Xen extended regions

Allocate, free, and map buffers from Xen extended memory regions. More...

Files
file	regions.h
	Xen extended region management.

Functions
bool	xen_region_is_addr_extreg (void *ptr)
	Check whether an address belongs to a configured extended region.
void *	xen_region_get_pages (size_t nr_pages)
	Allocate one or more contiguous pages from an extended region.
int	xen_region_put_pages (void *ptr, size_t nr_pages)
	Release pages previously allocated from an extended region.
int	xen_region_map (void *ptr, size_t nr_pages)
	Map an extended-region buffer into the kernel address space.
int	xen_region_unmap (void *ptr, size_t nr_pages)
	Unmap an extended-region buffer from the kernel address space.

Detailed Description

Allocate, free, and map buffers from Xen extended memory regions.

Function Documentation

xen_region_get_pages()

void * xen_region_get_pages

(

size_t

nr_pages

)

#include <regions.h>

Allocate one or more contiguous pages from an extended region.

Attention

Available only when the following Kconfig option is enabled:

CONFIG_XEN_REGIONS 

.

Parameters

nr_pages

Number of Xen pages to allocate.

Returns

Base address of the allocated range, or NULL if no region can satisfy the request.

xen_region_is_addr_extreg()

bool xen_region_is_addr_extreg

(

void *

ptr

)

#include <regions.h>

Check whether an address belongs to a configured extended region.

Attention

Available only when the following Kconfig option is enabled:

CONFIG_XEN_REGIONS 

.

Parameters

ptr	Address to test.

Return values

true	ptr is inside one of the configured extended regions.
false	ptr is NULL or outside all configured extended regions.

xen_region_map()

int xen_region_map	(	void *	ptr,
		size_t	nr_pages )

#include <regions.h>

Map an extended-region buffer into the kernel address space.

Attention

Available only when the following Kconfig option is enabled:

CONFIG_XEN_REGIONS 

.

Parameters

ptr	Base address of the extended-region buffer.
nr_pages	Number of pages to map.

Return values

0	on success.
-EFAULT	ptr does not belong to an extended region.

xen_region_put_pages()

int xen_region_put_pages	(	void *	ptr,
		size_t	nr_pages )

#include <regions.h>

Release pages previously allocated from an extended region.

Attention

Available only when the following Kconfig option is enabled:

CONFIG_XEN_REGIONS 

.

Parameters

ptr	Base address returned by xen_region_get_pages().
nr_pages	Number of pages to release.

Returns

0 on success, negative errno value on failure.

Return values

-EIO	ptr does not belong to a known extended region.

xen_region_unmap()

int xen_region_unmap	(	void *	ptr,
		size_t	nr_pages )

#include <regions.h>

Unmap an extended-region buffer from the kernel address space.

Attention

Available only when the following Kconfig option is enabled:

CONFIG_XEN_REGIONS 

.

Parameters

ptr	Base address of the extended-region buffer.
nr_pages	Number of pages to unmap.

Return values

0	on success.
-EFAULT	ptr does not belong to an extended region.