include/asm-generic/bitops/instrumented-lock.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 /*
   4  * This file provides wrappers with sanitizer instrumentation for bit
   5  * locking operations.
   6  *
   7  * To use this functionality, an arch's bitops.h file needs to define each of
   8  * the below bit operations with an arch_ prefix (e.g. arch_set_bit(),
   9  * arch___set_bit(), etc.).
  10  */
  11 #ifndef _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H
  12 #define _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H
  13
  14 #include <linux/instrumented.h>
  15
  16 /**
  17  * clear_bit_unlock - Clear a bit in memory, for unlock
  18  * @nr: the bit to set
  19  * @addr: the address to start counting from
  20  *
  21  * This operation is atomic and provides release barrier semantics.
  22  */
  23 static inline void clear_bit_unlock(long nr, volatile unsigned long *addr)
  24 {
  25         instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long));
  26         arch_clear_bit_unlock(nr, addr);
  27 }
  28
  29 /**
  30  * __clear_bit_unlock - Clears a bit in memory
  31  * @nr: Bit to clear
  32  * @addr: Address to start counting from
  33  *
  34  * This is a non-atomic operation but implies a release barrier before the
  35  * memory operation. It can be used for an unlock if no other CPUs can
  36  * concurrently modify other bits in the word.
  37  */
  38 static inline void __clear_bit_unlock(long nr, volatile unsigned long *addr)
  39 {
  40         instrument_write(addr + BIT_WORD(nr), sizeof(long));
  41         arch___clear_bit_unlock(nr, addr);
  42 }
  43
  44 /**
  45  * test_and_set_bit_lock - Set a bit and return its old value, for lock
  46  * @nr: Bit to set
  47  * @addr: Address to count from
  48  *
  49  * This operation is atomic and provides acquire barrier semantics if
  50  * the returned value is 0.
  51  * It can be used to implement bit locks.
  52  */
  53 static inline bool test_and_set_bit_lock(long nr, volatile unsigned long *addr)
  54 {
  55         instrument_atomic_read_write(addr + BIT_WORD(nr), sizeof(long));
  56         return arch_test_and_set_bit_lock(nr, addr);
  57 }
  58
  59 #if defined(arch_clear_bit_unlock_is_negative_byte)
  60 /**
  61  * clear_bit_unlock_is_negative_byte - Clear a bit in memory and test if bottom
  62  *                                     byte is negative, for unlock.
  63  * @nr: the bit to clear
  64  * @addr: the address to start counting from
  65  *
  66  * This operation is atomic and provides release barrier semantics.
  67  *
  68  * This is a bit of a one-trick-pony for the filemap code, which clears
  69  * PG_locked and tests PG_waiters,
  70  */
  71 static inline bool
  72 clear_bit_unlock_is_negative_byte(long nr, volatile unsigned long *addr)
  73 {
  74         instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long));
  75         return arch_clear_bit_unlock_is_negative_byte(nr, addr);
  76 }
  77 /* Let everybody know we have it. */
  78 #define clear_bit_unlock_is_negative_byte clear_bit_unlock_is_negative_byte
  79 #endif
  80
  81 #endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H */