arch/powerpc/include/asm/bitops.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * PowerPC atomic bit operations.
   4  *
   5  * Merged version by David Gibson <david@gibson.dropbear.id.au>.
   6  * Based on ppc64 versions by: Dave Engebretsen, Todd Inglett, Don
   7  * Reed, Pat McCarthy, Peter Bergner, Anton Blanchard.  They
   8  * originally took it from the ppc32 code.
   9  *
  10  * Within a word, bits are numbered LSB first.  Lot's of places make
  11  * this assumption by directly testing bits with (val & (1<<nr)).
  12  * This can cause confusion for large (> 1 word) bitmaps on a
  13  * big-endian system because, unlike little endian, the number of each
  14  * bit depends on the word size.
  15  *
  16  * The bitop functions are defined to work on unsigned longs, so for a
  17  * ppc64 system the bits end up numbered:
  18  *   |63..............0|127............64|191...........128|255...........192|
  19  * and on ppc32:
  20  *   |31.....0|63....32|95....64|127...96|159..128|191..160|223..192|255..224|
  21  *
  22  * There are a few little-endian macros used mostly for filesystem
  23  * bitmaps, these work on similar bit arrays layouts, but
  24  * byte-oriented:
  25  *   |7...0|15...8|23...16|31...24|39...32|47...40|55...48|63...56|
  26  *
  27  * The main difference is that bit 3-5 (64b) or 3-4 (32b) in the bit
  28  * number field needs to be reversed compared to the big-endian bit
  29  * fields. This can be achieved by XOR with 0x38 (64b) or 0x18 (32b).
  30  */
  31
  32 #ifndef _ASM_POWERPC_BITOPS_H
  33 #define _ASM_POWERPC_BITOPS_H
  34
  35 #ifdef __KERNEL__
  36
  37 #ifndef _LINUX_BITOPS_H
  38 #error only <linux/bitops.h> can be included directly
  39 #endif
  40
  41 #include <linux/compiler.h>
  42 #include <asm/asm-compat.h>
  43 #include <asm/synch.h>
  44 #include <asm/asm-405.h>
  45
  46 /* PPC bit number conversion */
  47 #define PPC_BITLSHIFT(be)       (BITS_PER_LONG - 1 - (be))
  48 #define PPC_BIT(bit)            (1UL << PPC_BITLSHIFT(bit))
  49 #define PPC_BITMASK(bs, be)     ((PPC_BIT(bs) - PPC_BIT(be)) | PPC_BIT(bs))
  50
  51 /* Put a PPC bit into a "normal" bit position */
  52 #define PPC_BITEXTRACT(bits, ppc_bit, dst_bit)                  \
  53         ((((bits) >> PPC_BITLSHIFT(ppc_bit)) & 1) << (dst_bit))
  54
  55 #define PPC_BITLSHIFT32(be)     (32 - 1 - (be))
  56 #define PPC_BIT32(bit)          (1UL << PPC_BITLSHIFT32(bit))
  57 #define PPC_BITMASK32(bs, be)   ((PPC_BIT32(bs) - PPC_BIT32(be))|PPC_BIT32(bs))
  58
  59 #define PPC_BITLSHIFT8(be)      (8 - 1 - (be))
  60 #define PPC_BIT8(bit)           (1UL << PPC_BITLSHIFT8(bit))
  61 #define PPC_BITMASK8(bs, be)    ((PPC_BIT8(bs) - PPC_BIT8(be))|PPC_BIT8(bs))
  62
  63 #include <asm/barrier.h>
  64
  65 /* Macro for generating the ***_bits() functions */
  66 #define DEFINE_BITOP(fn, op, prefix)            \
  67 static __inline__ void fn(unsigned long mask,   \
  68                 volatile unsigned long *_p)     \
  69 {                                               \
  70         unsigned long old;                      \
  71         unsigned long *p = (unsigned long *)_p; \
  72         __asm__ __volatile__ (                  \
  73         prefix                                  \
  74 "1:"    PPC_LLARX(%0,0,%3,0) "\n"               \
  75         stringify_in_c(op) "%0,%0,%2\n"         \
  76         PPC405_ERR77(0,%3)                      \
  77         PPC_STLCX "%0,0,%3\n"                   \
  78         "bne- 1b\n"                             \
  79         : "=&r" (old), "+m" (*p)                \
  80         : "r" (mask), "r" (p)                   \
  81         : "cc", "memory");                      \
  82 }
  83
  84 DEFINE_BITOP(set_bits, or, "")
  85 DEFINE_BITOP(clear_bits, andc, "")
  86 DEFINE_BITOP(clear_bits_unlock, andc, PPC_RELEASE_BARRIER)
  87 DEFINE_BITOP(change_bits, xor, "")
  88
  89 static __inline__ void set_bit(int nr, volatile unsigned long *addr)
  90 {
  91         set_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
  92 }
  93
  94 static __inline__ void clear_bit(int nr, volatile unsigned long *addr)
  95 {
  96         clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
  97 }
  98
  99 static __inline__ void clear_bit_unlock(int nr, volatile unsigned long *addr)
 100 {
 101         clear_bits_unlock(BIT_MASK(nr), addr + BIT_WORD(nr));
 102 }
 103
 104 static __inline__ void change_bit(int nr, volatile unsigned long *addr)
 105 {
 106         change_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
 107 }
 108
 109 /* Like DEFINE_BITOP(), with changes to the arguments to 'op' and the output
 110  * operands. */
 111 #define DEFINE_TESTOP(fn, op, prefix, postfix, eh)      \
 112 static __inline__ unsigned long fn(                     \
 113                 unsigned long mask,                     \
 114                 volatile unsigned long *_p)             \
 115 {                                                       \
 116         unsigned long old, t;                           \
 117         unsigned long *p = (unsigned long *)_p;         \
 118         __asm__ __volatile__ (                          \
 119         prefix                                          \
 120 "1:"    PPC_LLARX(%0,0,%3,eh) "\n"                      \
 121         stringify_in_c(op) "%1,%0,%2\n"                 \
 122         PPC405_ERR77(0,%3)                              \
 123         PPC_STLCX "%1,0,%3\n"                           \
 124         "bne- 1b\n"                                     \
 125         postfix                                         \
 126         : "=&r" (old), "=&r" (t)                        \
 127         : "r" (mask), "r" (p)                           \
 128         : "cc", "memory");                              \
 129         return (old & mask);                            \
 130 }
 131
 132 DEFINE_TESTOP(test_and_set_bits, or, PPC_ATOMIC_ENTRY_BARRIER,
 133               PPC_ATOMIC_EXIT_BARRIER, 0)
 134 DEFINE_TESTOP(test_and_set_bits_lock, or, "",
 135               PPC_ACQUIRE_BARRIER, 1)
 136 DEFINE_TESTOP(test_and_clear_bits, andc, PPC_ATOMIC_ENTRY_BARRIER,
 137               PPC_ATOMIC_EXIT_BARRIER, 0)
 138 DEFINE_TESTOP(test_and_change_bits, xor, PPC_ATOMIC_ENTRY_BARRIER,
 139               PPC_ATOMIC_EXIT_BARRIER, 0)
 140
 141 static __inline__ int test_and_set_bit(unsigned long nr,
 142                                        volatile unsigned long *addr)
 143 {
 144         return test_and_set_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
 145 }
 146
 147 static __inline__ int test_and_set_bit_lock(unsigned long nr,
 148                                        volatile unsigned long *addr)
 149 {
 150         return test_and_set_bits_lock(BIT_MASK(nr),
 151                                 addr + BIT_WORD(nr)) != 0;
 152 }
 153
 154 static __inline__ int test_and_clear_bit(unsigned long nr,
 155                                          volatile unsigned long *addr)
 156 {
 157         return test_and_clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
 158 }
 159
 160 static __inline__ int test_and_change_bit(unsigned long nr,
 161                                           volatile unsigned long *addr)
 162 {
 163         return test_and_change_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
 164 }
 165
 166 #ifdef CONFIG_PPC64
 167 static __inline__ unsigned long clear_bit_unlock_return_word(int nr,
 168                                                 volatile unsigned long *addr)
 169 {
 170         unsigned long old, t;
 171         unsigned long *p = (unsigned long *)addr + BIT_WORD(nr);
 172         unsigned long mask = BIT_MASK(nr);
 173
 174         __asm__ __volatile__ (
 175         PPC_RELEASE_BARRIER
 176 "1:"    PPC_LLARX(%0,0,%3,0) "\n"
 177         "andc %1,%0,%2\n"
 178         PPC405_ERR77(0,%3)
 179         PPC_STLCX "%1,0,%3\n"
 180         "bne- 1b\n"
 181         : "=&r" (old), "=&r" (t)
 182         : "r" (mask), "r" (p)
 183         : "cc", "memory");
 184
 185         return old;
 186 }
 187
 188 /* This is a special function for mm/filemap.c */
 189 #define clear_bit_unlock_is_negative_byte(nr, addr)                     \
 190         (clear_bit_unlock_return_word(nr, addr) & BIT_MASK(PG_waiters))
 191
 192 #endif /* CONFIG_PPC64 */
 193
 194 #include <asm-generic/bitops/non-atomic.h>
 195
 196 static __inline__ void __clear_bit_unlock(int nr, volatile unsigned long *addr)
 197 {
 198         __asm__ __volatile__(PPC_RELEASE_BARRIER "" ::: "memory");
 199         __clear_bit(nr, addr);
 200 }
 201
 202 /*
 203  * Return the zero-based bit position (LE, not IBM bit numbering) of
 204  * the most significant 1-bit in a double word.
 205  */
 206 #define __ilog2(x)      ilog2(x)
 207
 208 #include <asm-generic/bitops/ffz.h>
 209
 210 #include <asm-generic/bitops/builtin-__ffs.h>
 211
 212 #include <asm-generic/bitops/builtin-ffs.h>
 213
 214 /*
 215  * fls: find last (most-significant) bit set.
 216  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 217  */
 218 static __inline__ int fls(unsigned int x)
 219 {
 220         return 32 - __builtin_clz(x);
 221 }
 222
 223 #include <asm-generic/bitops/builtin-__fls.h>
 224
 225 static __inline__ int fls64(__u64 x)
 226 {
 227         return 64 - __builtin_clzll(x);
 228 }
 229
 230 #ifdef CONFIG_PPC64
 231 unsigned int __arch_hweight8(unsigned int w);
 232 unsigned int __arch_hweight16(unsigned int w);
 233 unsigned int __arch_hweight32(unsigned int w);
 234 unsigned long __arch_hweight64(__u64 w);
 235 #include <asm-generic/bitops/const_hweight.h>
 236 #else
 237 #include <asm-generic/bitops/hweight.h>
 238 #endif
 239
 240 #include <asm-generic/bitops/find.h>
 241
 242 /* Little-endian versions */
 243 #include <asm-generic/bitops/le.h>
 244
 245 /* Bitmap functions for the ext2 filesystem */
 246
 247 #include <asm-generic/bitops/ext2-atomic-setbit.h>
 248
 249 #include <asm-generic/bitops/sched.h>
 250
 251 #endif /* __KERNEL__ */
 252
 253 #endif /* _ASM_POWERPC_BITOPS_H */