diff options
| author | Johannes Berg <johannes.berg@intel.com> | 2022-10-10 11:03:31 +0200 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2022-10-10 11:03:43 +0200 |
| commit | dfd2d876b3fda1790bc0239ba4c6967e25d16e91 (patch) | |
| tree | 45c2ec4b25afdf7b521dec642f6b75112bb401a3 /include/linux/once.h | |
| parent | a790cc3a4fad75048295571a350b95b87e022a5a (diff) | |
| parent | 10d5ea5a436da8d60cdb5845f454d595accdbce0 (diff) | |
Merge remote-tracking branch 'wireless/main' into wireless-next
Pull in wireless/main content since some new code would
otherwise conflict with it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'include/linux/once.h')
| -rw-r--r-- | include/linux/once.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/include/linux/once.h b/include/linux/once.h index b14d8b309d52..bc714d414448 100644 --- a/include/linux/once.h +++ b/include/linux/once.h @@ -5,10 +5,18 @@ #include <linux/types.h> #include <linux/jump_label.h> +/* Helpers used from arbitrary contexts. + * Hard irqs are blocked, be cautious. + */ bool __do_once_start(bool *done, unsigned long *flags); void __do_once_done(bool *done, struct static_key_true *once_key, unsigned long *flags, struct module *mod); +/* Variant for process contexts only. */ +bool __do_once_sleepable_start(bool *done); +void __do_once_sleepable_done(bool *done, struct static_key_true *once_key, + struct module *mod); + /* Call a function exactly once. The idea of DO_ONCE() is to perform * a function call such as initialization of random seeds, etc, only * once, where DO_ONCE() can live in the fast-path. After @func has @@ -52,7 +60,27 @@ void __do_once_done(bool *done, struct static_key_true *once_key, ___ret; \ }) +/* Variant of DO_ONCE() for process/sleepable contexts. */ +#define DO_ONCE_SLEEPABLE(func, ...) \ + ({ \ + bool ___ret = false; \ + static bool __section(".data.once") ___done = false; \ + static DEFINE_STATIC_KEY_TRUE(___once_key); \ + if (static_branch_unlikely(&___once_key)) { \ + ___ret = __do_once_sleepable_start(&___done); \ + if (unlikely(___ret)) { \ + func(__VA_ARGS__); \ + __do_once_sleepable_done(&___done, &___once_key,\ + THIS_MODULE); \ + } \ + } \ + ___ret; \ + }) + #define get_random_once(buf, nbytes) \ DO_ONCE(get_random_bytes, (buf), (nbytes)) +#define get_random_sleepable_once(buf, nbytes) \ + DO_ONCE_SLEEPABLE(get_random_bytes, (buf), (nbytes)) + #endif /* _LINUX_ONCE_H */ |