litmus-rt.git - The LITMUS^RT kernel.

#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 seq_file;
struct irq_desc;
struct irq_data;
typedef	void (*irq_flow_handler_t)(unsigned int irq,
					    struct irq_desc *desc);
typedef	void (*irq_preflow_handler_t)(struct irq_data *data);

/*
 * IRQ line status.
 *
 * Bits 0-7 are the same as the IRQF_* bits in linux/interrupt.h
 *
 * IRQ_TYPE_NONE		- default, unspecified type
 * IRQ_TYPE_EDGE_RISING		- rising edge triggered
 * IRQ_TYPE_EDGE_FALLING	- falling edge triggered
 * IRQ_TYPE_EDGE_BOTH		- rising and falling edge triggered
 * IRQ_TYPE_LEVEL_HIGH		- high level triggered
 * IRQ_TYPE_LEVEL_LOW		- low level triggered
 * IRQ_TYPE_LEVEL_MASK		- Mask to filter out the level bits
 * IRQ_TYPE_SENSE_MASK		- Mask for all the above bits
 * IRQ_TYPE_PROBE		- Special flag for probing in progress
 *
 * Bits which can be modified via irq_set/clear/modify_status_flags()
 * IRQ_LEVEL			- Interrupt is level type. Will be also
 *				  updated in the code when the above trigger
 *				  bits are modified via irq_set_irq_type()
 * IRQ_PER_CPU			- Mark an interrupt PER_CPU. Will protect
 *				  it from affinity setting
 * IRQ_NOPROBE			- Interrupt cannot be probed by autoprobing
 * IRQ_NOREQUEST		- Interrupt cannot be requested via
 *				  request_irq()
 * IRQ_NOTHREAD			- Interrupt cannot be threaded
 * IRQ_NOAUTOEN			- Interrupt is not automatically enabled in
 *				  request/setup_irq()
 * IRQ_NO_BALANCING		- Interrupt cannot be balanced (affinity set)
 * IRQ_MOVE_PCNTXT		- Interrupt can be migrated from process context
 * IRQ_NESTED_TRHEAD		- Interrupt nests into another thread
 */
enum {
	IRQ_TYPE_NONE		= 0x00000000,
	IRQ_TYPE_EDGE_RISING	= 0x00000001,
	IRQ_TYPE_EDGE_FALLING	= 0x00000002,
	IRQ_TYPE_EDGE_BOTH	= (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING),
	IRQ_TYPE_LEVEL_HIGH	= 0x00000004,
	IRQ_TYPE_LEVEL_LOW	= 0x00000008,
	IRQ_TYPE_LEVEL_MASK	= (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH),
	IRQ_TYPE_SENSE_MASK	= 0x0000000f,

	IRQ_TYPE_PROBE		= 0x00000010,

	IRQ_LEVEL		= (1 <<  8),
	IRQ_PER_CPU		= (1 <<  9),
	IRQ_NOPROBE		= (1 << 10),
	IRQ_NOREQUEST		= (1 << 11),
	IRQ_NOAUTOEN		= (1 << 12),
	IRQ_NO_BALANCING	= (1 << 13),
	IRQ_MOVE_PCNTXT		= (1 << 14),
	IRQ_NESTED_THREAD	= (1 << 15),
	IRQ_NOTHREAD		= (1 << 16),
};

#define IRQF_MODIFY_MASK	\
	(IRQ_TYPE_SENSE_MASK | IRQ_NOPROBE | IRQ_NOREQUEST | \
	 IRQ_NOAUTOEN | IRQ_MOVE_PCNTXT | IRQ_LEVEL | IRQ_NO_BALANCING | \
	 IRQ_PER_CPU | IRQ_NESTED_THREAD)

#define IRQ_NO_BALANCING_MASK	(IRQ_PER_CPU | IRQ_NO_BALANCING)

/*
 * Return value for chip->irq_set_affinity()
 *
 * IRQ_SET_MASK_OK	- OK, core updates irq_data.affinity
 * IRQ_SET_MASK_NOCPY	- OK, chip did update irq_data.affinity
 */
enum {
	IRQ_SET_MASK_OK = 0,
	IRQ_SET_MASK_OK_NOCOPY,
};

struct msi_desc;
struct irq_domain;

/**
 * struct irq_data - per irq and irq chip data passed down to chip functions
 * @irq:		interrupt number
 * @hwirq:		hardware interrupt number, local to the interrupt domain
 * @node:		node index useful for balancing
 * @state_use_accessors: status information for irq chip functions.
 *			Use accessor functions to deal with it
 * @chip:		low level interrupt hardware access
 * @domain:		Interrupt translation domain; responsible for mapping
 *			between hwirq number and linux irq number.
 * @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
 * @msi_desc:		MSI descriptor
 * @affinity:		IRQ affinity on SMP
 *
 * The fields here need to overlay the ones in irq_desc until we
 * cleaned up the direct references and switched everything over to
 * irq_data.
 */
struct irq_data {
	unsigned int		irq;
	unsigned long		hwirq;
	unsigned int		node;
	unsigned int		state_use_accessors;
	struct irq_chip		*chip;
	struct irq_domain	*domain;
	void			*handler_data;
	void			*chip_data;
	struct msi_desc		*msi_desc;
#ifdef CONFIG_SMP
	cpumask_var_t		affinity;
#endif
};

/*
 * Bit masks for irq_data.state
 *
 * IRQD_TRIGGER_MASK		- Mask for the trigger type bits
 * IRQD_SETAFFINITY_PENDING	- Affinity setting is pending
 * IRQD_NO_BALANCING		- Balancing disabled for this IRQ
 * IRQD_PER_CPU			- Interrupt is per cpu
 * IRQD_AFFINITY_SET		- Interrupt affinity was set
 * IRQD_LEVEL			- Interrupt is level triggered
 * IRQD_WAKEUP_STATE		- Interrupt is configured for wakeup
 *				  from suspend
 * IRDQ_MOVE_PCNTXT		- Interrupt can be moved in process
 *				  context
 * IRQD_IRQ_DISABLED		- Disabled state of the interrupt
 * IRQD_IRQ_MASKED		- Masked state of the interrupt
 * IRQD_IRQ_INPROGRESS		- In progress state of the interrupt
 */
enum {
	IRQD_TRIGGER_MASK		= 0xf,
	IRQD_SETAFFINITY_PENDING	= (1 <<  8),
	IRQD_NO_BALANCING		= (1 << 10),
	IRQD_PER_CPU			= (1 << 11),
	IRQD_AFFINITY_SET		= (1 << 12),
	IRQD_LEVEL			= (1 << 13),
	IRQD_WAKEUP_STATE		= (1 << 14),
	IRQD_MOVE_PCNTXT		= (1 << 15),
	IRQD_IRQ_DISABLED		= (1 << 16),
	IRQD_IRQ_MASKED			= (1 << 17),
	IRQD_IRQ_INPROGRESS		= (1 << 18),
};

static inline bool irqd_is_setaffinity_pending(struct irq_data *d)
{
	return d->state_use_accessors & IRQD_SETAFFINITY_PENDING;
}

static inline bool irqd_is_per_cpu(struct irq_data *d)
{
	return d->state_use_accessors & IRQD_PER_CPU;
}

static inline bool irqd_can_balance(struct irq_data *d)
{
	return !(d->state_use_accessors & (IRQD_PER_CPU | IRQD_NO_BALANCING));
}

static inline bool irqd_affinity_was_set(struct irq_data *d)
{
	return d->state_use_accessors & IRQD_AFFINITY_SET;
}

static inline void irqd_mark_affinity_was_set(struct irq_data *d)
{
	d->state_use_accessors |= IRQD_AFFINITY_SET;
}

static inline u32 irqd_get_trigger_type(struct irq_data *d)
{
	return d->state_use_accessors & IRQD_TRIGGER_MASK;
}

/*
 * Must only be called inside irq_chip.irq_set_type() functions.
 */
static inline void irqd_set_trigger_type(struct irq_data *d, u32 type)
{
	d->state_use_accessors &= ~IRQD_TRIGGER_MASK;
	d->state_use_accessors |= type & IRQD_TRIGGER_MASK;
}

static inline bool irqd_is_level_type(struct irq_data *d)
{
	return d->state_use_accessors & IRQD_LEVEL;
}

static inline bool irqd_is_wakeup_set(struct irq_data *d)
{
	return d->state_use_accessors & IRQD_WAKEUP_STATE;
}

static inline bool irqd_can_move_in_process_context(struct irq_data *d)
{
	return d->state_use_accessors & IRQD_MOVE_PCNTXT;
}

static inline bool irqd_irq_disabled(struct irq_data *d)
{
	return d->state_use_accessors & IRQD_IRQ_DISABLED;
}

static inline bool irqd_irq_masked(struct irq_data *d)
{
	return d->state_use_accessors & IRQD_IRQ_MASKED;
}

static inline bool irqd_irq_inprogress(struct irq_data *d)
{
	return d->state_use_accessors & IRQD_IRQ_INPROGRESS;
}

/*
 * Functions for chained handlers which can be enabled/disabled by the
 * standard disable_irq/enable_irq calls. Must be called with
 * irq_desc->lock held.
 */
static inline void irqd_set_chained_irq_inprogress(struct irq_data *d)
{
	d->state_use_accessors |= IRQD_IRQ_INPROGRESS;
}

static inline void irqd_clr_chained_irq_inprogress(struct irq_data *d)
{
	d->state_use_accessors &= ~IRQD_IRQ_INPROGRESS;
}

/**
 * struct irq_chip - hardware interrupt chip descriptor
 *
 * @name:		name for /proc/interrupts
 * @irq_startup:	start up the interrupt (defaults to ->enable if NULL)
 * @irq_shutdown:	shut down the interrupt (defaults to ->disable if NULL)
 * @irq_enable:		enable the interrupt (defaults to chip->unmask if NULL)
 * @irq_disable:	disable the interrupt
 * @irq_ack:		start of a new interrupt
 * @irq_mask:		mask an interrupt source
 * @irq_mask_ack:	ack and mask an interrupt source
 * @irq_unmask:		unmask an interrupt source
 * @irq_eoi:		end of interrupt
 * @irq_set_affinity:	set the CPU affinity on SMP machines
 * @irq_retrigger:	resend an IRQ to the CPU
 * @irq_set_type:	set the flow type (IRQ_TYPE_LEVEL/etc.) of an IRQ
 * @irq_set_wake:	enable/disable power-management wake-on of an IRQ
 * @irq_bus_lock:	function to lock access to slow bus (i2c) chips
 * @irq_bus_sync_unlock:function to sync and unlock slow bus (i2c) chips
 * @irq_cpu_online:	configure an interrupt source for a secondary CPU
 * @irq_cpu_offline:	un-configure an interrupt source for a secondary CPU
 * @irq_suspend:	function called from core code on suspend once per chip
 * @irq_resume:		function called from core code on resume once per chip
 * @irq_pm_shutdown:	function called from core code on shutdown once per chip
 * @irq_print_chip:	optional to print special chip info in show_interrupts
 * @flags:		chip specific flags
 *
 * @release:		release function solely used by UML
 */
struct irq_chip {
	const char	*name;
	unsigned int	(*irq_startup)(struct irq_data *data);
	void		(*irq_shutdown)(struct irq_data *data);
	void		(*irq_enable)(struct irq_data *data);
	void		(*irq_disable)(struct irq_data *data);

	void		(*irq_ack)(struct irq_data *data);
	void		(*irq_mask)(struct irq_data *data);
	void		(*irq_mask_ack)(struct irq_data *data);
	void		(*irq_unmask)(struct irq_data *data);
	void		(*irq_eoi)(struct irq_data *data);

	int		(*irq_set_affinity)(struct irq_data *data, const struct cpumask *dest, bool force);
	int		(*irq_retrigger)(struct irq_data *data);
	int		(*irq_set_type)(struct irq_data *data, unsigned int flow_type);
	int		(*irq_set_wake)(struct irq_data *data, unsigned int on);

	void		(*irq_bus_lock)(struct irq_data *data);
	void		(*irq_bus_sync_unlock)(struct irq_data *data);

	void		(*irq_cpu_online)(struct irq_data *data);
	void		(*irq_cpu_offline)(struct irq_data *data);

	void		(*irq_suspend)(struct irq_data *data);
	void		(*irq_resume)(struct irq_data *data);
	void		(*irq_pm_shutdown)(struct irq_data *data);


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