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