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asm/sections: add helpers to check for section data

Add a helper to check if an object (given an address and a size) is part
of a section (given beginning and end addresses).  For convenience, also
provide a helper that performs this check for __init data using the
__init_begin and __init_end limits.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Thierry Reding 2016-01-15 16:58:18 -08:00 committed by Linus Torvalds
parent b493c34309
commit 9795593625

View File

@ -4,6 +4,7 @@
/* References to section boundaries */
#include <linux/compiler.h>
#include <linux/types.h>
/*
* Usage guidelines:
@ -63,4 +64,68 @@ static inline int arch_is_kernel_data(unsigned long addr)
}
#endif
/**
* memory_contains - checks if an object is contained within a memory region
* @begin: virtual address of the beginning of the memory region
* @end: virtual address of the end of the memory region
* @virt: virtual address of the memory object
* @size: size of the memory object
*
* Returns: true if the object specified by @virt and @size is entirely
* contained within the memory region defined by @begin and @end, false
* otherwise.
*/
static inline bool memory_contains(void *begin, void *end, void *virt,
size_t size)
{
return virt >= begin && virt + size <= end;
}
/**
* memory_intersects - checks if the region occupied by an object intersects
* with another memory region
* @begin: virtual address of the beginning of the memory regien
* @end: virtual address of the end of the memory region
* @virt: virtual address of the memory object
* @size: size of the memory object
*
* Returns: true if an object's memory region, specified by @virt and @size,
* intersects with the region specified by @begin and @end, false otherwise.
*/
static inline bool memory_intersects(void *begin, void *end, void *virt,
size_t size)
{
void *vend = virt + size;
return (virt >= begin && virt < end) || (vend >= begin && vend < end);
}
/**
* init_section_contains - checks if an object is contained within the init
* section
* @virt: virtual address of the memory object
* @size: size of the memory object
*
* Returns: true if the object specified by @virt and @size is entirely
* contained within the init section, false otherwise.
*/
static inline bool init_section_contains(void *virt, size_t size)
{
return memory_contains(__init_begin, __init_end, virt, size);
}
/**
* init_section_intersects - checks if the region occupied by an object
* intersects with the init section
* @virt: virtual address of the memory object
* @size: size of the memory object
*
* Returns: true if an object's memory region, specified by @virt and @size,
* intersects with the init section, false otherwise.
*/
static inline bool init_section_intersects(void *virt, size_t size)
{
return memory_intersects(__init_begin, __init_end, virt, size);
}
#endif /* _ASM_GENERIC_SECTIONS_H_ */