Dataspace interface

Dataspace C interface. More...

Collaboration diagram for Dataspace interface:

Data Structures
struct	l4re_ds_stats_t
	Information about the data space. More...

Typedefs
typedef l4_cap_idx_t	l4re_ds_t
	Dataspace type.

Enumerations
enum	l4re_ds_map_flags { }
	Flags to specify the memory mapping type of a request. More...

Functions
long	l4re_ds_clear (l4re_ds_t ds, l4re_ds_offset_t offset, l4re_ds_size_t size) L4_NOTHROW
	Clear parts of a dataspace.
long	l4re_ds_allocate (l4re_ds_t ds, l4re_ds_offset_t offset, l4re_ds_size_t size) L4_NOTHROW
	Allocate a range in the dataspace.
int	l4re_ds_copy_in (l4re_ds_t ds, l4re_ds_offset_t dst_offs, l4re_ds_t src, l4re_ds_offset_t src_offs, l4re_ds_size_t size) L4_NOTHROW
	Copy contents from another dataspace.
l4re_ds_size_t	l4re_ds_size (l4re_ds_t ds) L4_NOTHROW
	Get size of a dataspace.
l4re_ds_flags_t	l4re_ds_flags (l4re_ds_t ds) L4_NOTHROW
	Get flags of the dataspace.
int	l4re_ds_info (l4re_ds_t ds, l4re_ds_stats_t *stats) L4_NOTHROW
	Get information on the dataspace.
int	l4re_ds_map_info (l4re_ds_t ds, l4_addr_t *start_addr, l4_addr_t *end_addr) L4_NOTHROW
	Get mapping range of dataspace.

Detailed Description

Dataspace C interface.

Enumeration Type Documentation

l4re_ds_map_flags

enum l4re_ds_map_flags

Flags to specify the memory mapping type of a request.

Enumerator
L4RE_DS_F_NORMAL	request normal memory mapping
L4RE_DS_F_CACHEABLE	request normal memory mapping
L4RE_DS_F_BUFFERABLE	request bufferable (write buffered) mappings
L4RE_DS_F_UNCACHEABLE	request uncacheable memory mappings
L4RE_DS_F_CACHING_MASK	mask for caching flags
L4RE_DS_F_CACHING_SHIFT	shift value for caching flags

Definition at line 58 of file dataspace.h.

Function Documentation

l4re_ds_allocate()

long l4re_ds_allocate	(	l4re_ds_t	ds,
		l4re_ds_offset_t	offset,
		l4re_ds_size_t	size
	)

Allocate a range in the dataspace.

Parameters

ds	Dataspace capability.
offset	Offset in the dataspace, in bytes.
size	Size of the range, in bytes.

Return values

L4_EOK	Success
-L4_ERANGE	Given range is outside the dataspace. (A dataspace provider may also silently ignore areas outside the dataspace.)
-L4_ENOMEM	Not enough memory available.
<0	IPC errors

On success, at least the given range is guaranteed to be allocated. The dataspace manager may also allocate more memory due to page granularity.

The memory is allocated with the same rights as the dataspace capability.

l4re_ds_clear()

long l4re_ds_clear	(	l4re_ds_t	ds,
		l4re_ds_offset_t	offset,
		l4re_ds_size_t	size
	)

Clear parts of a dataspace.

Parameters

ds	Dataspace capability.
offset	Offset within dataspace (in bytes).
size	Size of region to clear (in bytes).

Return values

>=0	Success.
-L4_ERANGE	Given range is outside the dataspace. (A dataspace provider may also silently ignore areas outside the dataspace.)
-L4_EACCESS	No L4_CAP_FPAGE_W right on dataspace capability.
<0	IPC errors

Zeroes out the memory. Depending on the type of memory the memory could also be deallocated and replaced by a shared zero-page.

l4re_ds_copy_in()

int l4re_ds_copy_in	(	l4re_ds_t	ds,
		l4re_ds_offset_t	dst_offs,
		l4re_ds_t	src,
		l4re_ds_offset_t	src_offs,
		l4re_ds_size_t	size
	)

Copy contents from another dataspace.

Parameters

ds	Destination dataspace.
dst_offs	Offset in destination dataspace.
src	Source dataspace to copy from.
src_offs	Offset in the source dataspace.
size	Size to copy (in bytes).

Return values

L4_EOK	Success
-L4_EACCESS	No L4_CAP_FPAGE_W right on the destination dataspace.
-L4_EINVAL	Invalid parameter supplied.
<0	IPC errors

The copy operation may use copy-on-write mechanisms. The operation may also fail if both dataspaces are not from the same dataspace manager or the dataspace managers do not cooperate.

l4re_ds_flags()

l4re_ds_flags_t l4re_ds_flags

(

l4re_ds_t

ds

)

Get flags of the dataspace.

Parameters

ds	Dataspace capability.

Return values

>=0	Flags of the dataspace
<0	IPC errors

See also

L4Re::Dataspace::F::Flags

l4re_ds_info()

int l4re_ds_info	(	l4re_ds_t	ds,
		l4re_ds_stats_t *	stats
	)

Get information on the dataspace.

Parameters

	ds	Dataspace capability.
[out]	stats	Dataspace information

Return values

0	Success
<0	IPC errors

l4re_ds_map_info()

int l4re_ds_map_info	(	l4re_ds_t	ds,
		l4_addr_t *	start_addr,
		l4_addr_t *	end_addr
	)

Get mapping range of dataspace.

Parameters

ds	Dataspace capability.

In case of a MMU-less system, the dataspace must be mapped at the correct address in the task because virtual and physical address must match. This method returns the start and end address of the physically contiguous buffer backing the dataspace.

On MMU-enabled system any page aligned address is permissible. On such systems the method is just a stub.

Parameters

[out]	start_addr	Start address of dataspace.
[out]	end_addr	End address (inclusive) of dataspace.

Return values

>0	Start/end address have been set and need to be obeyed.
0	No constraint of mapping address.
-L4_EPERM	Cannot infer mapping address. Dataspace not mappable.
<0	IPC errors.

l4re_ds_size()

l4re_ds_size_t l4re_ds_size

(

l4re_ds_t

ds

)

Get size of a dataspace.

Parameters

ds	Dataspace capability.

Returns

Size of the dataspace in bytes.