Commit 97955936 authored by Thierry Reding's avatar Thierry Reding Committed by Linus Torvalds
Browse files

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: default avatarThierry 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b493c343

include/asm-generic/sections.h

+65 −0
Original line number Diff line number Diff line
@@ -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_ */

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