From 04e1c83806e30ae339fc45def595960c7fef1697 Mon Sep 17 00:00:00 2001 From: Russell King Date: Wed, 6 Jul 2011 12:49:59 +0100 Subject: 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: Russell King --- arch/arm/include/asm/io.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'arch/arm/include/asm/io.h') diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h index d66605dea55a..ffb089d46a17 100644 --- a/arch/arm/include/asm/io.h +++ b/arch/arm/include/asm/io.h @@ -109,6 +109,27 @@ static inline void __iomem *__typesafe_io(unsigned long addr) */ #include +/* + * 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 * ------------------------- -- cgit v1.2.3