Commit 04e1c838 authored by Russell King's avatar Russell King
Browse files

ARM: io: add a default IO_SPACE_LIMIT definition 



Add a default IO_SPACE_LIMIT definition.  Explain the chosen value and
suggest why platforms would want to make it larger.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 0d26449d

arch/arm/include/asm/io.h

+21 −0
Original line number Diff line number Diff line
@@ -109,6 +109,27 @@ static inline void __iomem *__typesafe_io(unsigned long addr) 
 */

#include <mach/io.h>



/*

 * This is the limit of PC card/PCI/ISA IO space, which is by default

 * 64K if we have PC card, PCI or ISA support.  Otherwise, default to

 * zero to prevent ISA/PCI drivers claiming IO space (and potentially

 * oopsing.)

 *

 * Only set this larger if you really need inb() et.al. to operate over

 * a larger address space.  Note that SOC_COMMON ioremaps each sockets

 * IO space area, and so inb() et.al. must be defined to operate as per

 * readb() et.al. on such platforms.

 */

#ifndef IO_SPACE_LIMIT

#if defined(CONFIG_PCMCIA_SOC_COMMON) || defined(CONFIG_PCMCIA_SOC_COMMON_MODULE)

#define IO_SPACE_LIMIT ((resource_size_t)0xffffffff)

#elif defined(CONFIG_PCI) || defined(CONFIG_ISA) || defined(CONFIG_PCCARD)

#define IO_SPACE_LIMIT ((resource_size_t)0xffff)

#else

#define IO_SPACE_LIMIT ((resource_size_t)0)

#endif

#endif



/*

 *  IO port access primitives

 *  -------------------------