1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright The Asahi Linux Contributors 4 * 5 * Based on irq-lpc32xx: 6 * Copyright 2015-2016 Vladimir Zapolskiy <vz@mleia.com> 7 * Based on irq-bcm2836: 8 * Copyright 2015 Broadcom 9 */ 10 11 /* 12 * AIC is a fairly simple interrupt controller with the following features: 13 * 14 * - 896 level-triggered hardware IRQs 15 * - Single mask bit per IRQ 16 * - Per-IRQ affinity setting 17 * - Automatic masking on event delivery (auto-ack) 18 * - Software triggering (ORed with hw line) 19 * - 2 per-CPU IPIs (meant as "self" and "other", but they are 20 * interchangeable if not symmetric) 21 * - Automatic prioritization (single event/ack register per CPU, lower IRQs = 22 * higher priority) 23 * - Automatic masking on ack 24 * - Default "this CPU" register view and explicit per-CPU views 25 * 26 * In addition, this driver also handles FIQs, as these are routed to the same 27 * IRQ vector. These are used for Fast IPIs (TODO), the ARMv8 timer IRQs, and 28 * performance counters (TODO). 29 * 30 * Implementation notes: 31 * 32 * - This driver creates two IRQ domains, one for HW IRQs and internal FIQs, 33 * and one for IPIs. 34 * - Since Linux needs more than 2 IPIs, we implement a software IRQ controller 35 * and funnel all IPIs into one per-CPU IPI (the second "self" IPI is unused). 36 * - FIQ hwirq numbers are assigned after true hwirqs, and are per-cpu. 37 * - DT bindings use 3-cell form (like GIC): 38 * - <0 nr flags> - hwirq #nr 39 * - <1 nr flags> - FIQ #nr 40 * - nr=0 Physical HV timer 41 * - nr=1 Virtual HV timer 42 * - nr=2 Physical guest timer 43 * - nr=3 Virtual guest timer 44 */ 45 46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 47 48 #include <linux/bits.h> 49 #include <linux/bitfield.h> 50 #include <linux/cpuhotplug.h> 51 #include <linux/io.h> 52 #include <linux/irqchip.h> 53 #include <linux/irqchip/arm-vgic-info.h> 54 #include <linux/irqdomain.h> 55 #include <linux/limits.h> 56 #include <linux/of_address.h> 57 #include <linux/slab.h> 58 #include <asm/exception.h> 59 #include <asm/sysreg.h> 60 #include <asm/virt.h> 61 62 #include <dt-bindings/interrupt-controller/apple-aic.h> 63 64 /* 65 * AIC registers (MMIO) 66 */ 67 68 #define AIC_INFO 0x0004 69 #define AIC_INFO_NR_HW GENMASK(15, 0) 70 71 #define AIC_CONFIG 0x0010 72 73 #define AIC_WHOAMI 0x2000 74 #define AIC_EVENT 0x2004 75 #define AIC_EVENT_TYPE GENMASK(31, 16) 76 #define AIC_EVENT_NUM GENMASK(15, 0) 77 78 #define AIC_EVENT_TYPE_HW 1 79 #define AIC_EVENT_TYPE_IPI 4 80 #define AIC_EVENT_IPI_OTHER 1 81 #define AIC_EVENT_IPI_SELF 2 82 83 #define AIC_IPI_SEND 0x2008 84 #define AIC_IPI_ACK 0x200c 85 #define AIC_IPI_MASK_SET 0x2024 86 #define AIC_IPI_MASK_CLR 0x2028 87 88 #define AIC_IPI_SEND_CPU(cpu) BIT(cpu) 89 90 #define AIC_IPI_OTHER BIT(0) 91 #define AIC_IPI_SELF BIT(31) 92 93 #define AIC_TARGET_CPU 0x3000 94 #define AIC_SW_SET 0x4000 95 #define AIC_SW_CLR 0x4080 96 #define AIC_MASK_SET 0x4100 97 #define AIC_MASK_CLR 0x4180 98 99 #define AIC_CPU_IPI_SET(cpu) (0x5008 + ((cpu) << 7)) 100 #define AIC_CPU_IPI_CLR(cpu) (0x500c + ((cpu) << 7)) 101 #define AIC_CPU_IPI_MASK_SET(cpu) (0x5024 + ((cpu) << 7)) 102 #define AIC_CPU_IPI_MASK_CLR(cpu) (0x5028 + ((cpu) << 7)) 103 104 #define MASK_REG(x) (4 * ((x) >> 5)) 105 #define MASK_BIT(x) BIT((x) & GENMASK(4, 0)) 106 107 /* 108 * IMP-DEF sysregs that control FIQ sources 109 * Note: sysreg-based IPIs are not supported yet. 110 */ 111 112 /* Core PMC control register */ 113 #define SYS_IMP_APL_PMCR0_EL1 sys_reg(3, 1, 15, 0, 0) 114 #define PMCR0_IMODE GENMASK(10, 8) 115 #define PMCR0_IMODE_OFF 0 116 #define PMCR0_IMODE_PMI 1 117 #define PMCR0_IMODE_AIC 2 118 #define PMCR0_IMODE_HALT 3 119 #define PMCR0_IMODE_FIQ 4 120 #define PMCR0_IACT BIT(11) 121 122 /* IPI request registers */ 123 #define SYS_IMP_APL_IPI_RR_LOCAL_EL1 sys_reg(3, 5, 15, 0, 0) 124 #define SYS_IMP_APL_IPI_RR_GLOBAL_EL1 sys_reg(3, 5, 15, 0, 1) 125 #define IPI_RR_CPU GENMASK(7, 0) 126 /* Cluster only used for the GLOBAL register */ 127 #define IPI_RR_CLUSTER GENMASK(23, 16) 128 #define IPI_RR_TYPE GENMASK(29, 28) 129 #define IPI_RR_IMMEDIATE 0 130 #define IPI_RR_RETRACT 1 131 #define IPI_RR_DEFERRED 2 132 #define IPI_RR_NOWAKE 3 133 134 /* IPI status register */ 135 #define SYS_IMP_APL_IPI_SR_EL1 sys_reg(3, 5, 15, 1, 1) 136 #define IPI_SR_PENDING BIT(0) 137 138 /* Guest timer FIQ enable register */ 139 #define SYS_IMP_APL_VM_TMR_FIQ_ENA_EL2 sys_reg(3, 5, 15, 1, 3) 140 #define VM_TMR_FIQ_ENABLE_V BIT(0) 141 #define VM_TMR_FIQ_ENABLE_P BIT(1) 142 143 /* Deferred IPI countdown register */ 144 #define SYS_IMP_APL_IPI_CR_EL1 sys_reg(3, 5, 15, 3, 1) 145 146 /* Uncore PMC control register */ 147 #define SYS_IMP_APL_UPMCR0_EL1 sys_reg(3, 7, 15, 0, 4) 148 #define UPMCR0_IMODE GENMASK(18, 16) 149 #define UPMCR0_IMODE_OFF 0 150 #define UPMCR0_IMODE_AIC 2 151 #define UPMCR0_IMODE_HALT 3 152 #define UPMCR0_IMODE_FIQ 4 153 154 /* Uncore PMC status register */ 155 #define SYS_IMP_APL_UPMSR_EL1 sys_reg(3, 7, 15, 6, 4) 156 #define UPMSR_IACT BIT(0) 157 158 #define AIC_NR_FIQ 4 159 #define AIC_NR_SWIPI 32 160 161 /* 162 * FIQ hwirq index definitions: FIQ sources use the DT binding defines 163 * directly, except that timers are special. At the irqchip level, the 164 * two timer types are represented by their access method: _EL0 registers 165 * or _EL02 registers. In the DT binding, the timers are represented 166 * by their purpose (HV or guest). This mapping is for when the kernel is 167 * running at EL2 (with VHE). When the kernel is running at EL1, the 168 * mapping differs and aic_irq_domain_translate() performs the remapping. 169 */ 170 171 #define AIC_TMR_EL0_PHYS AIC_TMR_HV_PHYS 172 #define AIC_TMR_EL0_VIRT AIC_TMR_HV_VIRT 173 #define AIC_TMR_EL02_PHYS AIC_TMR_GUEST_PHYS 174 #define AIC_TMR_EL02_VIRT AIC_TMR_GUEST_VIRT 175 176 struct aic_irq_chip { 177 void __iomem *base; 178 struct irq_domain *hw_domain; 179 struct irq_domain *ipi_domain; 180 int nr_hw; 181 int ipi_hwirq; 182 }; 183 184 static DEFINE_PER_CPU(uint32_t, aic_fiq_unmasked); 185 186 static DEFINE_PER_CPU(atomic_t, aic_vipi_flag); 187 static DEFINE_PER_CPU(atomic_t, aic_vipi_enable); 188 189 static struct aic_irq_chip *aic_irqc; 190 191 static void aic_handle_ipi(struct pt_regs *regs); 192 193 static u32 aic_ic_read(struct aic_irq_chip *ic, u32 reg) 194 { 195 return readl_relaxed(ic->base + reg); 196 } 197 198 static void aic_ic_write(struct aic_irq_chip *ic, u32 reg, u32 val) 199 { 200 writel_relaxed(val, ic->base + reg); 201 } 202 203 /* 204 * IRQ irqchip 205 */ 206 207 static void aic_irq_mask(struct irq_data *d) 208 { 209 struct aic_irq_chip *ic = irq_data_get_irq_chip_data(d); 210 211 aic_ic_write(ic, AIC_MASK_SET + MASK_REG(irqd_to_hwirq(d)), 212 MASK_BIT(irqd_to_hwirq(d))); 213 } 214 215 static void aic_irq_unmask(struct irq_data *d) 216 { 217 struct aic_irq_chip *ic = irq_data_get_irq_chip_data(d); 218 219 aic_ic_write(ic, AIC_MASK_CLR + MASK_REG(d->hwirq), 220 MASK_BIT(irqd_to_hwirq(d))); 221 } 222 223 static void aic_irq_eoi(struct irq_data *d) 224 { 225 /* 226 * Reading the interrupt reason automatically acknowledges and masks 227 * the IRQ, so we just unmask it here if needed. 228 */ 229 if (!irqd_irq_masked(d)) 230 aic_irq_unmask(d); 231 } 232 233 static void __exception_irq_entry aic_handle_irq(struct pt_regs *regs) 234 { 235 struct aic_irq_chip *ic = aic_irqc; 236 u32 event, type, irq; 237 238 do { 239 /* 240 * We cannot use a relaxed read here, as reads from DMA buffers 241 * need to be ordered after the IRQ fires. 242 */ 243 event = readl(ic->base + AIC_EVENT); 244 type = FIELD_GET(AIC_EVENT_TYPE, event); 245 irq = FIELD_GET(AIC_EVENT_NUM, event); 246 247 if (type == AIC_EVENT_TYPE_HW) 248 generic_handle_domain_irq(aic_irqc->hw_domain, irq); 249 else if (type == AIC_EVENT_TYPE_IPI && irq == 1) 250 aic_handle_ipi(regs); 251 else if (event != 0) 252 pr_err_ratelimited("Unknown IRQ event %d, %d\n", type, irq); 253 } while (event); 254 255 /* 256 * vGIC maintenance interrupts end up here too, so we need to check 257 * for them separately. This should never trigger if KVM is working 258 * properly, because it will have already taken care of clearing it 259 * on guest exit before this handler runs. 260 */ 261 if (is_kernel_in_hyp_mode() && (read_sysreg_s(SYS_ICH_HCR_EL2) & ICH_HCR_EN) && 262 read_sysreg_s(SYS_ICH_MISR_EL2) != 0) { 263 pr_err_ratelimited("vGIC IRQ fired and not handled by KVM, disabling.\n"); 264 sysreg_clear_set_s(SYS_ICH_HCR_EL2, ICH_HCR_EN, 0); 265 } 266 } 267 268 static int aic_irq_set_affinity(struct irq_data *d, 269 const struct cpumask *mask_val, bool force) 270 { 271 irq_hw_number_t hwirq = irqd_to_hwirq(d); 272 struct aic_irq_chip *ic = irq_data_get_irq_chip_data(d); 273 int cpu; 274 275 if (force) 276 cpu = cpumask_first(mask_val); 277 else 278 cpu = cpumask_any_and(mask_val, cpu_online_mask); 279 280 aic_ic_write(ic, AIC_TARGET_CPU + hwirq * 4, BIT(cpu)); 281 irq_data_update_effective_affinity(d, cpumask_of(cpu)); 282 283 return IRQ_SET_MASK_OK; 284 } 285 286 static int aic_irq_set_type(struct irq_data *d, unsigned int type) 287 { 288 /* 289 * Some IRQs (e.g. MSIs) implicitly have edge semantics, and we don't 290 * have a way to find out the type of any given IRQ, so just allow both. 291 */ 292 return (type == IRQ_TYPE_LEVEL_HIGH || type == IRQ_TYPE_EDGE_RISING) ? 0 : -EINVAL; 293 } 294 295 static struct irq_chip aic_chip = { 296 .name = "AIC", 297 .irq_mask = aic_irq_mask, 298 .irq_unmask = aic_irq_unmask, 299 .irq_eoi = aic_irq_eoi, 300 .irq_set_affinity = aic_irq_set_affinity, 301 .irq_set_type = aic_irq_set_type, 302 }; 303 304 /* 305 * FIQ irqchip 306 */ 307 308 static unsigned long aic_fiq_get_idx(struct irq_data *d) 309 { 310 struct aic_irq_chip *ic = irq_data_get_irq_chip_data(d); 311 312 return irqd_to_hwirq(d) - ic->nr_hw; 313 } 314 315 static void aic_fiq_set_mask(struct irq_data *d) 316 { 317 /* Only the guest timers have real mask bits, unfortunately. */ 318 switch (aic_fiq_get_idx(d)) { 319 case AIC_TMR_EL02_PHYS: 320 sysreg_clear_set_s(SYS_IMP_APL_VM_TMR_FIQ_ENA_EL2, VM_TMR_FIQ_ENABLE_P, 0); 321 isb(); 322 break; 323 case AIC_TMR_EL02_VIRT: 324 sysreg_clear_set_s(SYS_IMP_APL_VM_TMR_FIQ_ENA_EL2, VM_TMR_FIQ_ENABLE_V, 0); 325 isb(); 326 break; 327 default: 328 break; 329 } 330 } 331 332 static void aic_fiq_clear_mask(struct irq_data *d) 333 { 334 switch (aic_fiq_get_idx(d)) { 335 case AIC_TMR_EL02_PHYS: 336 sysreg_clear_set_s(SYS_IMP_APL_VM_TMR_FIQ_ENA_EL2, 0, VM_TMR_FIQ_ENABLE_P); 337 isb(); 338 break; 339 case AIC_TMR_EL02_VIRT: 340 sysreg_clear_set_s(SYS_IMP_APL_VM_TMR_FIQ_ENA_EL2, 0, VM_TMR_FIQ_ENABLE_V); 341 isb(); 342 break; 343 default: 344 break; 345 } 346 } 347 348 static void aic_fiq_mask(struct irq_data *d) 349 { 350 aic_fiq_set_mask(d); 351 __this_cpu_and(aic_fiq_unmasked, ~BIT(aic_fiq_get_idx(d))); 352 } 353 354 static void aic_fiq_unmask(struct irq_data *d) 355 { 356 aic_fiq_clear_mask(d); 357 __this_cpu_or(aic_fiq_unmasked, BIT(aic_fiq_get_idx(d))); 358 } 359 360 static void aic_fiq_eoi(struct irq_data *d) 361 { 362 /* We mask to ack (where we can), so we need to unmask at EOI. */ 363 if (__this_cpu_read(aic_fiq_unmasked) & BIT(aic_fiq_get_idx(d))) 364 aic_fiq_clear_mask(d); 365 } 366 367 #define TIMER_FIRING(x) \ 368 (((x) & (ARCH_TIMER_CTRL_ENABLE | ARCH_TIMER_CTRL_IT_MASK | \ 369 ARCH_TIMER_CTRL_IT_STAT)) == \ 370 (ARCH_TIMER_CTRL_ENABLE | ARCH_TIMER_CTRL_IT_STAT)) 371 372 static void __exception_irq_entry aic_handle_fiq(struct pt_regs *regs) 373 { 374 /* 375 * It would be really nice if we had a system register that lets us get 376 * the FIQ source state without having to peek down into sources... 377 * but such a register does not seem to exist. 378 * 379 * So, we have these potential sources to test for: 380 * - Fast IPIs (not yet used) 381 * - The 4 timers (CNTP, CNTV for each of HV and guest) 382 * - Per-core PMCs (not yet supported) 383 * - Per-cluster uncore PMCs (not yet supported) 384 * 385 * Since not dealing with any of these results in a FIQ storm, 386 * we check for everything here, even things we don't support yet. 387 */ 388 389 if (read_sysreg_s(SYS_IMP_APL_IPI_SR_EL1) & IPI_SR_PENDING) { 390 pr_err_ratelimited("Fast IPI fired. Acking.\n"); 391 write_sysreg_s(IPI_SR_PENDING, SYS_IMP_APL_IPI_SR_EL1); 392 } 393 394 if (TIMER_FIRING(read_sysreg(cntp_ctl_el0))) 395 generic_handle_domain_irq(aic_irqc->hw_domain, 396 aic_irqc->nr_hw + AIC_TMR_EL0_PHYS); 397 398 if (TIMER_FIRING(read_sysreg(cntv_ctl_el0))) 399 generic_handle_domain_irq(aic_irqc->hw_domain, 400 aic_irqc->nr_hw + AIC_TMR_EL0_VIRT); 401 402 if (is_kernel_in_hyp_mode()) { 403 uint64_t enabled = read_sysreg_s(SYS_IMP_APL_VM_TMR_FIQ_ENA_EL2); 404 405 if ((enabled & VM_TMR_FIQ_ENABLE_P) && 406 TIMER_FIRING(read_sysreg_s(SYS_CNTP_CTL_EL02))) 407 generic_handle_domain_irq(aic_irqc->hw_domain, 408 aic_irqc->nr_hw + AIC_TMR_EL02_PHYS); 409 410 if ((enabled & VM_TMR_FIQ_ENABLE_V) && 411 TIMER_FIRING(read_sysreg_s(SYS_CNTV_CTL_EL02))) 412 generic_handle_domain_irq(aic_irqc->hw_domain, 413 aic_irqc->nr_hw + AIC_TMR_EL02_VIRT); 414 } 415 416 if ((read_sysreg_s(SYS_IMP_APL_PMCR0_EL1) & (PMCR0_IMODE | PMCR0_IACT)) == 417 (FIELD_PREP(PMCR0_IMODE, PMCR0_IMODE_FIQ) | PMCR0_IACT)) { 418 /* 419 * Not supported yet, let's figure out how to handle this when 420 * we implement these proprietary performance counters. For now, 421 * just mask it and move on. 422 */ 423 pr_err_ratelimited("PMC FIQ fired. Masking.\n"); 424 sysreg_clear_set_s(SYS_IMP_APL_PMCR0_EL1, PMCR0_IMODE | PMCR0_IACT, 425 FIELD_PREP(PMCR0_IMODE, PMCR0_IMODE_OFF)); 426 } 427 428 if (FIELD_GET(UPMCR0_IMODE, read_sysreg_s(SYS_IMP_APL_UPMCR0_EL1)) == UPMCR0_IMODE_FIQ && 429 (read_sysreg_s(SYS_IMP_APL_UPMSR_EL1) & UPMSR_IACT)) { 430 /* Same story with uncore PMCs */ 431 pr_err_ratelimited("Uncore PMC FIQ fired. Masking.\n"); 432 sysreg_clear_set_s(SYS_IMP_APL_UPMCR0_EL1, UPMCR0_IMODE, 433 FIELD_PREP(UPMCR0_IMODE, UPMCR0_IMODE_OFF)); 434 } 435 } 436 437 static int aic_fiq_set_type(struct irq_data *d, unsigned int type) 438 { 439 return (type == IRQ_TYPE_LEVEL_HIGH) ? 0 : -EINVAL; 440 } 441 442 static struct irq_chip fiq_chip = { 443 .name = "AIC-FIQ", 444 .irq_mask = aic_fiq_mask, 445 .irq_unmask = aic_fiq_unmask, 446 .irq_ack = aic_fiq_set_mask, 447 .irq_eoi = aic_fiq_eoi, 448 .irq_set_type = aic_fiq_set_type, 449 }; 450 451 /* 452 * Main IRQ domain 453 */ 454 455 static int aic_irq_domain_map(struct irq_domain *id, unsigned int irq, 456 irq_hw_number_t hw) 457 { 458 struct aic_irq_chip *ic = id->host_data; 459 460 if (hw < ic->nr_hw) { 461 irq_domain_set_info(id, irq, hw, &aic_chip, id->host_data, 462 handle_fasteoi_irq, NULL, NULL); 463 irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(irq))); 464 } else { 465 irq_set_percpu_devid(irq); 466 irq_domain_set_info(id, irq, hw, &fiq_chip, id->host_data, 467 handle_percpu_devid_irq, NULL, NULL); 468 } 469 470 return 0; 471 } 472 473 static int aic_irq_domain_translate(struct irq_domain *id, 474 struct irq_fwspec *fwspec, 475 unsigned long *hwirq, 476 unsigned int *type) 477 { 478 struct aic_irq_chip *ic = id->host_data; 479 480 if (fwspec->param_count != 3 || !is_of_node(fwspec->fwnode)) 481 return -EINVAL; 482 483 switch (fwspec->param[0]) { 484 case AIC_IRQ: 485 if (fwspec->param[1] >= ic->nr_hw) 486 return -EINVAL; 487 *hwirq = fwspec->param[1]; 488 break; 489 case AIC_FIQ: 490 if (fwspec->param[1] >= AIC_NR_FIQ) 491 return -EINVAL; 492 *hwirq = ic->nr_hw + fwspec->param[1]; 493 494 /* 495 * In EL1 the non-redirected registers are the guest's, 496 * not EL2's, so remap the hwirqs to match. 497 */ 498 if (!is_kernel_in_hyp_mode()) { 499 switch (fwspec->param[1]) { 500 case AIC_TMR_GUEST_PHYS: 501 *hwirq = ic->nr_hw + AIC_TMR_EL0_PHYS; 502 break; 503 case AIC_TMR_GUEST_VIRT: 504 *hwirq = ic->nr_hw + AIC_TMR_EL0_VIRT; 505 break; 506 case AIC_TMR_HV_PHYS: 507 case AIC_TMR_HV_VIRT: 508 return -ENOENT; 509 default: 510 break; 511 } 512 } 513 break; 514 default: 515 return -EINVAL; 516 } 517 518 *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK; 519 520 return 0; 521 } 522 523 static int aic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, 524 unsigned int nr_irqs, void *arg) 525 { 526 unsigned int type = IRQ_TYPE_NONE; 527 struct irq_fwspec *fwspec = arg; 528 irq_hw_number_t hwirq; 529 int i, ret; 530 531 ret = aic_irq_domain_translate(domain, fwspec, &hwirq, &type); 532 if (ret) 533 return ret; 534 535 for (i = 0; i < nr_irqs; i++) { 536 ret = aic_irq_domain_map(domain, virq + i, hwirq + i); 537 if (ret) 538 return ret; 539 } 540 541 return 0; 542 } 543 544 static void aic_irq_domain_free(struct irq_domain *domain, unsigned int virq, 545 unsigned int nr_irqs) 546 { 547 int i; 548 549 for (i = 0; i < nr_irqs; i++) { 550 struct irq_data *d = irq_domain_get_irq_data(domain, virq + i); 551 552 irq_set_handler(virq + i, NULL); 553 irq_domain_reset_irq_data(d); 554 } 555 } 556 557 static const struct irq_domain_ops aic_irq_domain_ops = { 558 .translate = aic_irq_domain_translate, 559 .alloc = aic_irq_domain_alloc, 560 .free = aic_irq_domain_free, 561 }; 562 563 /* 564 * IPI irqchip 565 */ 566 567 static void aic_ipi_mask(struct irq_data *d) 568 { 569 u32 irq_bit = BIT(irqd_to_hwirq(d)); 570 571 /* No specific ordering requirements needed here. */ 572 atomic_andnot(irq_bit, this_cpu_ptr(&aic_vipi_enable)); 573 } 574 575 static void aic_ipi_unmask(struct irq_data *d) 576 { 577 struct aic_irq_chip *ic = irq_data_get_irq_chip_data(d); 578 u32 irq_bit = BIT(irqd_to_hwirq(d)); 579 580 atomic_or(irq_bit, this_cpu_ptr(&aic_vipi_enable)); 581 582 /* 583 * The atomic_or() above must complete before the atomic_read() 584 * below to avoid racing aic_ipi_send_mask(). 585 */ 586 smp_mb__after_atomic(); 587 588 /* 589 * If a pending vIPI was unmasked, raise a HW IPI to ourselves. 590 * No barriers needed here since this is a self-IPI. 591 */ 592 if (atomic_read(this_cpu_ptr(&aic_vipi_flag)) & irq_bit) 593 aic_ic_write(ic, AIC_IPI_SEND, AIC_IPI_SEND_CPU(smp_processor_id())); 594 } 595 596 static void aic_ipi_send_mask(struct irq_data *d, const struct cpumask *mask) 597 { 598 struct aic_irq_chip *ic = irq_data_get_irq_chip_data(d); 599 u32 irq_bit = BIT(irqd_to_hwirq(d)); 600 u32 send = 0; 601 int cpu; 602 unsigned long pending; 603 604 for_each_cpu(cpu, mask) { 605 /* 606 * This sequence is the mirror of the one in aic_ipi_unmask(); 607 * see the comment there. Additionally, release semantics 608 * ensure that the vIPI flag set is ordered after any shared 609 * memory accesses that precede it. This therefore also pairs 610 * with the atomic_fetch_andnot in aic_handle_ipi(). 611 */ 612 pending = atomic_fetch_or_release(irq_bit, per_cpu_ptr(&aic_vipi_flag, cpu)); 613 614 /* 615 * The atomic_fetch_or_release() above must complete before the 616 * atomic_read() below to avoid racing aic_ipi_unmask(). 617 */ 618 smp_mb__after_atomic(); 619 620 if (!(pending & irq_bit) && 621 (atomic_read(per_cpu_ptr(&aic_vipi_enable, cpu)) & irq_bit)) 622 send |= AIC_IPI_SEND_CPU(cpu); 623 } 624 625 /* 626 * The flag writes must complete before the physical IPI is issued 627 * to another CPU. This is implied by the control dependency on 628 * the result of atomic_read_acquire() above, which is itself 629 * already ordered after the vIPI flag write. 630 */ 631 if (send) 632 aic_ic_write(ic, AIC_IPI_SEND, send); 633 } 634 635 static struct irq_chip ipi_chip = { 636 .name = "AIC-IPI", 637 .irq_mask = aic_ipi_mask, 638 .irq_unmask = aic_ipi_unmask, 639 .ipi_send_mask = aic_ipi_send_mask, 640 }; 641 642 /* 643 * IPI IRQ domain 644 */ 645 646 static void aic_handle_ipi(struct pt_regs *regs) 647 { 648 int i; 649 unsigned long enabled, firing; 650 651 /* 652 * Ack the IPI. We need to order this after the AIC event read, but 653 * that is enforced by normal MMIO ordering guarantees. 654 */ 655 aic_ic_write(aic_irqc, AIC_IPI_ACK, AIC_IPI_OTHER); 656 657 /* 658 * The mask read does not need to be ordered. Only we can change 659 * our own mask anyway, so no races are possible here, as long as 660 * we are properly in the interrupt handler (which is covered by 661 * the barrier that is part of the top-level AIC handler's readl()). 662 */ 663 enabled = atomic_read(this_cpu_ptr(&aic_vipi_enable)); 664 665 /* 666 * Clear the IPIs we are about to handle. This pairs with the 667 * atomic_fetch_or_release() in aic_ipi_send_mask(), and needs to be 668 * ordered after the aic_ic_write() above (to avoid dropping vIPIs) and 669 * before IPI handling code (to avoid races handling vIPIs before they 670 * are signaled). The former is taken care of by the release semantics 671 * of the write portion, while the latter is taken care of by the 672 * acquire semantics of the read portion. 673 */ 674 firing = atomic_fetch_andnot(enabled, this_cpu_ptr(&aic_vipi_flag)) & enabled; 675 676 for_each_set_bit(i, &firing, AIC_NR_SWIPI) 677 generic_handle_domain_irq(aic_irqc->ipi_domain, i); 678 679 /* 680 * No ordering needed here; at worst this just changes the timing of 681 * when the next IPI will be delivered. 682 */ 683 aic_ic_write(aic_irqc, AIC_IPI_MASK_CLR, AIC_IPI_OTHER); 684 } 685 686 static int aic_ipi_alloc(struct irq_domain *d, unsigned int virq, 687 unsigned int nr_irqs, void *args) 688 { 689 int i; 690 691 for (i = 0; i < nr_irqs; i++) { 692 irq_set_percpu_devid(virq + i); 693 irq_domain_set_info(d, virq + i, i, &ipi_chip, d->host_data, 694 handle_percpu_devid_irq, NULL, NULL); 695 } 696 697 return 0; 698 } 699 700 static void aic_ipi_free(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs) 701 { 702 /* Not freeing IPIs */ 703 } 704 705 static const struct irq_domain_ops aic_ipi_domain_ops = { 706 .alloc = aic_ipi_alloc, 707 .free = aic_ipi_free, 708 }; 709 710 static int __init aic_init_smp(struct aic_irq_chip *irqc, struct device_node *node) 711 { 712 struct irq_domain *ipi_domain; 713 int base_ipi; 714 715 ipi_domain = irq_domain_create_linear(irqc->hw_domain->fwnode, AIC_NR_SWIPI, 716 &aic_ipi_domain_ops, irqc); 717 if (WARN_ON(!ipi_domain)) 718 return -ENODEV; 719 720 ipi_domain->flags |= IRQ_DOMAIN_FLAG_IPI_SINGLE; 721 irq_domain_update_bus_token(ipi_domain, DOMAIN_BUS_IPI); 722 723 base_ipi = __irq_domain_alloc_irqs(ipi_domain, -1, AIC_NR_SWIPI, 724 NUMA_NO_NODE, NULL, false, NULL); 725 726 if (WARN_ON(!base_ipi)) { 727 irq_domain_remove(ipi_domain); 728 return -ENODEV; 729 } 730 731 set_smp_ipi_range(base_ipi, AIC_NR_SWIPI); 732 733 irqc->ipi_domain = ipi_domain; 734 735 return 0; 736 } 737 738 static int aic_init_cpu(unsigned int cpu) 739 { 740 /* Mask all hard-wired per-CPU IRQ/FIQ sources */ 741 742 /* Pending Fast IPI FIQs */ 743 write_sysreg_s(IPI_SR_PENDING, SYS_IMP_APL_IPI_SR_EL1); 744 745 /* Timer FIQs */ 746 sysreg_clear_set(cntp_ctl_el0, 0, ARCH_TIMER_CTRL_IT_MASK); 747 sysreg_clear_set(cntv_ctl_el0, 0, ARCH_TIMER_CTRL_IT_MASK); 748 749 /* EL2-only (VHE mode) IRQ sources */ 750 if (is_kernel_in_hyp_mode()) { 751 /* Guest timers */ 752 sysreg_clear_set_s(SYS_IMP_APL_VM_TMR_FIQ_ENA_EL2, 753 VM_TMR_FIQ_ENABLE_V | VM_TMR_FIQ_ENABLE_P, 0); 754 755 /* vGIC maintenance IRQ */ 756 sysreg_clear_set_s(SYS_ICH_HCR_EL2, ICH_HCR_EN, 0); 757 } 758 759 /* PMC FIQ */ 760 sysreg_clear_set_s(SYS_IMP_APL_PMCR0_EL1, PMCR0_IMODE | PMCR0_IACT, 761 FIELD_PREP(PMCR0_IMODE, PMCR0_IMODE_OFF)); 762 763 /* Uncore PMC FIQ */ 764 sysreg_clear_set_s(SYS_IMP_APL_UPMCR0_EL1, UPMCR0_IMODE, 765 FIELD_PREP(UPMCR0_IMODE, UPMCR0_IMODE_OFF)); 766 767 /* Commit all of the above */ 768 isb(); 769 770 /* 771 * Make sure the kernel's idea of logical CPU order is the same as AIC's 772 * If we ever end up with a mismatch here, we will have to introduce 773 * a mapping table similar to what other irqchip drivers do. 774 */ 775 WARN_ON(aic_ic_read(aic_irqc, AIC_WHOAMI) != smp_processor_id()); 776 777 /* 778 * Always keep IPIs unmasked at the hardware level (except auto-masking 779 * by AIC during processing). We manage masks at the vIPI level. 780 */ 781 aic_ic_write(aic_irqc, AIC_IPI_ACK, AIC_IPI_SELF | AIC_IPI_OTHER); 782 aic_ic_write(aic_irqc, AIC_IPI_MASK_SET, AIC_IPI_SELF); 783 aic_ic_write(aic_irqc, AIC_IPI_MASK_CLR, AIC_IPI_OTHER); 784 785 /* Initialize the local mask state */ 786 __this_cpu_write(aic_fiq_unmasked, 0); 787 788 return 0; 789 } 790 791 static struct gic_kvm_info vgic_info __initdata = { 792 .type = GIC_V3, 793 .no_maint_irq_mask = true, 794 .no_hw_deactivation = true, 795 }; 796 797 static int __init aic_of_ic_init(struct device_node *node, struct device_node *parent) 798 { 799 int i; 800 void __iomem *regs; 801 u32 info; 802 struct aic_irq_chip *irqc; 803 804 regs = of_iomap(node, 0); 805 if (WARN_ON(!regs)) 806 return -EIO; 807 808 irqc = kzalloc(sizeof(*irqc), GFP_KERNEL); 809 if (!irqc) 810 return -ENOMEM; 811 812 aic_irqc = irqc; 813 irqc->base = regs; 814 815 info = aic_ic_read(irqc, AIC_INFO); 816 irqc->nr_hw = FIELD_GET(AIC_INFO_NR_HW, info); 817 818 irqc->hw_domain = irq_domain_create_linear(of_node_to_fwnode(node), 819 irqc->nr_hw + AIC_NR_FIQ, 820 &aic_irq_domain_ops, irqc); 821 if (WARN_ON(!irqc->hw_domain)) { 822 iounmap(irqc->base); 823 kfree(irqc); 824 return -ENODEV; 825 } 826 827 irq_domain_update_bus_token(irqc->hw_domain, DOMAIN_BUS_WIRED); 828 829 if (aic_init_smp(irqc, node)) { 830 irq_domain_remove(irqc->hw_domain); 831 iounmap(irqc->base); 832 kfree(irqc); 833 return -ENODEV; 834 } 835 836 set_handle_irq(aic_handle_irq); 837 set_handle_fiq(aic_handle_fiq); 838 839 for (i = 0; i < BITS_TO_U32(irqc->nr_hw); i++) 840 aic_ic_write(irqc, AIC_MASK_SET + i * 4, U32_MAX); 841 for (i = 0; i < BITS_TO_U32(irqc->nr_hw); i++) 842 aic_ic_write(irqc, AIC_SW_CLR + i * 4, U32_MAX); 843 for (i = 0; i < irqc->nr_hw; i++) 844 aic_ic_write(irqc, AIC_TARGET_CPU + i * 4, 1); 845 846 if (!is_kernel_in_hyp_mode()) 847 pr_info("Kernel running in EL1, mapping interrupts"); 848 849 cpuhp_setup_state(CPUHP_AP_IRQ_APPLE_AIC_STARTING, 850 "irqchip/apple-aic/ipi:starting", 851 aic_init_cpu, NULL); 852 853 vgic_set_kvm_info(&vgic_info); 854 855 pr_info("Initialized with %d IRQs, %d FIQs, %d vIPIs\n", 856 irqc->nr_hw, AIC_NR_FIQ, AIC_NR_SWIPI); 857 858 return 0; 859 } 860 861 IRQCHIP_DECLARE(apple_m1_aic, "apple,aic", aic_of_ic_init); 862