random: allow architectures to optionally define random_get_entropy()
authorTheodore Ts'o <tytso@mit.edu>
Sat, 21 Sep 2013 17:58:22 +0000 (13:58 -0400)
committerTheodore Ts'o <tytso@mit.edu>
Thu, 10 Oct 2013 18:30:53 +0000 (14:30 -0400)
commit61875f30daf60305712e25b209ef41ced2635bad
tree176cda3ae729c520bff1b0f6a19806c18c0a7523
parent47d06e532e95b71c0db3839ebdef3fe8812fca2c
random: allow architectures to optionally define random_get_entropy()

Allow architectures which have a disabled get_cycles() function to
provide a random_get_entropy() function which provides a fine-grained,
rapidly changing counter that can be used by the /dev/random driver.

For example, an architecture might have a rapidly changing register
used to control random TLB cache eviction, or DRAM refresh that
doesn't meet the requirements of get_cycles(), but which is good
enough for the needs of the random driver.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
drivers/char/random.c
include/linux/timex.h