include/linux/irq.h - kernel/msm-4.19 - Gitiles

 #ifndef _LINUX_IRQ_H
 #define _LINUX_IRQ_H

 /*
  * Please do not include this file in generic code.  There is currently
  * no requirement for any architecture to implement anything held
  * within this file.
  *
  * Thanks. --rmk
  */

 #include <linux/smp.h>

 #ifndef CONFIG_S390

 #include <linux/linkage.h>
 #include <linux/cache.h>
 #include <linux/spinlock.h>
 #include <linux/cpumask.h>
 #include <linux/gfp.h>
 #include <linux/irqreturn.h>
 #include <linux/irqnr.h>
 #include <linux/errno.h>
 #include <linux/topology.h>
 #include <linux/wait.h>

 #include <asm/irq.h>
 #include <asm/ptrace.h>
 #include <asm/irq_regs.h>

 struct irq_desc;
 typedef	void (*irq_flow_handler_t)(unsigned int irq,
 					    struct irq_desc *desc);


 /*
  * IRQ line status.
  *
  * Bits 0-7 are reserved for the IRQF_* bits in linux/interrupt.h
  *
  * IRQ types
  */
 #define IRQ_TYPE_NONE		0x00000000	/* Default, unspecified type */
 #define IRQ_TYPE_EDGE_RISING	0x00000001	/* Edge rising type */
 #define IRQ_TYPE_EDGE_FALLING	0x00000002	/* Edge falling type */
 #define IRQ_TYPE_EDGE_BOTH (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)
 #define IRQ_TYPE_LEVEL_HIGH	0x00000004	/* Level high type */
 #define IRQ_TYPE_LEVEL_LOW	0x00000008	/* Level low type */
 #define IRQ_TYPE_SENSE_MASK	0x0000000f	/* Mask of the above */
 #define IRQ_TYPE_PROBE		0x00000010	/* Probing in progress */

 /* Internal flags */
 #define IRQ_INPROGRESS		0x00000100	/* IRQ handler active - do not enter! */
 #define IRQ_DISABLED		0x00000200	/* IRQ disabled - do not enter! */
 #define IRQ_PENDING		0x00000400	/* IRQ pending - replay on enable */
 #define IRQ_REPLAY		0x00000800	/* IRQ has been replayed but not acked yet */
 #define IRQ_AUTODETECT		0x00001000	/* IRQ is being autodetected */
 #define IRQ_WAITING		0x00002000	/* IRQ not yet seen - for autodetection */
 #define IRQ_LEVEL		0x00004000	/* IRQ level triggered */
 #define IRQ_MASKED		0x00008000	/* IRQ masked - shouldn't be seen again */
 #define IRQ_PER_CPU		0x00010000	/* IRQ is per CPU */
 #define IRQ_NOPROBE		0x00020000	/* IRQ is not valid for probing */
 #define IRQ_NOREQUEST		0x00040000	/* IRQ cannot be requested */
 #define IRQ_NOAUTOEN		0x00080000	/* IRQ will not be enabled on request irq */
 #define IRQ_WAKEUP		0x00100000	/* IRQ triggers system wakeup */
 #define IRQ_MOVE_PENDING	0x00200000	/* need to re-target IRQ destination */
 #define IRQ_NO_BALANCING	0x00400000	/* IRQ is excluded from balancing */
 #define IRQ_SPURIOUS_DISABLED	0x00800000	/* IRQ was disabled by the spurious trap */
 #define IRQ_MOVE_PCNTXT		0x01000000	/* IRQ migration from process context */
 #define IRQ_AFFINITY_SET	0x02000000	/* IRQ affinity was set from userspace*/
 #define IRQ_SUSPENDED		0x04000000	/* IRQ has gone through suspend sequence */
 #define IRQ_ONESHOT		0x08000000	/* IRQ is not unmasked after hardirq */
 #define IRQ_NESTED_THREAD	0x10000000	/* IRQ is nested into another, no own handler thread */

 #ifdef CONFIG_IRQ_PER_CPU
 # define CHECK_IRQ_PER_CPU(var) ((var) & IRQ_PER_CPU)
 # define IRQ_NO_BALANCING_MASK	(IRQ_PER_CPU | IRQ_NO_BALANCING)
 #else
 # define CHECK_IRQ_PER_CPU(var) 0
 # define IRQ_NO_BALANCING_MASK	IRQ_NO_BALANCING
 #endif

 struct proc_dir_entry;
 struct msi_desc;

 /**
  * struct irq_chip - hardware interrupt chip descriptor
  *
  * @name:		name for /proc/interrupts
  * @startup:		start up the interrupt (defaults to ->enable if NULL)
  * @shutdown:		shut down the interrupt (defaults to ->disable if NULL)
  * @enable:		enable the interrupt (defaults to chip->unmask if NULL)
  * @disable:		disable the interrupt (defaults to chip->mask if NULL)
  * @ack:		start of a new interrupt
  * @mask:		mask an interrupt source
  * @mask_ack:		ack and mask an interrupt source
  * @unmask:		unmask an interrupt source
  * @eoi:		end of interrupt - chip level
  * @end:		end of interrupt - flow level
  * @set_affinity:	set the CPU affinity on SMP machines
  * @retrigger:		resend an IRQ to the CPU
  * @set_type:		set the flow type (IRQ_TYPE_LEVEL/etc.) of an IRQ
  * @set_wake:		enable/disable power-management wake-on of an IRQ
  *
  * @bus_lock:		function to lock access to slow bus (i2c) chips
  * @bus_sync_unlock:	function to sync and unlock slow bus (i2c) chips
  *
  * @release:		release function solely used by UML
  * @typename:		obsoleted by name, kept as migration helper
  */
 struct irq_chip {
 	const char	*name;
 	unsigned int	(*startup)(unsigned int irq);
 	void		(*shutdown)(unsigned int irq);
 	void		(*enable)(unsigned int irq);
 	void		(*disable)(unsigned int irq);

 	void		(*ack)(unsigned int irq);
 	void		(*mask)(unsigned int irq);
 	void		(*mask_ack)(unsigned int irq);
 	void		(*unmask)(unsigned int irq);
 	void		(*eoi)(unsigned int irq);

 	void		(*end)(unsigned int irq);
 	int		(*set_affinity)(unsigned int irq,
 					const struct cpumask *dest);
 	int		(*retrigger)(unsigned int irq);
 	int		(*set_type)(unsigned int irq, unsigned int flow_type);
 	int		(*set_wake)(unsigned int irq, unsigned int on);

 	void		(*bus_lock)(unsigned int irq);
 	void		(*bus_sync_unlock)(unsigned int irq);

 	/* Currently used only by UML, might disappear one day.*/
 #ifdef CONFIG_IRQ_RELEASE_METHOD
 	void		(*release)(unsigned int irq, void *dev_id);
 #endif
 	/*
 	 * For compatibility, ->typename is copied into ->name.
 	 * Will disappear.
 	 */
 	const char	*typename;
 };

 struct timer_rand_state;
 struct irq_2_iommu;
 /**
  * struct irq_desc - interrupt descriptor
  * @irq:		interrupt number for this descriptor
  * @timer_rand_state:	pointer to timer rand state struct
  * @kstat_irqs:		irq stats per cpu
  * @irq_2_iommu:	iommu with this irq
  * @handle_irq:		highlevel irq-events handler [if NULL, __do_IRQ()]
  * @chip:		low level interrupt hardware access
  * @msi_desc:		MSI descriptor
  * @handler_data:	per-IRQ data for the irq_chip methods
  * @chip_data:		platform-specific per-chip private data for the chip
  *			methods, to allow shared chip implementations
  * @action:		the irq action chain
  * @status:		status information
  * @depth:		disable-depth, for nested irq_disable() calls
  * @wake_depth:		enable depth, for multiple set_irq_wake() callers
  * @irq_count:		stats field to detect stalled irqs
  * @last_unhandled:	aging timer for unhandled count
  * @irqs_unhandled:	stats field for spurious unhandled interrupts
  * @lock:		locking for SMP
  * @affinity:		IRQ affinity on SMP
  * @node:		node index useful for balancing
  * @pending_mask:	pending rebalanced interrupts
  * @threads_active:	number of irqaction threads currently running
  * @wait_for_threads:	wait queue for sync_irq to wait for threaded handlers
  * @dir:		/proc/irq/ procfs entry
  * @name:		flow handler name for /proc/interrupts output
  */
 struct irq_desc {
 	unsigned int		irq;
 	struct timer_rand_state *timer_rand_state;
 	unsigned int            *kstat_irqs;
 #ifdef CONFIG_INTR_REMAP
 	struct irq_2_iommu      *irq_2_iommu;
 #endif
 	irq_flow_handler_t	handle_irq;
 	struct irq_chip		*chip;
 	struct msi_desc		*msi_desc;
 	void			*handler_data;
 	void			*chip_data;
 	struct irqaction	*action;	/* IRQ action list */
 	unsigned int		status;		/* IRQ status */

 	unsigned int		depth;		/* nested irq disables */
 	unsigned int		wake_depth;	/* nested wake enables */
 	unsigned int		irq_count;	/* For detecting broken IRQs */
 	unsigned long		last_unhandled;	/* Aging timer for unhandled count */
 	unsigned int		irqs_unhandled;
 	spinlock_t		lock;
 #ifdef CONFIG_SMP
 	cpumask_var_t		affinity;
 	unsigned int		node;
 #ifdef CONFIG_GENERIC_PENDING_IRQ
 	cpumask_var_t		pending_mask;
 #endif
 #endif
 	atomic_t		threads_active;
 	wait_queue_head_t       wait_for_threads;
 #ifdef CONFIG_PROC_FS
 	struct proc_dir_entry	*dir;
 #endif
 	const char		*name;
 } ____cacheline_internodealigned_in_smp;

 extern void arch_init_copy_chip_data(struct irq_desc *old_desc,
 					struct irq_desc *desc, int node);
 extern void arch_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc);

 #ifndef CONFIG_SPARSE_IRQ
 extern struct irq_desc irq_desc[NR_IRQS];
 #endif

 #ifdef CONFIG_NUMA_IRQ_DESC
 extern struct irq_desc *move_irq_desc(struct irq_desc *old_desc, int node);
 #else
 static inline struct irq_desc *move_irq_desc(struct irq_desc *desc, int node)
 {
 	return desc;
 }
 #endif

 extern struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node);

 /*
  * Pick up the arch-dependent methods:
  */
 #include <asm/hw_irq.h>

 extern int setup_irq(unsigned int irq, struct irqaction *new);
 extern void remove_irq(unsigned int irq, struct irqaction *act);

 #ifdef CONFIG_GENERIC_HARDIRQS

 #ifdef CONFIG_SMP

 #ifdef CONFIG_GENERIC_PENDING_IRQ

 void move_native_irq(int irq);
 void move_masked_irq(int irq);

 #else /* CONFIG_GENERIC_PENDING_IRQ */

 static inline void move_irq(int irq)
 {
 }

 static inline void move_native_irq(int irq)
 {
 }

 static inline void move_masked_irq(int irq)
 {
 }

 #endif /* CONFIG_GENERIC_PENDING_IRQ */

 #else /* CONFIG_SMP */

 #define move_native_irq(x)
 #define move_masked_irq(x)

 #endif /* CONFIG_SMP */

 extern int no_irq_affinity;

 static inline int irq_balancing_disabled(unsigned int irq)
 {
 	struct irq_desc *desc;

 	desc = irq_to_desc(irq);
 	return desc->status & IRQ_NO_BALANCING_MASK;
 }

 /* Handle irq action chains: */
 extern irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action);

 /*
  * Built-in IRQ handlers for various IRQ types,
  * callable via desc->handle_irq()
  */
 extern void handle_level_irq(unsigned int irq, struct irq_desc *desc);
 extern void handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc);
 extern void handle_edge_irq(unsigned int irq, struct irq_desc *desc);
 extern void handle_simple_irq(unsigned int irq, struct irq_desc *desc);
 extern void handle_percpu_irq(unsigned int irq, struct irq_desc *desc);
 extern void handle_bad_irq(unsigned int irq, struct irq_desc *desc);
 extern void handle_nested_irq(unsigned int irq);

 /*
  * Monolithic do_IRQ implementation.
  */
 #ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
 extern unsigned int __do_IRQ(unsigned int irq);
 #endif

 /*
  * Architectures call this to let the generic IRQ layer
  * handle an interrupt. If the descriptor is attached to an
  * irqchip-style controller then we call the ->handle_irq() handler,
  * and it calls __do_IRQ() if it's attached to an irqtype-style controller.
  */
 static inline void generic_handle_irq_desc(unsigned int irq, struct irq_desc *desc)
 {
 #ifdef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
 	desc->handle_irq(irq, desc);
 #else
 	if (likely(desc->handle_irq))
 		desc->handle_irq(irq, desc);
 	else
 		__do_IRQ(irq);
 #endif
 }

 static inline void generic_handle_irq(unsigned int irq)
 {
 	generic_handle_irq_desc(irq, irq_to_desc(irq));
 }

 /* Handling of unhandled and spurious interrupts: */
 extern void note_interrupt(unsigned int irq, struct irq_desc *desc,
 			   irqreturn_t action_ret);

 /* Resending of interrupts :*/
 void check_irq_resend(struct irq_desc *desc, unsigned int irq);

 /* Enable/disable irq debugging output: */
 extern int noirqdebug_setup(char *str);

 /* Checks whether the interrupt can be requested by request_irq(): */
 extern int can_request_irq(unsigned int irq, unsigned long irqflags);

 /* Dummy irq-chip implementations: */
 extern struct irq_chip no_irq_chip;
 extern struct irq_chip dummy_irq_chip;

 extern void
 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
 			 irq_flow_handler_t handle);
 extern void
 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
 			      irq_flow_handler_t handle, const char *name);

 extern void
 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 		  const char *name);

 /* caller has locked the irq_desc and both params are valid */
 static inline void __set_irq_handler_unlocked(int irq,
 					      irq_flow_handler_t handler)
 {
 	struct irq_desc *desc;

 	desc = irq_to_desc(irq);
 	desc->handle_irq = handler;
 }

 /*
  * Set a highlevel flow handler for a given IRQ:
  */
 static inline void
 set_irq_handler(unsigned int irq, irq_flow_handler_t handle)
 {
 	__set_irq_handler(irq, handle, 0, NULL);
 }

 /*
  * Set a highlevel chained flow handler for a given IRQ.
  * (a chained handler is automatically enabled and set to
  *  IRQ_NOREQUEST and IRQ_NOPROBE)
  */
 static inline void
 set_irq_chained_handler(unsigned int irq,
 			irq_flow_handler_t handle)
 {
 	__set_irq_handler(irq, handle, 1, NULL);
 }

 extern void set_irq_nested_thread(unsigned int irq, int nest);

 extern void set_irq_noprobe(unsigned int irq);
 extern void set_irq_probe(unsigned int irq);

 /* Handle dynamic irq creation and destruction */
 extern unsigned int create_irq_nr(unsigned int irq_want, int node);
 extern int create_irq(void);
 extern void destroy_irq(unsigned int irq);

 /* Test to see if a driver has successfully requested an irq */
 static inline int irq_has_action(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	return desc->action != NULL;
 }

 /* Dynamic irq helper functions */
 extern void dynamic_irq_init(unsigned int irq);
 extern void dynamic_irq_cleanup(unsigned int irq);

 /* Set/get chip/data for an IRQ: */
 extern int set_irq_chip(unsigned int irq, struct irq_chip *chip);
 extern int set_irq_data(unsigned int irq, void *data);
 extern int set_irq_chip_data(unsigned int irq, void *data);
 extern int set_irq_type(unsigned int irq, unsigned int type);
 extern int set_irq_msi(unsigned int irq, struct msi_desc *entry);

 #define get_irq_chip(irq)	(irq_to_desc(irq)->chip)
 #define get_irq_chip_data(irq)	(irq_to_desc(irq)->chip_data)
 #define get_irq_data(irq)	(irq_to_desc(irq)->handler_data)
 #define get_irq_msi(irq)	(irq_to_desc(irq)->msi_desc)

 #define get_irq_desc_chip(desc)		((desc)->chip)
 #define get_irq_desc_chip_data(desc)	((desc)->chip_data)
 #define get_irq_desc_data(desc)		((desc)->handler_data)
 #define get_irq_desc_msi(desc)		((desc)->msi_desc)

 #endif /* CONFIG_GENERIC_HARDIRQS */

 #endif /* !CONFIG_S390 */

 #ifdef CONFIG_SMP
 /**
  * alloc_desc_masks - allocate cpumasks for irq_desc
  * @desc:	pointer to irq_desc struct
  * @node:	node which will be handling the cpumasks
  * @boot:	true if need bootmem
  *
  * Allocates affinity and pending_mask cpumask if required.
  * Returns true if successful (or not required).
  */
 static inline bool alloc_desc_masks(struct irq_desc *desc, int node,
 							bool boot)
 {
 	gfp_t gfp = GFP_ATOMIC;

 	if (boot)
 		gfp = GFP_NOWAIT;

 #ifdef CONFIG_CPUMASK_OFFSTACK
 	if (!alloc_cpumask_var_node(&desc->affinity, gfp, node))
 		return false;

 #ifdef CONFIG_GENERIC_PENDING_IRQ
 	if (!alloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
 		free_cpumask_var(desc->affinity);
 		return false;
 	}
 #endif
 #endif
 	return true;
 }

 static inline void init_desc_masks(struct irq_desc *desc)
 {
 	cpumask_setall(desc->affinity);
 #ifdef CONFIG_GENERIC_PENDING_IRQ
 	cpumask_clear(desc->pending_mask);
 #endif
 }

 /**
  * init_copy_desc_masks - copy cpumasks for irq_desc
  * @old_desc:	pointer to old irq_desc struct
  * @new_desc:	pointer to new irq_desc struct
  *
  * Insures affinity and pending_masks are copied to new irq_desc.
  * If !CONFIG_CPUMASKS_OFFSTACK the cpumasks are embedded in the
  * irq_desc struct so the copy is redundant.
  */

 static inline void init_copy_desc_masks(struct irq_desc *old_desc,
 					struct irq_desc *new_desc)
 {
 #ifdef CONFIG_CPUMASK_OFFSTACK
 	cpumask_copy(new_desc->affinity, old_desc->affinity);

 #ifdef CONFIG_GENERIC_PENDING_IRQ
 	cpumask_copy(new_desc->pending_mask, old_desc->pending_mask);
 #endif
 #endif
 }

 static inline void free_desc_masks(struct irq_desc *old_desc,
 				   struct irq_desc *new_desc)
 {
 	free_cpumask_var(old_desc->affinity);

 #ifdef CONFIG_GENERIC_PENDING_IRQ
 	free_cpumask_var(old_desc->pending_mask);
 #endif
 }

 #else /* !CONFIG_SMP */

 static inline bool alloc_desc_masks(struct irq_desc *desc, int node,
 								bool boot)
 {
 	return true;
 }

 static inline void init_desc_masks(struct irq_desc *desc)
 {
 }

 static inline void init_copy_desc_masks(struct irq_desc *old_desc,
 					struct irq_desc *new_desc)
 {
 }

 static inline void free_desc_masks(struct irq_desc *old_desc,
 				   struct irq_desc *new_desc)
 {
 }
 #endif	/* CONFIG_SMP */

 #endif /* _LINUX_IRQ_H */
	#ifndef _LINUX_IRQ_H
	#define _LINUX_IRQ_H

	/*
	* Please do not include this file in generic code. There is currently
	* no requirement for any architecture to implement anything held
	* within this file.
	*
	* Thanks. --rmk
	*/

	#include <linux/smp.h>

	#ifndef CONFIG_S390

	#include <linux/linkage.h>
	#include <linux/cache.h>
	#include <linux/spinlock.h>
	#include <linux/cpumask.h>
	#include <linux/gfp.h>
	#include <linux/irqreturn.h>
	#include <linux/irqnr.h>
	#include <linux/errno.h>
	#include <linux/topology.h>
	#include <linux/wait.h>

	#include <asm/irq.h>
	#include <asm/ptrace.h>
	#include <asm/irq_regs.h>

	struct irq_desc;
	typedef void (*irq_flow_handler_t)(unsigned int irq,
	struct irq_desc *desc);


	/*
	* IRQ line status.
	*
	* Bits 0-7 are reserved for the IRQF_* bits in linux/interrupt.h
	*
	* IRQ types
	*/
	#define IRQ_TYPE_NONE 0x00000000 /* Default, unspecified type */
	#define IRQ_TYPE_EDGE_RISING 0x00000001 /* Edge rising type */
	#define IRQ_TYPE_EDGE_FALLING 0x00000002 /* Edge falling type */
	#define IRQ_TYPE_EDGE_BOTH (IRQ_TYPE_EDGE_FALLING \| IRQ_TYPE_EDGE_RISING)
	#define IRQ_TYPE_LEVEL_HIGH 0x00000004 /* Level high type */
	#define IRQ_TYPE_LEVEL_LOW 0x00000008 /* Level low type */
	#define IRQ_TYPE_SENSE_MASK 0x0000000f /* Mask of the above */
	#define IRQ_TYPE_PROBE 0x00000010 /* Probing in progress */

	/* Internal flags */
	#define IRQ_INPROGRESS 0x00000100 /* IRQ handler active - do not enter! */
	#define IRQ_DISABLED 0x00000200 /* IRQ disabled - do not enter! */
	#define IRQ_PENDING 0x00000400 /* IRQ pending - replay on enable */
	#define IRQ_REPLAY 0x00000800 /* IRQ has been replayed but not acked yet */
	#define IRQ_AUTODETECT 0x00001000 /* IRQ is being autodetected */
	#define IRQ_WAITING 0x00002000 /* IRQ not yet seen - for autodetection */
	#define IRQ_LEVEL 0x00004000 /* IRQ level triggered */
	#define IRQ_MASKED 0x00008000 /* IRQ masked - shouldn't be seen again */
	#define IRQ_PER_CPU 0x00010000 /* IRQ is per CPU */
	#define IRQ_NOPROBE 0x00020000 /* IRQ is not valid for probing */
	#define IRQ_NOREQUEST 0x00040000 /* IRQ cannot be requested */
	#define IRQ_NOAUTOEN 0x00080000 /* IRQ will not be enabled on request irq */
	#define IRQ_WAKEUP 0x00100000 /* IRQ triggers system wakeup */
	#define IRQ_MOVE_PENDING 0x00200000 /* need to re-target IRQ destination */
	#define IRQ_NO_BALANCING 0x00400000 /* IRQ is excluded from balancing */
	#define IRQ_SPURIOUS_DISABLED 0x00800000 /* IRQ was disabled by the spurious trap */
	#define IRQ_MOVE_PCNTXT 0x01000000 /* IRQ migration from process context */
	#define IRQ_AFFINITY_SET 0x02000000 /* IRQ affinity was set from userspace*/
	#define IRQ_SUSPENDED 0x04000000 /* IRQ has gone through suspend sequence */
	#define IRQ_ONESHOT 0x08000000 /* IRQ is not unmasked after hardirq */
	#define IRQ_NESTED_THREAD 0x10000000 /* IRQ is nested into another, no own handler thread */

	#ifdef CONFIG_IRQ_PER_CPU
	# define CHECK_IRQ_PER_CPU(var) ((var) & IRQ_PER_CPU)
	# define IRQ_NO_BALANCING_MASK (IRQ_PER_CPU \| IRQ_NO_BALANCING)
	#else
	# define CHECK_IRQ_PER_CPU(var) 0
	# define IRQ_NO_BALANCING_MASK IRQ_NO_BALANCING
	#endif

	struct proc_dir_entry;
	struct msi_desc;

	/**
	* struct irq_chip - hardware interrupt chip descriptor
	*
	* @name: name for /proc/interrupts
	* @startup: start up the interrupt (defaults to ->enable if NULL)
	* @shutdown: shut down the interrupt (defaults to ->disable if NULL)
	* @enable: enable the interrupt (defaults to chip->unmask if NULL)
	* @disable: disable the interrupt (defaults to chip->mask if NULL)
	* @ack: start of a new interrupt
	* @mask: mask an interrupt source
	* @mask_ack: ack and mask an interrupt source
	* @unmask: unmask an interrupt source
	* @eoi: end of interrupt - chip level
	* @end: end of interrupt - flow level
	* @set_affinity: set the CPU affinity on SMP machines
	* @retrigger: resend an IRQ to the CPU
	* @set_type: set the flow type (IRQ_TYPE_LEVEL/etc.) of an IRQ
	* @set_wake: enable/disable power-management wake-on of an IRQ
	*
	* @bus_lock: function to lock access to slow bus (i2c) chips
	* @bus_sync_unlock: function to sync and unlock slow bus (i2c) chips
	*
	* @release: release function solely used by UML
	* @typename: obsoleted by name, kept as migration helper
	*/
	struct irq_chip {
	const char *name;
	unsigned int (*startup)(unsigned int irq);
	void (*shutdown)(unsigned int irq);
	void (*enable)(unsigned int irq);
	void (*disable)(unsigned int irq);

	void (*ack)(unsigned int irq);
	void (*mask)(unsigned int irq);
	void (*mask_ack)(unsigned int irq);
	void (*unmask)(unsigned int irq);
	void (*eoi)(unsigned int irq);

	void (*end)(unsigned int irq);
	int (*set_affinity)(unsigned int irq,
	const struct cpumask *dest);
	int (*retrigger)(unsigned int irq);
	int (*set_type)(unsigned int irq, unsigned int flow_type);
	int (*set_wake)(unsigned int irq, unsigned int on);

	void (*bus_lock)(unsigned int irq);
	void (*bus_sync_unlock)(unsigned int irq);

	/* Currently used only by UML, might disappear one day.*/
	#ifdef CONFIG_IRQ_RELEASE_METHOD
	void (release)(unsigned int irq, void dev_id);
	#endif
	/*
	* For compatibility, ->typename is copied into ->name.
	* Will disappear.
	*/
	const char *typename;
	};

	struct timer_rand_state;
	struct irq_2_iommu;
	/**
	* struct irq_desc - interrupt descriptor
	* @irq: interrupt number for this descriptor
	* @timer_rand_state: pointer to timer rand state struct
	* @kstat_irqs: irq stats per cpu
	* @irq_2_iommu: iommu with this irq
	* @handle_irq: highlevel irq-events handler [if NULL, __do_IRQ()]
	* @chip: low level interrupt hardware access
	* @msi_desc: MSI descriptor
	* @handler_data: per-IRQ data for the irq_chip methods
	* @chip_data: platform-specific per-chip private data for the chip
	* methods, to allow shared chip implementations
	* @action: the irq action chain
	* @status: status information
	* @depth: disable-depth, for nested irq_disable() calls
	* @wake_depth: enable depth, for multiple set_irq_wake() callers
	* @irq_count: stats field to detect stalled irqs
	* @last_unhandled: aging timer for unhandled count
	* @irqs_unhandled: stats field for spurious unhandled interrupts
	* @lock: locking for SMP
	* @affinity: IRQ affinity on SMP
	* @node: node index useful for balancing
	* @pending_mask: pending rebalanced interrupts
	* @threads_active: number of irqaction threads currently running
	* @wait_for_threads: wait queue for sync_irq to wait for threaded handlers
	* @dir: /proc/irq/ procfs entry
	* @name: flow handler name for /proc/interrupts output
	*/
	struct irq_desc {
	unsigned int irq;
	struct timer_rand_state *timer_rand_state;
	unsigned int *kstat_irqs;
	#ifdef CONFIG_INTR_REMAP
	struct irq_2_iommu *irq_2_iommu;
	#endif
	irq_flow_handler_t handle_irq;
	struct irq_chip *chip;
	struct msi_desc *msi_desc;
	void *handler_data;
	void *chip_data;
	struct irqaction action; / IRQ action list */
	unsigned int status; /* IRQ status */

	unsigned int depth; /* nested irq disables */
	unsigned int wake_depth; /* nested wake enables */
	unsigned int irq_count; /* For detecting broken IRQs */
	unsigned long last_unhandled; /* Aging timer for unhandled count */
	unsigned int irqs_unhandled;
	spinlock_t lock;
	#ifdef CONFIG_SMP
	cpumask_var_t affinity;
	unsigned int node;
	#ifdef CONFIG_GENERIC_PENDING_IRQ
	cpumask_var_t pending_mask;
	#endif
	#endif
	atomic_t threads_active;
	wait_queue_head_t wait_for_threads;
	#ifdef CONFIG_PROC_FS
	struct proc_dir_entry *dir;
	#endif
	const char *name;
	} ____cacheline_internodealigned_in_smp;

	extern void arch_init_copy_chip_data(struct irq_desc *old_desc,
	struct irq_desc *desc, int node);
	extern void arch_free_chip_data(struct irq_desc old_desc, struct irq_desc desc);

	#ifndef CONFIG_SPARSE_IRQ
	extern struct irq_desc irq_desc[NR_IRQS];
	#endif

	#ifdef CONFIG_NUMA_IRQ_DESC
	extern struct irq_desc move_irq_desc(struct irq_desc old_desc, int node);
	#else
	static inline struct irq_desc move_irq_desc(struct irq_desc desc, int node)
	{
	return desc;
	}
	#endif

	extern struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node);

	/*
	* Pick up the arch-dependent methods:
	*/
	#include <asm/hw_irq.h>

	extern int setup_irq(unsigned int irq, struct irqaction *new);
	extern void remove_irq(unsigned int irq, struct irqaction *act);

	#ifdef CONFIG_GENERIC_HARDIRQS

	#ifdef CONFIG_SMP

	#ifdef CONFIG_GENERIC_PENDING_IRQ

	void move_native_irq(int irq);
	void move_masked_irq(int irq);

	#else /* CONFIG_GENERIC_PENDING_IRQ */

	static inline void move_irq(int irq)
	{
	}

	static inline void move_native_irq(int irq)
	{
	}

	static inline void move_masked_irq(int irq)
	{
	}

	#endif /* CONFIG_GENERIC_PENDING_IRQ */

	#else /* CONFIG_SMP */

	#define move_native_irq(x)
	#define move_masked_irq(x)

	#endif /* CONFIG_SMP */

	extern int no_irq_affinity;

	static inline int irq_balancing_disabled(unsigned int irq)
	{
	struct irq_desc *desc;

	desc = irq_to_desc(irq);
	return desc->status & IRQ_NO_BALANCING_MASK;
	}

	/* Handle irq action chains: */
	extern irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action);

	/*
	* Built-in IRQ handlers for various IRQ types,
	* callable via desc->handle_irq()
	*/
	extern void handle_level_irq(unsigned int irq, struct irq_desc *desc);
	extern void handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc);
	extern void handle_edge_irq(unsigned int irq, struct irq_desc *desc);
	extern void handle_simple_irq(unsigned int irq, struct irq_desc *desc);
	extern void handle_percpu_irq(unsigned int irq, struct irq_desc *desc);
	extern void handle_bad_irq(unsigned int irq, struct irq_desc *desc);
	extern void handle_nested_irq(unsigned int irq);

	/*
	* Monolithic do_IRQ implementation.
	*/
	#ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
	extern unsigned int __do_IRQ(unsigned int irq);
	#endif

	/*
	* Architectures call this to let the generic IRQ layer
	* handle an interrupt. If the descriptor is attached to an
	* irqchip-style controller then we call the ->handle_irq() handler,
	* and it calls __do_IRQ() if it's attached to an irqtype-style controller.
	*/
	static inline void generic_handle_irq_desc(unsigned int irq, struct irq_desc *desc)
	{
	#ifdef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
	desc->handle_irq(irq, desc);
	#else
	if (likely(desc->handle_irq))
	desc->handle_irq(irq, desc);
	else
	__do_IRQ(irq);
	#endif
	}

	static inline void generic_handle_irq(unsigned int irq)
	{
	generic_handle_irq_desc(irq, irq_to_desc(irq));
	}

	/* Handling of unhandled and spurious interrupts: */
	extern void note_interrupt(unsigned int irq, struct irq_desc *desc,
	irqreturn_t action_ret);

	/* Resending of interrupts :*/
	void check_irq_resend(struct irq_desc *desc, unsigned int irq);

	/* Enable/disable irq debugging output: */
	extern int noirqdebug_setup(char *str);

	/* Checks whether the interrupt can be requested by request_irq(): */
	extern int can_request_irq(unsigned int irq, unsigned long irqflags);

	/* Dummy irq-chip implementations: */
	extern struct irq_chip no_irq_chip;
	extern struct irq_chip dummy_irq_chip;

	extern void
	set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
	irq_flow_handler_t handle);
	extern void
	set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
	irq_flow_handler_t handle, const char *name);

	extern void
	__set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
	const char *name);

	/* caller has locked the irq_desc and both params are valid */
	static inline void __set_irq_handler_unlocked(int irq,
	irq_flow_handler_t handler)
	{
	struct irq_desc *desc;

	desc = irq_to_desc(irq);
	desc->handle_irq = handler;
	}

	/*
	* Set a highlevel flow handler for a given IRQ:
	*/
	static inline void
	set_irq_handler(unsigned int irq, irq_flow_handler_t handle)
	{
	__set_irq_handler(irq, handle, 0, NULL);
	}

	/*
	* Set a highlevel chained flow handler for a given IRQ.
	* (a chained handler is automatically enabled and set to
	* IRQ_NOREQUEST and IRQ_NOPROBE)
	*/
	static inline void
	set_irq_chained_handler(unsigned int irq,
	irq_flow_handler_t handle)
	{
	__set_irq_handler(irq, handle, 1, NULL);
	}

	extern void set_irq_nested_thread(unsigned int irq, int nest);

	extern void set_irq_noprobe(unsigned int irq);
	extern void set_irq_probe(unsigned int irq);

	/* Handle dynamic irq creation and destruction */
	extern unsigned int create_irq_nr(unsigned int irq_want, int node);
	extern int create_irq(void);
	extern void destroy_irq(unsigned int irq);

	/* Test to see if a driver has successfully requested an irq */
	static inline int irq_has_action(unsigned int irq)
	{
	struct irq_desc *desc = irq_to_desc(irq);
	return desc->action != NULL;
	}

	/* Dynamic irq helper functions */
	extern void dynamic_irq_init(unsigned int irq);
	extern void dynamic_irq_cleanup(unsigned int irq);

	/* Set/get chip/data for an IRQ: */
	extern int set_irq_chip(unsigned int irq, struct irq_chip *chip);
	extern int set_irq_data(unsigned int irq, void *data);
	extern int set_irq_chip_data(unsigned int irq, void *data);
	extern int set_irq_type(unsigned int irq, unsigned int type);
	extern int set_irq_msi(unsigned int irq, struct msi_desc *entry);

	#define get_irq_chip(irq) (irq_to_desc(irq)->chip)
	#define get_irq_chip_data(irq) (irq_to_desc(irq)->chip_data)
	#define get_irq_data(irq) (irq_to_desc(irq)->handler_data)
	#define get_irq_msi(irq) (irq_to_desc(irq)->msi_desc)

	#define get_irq_desc_chip(desc) ((desc)->chip)
	#define get_irq_desc_chip_data(desc) ((desc)->chip_data)
	#define get_irq_desc_data(desc) ((desc)->handler_data)
	#define get_irq_desc_msi(desc) ((desc)->msi_desc)

	#endif /* CONFIG_GENERIC_HARDIRQS */

	#endif /* !CONFIG_S390 */

	#ifdef CONFIG_SMP
	/**
	* alloc_desc_masks - allocate cpumasks for irq_desc
	* @desc: pointer to irq_desc struct
	* @node: node which will be handling the cpumasks
	* @boot: true if need bootmem
	*
	* Allocates affinity and pending_mask cpumask if required.
	* Returns true if successful (or not required).
	*/
	static inline bool alloc_desc_masks(struct irq_desc *desc, int node,
	bool boot)
	{
	gfp_t gfp = GFP_ATOMIC;

	if (boot)
	gfp = GFP_NOWAIT;

	#ifdef CONFIG_CPUMASK_OFFSTACK
	if (!alloc_cpumask_var_node(&desc->affinity, gfp, node))
	return false;

	#ifdef CONFIG_GENERIC_PENDING_IRQ
	if (!alloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
	free_cpumask_var(desc->affinity);
	return false;
	}
	#endif
	#endif
	return true;
	}

	static inline void init_desc_masks(struct irq_desc *desc)
	{
	cpumask_setall(desc->affinity);
	#ifdef CONFIG_GENERIC_PENDING_IRQ
	cpumask_clear(desc->pending_mask);
	#endif
	}

	/**
	* init_copy_desc_masks - copy cpumasks for irq_desc
	* @old_desc: pointer to old irq_desc struct
	* @new_desc: pointer to new irq_desc struct
	*
	* Insures affinity and pending_masks are copied to new irq_desc.
	* If !CONFIG_CPUMASKS_OFFSTACK the cpumasks are embedded in the
	* irq_desc struct so the copy is redundant.
	*/

	static inline void init_copy_desc_masks(struct irq_desc *old_desc,
	struct irq_desc *new_desc)
	{
	#ifdef CONFIG_CPUMASK_OFFSTACK
	cpumask_copy(new_desc->affinity, old_desc->affinity);

	#ifdef CONFIG_GENERIC_PENDING_IRQ
	cpumask_copy(new_desc->pending_mask, old_desc->pending_mask);
	#endif
	#endif
	}

	static inline void free_desc_masks(struct irq_desc *old_desc,
	struct irq_desc *new_desc)
	{
	free_cpumask_var(old_desc->affinity);

	#ifdef CONFIG_GENERIC_PENDING_IRQ
	free_cpumask_var(old_desc->pending_mask);
	#endif
	}

	#else /* !CONFIG_SMP */

	static inline bool alloc_desc_masks(struct irq_desc *desc, int node,
	bool boot)
	{
	return true;
	}

	static inline void init_desc_masks(struct irq_desc *desc)
	{
	}

	static inline void init_copy_desc_masks(struct irq_desc *old_desc,
	struct irq_desc *new_desc)
	{
	}

	static inline void free_desc_masks(struct irq_desc *old_desc,
	struct irq_desc *new_desc)
	{
	}
	#endif /* CONFIG_SMP */

	#endif /* _LINUX_IRQ_H */