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#ifndef _LINUX_BITOPS_H 42#error only <linux/bitops.h> can be included directly 43#endif 44 45#include <linux/compiler.h> 46#include <asm/asm-compat.h> 47#include <asm/synch.h> 48 49/* 50 * clear_bit doesn't imply a memory barrier 51 */ 52#define smp_mb__before_clear_bit() smp_mb() 53#define smp_mb__after_clear_bit() smp_mb() 54 55#define BITOP_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) 56#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG) 57#define BITOP_LE_SWIZZLE ((BITS_PER_LONG-1) & ~0x7) 58 59/* Macro for generating the ***_bits() functions */ 60#define DEFINE_BITOP(fn, op, prefix, postfix) \ 61static __inline__ void fn(unsigned long mask, \ 62 volatile unsigned long *_p) \ 63{ \ 64 unsigned long old; \ 65 unsigned long *p = (unsigned long *)_p; \ 66 __asm__ __volatile__ ( \ 67 prefix \ 68"1:" PPC_LLARX(%0,0,%3,0) "\n" \ 69 stringify_in_c(op) "%0,%0,%2\n" \ 70 PPC405_ERR77(0,%3) \ 71 PPC_STLCX "%0,0,%3\n" \ 72 "bne- 1b\n" \ 73 postfix \ 74 : "=&r" (old), "+m" (*p) \ 75 : "r" (mask), "r" (p) \ 76 : "cc", "memory"); \ 77} 78 79DEFINE_BITOP(set_bits, or, "", "") 80DEFINE_BITOP(clear_bits, andc, "", "") 81DEFINE_BITOP(clear_bits_unlock, andc, PPC_RELEASE_BARRIER, "") 82DEFINE_BITOP(change_bits, xor, "", "") 83 84static __inline__ void set_bit(int nr, volatile unsigned long *addr) 85{ 86 set_bits(BITOP_MASK(nr), addr + BITOP_WORD(nr)); 87} 88 89static __inline__ void clear_bit(int nr, volatile unsigned long *addr) 90{ 91 clear_bits(BITOP_MASK(nr), addr + BITOP_WORD(nr)); 92} 93 94static __inline__ void clear_bit_unlock(int nr, volatile unsigned long *addr) 95{ 96 clear_bits_unlock(BITOP_MASK(nr), addr + BITOP_WORD(nr)); 97} 98 99static __inline__ void change_bit(int nr, volatile unsigned long *addr) 100{ 101 change_bits(BITOP_MASK(nr), addr + BITOP_WORD(nr)); 102} 103 104/* Like DEFINE_BITOP(), with changes to the arguments to 'op' and the output 105 * operands. */ 106#define DEFINE_TESTOP(fn, op, prefix, postfix, eh) \ 107static __inline__ unsigned long fn( \ 108 unsigned long mask, \ 109 volatile unsigned long *_p) \ 110{ \ 111 unsigned long old, t; \ 112 unsigned long *p = (unsigned long *)_p; \ 113 __asm__ __volatile__ ( \ 114 prefix \ 115"1:" PPC_LLARX(%0,0,%3,eh) "\n" \ 116 stringify_in_c(op) "%1,%0,%2\n" \ 117 PPC405_ERR77(0,%3) \ 118 PPC_STLCX "%1,0,%3\n" \ 119 "bne- 1b\n" \ 120 postfix \ 121 : "=&r" (old), "=&r" (t) \ 122 : "r" (mask), "r" (p) \ 123 : "cc", "memory"); \ 124 return (old & mask); \ 125} 126 127DEFINE_TESTOP(test_and_set_bits, or, PPC_RELEASE_BARRIER, 128 PPC_ACQUIRE_BARRIER, 0) 129DEFINE_TESTOP(test_and_set_bits_lock, or, "", 130 PPC_ACQUIRE_BARRIER, 1) 131DEFINE_TESTOP(test_and_clear_bits, andc, PPC_RELEASE_BARRIER, 132 PPC_ACQUIRE_BARRIER, 0) 133DEFINE_TESTOP(test_and_change_bits, xor, PPC_RELEASE_BARRIER, 134 PPC_ACQUIRE_BARRIER, 0) 135 136static __inline__ int test_and_set_bit(unsigned long nr, 137 volatile unsigned long *addr) 138{ 139 return test_and_set_bits(BITOP_MASK(nr), addr + BITOP_WORD(nr)) != 0; 140} 141 142static __inline__ int test_and_set_bit_lock(unsigned long nr, 143 volatile unsigned long *addr) 144{ 145 return test_and_set_bits_lock(BITOP_MASK(nr), 146 addr + BITOP_WORD(nr)) != 0; 147} 148 149static __inline__ int test_and_clear_bit(unsigned long nr, 150 volatile unsigned long *addr) 151{ 152 return test_and_clear_bits(BITOP_MASK(nr), addr + BITOP_WORD(nr)) != 0; 153} 154 155static __inline__ int test_and_change_bit(unsigned long nr, 156 volatile unsigned long *addr) 157{ 158 return test_and_change_bits(BITOP_MASK(nr), addr + BITOP_WORD(nr)) != 0; 159} 160 161#include <asm-generic/bitops/non-atomic.h> 162 163static __inline__ void __clear_bit_unlock(int nr, volatile unsigned long *addr) 164{ 165 __asm__ __volatile__(PPC_RELEASE_BARRIER "" ::: "memory"); 166 __clear_bit(nr, addr); 167} 168 169/* 170 * Return the zero-based bit position (LE, not IBM bit numbering) of 171 * the most significant 1-bit in a double word. 172 */ 173static __inline__ __attribute__((const)) 174int __ilog2(unsigned long x) 175{ 176 int lz; 177 178 asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (x)); 179 return BITS_PER_LONG - 1 - lz; 180} 181 182static inline __attribute__((const)) 183int __ilog2_u32(u32 n) 184{ 185 int bit; 186 asm ("cntlzw %0,%1" : "=r" (bit) : "r" (n)); 187 return 31 - bit; 188} 189 190#ifdef __powerpc64__ 191static inline __attribute__((const)) 192int __ilog2_u64(u64 n) 193{ 194 int bit; 195 asm ("cntlzd %0,%1" : "=r" (bit) : "r" (n)); 196 return 63 - bit; 197} 198#endif 199 200/* 201 * Determines the bit position of the least significant 0 bit in the 202 * specified double word. The returned bit position will be 203 * zero-based, starting from the right side (63/31 - 0). 204 */ 205static __inline__ unsigned long ffz(unsigned long x) 206{ 207 /* no zero exists anywhere in the 8 byte area. */ 208 if ((x = ~x) == 0) 209 return BITS_PER_LONG; 210 211 /* 212 * Calculate the bit position of the least signficant '1' bit in x 213 * (since x has been changed this will actually be the least signficant 214 * '0' bit in * the original x). Note: (x & -x) gives us a mask that 215 * is the least significant * (RIGHT-most) 1-bit of the value in x. 216 */ 217 return __ilog2(x & -x); 218} 219 220static __inline__ int __ffs(unsigned long x) 221{ 222 return __ilog2(x & -x); 223} 224 225/* 226 * ffs: find first bit set. This is defined the same way as 227 * the libc and compiler builtin ffs routines, therefore 228 * differs in spirit from the above ffz (man ffs). 229 */ 230static __inline__ int ffs(int x) 231{ 232 unsigned long i = (unsigned long)x; 233 return __ilog2(i & -i) + 1; 234} 235 236/* 237 * fls: find last (most-significant) bit set. 238 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. 239 */ 240static __inline__ int fls(unsigned int x) 241{ 242 int lz; 243 244 asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x)); 245 return 32 - lz; 246} 247 248static __inline__ unsigned long __fls(unsigned long x) 249{ 250 return __ilog2(x); 251} 252 253/* 254 * 64-bit can do this using one cntlzd (count leading zeroes doubleword) 255 * instruction; for 32-bit we use the generic version, which does two 256 * 32-bit fls calls. 257 */ 258#ifdef __powerpc64__ 259static __inline__ int fls64(__u64 x) 260{ 261 int lz; 262 263 asm ("cntlzd %0,%1" : "=r" (lz) : "r" (x)); 264 return 64 - lz; 265} 266#else 267#include <asm-generic/bitops/fls64.h> 268#endif /* __powerpc64__ */ 269 270#include <asm-generic/bitops/hweight.h> 271#include <asm-generic/bitops/find.h> 272 273/* Little-endian versions */ 274 275static __inline__ int test_le_bit(unsigned long nr, 276 __const__ unsigned long *addr) 277{ 278 __const__ unsigned char *tmp = (__const__ unsigned char *) addr; 279 return (tmp[nr >> 3] >> (nr & 7)) & 1; 280} 281 282#define __set_le_bit(nr, addr) \ 283 __set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) 284#define __clear_le_bit(nr, addr) \ 285 __clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) 286 287#define test_and_set_le_bit(nr, addr) \ 288 test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) 289#define test_and_clear_le_bit(nr, addr) \ 290 test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) 291 292#define __test_and_set_le_bit(nr, addr) \ 293 __test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) 294#define __test_and_clear_le_bit(nr, addr) \ 295 __test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr)) 296 297#define find_first_zero_le_bit(addr, size) generic_find_next_zero_le_bit((addr), (size), 0) 298unsigned long generic_find_next_zero_le_bit(const unsigned long *addr, 299 unsigned long size, unsigned long offset); 300 301unsigned long generic_find_next_le_bit(const unsigned long *addr, 302 unsigned long size, unsigned long offset); 303/* Bitmap functions for the ext2 filesystem */ 304 305#define ext2_set_bit(nr,addr) \ 306 __test_and_set_le_bit((nr), (unsigned long*)addr) 307#define ext2_clear_bit(nr, addr) \ 308 __test_and_clear_le_bit((nr), (unsigned long*)addr) 309 310#define ext2_set_bit_atomic(lock, nr, addr) \ 311 test_and_set_le_bit((nr), (unsigned long*)addr) 312#define ext2_clear_bit_atomic(lock, nr, addr) \ 313 test_and_clear_le_bit((nr), (unsigned long*)addr) 314 315#define ext2_test_bit(nr, addr) test_le_bit((nr),(unsigned long*)addr) 316 317#define ext2_find_first_zero_bit(addr, size) \ 318 find_first_zero_le_bit((unsigned long*)addr, size) 319#define ext2_find_next_zero_bit(addr, size, off) \ 320 generic_find_next_zero_le_bit((unsigned long*)addr, size, off) 321 322#define ext2_find_next_bit(addr, size, off) \ 323 generic_find_next_le_bit((unsigned long *)addr, size, off) 324/* Bitmap functions for the minix filesystem. */ 325 326#define minix_test_and_set_bit(nr,addr) \ 327 __test_and_set_le_bit(nr, (unsigned long *)addr) 328#define minix_set_bit(nr,addr) \ 329 __set_le_bit(nr, (unsigned long *)addr) 330#define minix_test_and_clear_bit(nr,addr) \ 331 __test_and_clear_le_bit(nr, (unsigned long *)addr) 332#define minix_test_bit(nr,addr) \ 333 test_le_bit(nr, (unsigned long *)addr) 334 335#define minix_find_first_zero_bit(addr,size) \ 336 find_first_zero_le_bit((unsigned long *)addr, size) 337 338#include <asm-generic/bitops/sched.h> 339 340#endif /* __KERNEL__ */ 341 342#endif /* _ASM_POWERPC_BITOPS_H */ 343