1/* 2 * PowerPC atomic bit operations. 3 * 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. 8 * 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. 14 * 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| 18 * and on ppc32: 19 * |31.....0|63....31|95....64|127...96|159..128|191..160|223..192|255..224| 20 * 21 * There are a few little-endian macros used mostly for filesystem 22 * bitmaps, these work on similar bit arrays layouts, but 23 * byte-oriented: 24 * |7...0|15...8|23...16|31...24|39...32|47...40|55...48|63...56| 25 * 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). 29 * 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. 34 */ 35 36#ifndef _ASM_POWERPC_BITOPS_H 37#define _ASM_POWERPC_BITOPS_H 38 39#ifdef __KERNEL__ 40 41#include <linux/compiler.h> 42#include <asm/asm-compat.h> 43#include <asm/synch.h> 44 45/* 46 * clear_bit doesn't imply a memory barrier 47 */ 48#define smp_mb__before_clear_bit() smp_mb() 49#define smp_mb__after_clear_bit() smp_mb() 50 51#define BITOP_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) 52#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG) 53#define BITOP_LE_SWIZZLE ((BITS_PER_LONG-1) & ~0x7) 54 55static __inline__ void set_bit(int nr, volatile unsigned long *addr) 56{ 57 unsigned long old; 58 unsigned long mask = BITOP_MASK(nr); 59 unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); 60 61 __asm__ __volatile__( 62"1:" PPC_LLARX "%0,0,%3 # set_bit\n" 63 "or %0,%0,%2\n" 64 PPC405_ERR77(0,%3) 65 PPC_STLCX "%0,0,%3\n" 66 "bne- 1b" 67 : "=&r" (old), "+m" (*p) 68 : "r" (mask), "r" (p) 69 : "cc" ); 70} 71 72static __inline__ void clear_bit(int nr, volatile unsigned long *addr) 73{ 74 unsigned long old; 75 unsigned long mask = BITOP_MASK(nr); 76 unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); 77 78 __asm__ __volatile__( 79"1:" PPC_LLARX "%0,0,%3 # clear_bit\n" 80 "andc %0,%0,%2\n" 81 PPC405_ERR77(0,%3) 82 PPC_STLCX "%0,0,%3\n" 83 "bne- 1b" 84 : "=&r" (old), "+m" (*p) 85 : "r" (mask), "r" (p) 86 : "cc" ); 87} 88 89static __inline__ void change_bit(int nr, volatile unsigned long *addr) 90{ 91 unsigned long old; 92 unsigned long mask = BITOP_MASK(nr); 93 unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); 94 95 __asm__ __volatile__( 96"1:" PPC_LLARX "%0,0,%3 # change_bit\n" 97 "xor %0,%0,%2\n" 98 PPC405_ERR77(0,%3) 99 PPC_STLCX "%0,0,%3\n" 100 "bne- 1b" 101 : "=&r" (old), "+m" (*p) 102 : "r" (mask), "r" (p) 103 : "cc" ); 104} 105 106static __inline__ int test_and_set_bit(unsigned long nr, 107 volatile unsigned long *addr) 108{ 109 unsigned long old, t; 110 unsigned long mask = BITOP_MASK(nr); 111 unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); 112 113 __asm__ __volatile__( 114 LWSYNC_ON_SMP 115"1:" PPC_LLARX "%0,0,%3 # test_and_set_bit\n" 116 "or %1,%0,%2 \n" 117 PPC405_ERR77(0,%3) 118 PPC_STLCX "%1,0,%3 \n" 119 "bne- 1b" 120 ISYNC_ON_SMP 121 : "=&r" (old), "=&r" (t) 122 : "r" (mask), "r" (p) 123 : "cc", "memory"); 124 125 return (old & mask) != 0; 126} 127 128static __inline__ int test_and_clear_bit(unsigned long nr, 129 volatile unsigned long *addr) 130{ 131 unsigned long old, t; 132 unsigned long mask = BITOP_MASK(nr); 133 unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); 134 135 __asm__ __volatile__( 136 LWSYNC_ON_SMP 137"1:" PPC_LLARX "%0,0,%3 # test_and_clear_bit\n" 138 "andc %1,%0,%2 \n" 139 PPC405_ERR77(0,%3) 140 PPC_STLCX "%1,0,%3 \n" 141 "bne- 1b" 142 ISYNC_ON_SMP 143 : "=&r" (old), "=&r" (t) 144 : "r" (mask), "r" (p) 145 : "cc", "memory"); 146 147 return (old & mask) != 0; 148} 149 150static __inline__ int test_and_change_bit(unsigned long nr, 151 volatile unsigned long *addr) 152{ 153 unsigned long old, t; 154 unsigned long mask = BITOP_MASK(nr); 155 unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); 156 157 __asm__ __volatile__( 158 LWSYNC_ON_SMP 159"1:" PPC_LLARX "%0,0,%3 # test_and_change_bit\n" 160 "xor %1,%0,%2 \n" 161 PPC405_ERR77(0,%3) 162 PPC_STLCX "%1,0,%3 \n" 163 "bne- 1b" 164 ISYNC_ON_SMP 165 : "=&r" (old), "=&r" (t) 166 : "r" (mask), "r" (p) 167 : "cc", "memory"); 168 169 return (old & mask) != 0; 170} 171 172static __inline__ void set_bits(unsigned long mask, unsigned long *addr) 173{ 174 unsigned long old; 175 176 __asm__ __volatile__( 177"1:" PPC_LLARX "%0,0,%3 # set_bits\n" 178 "or %0,%0,%2\n" 179 PPC_STLCX "%0,0,%3\n" 180 "bne- 1b" 181 : "=&r" (old), "+m" (*addr) 182 : "r" (mask), "r" (addr) 183 : "cc"); 184} 185 186#include <asm-generic/bitops/non-atomic.h> 187 188/* 189 * Return the zero-based bit position (LE, not IBM bit numbering) of 190 * the most significant 1-bit in a double word. 191 */ 192static __inline__ __attribute__((const)) 193int __ilog2(unsigned long x) 194{ 195 int lz; 196 197 asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (x)); 198 return BITS_PER_LONG - 1 - lz; 199} 200 201static inline __attribute__((const)) 202int __ilog2_u32(u32 n) 203{ 204 int bit; 205 asm ("cntlzw %0,%1" : "=r" (bit) : "r" (n)); 206 return 31 - bit; 207} 208 209#ifdef __powerpc64__ 210static inline __attribute__((const)) 211int __ilog2_u64(u64 n) 212{ 213 int bit; 214 asm ("cntlzd %0,%1" : "=r" (bit) : "r" (n)); 215 return 63 - bit; 216} 217#endif 218 219/* 220 * Determines the bit position of the least significant 0 bit in the 221 * specified double word. The returned bit position will be 222 * zero-based, starting from the right side (63/31 - 0). 223 */ 224static __inline__ unsigned long ffz(unsigned long x) 225{ 226 /* no zero exists anywhere in the 8 byte area. */ 227 if ((x = ~x) == 0) 228 return BITS_PER_LONG; 229 230 /* 231 * Calculate the bit position of the least signficant '1' bit in x 232 * (since x has been changed this will actually be the least signficant 233 * '0' bit in * the original x). Note: (x & -x) gives us a mask that 234 * is the least significant * (RIGHT-most) 1-bit of the value in x. 235 */ 236 return __ilog2(x & -x); 237} 238 239static __inline__ int __ffs(unsigned long x) 240{ 241 return __ilog2(x & -x); 242} 243 244/* 245 * ffs: find first bit set. This is defined the same way as 246 * the libc and compiler builtin ffs routines, therefore 247 * differs in spirit from the above ffz (man ffs). 248 */ 249static __inline__ int ffs(int x) 250{ 251 unsigned long i = (unsigned long)x; 252 return __ilog2(i & -i) + 1; 253} 254 255/* 256 * fls: find last (most-significant) bit set. 257 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. 258 */ 259static __inline__ int fls(unsigned int x) 260{ 261 int lz; 262 263 asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x)); 264 return 32 - lz; 265} 266#include <asm-generic/bitops/fls64.h> 267 268#include <asm-generic/bitops/hweight.h> 269 270#define find_first_zero_bit(addr, size) find_next_zero_bit((addr), (size), 0) 271unsigned long find_next_zero_bit(const unsigned long *addr, 272 unsigned long size, unsigned long offset); 273/** 274 * find_first_bit - find the first set bit in a memory region 275 * @addr: The address to start the search at 276 * @size: The maximum size to search 277 * 278 * Returns the bit-number of the first set bit, not the number of the byte 279 * containing a bit. 280 */ 281#define find_first_bit(addr, size) find_next_bit((addr), (size), 0) 282unsigned long find_next_bit(const unsigned long *addr, 283 unsigned long size, unsigned long offset); 284 285/* Little-endian versions */ 286 287static __inline__ int test_le_bit(unsigned long nr, 288 __const__ unsigned long *addr) 289{ 290 __const__ unsigned char *tmp = (__const__ unsigned char *) addr; 291 return (tmp[nr >> 3] >> (nr & 7)) & 1; 292} 293 294#define __set_le_bit(nr, addr) \ 295 __set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) 296#define __clear_le_bit(nr, addr) \ 297 __clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) 298 299#define test_and_set_le_bit(nr, addr) \ 300 test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) 301#define test_and_clear_le_bit(nr, addr) \ 302 test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) 303 304#define __test_and_set_le_bit(nr, addr) \ 305 __test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) 306#define __test_and_clear_le_bit(nr, addr) \ 307 __test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) 308 309#define find_first_zero_le_bit(addr, size) generic_find_next_zero_le_bit((addr), (size), 0) 310unsigned long generic_find_next_zero_le_bit(const unsigned long *addr, 311 unsigned long size, unsigned long offset); 312 313/* Bitmap functions for the ext2 filesystem */ 314 315#define ext2_set_bit(nr,addr) \ 316 __test_and_set_le_bit((nr), (unsigned long*)addr) 317#define ext2_clear_bit(nr, addr) \ 318 __test_and_clear_le_bit((nr), (unsigned long*)addr) 319 320#define ext2_set_bit_atomic(lock, nr, addr) \ 321 test_and_set_le_bit((nr), (unsigned long*)addr) 322#define ext2_clear_bit_atomic(lock, nr, addr) \ 323 test_and_clear_le_bit((nr), (unsigned long*)addr) 324 325#define ext2_test_bit(nr, addr) test_le_bit((nr),(unsigned long*)addr) 326 327#define ext2_find_first_zero_bit(addr, size) \ 328 find_first_zero_le_bit((unsigned long*)addr, size) 329#define ext2_find_next_zero_bit(addr, size, off) \ 330 generic_find_next_zero_le_bit((unsigned long*)addr, size, off) 331 332/* Bitmap functions for the minix filesystem. */ 333 334#define minix_test_and_set_bit(nr,addr) \ 335 __test_and_set_le_bit(nr, (unsigned long *)addr) 336#define minix_set_bit(nr,addr) \ 337 __set_le_bit(nr, (unsigned long *)addr) 338#define minix_test_and_clear_bit(nr,addr) \ 339 __test_and_clear_le_bit(nr, (unsigned long *)addr) 340#define minix_test_bit(nr,addr) \ 341 test_le_bit(nr, (unsigned long *)addr) 342 343#define minix_find_first_zero_bit(addr,size) \ 344 find_first_zero_le_bit((unsigned long *)addr, size) 345 346#include <asm-generic/bitops/sched.h> 347 348#endif /* __KERNEL__ */ 349 350#endif /* _ASM_POWERPC_BITOPS_H */ 351