summaryrefslogtreecommitdiff
path: root/include/asm-generic/bitops/instrumented-lock.h
diff options
context:
space:
mode:
authorRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2024-03-26 12:08:35 +0000
committerRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2024-03-26 12:08:35 +0000
commitf843bc9bc952bdeb21586ee921d29f5c2ae5a863 (patch)
tree05daf639c7add0e0fcb94f65143f10d7d87bd0b5 /include/asm-generic/bitops/instrumented-lock.h
parent3c688a55831db128cc709396992886396d4f1654 (diff)
parent3d5a640ecf92e4c8d6e157849217b68984a819bc (diff)
Merge branches 'sa1100-for-next' and 'unstable/sa11x0-asoc' into sa1100
Diffstat (limited to 'include/asm-generic/bitops/instrumented-lock.h')
-rw-r--r--include/asm-generic/bitops/instrumented-lock.h28
1 files changed, 13 insertions, 15 deletions
diff --git a/include/asm-generic/bitops/instrumented-lock.h b/include/asm-generic/bitops/instrumented-lock.h
index eb64bd4f11f3..542d3727ee4e 100644
--- a/include/asm-generic/bitops/instrumented-lock.h
+++ b/include/asm-generic/bitops/instrumented-lock.h
@@ -58,27 +58,25 @@ static inline bool test_and_set_bit_lock(long nr, volatile unsigned long *addr)
return arch_test_and_set_bit_lock(nr, addr);
}
-#if defined(arch_clear_bit_unlock_is_negative_byte)
/**
- * clear_bit_unlock_is_negative_byte - Clear a bit in memory and test if bottom
- * byte is negative, for unlock.
- * @nr: the bit to clear
- * @addr: the address to start counting from
+ * xor_unlock_is_negative_byte - XOR a single byte in memory and test if
+ * it is negative, for unlock.
+ * @mask: Change the bits which are set in this mask.
+ * @addr: The address of the word containing the byte to change.
*
+ * Changes some of bits 0-6 in the word pointed to by @addr.
* This operation is atomic and provides release barrier semantics.
+ * Used to optimise some folio operations which are commonly paired
+ * with an unlock or end of writeback. Bit 7 is used as PG_waiters to
+ * indicate whether anybody is waiting for the unlock.
*
- * This is a bit of a one-trick-pony for the filemap code, which clears
- * PG_locked and tests PG_waiters,
+ * Return: Whether the top bit of the byte is set.
*/
-static inline bool
-clear_bit_unlock_is_negative_byte(long nr, volatile unsigned long *addr)
+static inline bool xor_unlock_is_negative_byte(unsigned long mask,
+ volatile unsigned long *addr)
{
kcsan_release();
- instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long));
- return arch_clear_bit_unlock_is_negative_byte(nr, addr);
+ instrument_atomic_write(addr, sizeof(long));
+ return arch_xor_unlock_is_negative_byte(mask, addr);
}
-/* Let everybody know we have it. */
-#define clear_bit_unlock_is_negative_byte clear_bit_unlock_is_negative_byte
-#endif
-
#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H */