXT)); 563 disable_percpu_irq(hgei_parent_irq); 564 565 aia_set_hvictl(false); 566 567 raw_spin_lock_irqsave(&hgctrl->lock, flags); 568 569 for (i = 0; i <= kvm_riscv_aia_nr_hgei; i++) { 570 vcpu = hgctrl->owners[i]; 571 if (!vcpu) 572 continue; 573 574 /* 575 * We release hgctrl->lock before notifying IMSIC 576 * so that we don't have lock ordering issues. 577 */ 578 raw_spin_unlock_irqrestore(&hgctrl->lock, flags); 579 580 /* Notify IMSIC */ 581 kvm_riscv_vcpu_aia_imsic_release(vcpu); 582 583 /* 584 * Wakeup VCPU if it was blocked so that it can 585 * run on other HARTs 586 */ 587 if (csr_read(CSR_HGEIE) & BIT(i)) { 588 csr_clear(CSR_HGEIE, BIT(i)); 589 kvm_vcpu_kick(vcpu); 590 } 591 592 raw_spin_lock_irqsave(&hgctrl->lock, flags); 593 } 594 595 raw_spin_unlock_irqrestore(&hgctrl->lock, flags); 596 597 put_cpu_ptr(&aia_hgei); 598 } 599 600 int kvm_riscv_aia_init(void) 601 { 602 int rc; 603 604 if (!riscv_isa_extension_available(NULL, SxAIA)) 605 return -ENODEV; 606 607 /* Figure-out number of bits in HGEIE */ 608 csr_write(CSR_HGEIE, -1UL); 609 kvm_riscv_aia_nr_hgei = fls_long(csr_read(CSR_HGEIE)); 610 csr_write(CSR_HGEIE, 0); 611 if (kvm_riscv_aia_nr_hgei) 612 kvm_riscv_aia_nr_hgei--; 613 614 /* 615 * Number of usable HGEI lines should be minimum of per-HART 616 * IMSIC guest files and number of bits in HGEIE 617 * 618 * TODO: To be updated later by AIA IMSIC HW guest file support 619 */ 620 kvm_riscv_aia_nr_hgei = 0; 621 622 /* 623 * Find number of guest MSI IDs 624 * 625 * TODO: To be updated later by AIA IMSIC HW guest file support 626 */ 627 kvm_riscv_aia_max_ids = IMSIC_MAX_ID; 628 629 /* Initialize guest external interrupt line management */ 630 rc = aia_hgei_init(); 631 if (rc) 632 return rc; 633 634 /* Register device operations */ 635 rc = kvm_register_device_ops(&kvm_riscv_aia_device_ops, 636 KVM_DEV_TYPE_RISCV_AIA); 637 if (rc) { 638 aia_hgei_exit(); 639 return rc; 640 } 641 642 /* Enable KVM AIA support */ 643 static_branch_enable(&kvm_riscv_aia_available); 644 645 return 0; 646 } 647 648 void kvm_riscv_aia_exit(void) 649 { 650 if (!kvm_riscv_aia_available()) 651 return; 652 653 /* Unregister device operations */ 654 kvm_unregister_device_ops(KVM_DEV_TYPE_RISCV_AIA); 655 656 /* Cleanup the HGEI state */ 657 aia_hgei_exit(); 658 } 659