/* * include/asm-xtensa/bitops.h * * Atomic operations that C can't guarantee us.Useful for resource counting etc. * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 2001 - 2007 Tensilica Inc. */ #ifndef _XTENSA_BITOPS_H #define _XTENSA_BITOPS_H #ifdef __KERNEL__ #include <asm/processor.h> #include <asm/byteorder.h> #include <asm/system.h> #ifdef CONFIG_SMP # error SMP not supported on this architecture #endif #define smp_mb__before_clear_bit() barrier() #define smp_mb__after_clear_bit() barrier() #include <asm-generic/bitops/atomic.h> #include <asm-generic/bitops/non-atomic.h> #if XCHAL_HAVE_NSA static inline unsigned long __cntlz (unsigned long x) { int lz; asm ("nsau %0, %1" : "=r" (lz) : "r" (x)); return lz; } /* * ffz: Find first zero in word. Undefined if no zero exists. * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1). */ static inline int ffz(unsigned long x) { return 31 - __cntlz(~x & -~x); } /* * __ffs: Find first bit set in word. Return 0 for bit 0 */ static inline int __ffs(unsigned long x) { return 31 - __cntlz(x & -x); } /* * ffs: Find first bit set in word. This is defined the same way as * the libc and compiler builtin ffs routines, therefore * differs in spirit from the above ffz (man ffs). */ static inline int ffs(unsigned long x) { return 32 - __cntlz(x & -x); } /* * fls: Find last (most-significant) bit set in word. * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. */ static inline int fls (unsigned int x) { return 32 - __cntlz(x); } #else /* Use the generic implementation if we don't have the nsa/nsau instructions. */ # include <asm-generic/bitops/ffs.h> # include <asm-generic/bitops/__ffs.h> # include <asm-generic/bitops/ffz.h> # include <asm-generic/bitops/fls.h> #endif #include <asm-generic/bitops/fls64.h> #include <asm-generic/bitops/find.h> #include <asm-generic/bitops/ext2-non-atomic.h> #ifdef __XTENSA_EL__ # define ext2_set_bit_atomic(lock,nr,addr) \ test_and_set_bit((nr), (unsigned long*)(addr)) # define ext2_clear_bit_atomic(lock,nr,addr) \ test_and_clear_bit((nr), (unsigned long*)(addr)) #elif defined(__XTENSA_EB__) # define ext2_set_bit_atomic(lock,nr,addr) \ test_and_set_bit((nr) ^ 0x18, (unsigned long*)(addr)) # define ext2_clear_bit_atomic(lock,nr,addr) \ test_and_clear_bit((nr) ^ 0x18, (unsigned long*)(addr)) #else # error processor byte order undefined! #endif #include <asm-generic/bitops/hweight.h> #include <asm-generic/bitops/sched.h> #include <asm-generic/bitops/minix.h> #endif /* __KERNEL__ */ #endif /* _XTENSA_BITOPS_H */