include/linux/interrupt.h

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