diff options
| author | Linus Walleij <linus.walleij@linaro.org> | 2018-03-18 17:48:59 +0100 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2018-03-18 17:48:59 +0100 |
| commit | 95260c17b27e4bdacf85022e629fb701b42cc190 (patch) | |
| tree | cfc6963180d99e5f36752ca028821aaa109e860d /Documentation/atomic_bitops.txt | |
| parent | 4f9a4cd66c1201ce2b26ba895b2be63b8b38bb68 (diff) | |
| parent | 0c8efd610b58cb23cefdfa12015799079aef94ae (diff) | |
Merge tag 'v4.16-rc5' into devel
Linux 4.16-rc5 merged into the GPIO devel branch to resolve
a nasty conflict between fixes and devel in the RCAR driver.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'Documentation/atomic_bitops.txt')
| -rw-r--r-- | Documentation/atomic_bitops.txt | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/Documentation/atomic_bitops.txt b/Documentation/atomic_bitops.txt index 5550bfdcce5f..be70b32c95d9 100644 --- a/Documentation/atomic_bitops.txt +++ b/Documentation/atomic_bitops.txt @@ -58,7 +58,12 @@ Like with atomic_t, the rule of thumb is: - RMW operations that have a return value are fully ordered. -Except for test_and_set_bit_lock() which has ACQUIRE semantics and + - RMW operations that are conditional are unordered on FAILURE, + otherwise the above rules apply. In the case of test_and_{}_bit() operations, + if the bit in memory is unchanged by the operation then it is deemed to have + failed. + +Except for a successful test_and_set_bit_lock() which has ACQUIRE semantics and clear_bit_unlock() which has RELEASE semantics. Since a platform only has a single means of achieving atomic operations |