diff options
Diffstat (limited to 'include/asm-mips/mach-generic/mangle-port.h')
| -rw-r--r-- | include/asm-mips/mach-generic/mangle-port.h | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/include/asm-mips/mach-generic/mangle-port.h b/include/asm-mips/mach-generic/mangle-port.h index 4a98d83b8ec..6e1b0c075de 100644 --- a/include/asm-mips/mach-generic/mangle-port.h +++ b/include/asm-mips/mach-generic/mangle-port.h @@ -13,4 +13,40 @@ #define __swizzle_addr_l(port) (port) #define __swizzle_addr_q(port) (port) +/* + * Sane hardware offers swapping of PCI/ISA I/O space accesses in hardware; + * less sane hardware forces software to fiddle with this... + * + * Regardless, if the host bus endianness mismatches that of PCI/ISA, then + * you can't have the numerical value of data and byte addresses within + * multibyte quantities both preserved at the same time. Hence two + * variations of functions: non-prefixed ones that preserve the value + * and prefixed ones that preserve byte addresses. The latters are + * typically used for moving raw data between a peripheral and memory (cf. + * string I/O functions), hence the "__mem_" prefix. + */ +#if defined(CONFIG_SWAP_IO_SPACE) + +# define ioswabb(a,x) (x) +# define __mem_ioswabb(a,x) (x) +# define ioswabw(a,x) le16_to_cpu(x) +# define __mem_ioswabw(a,x) (x) +# define ioswabl(a,x) le32_to_cpu(x) +# define __mem_ioswabl(a,x) (x) +# define ioswabq(a,x) le64_to_cpu(x) +# define __mem_ioswabq(a,x) (x) + +#else + +# define ioswabb(a,x) (x) +# define __mem_ioswabb(a,x) (x) +# define ioswabw(a,x) (x) +# define __mem_ioswabw(a,x) cpu_to_le16(x) +# define ioswabl(a,x) (x) +# define __mem_ioswabl(a,x) cpu_to_le32(x) +# define ioswabq(a,x) (x) +# define __mem_ioswabq(a,x) cpu_to_le32(x) + +#endif + #endif /* __ASM_MACH_GENERIC_MANGLE_PORT_H */ |