diff options
Diffstat (limited to 'include/asm-alpha/io.h')
| -rw-r--r-- | include/asm-alpha/io.h | 35 |
1 files changed, 31 insertions, 4 deletions
diff --git a/include/asm-alpha/io.h b/include/asm-alpha/io.h index 33c7b0006..59eeb9545 100644 --- a/include/asm-alpha/io.h +++ b/include/asm-alpha/io.h @@ -51,7 +51,7 @@ static inline void set_hae(unsigned long new_hae) /* * Change virtual addresses to physical addresses and vv. */ -static inline unsigned long virt_to_phys(volatile void * address) +static inline unsigned long virt_to_phys(void *address) { return (unsigned long)address - IDENT_ADDR; } @@ -61,6 +61,36 @@ static inline void * phys_to_virt(unsigned long address) return (void *) (address + IDENT_ADDR); } +/* + * Change addresses as seen by the kernel (virtual) to addresses as + * seen by a device (bus), and vice versa. + * + * Note that this only works for a limited range of kernel addresses, + * and very well may not span all memory. Consider this interface + * deprecated in favour of the mapping functions in <asm/pci.h>. + */ +extern unsigned long __direct_map_base; +extern unsigned long __direct_map_size; + +static inline unsigned long virt_to_bus(void *address) +{ + unsigned long phys = virt_to_phys(address); + unsigned long bus = phys + __direct_map_base; + return phys <= __direct_map_size ? bus : 0; +} + +static inline void *bus_to_virt(unsigned long address) +{ + void *virt; + + /* This check is a sanity check but also ensures that bus address 0 + maps to virtual address 0 which is useful to detect null pointers + (the NCR driver is much simpler if NULL pointers are preserved). */ + address -= __direct_map_base; + virt = phys_to_virt(address); + return (long)address <= 0 ? NULL : virt; +} + #else /* !__KERNEL__ */ /* @@ -82,9 +112,6 @@ extern void _sethae (unsigned long addr); /* cached version */ /* In a generic kernel, we always go through the machine vector. */ -# define virt_to_bus(a) alpha_mv.mv_virt_to_bus(a) -# define bus_to_virt(a) alpha_mv.mv_bus_to_virt(a) - # define __inb alpha_mv.mv_inb # define __inw alpha_mv.mv_inw # define __inl alpha_mv.mv_inl |