X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Fasm-generic%2Fbitops.h;h=0e6d9852008ca36c4826a27f46b9cc26b303ab62;hb=987b0145d94eecf292d8b301228356f44611ab7c;hp=1f9d99193df8ef368c70d8abb18ddcf3a885f91a;hpb=f7ed79d23a47594e7834d66a8f14449796d4f3e6;p=linux-2.6.git diff --git a/include/asm-generic/bitops.h b/include/asm-generic/bitops.h index 1f9d99193..0e6d98520 100644 --- a/include/asm-generic/bitops.h +++ b/include/asm-generic/bitops.h @@ -5,27 +5,77 @@ * For the benefit of those who are trying to port Linux to another * architecture, here are some C-language equivalents. You should * recode these in the native assembly language, if at all possible. + * To guarantee atomicity, these routines call cli() and sti() to + * disable interrupts while they operate. (You have to provide inline + * routines to cli() and sti().) + * + * Also note, these routines assume that you have 32 bit longs. + * You will have to change this if you are trying to port Linux to the + * Alpha architecture or to a Cray. :-) * * C language equivalents written by Theodore Ts'o, 9/26/92 */ -#include -#include -#include -#include -#include -#include -#include +extern __inline__ int set_bit(int nr,long * addr) +{ + int mask, retval; + + addr += nr >> 5; + mask = 1 << (nr & 0x1f); + cli(); + retval = (mask & *addr) != 0; + *addr |= mask; + sti(); + return retval; +} + +extern __inline__ int clear_bit(int nr, long * addr) +{ + int mask, retval; + + addr += nr >> 5; + mask = 1 << (nr & 0x1f); + cli(); + retval = (mask & *addr) != 0; + *addr &= ~mask; + sti(); + return retval; +} + +extern __inline__ int test_bit(int nr, const unsigned long * addr) +{ + int mask; + + addr += nr >> 5; + mask = 1 << (nr & 0x1f); + return ((mask & *addr) != 0); +} + +/* + * fls: find last bit set. + */ + +#define fls(x) generic_fls(x) +#define fls64(x) generic_fls64(x) #ifdef __KERNEL__ -#include -#include -#include +/* + * ffs: find first bit set. This is defined the same way as + * the libc and compiler builtin ffs routines, therefore + * differs in spirit from the above ffz (man ffs). + */ + +#define ffs(x) generic_ffs(x) + +/* + * hweightN: returns the hamming weight (i.e. the number + * of bits set) of a N-bit word + */ -#include -#include -#include +#define hweight32(x) generic_hweight32(x) +#define hweight16(x) generic_hweight16(x) +#define hweight8(x) generic_hweight8(x) #endif /* __KERNEL__ */