The C Icu interface, see L4::Icu for the C++ interface. More...

Collaboration diagram for Interrupt controller:

Data Structures
struct	l4_icu_info_t
	Info structure for an ICU. More...

Typedefs
typedef struct l4_icu_info_t	l4_icu_info_t
	Info structure for an ICU.

Enumerations
enum	L4_icu_flags { L4_ICU_FLAG_MSI }
	Flags for IRQ numbers used for the ICU. More...

Functions
l4_msgtag_t	l4_icu_bind (l4_cap_idx_t icu, unsigned irqnum, l4_cap_idx_t irq) L4_NOTHROW
	Bind an interrupt line of an interrupt controller to an interrupt object.

l4_msgtag_t	l4_icu_bind_u (l4_cap_idx_t icu, unsigned irqnum, l4_cap_idx_t irq, l4_utcb_t *utcb) L4_NOTHROW
	Bind an interrupt line of an interrupt controller to an interrupt object.

l4_msgtag_t	l4_icu_unbind (l4_cap_idx_t icu, unsigned irqnum, l4_cap_idx_t irq) L4_NOTHROW
	Remove binding of an interrupt line from the interrupt controller object.

l4_msgtag_t	l4_icu_unbind_u (l4_cap_idx_t icu, unsigned irqnum, l4_cap_idx_t irq, l4_utcb_t *utcb) L4_NOTHROW
	Remove binding of an interrupt line from the interrupt controller object.

l4_msgtag_t	l4_icu_set_mode (l4_cap_idx_t icu, unsigned irqnum, l4_umword_t mode) L4_NOTHROW
	Set interrupt mode.

l4_msgtag_t	l4_icu_set_mode_u (l4_cap_idx_t icu, unsigned irqnum, l4_umword_t mode, l4_utcb_t *utcb) L4_NOTHROW
	Set interrupt mode.

l4_msgtag_t	l4_icu_info (l4_cap_idx_t icu, l4_icu_info_t *info) L4_NOTHROW
	Get information about the ICU features.

l4_msgtag_t	l4_icu_info_u (l4_cap_idx_t icu, l4_icu_info_t info, l4_utcb_t utcb) L4_NOTHROW
	Get information about the ICU features.

l4_msgtag_t	l4_icu_msi_info (l4_cap_idx_t icu, unsigned irqnum, l4_uint64_t source, l4_icu_msi_info_t *msi_info) L4_NOTHROW
	Get MSI info about IRQ.

l4_msgtag_t	l4_icu_msi_info_u (l4_cap_idx_t icu, unsigned irqnum, l4_uint64_t source, l4_icu_msi_info_t msi_info, l4_utcb_t utcb) L4_NOTHROW
	Get MSI info about IRQ.

l4_msgtag_t	l4_icu_unmask (l4_cap_idx_t icu, unsigned irqnum, l4_umword_t *label, l4_timeout_t to) L4_NOTHROW
	Unmask an IRQ line.

l4_msgtag_t	l4_icu_unmask_u (l4_cap_idx_t icu, unsigned irqnum, l4_umword_t label, l4_timeout_t to, l4_utcb_t utcb) L4_NOTHROW
	Unmask the given interrupt line.

l4_msgtag_t	l4_icu_mask (l4_cap_idx_t icu, unsigned irqnum, l4_umword_t *label, l4_timeout_t to) L4_NOTHROW
	Mask an IRQ line.

l4_msgtag_t	l4_icu_mask_u (l4_cap_idx_t icu, unsigned irqnum, l4_umword_t label, l4_timeout_t to, l4_utcb_t utcb) L4_NOTHROW
	Mask an IRQ line.

Detailed Description

The C Icu interface, see L4::Icu for the C++ interface.

Note: "ICU" is short for "interrupt control unit".

These functions define the interface for interrupt controllers, for binding IRQ objects to interrupt lines and other interrupt sources, as well as functions for masking and unmasking of interrupts.

To setup an IRQ line the following steps are required:

l4_icu_set_mode() (optional if IRQ has a default mode)
l4_rcv_ep_bind_thread() to attach the IRQ object to a thread
l4_icu_bind()
l4_icu_unmask() to receive the first IRQ

For certain interrupt sources only some of these steps are necessary and supported, see Scheduler and Virtual Console.

At most one IRQs object can be bound to a certain interrupt source and a certain IRQs object can be bound to at most one interrupt source.

Include File: #include <l4/sys/icu.h>

icu.h
Interrupt controller.

Typedef Documentation

◆ l4_icu_info_t

typedef struct l4_icu_info_t l4_icu_info_t

Info structure for an ICU.

This structure contains information about the features of an ICU.

See also: l4_icu_info().

Enumeration Type Documentation

◆ L4_icu_flags

enum L4_icu_flags

Flags for IRQ numbers used for the ICU.

Enumerator

L4_ICU_FLAG_MSI

Flag to denote that the IRQ is actually an MSI.

This flag may be used for l4_icu_bind() and l4_icu_unbind() functions to denote that the IRQ number is meant to be an MSI.

Definition at line 63 of file icu.h.

Function Documentation

◆ l4_icu_bind()

l4_msgtag_t l4_icu_bind	(	l4_cap_idx_t	icu,
		unsigned	irqnum,
		l4_cap_idx_t	irq
	)

inline

Bind an interrupt line of an interrupt controller to an interrupt object.

Parameters

icu	ICU object to bind `irq` to.
irqnum	IRQ line at the ICU.
irq	IRQ object to bind to this ICU.

Returns: Syscall return tag. The caller should check the return value using l4_error() to check for errors and to identify the correct method for unmasking the interrupt. Return values < 0 indicate an error. A return value of 0 means a direct unmask via the IRQ object using l4_irq_unmask(). A return value of 1 means that the interrupt has to be unmasked via the ICU using l4_icu_unmask().

Return values

-L4_EINVAL	`irq` is bound to an interrupt source.
-L4_EPERM	The ICU instance requires L4_CAP_FPAGE_W on `irq` and L4_CAP_FPAGE_W was not present.

In case the irq is already bound to an interrupt source, it is unbound first. In case the irq is bound and the interrupt source is bound to a different IRQ object, only the unbinding happens. An IRQ object that is bound to an interrupt source will get unbound if the IRQ object is deleted.

Examples: examples/sys/isr/main.c.

Definition at line 504 of file icu.h.

References l4_icu_bind_u(), and l4_utcb().

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◆ l4_icu_bind_u()

l4_msgtag_t l4_icu_bind_u	(	l4_cap_idx_t	icu,
		unsigned	irqnum,
		l4_cap_idx_t	irq,
		l4_utcb_t *	utcb
	)

inline

Bind an interrupt line of an interrupt controller to an interrupt object.

Parameters

icu	The ICU object to bind `irq` to.
irqnum	IRQ line at the ICU.
irq	IRQ object for the given IRQ line to bind to this ICU.
utcb	UTCB to be used for this operation, shall be the UTCB of the calling thread. See l4_utcb.

Returns: Syscall return tag. The caller should check the return value using l4_error() to check for errors and to identify the correct method for unmasking the interrupt. Return values < 0 indicate an error. A return value of 0 means a direct unmask via the IRQ object using L4::Irq::unmask. A return value of 1 means that the interrupt has to be unmasked via the ICU using L4::Icu::unmask.

Return values

-L4_EINVAL	`irq` is bound to an interrupt source.
-L4_EPERM	The ICU instance requires L4_CAP_FPAGE_W on `irq` and L4_CAP_FPAGE_W was not present.

In case the irq is already bound to an interrupt source, it is unbound first. In case the irq is bound and the interrupt source is bound to a different L4::Irq object, only the unbinding happens. An L4::Irq object that is bound to an interrupt source will get unbound if the L4::Irq object is deleted.

Definition at line 404 of file icu.h.

References L4_CAP_FPAGE_RWS, L4_ICU_OP_BIND, l4_ipc_call(), L4_IPC_NEVER, l4_map_obj_control(), l4_msgtag(), l4_obj_fpage(), L4_PROTO_IRQ, l4_msg_regs_t::mr, and l4_fpage_t::raw.

Referenced by L4::Icu::bind(), and l4_icu_bind().

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◆ l4_icu_info()

l4_msgtag_t l4_icu_info	(	l4_cap_idx_t	icu,
		l4_icu_info_t *	info
	)

inline

Get information about the ICU features.

Parameters

	icu	The ICU object from which information shall be retrieved.
[out]	info	Info structure to be filled with information.

Returns: Syscall return tag

Definition at line 512 of file icu.h.

References l4_icu_info_u(), and l4_utcb().

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◆ l4_icu_info_u()

l4_msgtag_t l4_icu_info_u	(	l4_cap_idx_t	icu,
		l4_icu_info_t *	info,
		l4_utcb_t *	utcb
	)

inline

Get information about the ICU features.

Parameters

	icu	The ICU object from which MSI information shall be retrieved.
[out]	info	Info structure to be filled with information.
	utcb	UTCB to be used for this operation, shall be the UTCB of the calling thread. See l4_utcb.

Returns: Syscall return tag

Definition at line 428 of file icu.h.

References L4_ICU_OP_INFO, l4_ipc_call(), L4_IPC_NEVER, l4_msgtag(), L4_PROTO_IRQ, and l4_msg_regs_t::mr.

Referenced by L4::Icu::info(), and l4_icu_info().

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◆ l4_icu_mask()

l4_msgtag_t l4_icu_mask	(	l4_cap_idx_t	icu,
		unsigned	irqnum,
		l4_umword_t *	label,
		l4_timeout_t	to
	)

inline

Mask an IRQ line.

Parameters

icu	The ICU object where the IRQ line shall be masked.
irqnum	IRQ line at the ICU.
label	If non-NULL, the function also performs an open wait IPC operation waiting for the next message, and the received label is returned here.
to	IPC timeout, if unsure use L4_IPC_NEVER.

Returns: Syscall return tag. If label is NULL, this function performs an IPC send-only operation and there is no return value except L4_MSGTAG_ERROR indicating success or failure of the send operation. In this case use l4_ipc_error() to check for errors and do not use l4_error().

Definition at line 526 of file icu.h.

References l4_utcb().

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◆ l4_icu_mask_u()

l4_msgtag_t l4_icu_mask_u	(	l4_cap_idx_t	icu,
		unsigned	irqnum,
		l4_umword_t *	label,
		l4_timeout_t	to,
		l4_utcb_t *	utcb
	)

inline

Mask an IRQ line.

Parameters

icu	The ICU object where the IRQ line shall be masked.
irqnum	IRQ line at the ICU.
label	If NULL, this function is a send-only message to the ICU. If not NULL, this function will enter an open wait after sending the mask message and the received label is returned here.
to	The timeout-pair (send and receive) that shall be used for this operation. The receive timeout is used with a non-NULL `label` only.
utcb	UTCB to be used for this operation, shall be the UTCB of the calling thread. See l4_utcb.

Returns: Syscall return tag. If label is NULL, this function performs an IPC send-only operation and there is no return value except L4_MSGTAG_ERROR indicating success or failure of the send operation. In this case use l4_ipc_error() to check for errors and do not use l4_error().

Definition at line 491 of file icu.h.

Referenced by L4::Icu::mask().

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◆ l4_icu_msi_info()

l4_msgtag_t l4_icu_msi_info	(	l4_cap_idx_t	icu,
		unsigned	irqnum,
		l4_uint64_t	source,
		l4_icu_msi_info_t *	msi_info
	)

inline

Get MSI info about IRQ.

Parameters

	icu	The ICU object from which MSI information shall be retrieved.
	irqnum	IRQ line at the ICU.
	source	Platform dependent requester ID for MSIs. On IA32 we use a 20bit source filter value as described in the Intel IRQ remapping specification.
[out]	msi_info	A l4_icu_msi_info_t structure receiving the address and the data value to trigger this MSI.

Returns: Syscall return tag

Definition at line 516 of file icu.h.

References l4_icu_msi_info_u(), and l4_utcb().

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◆ l4_icu_msi_info_u()

l4_msgtag_t l4_icu_msi_info_u	(	l4_cap_idx_t	icu,
		unsigned	irqnum,
		l4_uint64_t	source,
		l4_icu_msi_info_t *	msi_info,
		l4_utcb_t *	utcb
	)

inline

Get MSI info about IRQ.

Parameters

	utcb	UTCB to be used for this operation, shall be the UTCB of the calling thread. See l4_utcb.
	icu	The ICU object from which MSI information shall be retrieved.
	irqnum	IRQ line at the ICU.
	source	Platform dependent requester ID for MSIs. On IA32 we use a 20bit source filter value as described in the Intel IRQ remapping specification.
[out]	msi_info	A l4_icu_msi_info_t structure receiving the address and the data value to trigger this MSI.

Returns: Syscall return tag

Definition at line 442 of file icu.h.

References L4_ICU_OP_MSI_INFO, l4_ipc_call(), L4_IPC_NEVER, l4_msgtag(), l4_msgtag_has_error(), l4_msgtag_words(), L4_PROTO_IRQ, L4_UNLIKELY, l4_utcb_mr64_idx(), l4_msg_regs_t::mr, and l4_msg_regs_t::mr64.

Referenced by l4_icu_msi_info().

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◆ l4_icu_set_mode()

l4_msgtag_t l4_icu_set_mode	(	l4_cap_idx_t	icu,
		unsigned	irqnum,
		l4_umword_t	mode
	)

inline

Set interrupt mode.

Parameters

icu	The ICU object.
irqnum	IRQ line at the ICU.
mode	Mode, see L4_irq_mode.

Returns: Syscall return tag

Definition at line 531 of file icu.h.

References l4_icu_set_mode_u(), and l4_utcb().

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◆ l4_icu_set_mode_u()

l4_msgtag_t l4_icu_set_mode_u	(	l4_cap_idx_t	icu,
		unsigned	irqnum,
		l4_umword_t	mode,
		l4_utcb_t *	utcb
	)

inline

Set interrupt mode.

Parameters

icu	The ICU object.
irqnum	IRQ line at the ICU.
mode	Mode, see L4_irq_mode.
utcb	UTCB to be used for this operation, shall be the UTCB of the calling thread. See l4_utcb.

Returns: Syscall return tag

Definition at line 465 of file icu.h.

References L4_ICU_OP_SET_MODE, l4_ipc_call(), L4_IPC_NEVER, l4_msgtag(), L4_PROTO_IRQ, and l4_msg_regs_t::mr.

Referenced by l4_icu_set_mode(), and L4::Icu::set_mode().

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◆ l4_icu_unbind()

l4_msgtag_t l4_icu_unbind	(	l4_cap_idx_t	icu,
		unsigned	irqnum,
		l4_cap_idx_t	irq
	)

inline

Remove binding of an interrupt line from the interrupt controller object.

Parameters

icu	The ICU object from where the binding shall be removed.
irqnum	IRQ line at the ICU.
irq	IRQ object to remove from the ICU.

Returns: Syscall return tag

Definition at line 508 of file icu.h.

References l4_icu_unbind_u(), and l4_utcb().

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◆ l4_icu_unbind_u()

l4_msgtag_t l4_icu_unbind_u	(	l4_cap_idx_t	icu,
		unsigned	irqnum,
		l4_cap_idx_t	irq,
		l4_utcb_t *	utcb
	)

inline

Remove binding of an interrupt line from the interrupt controller object.

Parameters

icu	The ICU object from where the binding shall be removed.
irqnum	IRQ line at the ICU.
irq	IRQ object to remove from the ICU.
utcb	UTCB to be used for this operation, shall be the UTCB of the calling thread. See l4_utcb.

Returns: Syscall return tag

Definition at line 416 of file icu.h.

References L4_CAP_FPAGE_RWS, L4_ICU_OP_UNBIND, l4_ipc_call(), L4_IPC_NEVER, l4_map_obj_control(), l4_msgtag(), l4_obj_fpage(), L4_PROTO_IRQ, l4_msg_regs_t::mr, and l4_fpage_t::raw.

Referenced by l4_icu_unbind(), and L4::Icu::unbind().

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◆ l4_icu_unmask()

l4_msgtag_t l4_icu_unmask	(	l4_cap_idx_t	icu,
		unsigned	irqnum,
		l4_umword_t *	label,
		l4_timeout_t	to
	)

inline

Unmask an IRQ line.

Parameters

icu	The ICU object where the IRQ line shall be unmasked.
irqnum	IRQ line at the ICU.
label	If non-NULL, the function also performs an open wait IPC operation waiting for the next message, and the received label is returned here.
to	IPC timeout, if unsure use L4_IPC_NEVER.

Returns: Syscall return tag. If label is NULL, this function performs an IPC send-only operation and there is no return value except L4_MSGTAG_ERROR indicating success or failure of the send operation. In this case use l4_ipc_error() to check for errors and do not use l4_error().

Definition at line 521 of file icu.h.

References l4_utcb().

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◆ l4_icu_unmask_u()

l4_msgtag_t l4_icu_unmask_u	(	l4_cap_idx_t	icu,
		unsigned	irqnum,
		l4_umword_t *	label,
		l4_timeout_t	to,
		l4_utcb_t *	utcb
	)

inline

Unmask the given interrupt line.

Parameters

icu	The ICU object where the IRQ line shall be unmasked.

When the object is an IRQ, the given interrupt line is ignored and instead the line which the IRQ is bound to (if any) is unmasked.

Its counterpart for explicitly masking an interrupt line is L4::Icu::mask().

Parameters

	irqnum	The interrupt line that shall be unmasked. Ignored if the object is an IRQ.
[out]	label	If NULL, this is a send-only unmask. If not NULL, this operation enters an open wait and the protected label shall be received here.
	to	The timeout-pair (send and receive) that shall be used for this operation. The receive timeout is used with a non-NULL `label` only.
	utcb	UTCB to be used for this operation, shall be the UTCB of the calling thread. See l4_utcb.

Returns: Syscall return tag. If label is NULL, this function performs an IPC send-only operation and there is no return value except L4_MSGTAG_ERROR indicating success or failure of the send operation. In this case use l4_ipc_error() to check for errors and do not use l4_error().

Definition at line 496 of file icu.h.

Data Structures

Typedefs

Enumerations

Functions

Detailed Description

Typedef Documentation

◆ l4_icu_info_t

Enumeration Type Documentation

◆ L4_icu_flags

Function Documentation

◆ l4_icu_bind()

◆ l4_icu_bind_u()

◆ l4_icu_info()

◆ l4_icu_info_u()

◆ l4_icu_mask()

◆ l4_icu_mask_u()

◆ l4_icu_msi_info()

◆ l4_icu_msi_info_u()

◆ l4_icu_set_mode()

◆ l4_icu_set_mode_u()

◆ l4_icu_unbind()

◆ l4_icu_unbind_u()

◆ l4_icu_unmask()

◆ l4_icu_unmask_u()