diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2011-07-06 12:49:59 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2011-08-17 08:44:17 +0100 |
| commit | 04e1c83806e30ae339fc45def595960c7fef1697 (patch) | |
| tree | 7a6327814c3b6cf679c5fa4d3809571bac83bb30 | |
| parent | 0d26449dd61852358477ade4afe3759edf5cab1b (diff) | |
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 <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/include/asm/io.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h index d66605dea55..ffb089d46a1 100644 --- a/arch/arm/include/asm/io.h +++ b/arch/arm/include/asm/io.h @@ -110,6 +110,27 @@ 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 * ------------------------- * |