2 * PowerPC atomic bit operations.
4 * Merged version by David Gibson <david@gibson.dropbear.id.au>.
5 * Based on ppc64 versions by: Dave Engebretsen, Todd Inglett, Don
6 * Reed, Pat McCarthy, Peter Bergner, Anton Blanchard. They
7 * originally took it from the ppc32 code.
9 * Within a word, bits are numbered LSB first. Lot's of places make
10 * this assumption by directly testing bits with (val & (1<<nr)).
11 * This can cause confusion for large (> 1 word) bitmaps on a
12 * big-endian system because, unlike little endian, the number of each
13 * bit depends on the word size.
15 * The bitop functions are defined to work on unsigned longs, so for a
16 * ppc64 system the bits end up numbered:
17 * |63..............0|127............64|191...........128|255...........196|
19 * |31.....0|63....31|95....64|127...96|159..128|191..160|223..192|255..224|
21 * There are a few little-endian macros used mostly for filesystem
22 * bitmaps, these work on similar bit arrays layouts, but
24 * |7...0|15...8|23...16|31...24|39...32|47...40|55...48|63...56|
26 * The main difference is that bit 3-5 (64b) or 3-4 (32b) in the bit
27 * number field needs to be reversed compared to the big-endian bit
28 * fields. This can be achieved by XOR with 0x38 (64b) or 0x18 (32b).
30 * This program is free software; you can redistribute it and/or
31 * modify it under the terms of the GNU General Public License
32 * as published by the Free Software Foundation; either version
33 * 2 of the License, or (at your option) any later version.
36 #ifndef _ASM_POWERPC_BITOPS_H
37 #define _ASM_POWERPC_BITOPS_H
41 #ifndef _LINUX_BITOPS_H
42 #error only <linux/bitops.h> can be included directly
45 #include <linux/compiler.h>
46 #include <asm/asm-compat.h>
47 #include <asm/synch.h>
50 * clear_bit doesn't imply a memory barrier
52 #define smp_mb__before_clear_bit() smp_mb()
53 #define smp_mb__after_clear_bit() smp_mb()
55 #define BITOP_LE_SWIZZLE ((BITS_PER_LONG-1) & ~0x7)
57 /* Macro for generating the ***_bits() functions */
58 #define DEFINE_BITOP(fn, op, prefix, postfix) \
59 static __inline__ void fn(unsigned long mask, \
60 volatile unsigned long *_p) \
63 unsigned long *p = (unsigned long *)_p; \
64 __asm__ __volatile__ ( \
66 "1:" PPC_LLARX(%0,0,%3,0) "\n" \
67 stringify_in_c(op) "%0,%0,%2\n" \
69 PPC_STLCX "%0,0,%3\n" \
72 : "=&r" (old), "+m" (*p) \
73 : "r" (mask), "r" (p) \
77 DEFINE_BITOP(set_bits, or, "", "")
78 DEFINE_BITOP(clear_bits, andc, "", "")
79 DEFINE_BITOP(clear_bits_unlock, andc, PPC_RELEASE_BARRIER, "")
80 DEFINE_BITOP(change_bits, xor, "", "")
82 static __inline__ void set_bit(int nr, volatile unsigned long *addr)
84 set_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
87 static __inline__ void clear_bit(int nr, volatile unsigned long *addr)
89 clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
92 static __inline__ void clear_bit_unlock(int nr, volatile unsigned long *addr)
94 clear_bits_unlock(BIT_MASK(nr), addr + BIT_WORD(nr));
97 static __inline__ void change_bit(int nr, volatile unsigned long *addr)
99 change_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
102 /* Like DEFINE_BITOP(), with changes to the arguments to 'op' and the output
104 #define DEFINE_TESTOP(fn, op, prefix, postfix, eh) \
105 static __inline__ unsigned long fn( \
106 unsigned long mask, \
107 volatile unsigned long *_p) \
109 unsigned long old, t; \
110 unsigned long *p = (unsigned long *)_p; \
111 __asm__ __volatile__ ( \
113 "1:" PPC_LLARX(%0,0,%3,eh) "\n" \
114 stringify_in_c(op) "%1,%0,%2\n" \
116 PPC_STLCX "%1,0,%3\n" \
119 : "=&r" (old), "=&r" (t) \
120 : "r" (mask), "r" (p) \
122 return (old & mask); \
125 DEFINE_TESTOP(test_and_set_bits, or, PPC_ATOMIC_ENTRY_BARRIER,
126 PPC_ATOMIC_EXIT_BARRIER, 0)
127 DEFINE_TESTOP(test_and_set_bits_lock, or, "",
128 PPC_ACQUIRE_BARRIER, 1)
129 DEFINE_TESTOP(test_and_clear_bits, andc, PPC_ATOMIC_ENTRY_BARRIER,
130 PPC_ATOMIC_EXIT_BARRIER, 0)
131 DEFINE_TESTOP(test_and_change_bits, xor, PPC_ATOMIC_ENTRY_BARRIER,
132 PPC_ATOMIC_EXIT_BARRIER, 0)
134 static __inline__ int test_and_set_bit(unsigned long nr,
135 volatile unsigned long *addr)
137 return test_and_set_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
140 static __inline__ int test_and_set_bit_lock(unsigned long nr,
141 volatile unsigned long *addr)
143 return test_and_set_bits_lock(BIT_MASK(nr),
144 addr + BIT_WORD(nr)) != 0;
147 static __inline__ int test_and_clear_bit(unsigned long nr,
148 volatile unsigned long *addr)
150 return test_and_clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
153 static __inline__ int test_and_change_bit(unsigned long nr,
154 volatile unsigned long *addr)
156 return test_and_change_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
159 #include <asm-generic/bitops/non-atomic.h>
161 static __inline__ void __clear_bit_unlock(int nr, volatile unsigned long *addr)
163 __asm__ __volatile__(PPC_RELEASE_BARRIER "" ::: "memory");
164 __clear_bit(nr, addr);
168 * Return the zero-based bit position (LE, not IBM bit numbering) of
169 * the most significant 1-bit in a double word.
171 static __inline__ __attribute__((const))
172 int __ilog2(unsigned long x)
176 asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (x));
177 return BITS_PER_LONG - 1 - lz;
180 static inline __attribute__((const))
181 int __ilog2_u32(u32 n)
184 asm ("cntlzw %0,%1" : "=r" (bit) : "r" (n));
189 static inline __attribute__((const))
190 int __ilog2_u64(u64 n)
193 asm ("cntlzd %0,%1" : "=r" (bit) : "r" (n));
199 * Determines the bit position of the least significant 0 bit in the
200 * specified double word. The returned bit position will be
201 * zero-based, starting from the right side (63/31 - 0).
203 static __inline__ unsigned long ffz(unsigned long x)
205 /* no zero exists anywhere in the 8 byte area. */
207 return BITS_PER_LONG;
210 * Calculate the bit position of the least significant '1' bit in x
211 * (since x has been changed this will actually be the least significant
212 * '0' bit in * the original x). Note: (x & -x) gives us a mask that
213 * is the least significant * (RIGHT-most) 1-bit of the value in x.
215 return __ilog2(x & -x);
218 static __inline__ int __ffs(unsigned long x)
220 return __ilog2(x & -x);
224 * ffs: find first bit set. This is defined the same way as
225 * the libc and compiler builtin ffs routines, therefore
226 * differs in spirit from the above ffz (man ffs).
228 static __inline__ int ffs(int x)
230 unsigned long i = (unsigned long)x;
231 return __ilog2(i & -i) + 1;
235 * fls: find last (most-significant) bit set.
236 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
238 static __inline__ int fls(unsigned int x)
242 asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x));
246 static __inline__ unsigned long __fls(unsigned long x)
252 * 64-bit can do this using one cntlzd (count leading zeroes doubleword)
253 * instruction; for 32-bit we use the generic version, which does two
257 static __inline__ int fls64(__u64 x)
261 asm ("cntlzd %0,%1" : "=r" (lz) : "r" (x));
265 #include <asm-generic/bitops/fls64.h>
266 #endif /* __powerpc64__ */
269 unsigned int __arch_hweight8(unsigned int w);
270 unsigned int __arch_hweight16(unsigned int w);
271 unsigned int __arch_hweight32(unsigned int w);
272 unsigned long __arch_hweight64(__u64 w);
273 #include <asm-generic/bitops/const_hweight.h>
275 #include <asm-generic/bitops/hweight.h>
278 #include <asm-generic/bitops/find.h>
280 /* Little-endian versions */
282 static __inline__ int test_bit_le(unsigned long nr,
283 __const__ void *addr)
285 __const__ unsigned char *tmp = (__const__ unsigned char *) addr;
286 return (tmp[nr >> 3] >> (nr & 7)) & 1;
289 static inline void set_bit_le(int nr, void *addr)
291 set_bit(nr ^ BITOP_LE_SWIZZLE, addr);
294 static inline void clear_bit_le(int nr, void *addr)
296 clear_bit(nr ^ BITOP_LE_SWIZZLE, addr);
299 static inline void __set_bit_le(int nr, void *addr)
301 __set_bit(nr ^ BITOP_LE_SWIZZLE, addr);
304 static inline void __clear_bit_le(int nr, void *addr)
306 __clear_bit(nr ^ BITOP_LE_SWIZZLE, addr);
309 static inline int test_and_set_bit_le(int nr, void *addr)
311 return test_and_set_bit(nr ^ BITOP_LE_SWIZZLE, addr);
314 static inline int test_and_clear_bit_le(int nr, void *addr)
316 return test_and_clear_bit(nr ^ BITOP_LE_SWIZZLE, addr);
319 static inline int __test_and_set_bit_le(int nr, void *addr)
321 return __test_and_set_bit(nr ^ BITOP_LE_SWIZZLE, addr);
324 static inline int __test_and_clear_bit_le(int nr, void *addr)
326 return __test_and_clear_bit(nr ^ BITOP_LE_SWIZZLE, addr);
329 #define find_first_zero_bit_le(addr, size) \
330 find_next_zero_bit_le((addr), (size), 0)
331 unsigned long find_next_zero_bit_le(const void *addr,
332 unsigned long size, unsigned long offset);
334 unsigned long find_next_bit_le(const void *addr,
335 unsigned long size, unsigned long offset);
336 /* Bitmap functions for the ext2 filesystem */
338 #include <asm-generic/bitops/ext2-atomic-setbit.h>
340 #include <asm-generic/bitops/sched.h>
342 #endif /* __KERNEL__ */
344 #endif /* _ASM_POWERPC_BITOPS_H */