/* * PowerPC atomic bit operations. * * Merged version by David Gibson <david@gibson.dropbear.id.au>. * Based on ppc64 versions by: Dave Engebretsen, Todd Inglett, Don * Reed, Pat McCarthy, Peter Bergner, Anton Blanchard. They * originally took it from the ppc32 code. * * Within a word, bits are numbered LSB first. Lot's of places make * this assumption by directly testing bits with (val & (1<<nr)). * This can cause confusion for large (> 1 word) bitmaps on a * big-endian system because, unlike little endian, the number of each * bit depends on the word size. * * The bitop functions are defined to work on unsigned longs, so for a * ppc64 system the bits end up numbered: * |63..............0|127............64|191...........128|255...........196| * and on ppc32: * |31.....0|63....31|95....64|127...96|159..128|191..160|223..192|255..224| * * There are a few little-endian macros used mostly for filesystem * bitmaps, these work on similar bit arrays layouts, but * byte-oriented: * |7...0|15...8|23...16|31...24|39...32|47...40|55...48|63...56| * * The main difference is that bit 3-5 (64b) or 3-4 (32b) in the bit * number field needs to be reversed compared to the big-endian bit * fields. This can be achieved by XOR with 0x38 (64b) or 0x18 (32b). * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #ifndef _ASM_POWERPC_BITOPS_H #define _ASM_POWERPC_BITOPS_H #ifdef __KERNEL__ #include <linux/compiler.h> #include <asm/atomic.h> #include <asm/asm-compat.h> #include <asm/synch.h> /* * clear_bit doesn't imply a memory barrier */ #define smp_mb__before_clear_bit() smp_mb() #define smp_mb__after_clear_bit() smp_mb() #define BITOP_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) #define BITOP_WORD(nr) ((nr) / BITS_PER_LONG) #define BITOP_LE_SWIZZLE ((BITS_PER_LONG-1) & ~0x7) static __inline__ void set_bit(int nr, volatile unsigned long *addr) { unsigned long old; unsigned long mask = BITOP_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); __asm__ __volatile__( "1:" PPC_LLARX "%0,0,%3 # set_bit\n" "or %0,%0,%2\n" PPC405_ERR77(0,%3) PPC_STLCX "%0,0,%3\n" "bne- 1b" : "=&r" (old), "+m" (*p) : "r" (mask), "r" (p) : "cc" ); } static __inline__ void clear_bit(int nr, volatile unsigned long *addr) { unsigned long old; unsigned long mask = BITOP_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); __asm__ __volatile__( "1:" PPC_LLARX "%0,0,%3 # clear_bit\n" "andc %0,%0,%2\n" PPC405_ERR77(0,%3) PPC_STLCX "%0,0,%3\n" "bne- 1b" : "=&r" (old), "+m" (*p) : "r" (mask), "r" (p) : "cc" ); } static __inline__ void change_bit(int nr, volatile unsigned long *addr) { unsigned long old; unsigned long mask = BITOP_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); __asm__ __volatile__( "1:" PPC_LLARX "%0,0,%3 # change_bit\n" "xor %0,%0,%2\n" PPC405_ERR77(0,%3) PPC_STLCX "%0,0,%3\n" "bne- 1b" : "=&r" (old), "+m" (*p) : "r" (mask), "r" (p) : "cc" ); } static __inline__ int test_and_set_bit(unsigned long nr, volatile unsigned long *addr) { unsigned long old, t; unsigned long mask = BITOP_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); __asm__ __volatile__( LWSYNC_ON_SMP "1:" PPC_LLARX "%0,0,%3 # test_and_set_bit\n" "or %1,%0,%2 \n" PPC405_ERR77(0,%3) PPC_STLCX "%1,0,%3 \n" "bne- 1b" ISYNC_ON_SMP : "=&r" (old), "=&r" (t) : "r" (mask), "r" (p) : "cc", "memory"); return (old & mask) != 0; } static __inline__ int test_and_clear_bit(unsigned long nr, volatile unsigned long *addr) { unsigned long old, t; unsigned long mask = BITOP_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); __asm__ __volatile__( LWSYNC_ON_SMP "1:" PPC_LLARX "%0,0,%3 # test_and_clear_bit\n" "andc %1,%0,%2 \n" PPC405_ERR77(0,%3) PPC_STLCX "%1,0,%3 \n" "bne- 1b" ISYNC_ON_SMP : "=&r" (old), "=&r" (t) : "r" (mask), "r" (p) : "cc", "memory"); return (old & mask) != 0; } static __inline__ int test_and_change_bit(unsigned long nr, volatile unsigned long *addr) { unsigned long old, t; unsigned long mask = BITOP_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); __asm__ __volatile__( LWSYNC_ON_SMP "1:" PPC_LLARX "%0,0,%3 # test_and_change_bit\n" "xor %1,%0,%2 \n" PPC405_ERR77(0,%3) PPC_STLCX "%1,0,%3 \n" "bne- 1b" ISYNC_ON_SMP : "=&r" (old), "=&r" (t) : "r" (mask), "r" (p) : "cc", "memory"); return (old & mask) != 0; } static __inline__ void set_bits(unsigned long mask, unsigned long *addr) { unsigned long old; __asm__ __volatile__( "1:" PPC_LLARX "%0,0,%3 # set_bits\n" "or %0,%0,%2\n" PPC_STLCX "%0,0,%3\n" "bne- 1b" : "=&r" (old), "+m" (*addr) : "r" (mask), "r" (addr) : "cc"); } #include <asm-generic/bitops/non-atomic.h> /* * Return the zero-based bit position (LE, not IBM bit numbering) of * the most significant 1-bit in a double word. */ static __inline__ __attribute__((const)) int __ilog2(unsigned long x) { int lz; asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (x)); return BITS_PER_LONG - 1 - lz; } static inline __attribute__((const)) int __ilog2_u32(u32 n) { int bit; asm ("cntlzw %0,%1" : "=r" (bit) : "r" (n)); return 31 - bit; } #ifdef __powerpc64__ static inline __attribute__((const)) int __ilog2_u64(u64 n) { int bit; asm ("cntlzd %0,%1" : "=r" (bit) : "r" (n)); return 63 - bit; } #endif /* * Determines the bit position of the least significant 0 bit in the * specified double word. The returned bit position will be * zero-based, starting from the right side (63/31 - 0). */ static __inline__ unsigned long ffz(unsigned long x) { /* no zero exists anywhere in the 8 byte area. */ if ((x = ~x) == 0) return BITS_PER_LONG; /* * Calculate the bit position of the least signficant '1' bit in x * (since x has been changed this will actually be the least signficant * '0' bit in * the original x). Note: (x & -x) gives us a mask that * is the least significant * (RIGHT-most) 1-bit of the value in x. */ return __ilog2(x & -x); } static __inline__ int __ffs(unsigned long x) { return __ilog2(x & -x); } /* * 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). */ static __inline__ int ffs(int x) { unsigned long i = (unsigned long)x; return __ilog2(i & -i) + 1; } /* * fls: find last (most-significant) bit set. * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. */ static __inline__ int fls(unsigned int x) { int lz; asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x)); return 32 - lz; } #include <asm-generic/bitops/fls64.h> #include <asm-generic/bitops/hweight.h> #define find_first_zero_bit(addr, size) find_next_zero_bit((addr), (size), 0) unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, unsigned long offset); /** * find_first_bit - find the first set bit in a memory region * @addr: The address to start the search at * @size: The maximum size to search * * Returns the bit-number of the first set bit, not the number of the byte * containing a bit. */ #define find_first_bit(addr, size) find_next_bit((addr), (size), 0) unsigned long find_next_bit(const unsigned long *addr, unsigned long size, unsigned long offset); /* Little-endian versions */ static __inline__ int test_le_bit(unsigned long nr, __const__ unsigned long *addr) { __const__ unsigned char *tmp = (__const__ unsigned char *) addr; return (tmp[nr >> 3] >> (nr & 7)) & 1; } #define __set_le_bit(nr, addr) \ __set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) #define __clear_le_bit(nr, addr) \ __clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) #define test_and_set_le_bit(nr, addr) \ test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) #define test_and_clear_le_bit(nr, addr) \ test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) #define __test_and_set_le_bit(nr, addr) \ __test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) #define __test_and_clear_le_bit(nr, addr) \ __test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) #define find_first_zero_le_bit(addr, size) generic_find_next_zero_le_bit((addr), (size), 0) unsigned long generic_find_next_zero_le_bit(const unsigned long *addr, unsigned long size, unsigned long offset); /* Bitmap functions for the ext2 filesystem */ #define ext2_set_bit(nr,addr) \ __test_and_set_le_bit((nr), (unsigned long*)addr) #define ext2_clear_bit(nr, addr) \ __test_and_clear_le_bit((nr), (unsigned long*)addr) #define ext2_set_bit_atomic(lock, nr, addr) \ test_and_set_le_bit((nr), (unsigned long*)addr) #define ext2_clear_bit_atomic(lock, nr, addr) \ test_and_clear_le_bit((nr), (unsigned long*)addr) #define ext2_test_bit(nr, addr) test_le_bit((nr),(unsigned long*)addr) #define ext2_find_first_zero_bit(addr, size) \ find_first_zero_le_bit((unsigned long*)addr, size) #define ext2_find_next_zero_bit(addr, size, off) \ generic_find_next_zero_le_bit((unsigned long*)addr, size, off) /* Bitmap functions for the minix filesystem. */ #define minix_test_and_set_bit(nr,addr) \ __test_and_set_le_bit(nr, (unsigned long *)addr) #define minix_set_bit(nr,addr) \ __set_le_bit(nr, (unsigned long *)addr) #define minix_test_and_clear_bit(nr,addr) \ __test_and_clear_le_bit(nr, (unsigned long *)addr) #define minix_test_bit(nr,addr) \ test_le_bit(nr, (unsigned long *)addr) #define minix_find_first_zero_bit(addr,size) \ find_first_zero_le_bit((unsigned long *)addr, size) #include <asm-generic/bitops/sched.h> #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_BITOPS_H */