1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* interrupt.h */ 3 #ifndef _LINUX_INTERRUPT_H 4 #define _LINUX_INTERRUPT_H 5 6 #include <linux/kernel.h> 7 #include <linux/bitops.h> 8 #include <linux/cleanup.h> 9 #include <linux/irqreturn.h> 10 #include <linux/irqnr.h> 11 #include <linux/hardirq.h> 12 #include <linux/irqflags.h> 13 #include <linux/hrtimer.h> 14 #include <linux/kref.h> 15 #include <linux/cpumask_types.h> 16 #include <linux/workqueue.h> 17 #include <linux/jump_label.h> 18 19 #include <linux/atomic.h> 20 #include <asm/ptrace.h> 21 #include <asm/irq.h> 22 #include <asm/sections.h> 23 24 /* 25 * These correspond to the IORESOURCE_IRQ_* defines in 26 * linux/ioport.h to select the interrupt line behaviour. When 27 * requesting an interrupt without specifying a IRQF_TRIGGER, the 28 * setting should be assumed to be "as already configured", which 29 * may be as per machine or firmware initialisation. 30 */ 31 #define IRQF_TRIGGER_NONE 0x00000000 32 #define IRQF_TRIGGER_RISING 0x00000001 33 #define IRQF_TRIGGER_FALLING 0x00000002 34 #define IRQF_TRIGGER_HIGH 0x00000004 35 #define IRQF_TRIGGER_LOW 0x00000008 36 #define IRQF_TRIGGER_MASK (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \ 37 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING) 38 #define IRQF_TRIGGER_PROBE 0x00000010 39 40 /* 41 * These flags used only by the kernel as part of the 42 * irq handling routines. 43 * 44 * IRQF_SHARED - allow sharing the irq among several devices 45 * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur 46 * IRQF_TIMER - Flag to mark this interrupt as timer interrupt 47 * IRQF_PERCPU - Interrupt is per cpu 48 * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing 49 * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is 50 * registered first in a shared interrupt is considered for 51 * performance reasons) 52 * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished. 53 * Used by threaded interrupts which need to keep the 54 * irq line disabled until the threaded handler has been run. 55 * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend. Does not guarantee 56 * that this interrupt will wake the system from a suspended 57 * state. See Documentation/power/suspend-and-interrupts.rst 58 * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set 59 * IRQF_NO_THREAD - Interrupt cannot be threaded 60 * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device 61 * resume time. 62 * IRQF_COND_SUSPEND - If the IRQ is shared with a NO_SUSPEND user, execute this 63 * interrupt handler after suspending interrupts. For system 64 * wakeup devices users need to implement wakeup detection in 65 * their interrupt handlers. 66 * IRQF_NO_AUTOEN - Don't enable IRQ or NMI automatically when users request it. 67 * Users will enable it explicitly by enable_irq() or enable_nmi() 68 * later. 69 * IRQF_NO_DEBUG - Exclude from runnaway detection for IPI and similar handlers, 70 * depends on IRQF_PERCPU. 71 * IRQF_COND_ONESHOT - Agree to do IRQF_ONESHOT if already set for a shared 72 * interrupt. 73 */ 74 #define IRQF_SHARED 0x00000080 75 #define IRQF_PROBE_SHARED 0x00000100 76 #define __IRQF_TIMER 0x00000200 77 #define IRQF_PERCPU 0x00000400 78 #define IRQF_NOBALANCING 0x00000800 79 #define IRQF_IRQPOLL 0x00001000 80 #define IRQF_ONESHOT 0x00002000 81 #define IRQF_NO_SUSPEND 0x00004000 82 #define IRQF_FORCE_RESUME 0x00008000 83 #define IRQF_NO_THREAD 0x00010000 84 #define IRQF_EARLY_RESUME 0x00020000 85 #define IRQF_COND_SUSPEND 0x00040000 86 #define IRQF_NO_AUTOEN 0x00080000 87 #define IRQF_NO_DEBUG 0x00100000 88 #define IRQF_COND_ONESHOT 0x00200000 89 90 #define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD) 91 92 /* 93 * These values can be returned by request_any_context_irq() and 94 * describe the context the interrupt will be run in. 95 * 96 * IRQC_IS_HARDIRQ - interrupt runs in hardirq context 97 * IRQC_IS_NESTED - interrupt runs in a nested threaded context 98 */ 99 enum { 100 IRQC_IS_HARDIRQ = 0, 101 IRQC_IS_NESTED, 102 }; 103 104 typedef irqreturn_t (*irq_handler_t)(int, void *); 105 106 /** 107 * struct irqaction - per interrupt action descriptor 108 * @handler: interrupt handler function 109 * @name: name of the device 110 * @dev_id: cookie to identify the device 111 * @percpu_dev_id: cookie to identify the device 112 * @next: pointer to the next irqaction for shared interrupts 113 * @irq: interrupt number 114 * @flags: flags (see IRQF_* above) 115 * @thread_fn: interrupt handler function for threaded interrupts 116 * @thread: thread pointer for threaded interrupts 117 * @secondary: pointer to secondary irqaction (force threading) 118 * @thread_flags: flags related to @thread 119 * @thread_mask: bitmask for keeping track of @thread activity 120 * @dir: pointer to the proc/irq/NN/name entry 121 */ 122 struct irqaction { 123 irq_handler_t handler; 124 void *dev_id; 125 void __percpu *percpu_dev_id; 126 struct irqaction *next; 127 irq_handler_t thread_fn; 128 struct task_struct *thread; 129 struct irqaction *secondary; 130 unsigned int irq; 131 unsigned int flags; 132 unsigned long thread_flags; 133 unsigned long thread_mask; 134 const char *name; 135 struct proc_dir_entry *dir; 136 } ____cacheline_internodealigned_in_smp; 137 138 extern irqreturn_t no_action(int cpl, void *dev_id); 139 140 /* 141 * If a (PCI) device interrupt is not connected we set dev->irq to 142 * IRQ_NOTCONNECTED. This causes request_irq() to fail with -ENOTCONN, so we 143 * can distingiush that case from other error returns. 144 * 145 * 0x80000000 is guaranteed to be outside the available range of interrupts 146 * and easy to distinguish from other possible incorrect values. 147 */ 148 #define IRQ_NOTCONNECTED (1U << 31) 149 150 extern int __must_check 151 request_threaded_irq(unsigned int irq, irq_handler_t handler, 152 irq_handler_t thread_fn, 153 unsigned long flags, const char *name, void *dev); 154 155 /** 156 * request_irq - Add a handler for an interrupt line 157 * @irq: The interrupt line to allocate 158 * @handler: Function to be called when the IRQ occurs. 159 * Primary handler for threaded interrupts 160 * If NULL, the default primary handler is installed 161 * @flags: Handling flags 162 * @name: Name of the device generating this interrupt 163 * @dev: A cookie passed to the handler function 164 * 165 * This call allocates an interrupt and establishes a handler; see 166 * the documentation for request_threaded_irq() for details. 167 */ 168 static inline int __must_check 169 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, 170 const char *name, void *dev) 171 { 172 return request_threaded_irq(irq, handler, NULL, flags | IRQF_COND_ONESHOT, name, dev); 173 } 174 175 extern int __must_check 176 request_any_context_irq(unsigned int irq, irq_handler_t handler, 177 unsigned long flags, const char *name, void *dev_id); 178 179 extern int __must_check 180 __request_percpu_irq(unsigned int irq, irq_handler_t handler, 181 unsigned long flags, const char *devname, 182 void __percpu *percpu_dev_id); 183 184 extern int __must_check 185 request_nmi(unsigned int irq, irq_handler_t handler, unsigned long flags, 186 const char *name, void *dev); 187 188 static inline int __must_check 189 request_percpu_irq(unsigned int irq, irq_handler_t handler, 190 const char *devname, void __percpu *percpu_dev_id) 191 { 192 return __request_percpu_irq(irq, handler, 0, 193 devname, percpu_dev_id); 194 } 195 196 extern int __must_check 197 request_percpu_nmi(unsigned int irq, irq_handler_t handler, 198 const char *devname, void __percpu *dev); 199 200 extern const void *free_irq(unsigned int, void *); 201 extern void free_percpu_irq(unsigned int, void __percpu *); 202 203 extern const void *free_nmi(unsigned int irq, void *dev_id); 204 extern void free_percpu_nmi(unsigned int irq, void __percpu *percpu_dev_id); 205 206 struct device; 207 208 extern int __must_check 209 devm_request_threaded_irq(struct device *dev, unsigned int irq, 210 irq_handler_t handler, irq_handler_t thread_fn, 211 unsigned long irqflags, const char *devname, 212 void *dev_id); 213 214 static inline int __must_check 215 devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler, 216 unsigned long irqflags, const char *devname, void *dev_id) 217 { 218 return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags, 219 devname, dev_id); 220 } 221 222 extern int __must_check 223 devm_request_any_context_irq(struct device *dev, unsigned int irq, 224 irq_handler_t handler, unsigned long irqflags, 225 const char *devname, void *dev_id); 226 227 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id); 228 229 bool irq_has_action(unsigned int irq); 230 extern void disable_irq_nosync(unsigned int irq); 231 extern bool disable_hardirq(unsigned int irq); 232 extern void disable_irq(unsigned int irq); 233 extern void disable_percpu_irq(unsigned int irq); 234 extern void enable_irq(unsigned int irq); 235 extern void enable_percpu_irq(unsigned int irq, unsigned int type); 236 extern bool irq_percpu_is_enabled(unsigned int irq); 237 extern void irq_wake_thread(unsigned int irq, void *dev_id); 238 239 DEFINE_LOCK_GUARD_1(disable_irq, int, 240 disable_irq(*_T->lock), enable_irq(*_T->lock)) 241 242 extern void disable_nmi_nosync(unsigned int irq); 243 extern void disable_percpu_nmi(unsigned int irq); 244 extern void enable_nmi(unsigned int irq); 245 extern void enable_percpu_nmi(unsigned int irq, unsigned int type); 246 extern int prepare_percpu_nmi(unsigned int irq); 247 extern void teardown_percpu_nmi(unsigned int irq); 248 249 extern int irq_inject_interrupt(unsigned int irq); 250 251 /* The following three functions are for the core kernel use only. */ 252 extern void suspend_device_irqs(void); 253 extern void resume_device_irqs(void); 254 extern void rearm_wake_irq(unsigned int irq); 255 256 /** 257 * struct irq_affinity_notify - context for notification of IRQ affinity changes 258 * @irq: Interrupt to which notification applies 259 * @kref: Reference count, for internal use 260 * @work: Work item, for internal use 261 * @notify: Function to be called on change. This will be 262 * called in process context. 263 * @release: Function to be called on release. This will be 264 * called in process context. Once registered, the 265 * structure must only be freed when this function is 266 * called or later. 267 */ 268 struct irq_affinity_notify { 269 unsigned int irq; 270 struct kref kref; 271 struct work_struct work; 272 void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask); 273 void (*release)(struct kref *ref); 274 }; 275 276 #define IRQ_AFFINITY_MAX_SETS 4 277 278 /** 279 * struct irq_affinity - Description for automatic irq affinity assignements 280 * @pre_vectors: Don't apply affinity to @pre_vectors at beginning of 281 * the MSI(-X) vector space 282 * @post_vectors: Don't apply affinity to @post_vectors at end of 283 * the MSI(-X) vector space 284 * @nr_sets: The number of interrupt sets for which affinity 285 * spreading is required 286 * @set_size: Array holding the size of each interrupt set 287 * @calc_sets: Callback for calculating the number and size 288 * of interrupt sets 289 * @priv: Private data for usage by @calc_sets, usually a 290 * pointer to driver/device specific data. 291 */ 292 struct irq_affinity { 293 unsigned int pre_vectors; 294 unsigned int post_vectors; 295 unsigned int nr_sets; 296 unsigned int set_size[IRQ_AFFINITY_MAX_SETS]; 297 void (*calc_sets)(struct irq_affinity *, unsigned int nvecs); 298 void *priv; 299 }; 300 301 /** 302 * struct irq_affinity_desc - Interrupt affinity descriptor 303 * @mask: cpumask to hold the affinity assignment 304 * @is_managed: 1 if the interrupt is managed internally 305 */ 306 struct irq_affinity_desc { 307 struct cpumask mask; 308 unsigned int is_managed : 1; 309 }; 310 311 #if defined(CONFIG_SMP) 312 313 extern cpumask_var_t irq_default_affinity; 314 315 extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask); 316 extern int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask); 317 318 extern int irq_can_set_affinity(unsigned int irq); 319 extern int irq_select_affinity(unsigned int irq); 320 321 extern int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m, 322 bool setaffinity); 323 324 /** 325 * irq_update_affinity_hint - Update the affinity hint 326 * @irq: Interrupt to update 327 * @m: cpumask pointer (NULL to clear the hint) 328 * 329 * Updates the affinity hint, but does not change the affinity of the interrupt. 330 */ 331 static inline int 332 irq_update_affinity_hint(unsigned int irq, const struct cpumask *m) 333 { 334 return __irq_apply_affinity_hint(irq, m, false); 335 } 336 337 /** 338 * irq_set_affinity_and_hint - Update the affinity hint and apply the provided 339 * cpumask to the interrupt 340 * @irq: Interrupt to update 341 * @m: cpumask pointer (NULL to clear the hint) 342 * 343 * Updates the affinity hint and if @m is not NULL it applies it as the 344 * affinity of that interrupt. 345 */ 346 static inline int 347 irq_set_affinity_and_hint(unsigned int irq, const struct cpumask *m) 348 { 349 return __irq_apply_affinity_hint(irq, m, true); 350 } 351 352 /* 353 * Deprecated. Use irq_update_affinity_hint() or irq_set_affinity_and_hint() 354 * instead. 355 */ 356 static inline int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m) 357 { 358 return irq_set_affinity_and_hint(irq, m); 359 } 360 361 extern int irq_update_affinity_desc(unsigned int irq, 362 struct irq_affinity_desc *affinity); 363 364 extern int 365 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify); 366 367 struct irq_affinity_desc * 368 irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd); 369 370 unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec, 371 const struct irq_affinity *affd); 372 373 #else /* CONFIG_SMP */ 374 375 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m) 376 { 377 return -EINVAL; 378 } 379 380 static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask) 381 { 382 return 0; 383 } 384 385 static inline int irq_can_set_affinity(unsigned int irq) 386 { 387 return 0; 388 } 389 390 static inline int irq_select_affinity(unsigned int irq) { return 0; } 391 392 static inline int irq_update_affinity_hint(unsigned int irq, 393 const struct cpumask *m) 394 { 395 return -EINVAL; 396 } 397 398 static inline int irq_set_affinity_and_hint(unsigned int irq, 399 const struct cpumask *m) 400 { 401 return -EINVAL; 402 } 403 404 static inline int irq_set_affinity_hint(unsigned int irq, 405 const struct cpumask *m) 406 { 407 return -EINVAL; 408 } 409 410 static inline int irq_update_affinity_desc(unsigned int irq, 411 struct irq_affinity_desc *affinity) 412 { 413 return -EINVAL; 414 } 415 416 static inline int 417 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify) 418 { 419 return 0; 420 } 421 422 static inline struct irq_affinity_desc * 423 irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd) 424 { 425 return NULL; 426 } 427 428 static inline unsigned int 429 irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec, 430 const struct irq_affinity *affd) 431 { 432 return maxvec; 433 } 434 435 #endif /* CONFIG_SMP */ 436 437 /* 438 * Special lockdep variants of irq disabling/enabling. 439 * These should be used for locking constructs that 440 * know that a particular irq context which is disabled, 441 * and which is the only irq-context user of a lock, 442 * that it's safe to take the lock in the irq-disabled 443 * section without disabling hardirqs. 444 * 445 * On !CONFIG_LOCKDEP they are equivalent to the normal 446 * irq disable/enable methods. 447 */ 448 static inline void disable_irq_nosync_lockdep(unsigned int irq) 449 { 450 disable_irq_nosync(irq); 451 #ifdef CONFIG_LOCKDEP 452 local_irq_disable(); 453 #endif 454 } 455 456 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags) 457 { 458 disable_irq_nosync(irq); 459 #ifdef CONFIG_LOCKDEP 460 local_irq_save(*flags); 461 #endif 462 } 463 464 static inline void disable_irq_lockdep(unsigned int irq) 465 { 466 disable_irq(irq); 467 #ifdef CONFIG_LOCKDEP 468 local_irq_disable(); 469 #endif 470 } 471 472 static inline void enable_irq_lockdep(unsigned int irq) 473 { 474 #ifdef CONFIG_LOCKDEP 475 local_irq_enable(); 476 #endif 477 enable_irq(irq); 478 } 479 480 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags) 481 { 482 #ifdef CONFIG_LOCKDEP 483 local_irq_restore(*flags); 484 #endif 485 enable_irq(irq); 486 } 487 488 /* IRQ wakeup (PM) control: */ 489 extern int irq_set_irq_wake(unsigned int irq, unsigned int on); 490 491 static inline int enable_irq_wake(unsigned int irq) 492 { 493 return irq_set_irq_wake(irq, 1); 494 } 495 496 static inline int disable_irq_wake(unsigned int irq) 497 { 498 return irq_set_irq_wake(irq, 0); 499 } 500 501 /* 502 * irq_get_irqchip_state/irq_set_irqchip_state specific flags 503 */ 504 enum irqchip_irq_state { 505 IRQCHIP_STATE_PENDING, /* Is interrupt pending? */ 506 IRQCHIP_STATE_ACTIVE, /* Is interrupt in progress? */ 507 IRQCHIP_STATE_MASKED, /* Is interrupt masked? */ 508 IRQCHIP_STATE_LINE_LEVEL, /* Is IRQ line high? */ 509 }; 510 511 extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which, 512 bool *state); 513 extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which, 514 bool state); 515 516 #ifdef CONFIG_IRQ_FORCED_THREADING 517 # ifdef CONFIG_PREEMPT_RT 518 # define force_irqthreads() (true) 519 # else 520 DECLARE_STATIC_KEY_FALSE(force_irqthreads_key); 521 # define force_irqthreads() (static_branch_unlikely(&force_irqthreads_key)) 522 # endif 523 #else 524 #define force_irqthreads() (false) 525 #endif 526 527 #ifndef local_softirq_pending 528 529 #ifndef local_softirq_pending_ref 530 #define local_softirq_pending_ref irq_stat.__softirq_pending 531 #endif 532 533 #define local_softirq_pending() (__this_cpu_read(local_softirq_pending_ref)) 534 #define set_softirq_pending(x) (__this_cpu_write(local_softirq_pending_ref, (x))) 535 #define or_softirq_pending(x) (__this_cpu_or(local_softirq_pending_ref, (x))) 536 537 #endif /* local_softirq_pending */ 538 539 /* Some architectures might implement lazy enabling/disabling of 540 * interrupts. In some cases, such as stop_machine, we might want 541 * to ensure that after a local_irq_disable(), interrupts have 542 * really been disabled in hardware. Such architectures need to 543 * implement the following hook. 544 */ 545 #ifndef hard_irq_disable 546 #define hard_irq_disable() do { } while(0) 547 #endif 548 549 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high 550 frequency threaded job scheduling. For almost all the purposes 551 tasklets are more than enough. F.e. all serial device BHs et 552 al. should be converted to tasklets, not to softirqs. 553 */ 554 555 enum 556 { 557 HI_SOFTIRQ=0, 558 TIMER_SOFTIRQ, 559 NET_TX_SOFTIRQ, 560 NET_RX_SOFTIRQ, 561 BLOCK_SOFTIRQ, 562 IRQ_POLL_SOFTIRQ, 563 TASKLET_SOFTIRQ, 564 SCHED_SOFTIRQ, 565 HRTIMER_SOFTIRQ, 566 RCU_SOFTIRQ, /* Preferable RCU should always be the last softirq */ 567 568 NR_SOFTIRQS 569 }; 570 571 /* 572 * The following vectors can be safely ignored after ksoftirqd is parked: 573 * 574 * _ RCU: 575 * 1) rcutree_migrate_callbacks() migrates the queue. 576 * 2) rcutree_report_cpu_dead() reports the final quiescent states. 577 * 578 * _ IRQ_POLL: irq_poll_cpu_dead() migrates the queue 579 * 580 * _ (HR)TIMER_SOFTIRQ: (hr)timers_dead_cpu() migrates the queue 581 */ 582 #define SOFTIRQ_HOTPLUG_SAFE_MASK (BIT(TIMER_SOFTIRQ) | BIT(IRQ_POLL_SOFTIRQ) |\ 583 BIT(HRTIMER_SOFTIRQ) | BIT(RCU_SOFTIRQ)) 584 585 586 /* map softirq index to softirq name. update 'softirq_to_name' in 587 * kernel/softirq.c when adding a new softirq. 588 */ 589 extern const char * const softirq_to_name[NR_SOFTIRQS]; 590 591 /* softirq mask and active fields moved to irq_cpustat_t in 592 * asm/hardirq.h to get better cache usage. KAO 593 */ 594 595 struct softirq_action 596 { 597 void (*action)(struct softirq_action *); 598 }; 599 600 asmlinkage void do_softirq(void); 601 asmlinkage void __do_softirq(void); 602 603 #ifdef CONFIG_PREEMPT_RT 604 extern void do_softirq_post_smp_call_flush(unsigned int was_pending); 605 #else 606 static inline void do_softirq_post_smp_call_flush(unsigned int unused) 607 { 608 do_softirq(); 609 } 610 #endif 611 612 extern void open_softirq(int nr, void (*action)(struct softirq_action *)); 613 extern void softirq_init(void); 614 extern void __raise_softirq_irqoff(unsigned int nr); 615 616 extern void raise_softirq_irqoff(unsigned int nr); 617 extern void raise_softirq(unsigned int nr); 618 619 DECLARE_PER_CPU(struct task_struct *, ksoftirqd); 620 621 static inline struct task_struct *this_cpu_ksoftirqd(void) 622 { 623 return this_cpu_read(ksoftirqd); 624 } 625 626 /* Tasklets --- multithreaded analogue of BHs. 627 628 This API is deprecated. Please consider using threaded IRQs instead: 629 https://lore.kernel.org/lkml/20200716081538.2sivhkj4hcyrusem@linutronix.de 630 631 Main feature differing them of generic softirqs: tasklet 632 is running only on one CPU simultaneously. 633 634 Main feature differing them of BHs: different tasklets 635 may be run simultaneously on different CPUs. 636 637 Properties: 638 * If tasklet_schedule() is called, then tasklet is guaranteed 639 to be executed on some cpu at least once after this. 640 * If the tasklet is already scheduled, but its execution is still not 641 started, it will be executed only once. 642 * If this tasklet is already running on another CPU (or schedule is called 643 from tasklet itself), it is rescheduled for later. 644 * Tasklet is strictly serialized wrt itself, but not 645 wrt another tasklets. If client needs some intertask synchronization, 646 he makes it with spinlocks. 647 */ 648 649 struct tasklet_struct 650 { 651 struct tasklet_struct *next; 652 unsigned long state; 653 atomic_t count; 654 bool use_callback; 655 union { 656 void (*func)(unsigned long data); 657 void (*callback)(struct tasklet_struct *t); 658 }; 659 unsigned long data; 660 }; 661 662 #define DECLARE_TASKLET(name, _callback) \ 663 struct tasklet_struct name = { \ 664 .count = ATOMIC_INIT(0), \ 665 .callback = _callback, \ 666 .use_callback = true, \ 667 } 668 669 #define DECLARE_TASKLET_DISABLED(name, _callback) \ 670 struct tasklet_struct name = { \ 671 .count = ATOMIC_INIT(1), \ 672 .callback = _callback, \ 673 .use_callback = true, \ 674 } 675 676 #define from_tasklet(var, callback_tasklet, tasklet_fieldname) \ 677 container_of(callback_tasklet, typeof(*var), tasklet_fieldname) 678 679 #define DECLARE_TASKLET_OLD(name, _func) \ 680 struct tasklet_struct name = { \ 681 .count = ATOMIC_INIT(0), \ 682 .func = _func, \ 683 } 684 685 #define DECLARE_TASKLET_DISABLED_OLD(name, _func) \ 686 struct tasklet_struct name = { \ 687 .count = ATOMIC_INIT(1), \ 688 .func = _func, \ 689 } 690 691 enum 692 { 693 TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */ 694 TASKLET_STATE_RUN /* Tasklet is running (SMP only) */ 695 }; 696 697 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT) 698 static inline int tasklet_trylock(struct tasklet_struct *t) 699 { 700 return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state); 701 } 702 703 void tasklet_unlock(struct tasklet_struct *t); 704 void tasklet_unlock_wait(struct tasklet_struct *t); 705 void tasklet_unlock_spin_wait(struct tasklet_struct *t); 706 707 #else 708 static inline int tasklet_trylock(struct tasklet_struct *t) { return 1; } 709 static inline void tasklet_unlock(struct tasklet_struct *t) { } 710 static inline void tasklet_unlock_wait(struct tasklet_struct *t) { } 711 static inline void tasklet_unlock_spin_wait(struct tasklet_struct *t) { } 712 #endif 713 714 extern void __tasklet_schedule(struct tasklet_struct *t); 715 716 static inline void tasklet_schedule(struct tasklet_struct *t) 717 { 718 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) 719 __tasklet_schedule(t); 720 } 721 722 extern void __tasklet_hi_schedule(struct tasklet_struct *t); 723 724 static inline void tasklet_hi_schedule(struct tasklet_struct *t) 725 { 726 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) 727 __tasklet_hi_schedule(t); 728 } 729 730 static inline void tasklet_disable_nosync(struct tasklet_struct *t) 731 { 732 atomic_inc(&t->count); 733 smp_mb__after_atomic(); 734 } 735 736 /* 737 * Do not use in new code. Disabling tasklets from atomic contexts is 738 * error prone and should be avoided. 739 */ 740 static inline void tasklet_disable_in_atomic(struct tasklet_struct *t) 741 { 742 tasklet_disable_nosync(t); 743 tasklet_unlock_spin_wait(t); 744 smp_mb(); 745 } 746 747 static inline void tasklet_disable(struct tasklet_struct *t) 748 { 749 tasklet_disable_nosync(t); 750 tasklet_unlock_wait(t); 751 smp_mb(); 752 } 753 754 static inline void tasklet_enable(struct tasklet_struct *t) 755 { 756 smp_mb__before_atomic(); 757 atomic_dec(&t->count); 758 } 759 760 extern void tasklet_kill(struct tasklet_struct *t); 761 extern void tasklet_init(struct tasklet_struct *t, 762 void (*func)(unsigned long), unsigned long data); 763 extern void tasklet_setup(struct tasklet_struct *t, 764 void (*callback)(struct tasklet_struct *)); 765 766 /* 767 * Autoprobing for irqs: 768 * 769 * probe_irq_on() and probe_irq_off() provide robust primitives 770 * for accurate IRQ probing during kernel initialization. They are 771 * reasonably simple to use, are not "fooled" by spurious interrupts, 772 * and, unlike other attempts at IRQ probing, they do not get hung on 773 * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards). 774 * 775 * For reasonably foolproof probing, use them as follows: 776 * 777 * 1. clear and/or mask the device's internal interrupt. 778 * 2. sti(); 779 * 3. irqs = probe_irq_on(); // "take over" all unassigned idle IRQs 780 * 4. enable the device and cause it to trigger an interrupt. 781 * 5. wait for the device to interrupt, using non-intrusive polling or a delay. 782 * 6. irq = probe_irq_off(irqs); // get IRQ number, 0=none, negative=multiple 783 * 7. service the device to clear its pending interrupt. 784 * 8. loop again if paranoia is required. 785 * 786 * probe_irq_on() returns a mask of allocated irq's. 787 * 788 * probe_irq_off() takes the mask as a parameter, 789 * and returns the irq number which occurred, 790 * or zero if none occurred, or a negative irq number 791 * if more than one irq occurred. 792 */ 793 794 #if !defined(CONFIG_GENERIC_IRQ_PROBE) 795 static inline unsigned long probe_irq_on(void) 796 { 797 return 0; 798 } 799 static inline int probe_irq_off(unsigned long val) 800 { 801 return 0; 802 } 803 static inline unsigned int probe_irq_mask(unsigned long val) 804 { 805 return 0; 806 } 807 #else 808 extern unsigned long probe_irq_on(void); /* returns 0 on failure */ 809 extern int probe_irq_off(unsigned long); /* returns 0 or negative on failure */ 810 extern unsigned int probe_irq_mask(unsigned long); /* returns mask of ISA interrupts */ 811 #endif 812 813 #ifdef CONFIG_PROC_FS 814 /* Initialize /proc/irq/ */ 815 extern void init_irq_proc(void); 816 #else 817 static inline void init_irq_proc(void) 818 { 819 } 820 #endif 821 822 #ifdef CONFIG_IRQ_TIMINGS 823 void irq_timings_enable(void); 824 void irq_timings_disable(void); 825 u64 irq_timings_next_event(u64 now); 826 #endif 827 828 struct seq_file; 829 int show_interrupts(struct seq_file *p, void *v); 830 int arch_show_interrupts(struct seq_file *p, int prec); 831 832 extern int early_irq_init(void); 833 extern int arch_probe_nr_irqs(void); 834 extern int arch_early_irq_init(void); 835 836 /* 837 * We want to know which function is an entrypoint of a hardirq or a softirq. 838 */ 839 #ifndef __irq_entry 840 # define __irq_entry __section(".irqentry.text") 841 #endif 842 843 #define __softirq_entry __section(".softirqentry.text") 844 845 #endif 846