diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-10-10 12:31:43 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-10-10 12:31:43 -0700 |
| commit | f715729ee4cb666f51749f6cd86d06fff1e6e17b (patch) | |
| tree | cf8f2c6c2d90441d6a978915b5d7eb0b19981f44 /include/linux/timex.h | |
| parent | 8273548c5455e3ae27e905a77bad277535837329 (diff) | |
| parent | 61875f30daf60305712e25b209ef41ced2635bad (diff) | |
Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull /dev/random changes from Ted Ts'o:
"These patches are designed to enable improvements to /dev/random for
non-x86 platforms, in particular MIPS and ARM"
* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
random: allow architectures to optionally define random_get_entropy()
random: run random_int_secret_init() run after all late_initcalls
Diffstat (limited to 'include/linux/timex.h')
| -rw-r--r-- | include/linux/timex.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/timex.h b/include/linux/timex.h index dd3edd7dfc9..9d3f1a5b617 100644 --- a/include/linux/timex.h +++ b/include/linux/timex.h @@ -64,6 +64,20 @@ #include <asm/timex.h> +#ifndef random_get_entropy +/* + * The random_get_entropy() function is used by the /dev/random driver + * in order to extract entropy via the relative unpredictability of + * when an interrupt takes places versus a high speed, fine-grained + * timing source or cycle counter. Since it will be occurred on every + * single interrupt, it must have a very low cost/overhead. + * + * By default we use get_cycles() for this purpose, but individual + * architectures may override this in their asm/timex.h header file. + */ +#define random_get_entropy() get_cycles() +#endif + /* * SHIFT_PLL is used as a dampening factor to define how much we * adjust the frequency correction for a given offset in PLL mode. |