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
...@@ -109,6 +109,27 @@ static inline void __iomem *__typesafe_io(unsigned long addr) ...@@ -109,6 +109,27 @@ static inline void __iomem *__typesafe_io(unsigned long addr)
*/ */
#include <mach/io.h> #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 * IO port access primitives
* ------------------------- * -------------------------
......
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