[PATCH] ARM: omap2: throw the die id into the entropy pool
Linus Walleij
linus.walleij at linaro.org
Wed Sep 4 16:25:24 EDT 2013
Atleast eight bytes of this number are totally unique for the device
it seems, so this is a perfect candidate for feeding the entropy
pool. One byte more or less of constants does not matter so feed in
the entire OID struct.
Cc: Theodore Ts'o <tytso at mit.edu>
Cc: Paul Walmsley <paul at pwsan.com>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
arch/arm/mach-omap2/id.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/arch/arm/mach-omap2/id.c b/arch/arm/mach-omap2/id.c
index 2dc62a2..fc03cc6 100644
--- a/arch/arm/mach-omap2/id.c
+++ b/arch/arm/mach-omap2/id.c
@@ -18,6 +18,7 @@
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
+#include <linux/random.h>
#include <linux/slab.h>
#ifdef CONFIG_SOC_BUS
@@ -130,6 +131,17 @@ void omap_get_die_id(struct omap_die_id *odi)
odi->id_3 = read_tap_reg(OMAP_TAP_DIE_ID_3);
}
+static int __init omap_feed_randpool(void)
+{
+ struct omap_die_id odi;
+
+ /* Throw the die ID into the entropy pool at boot */
+ omap_get_die_id(&odi);
+ add_device_randomness(&odi, sizeof(odi));
+ return 0;
+}
+device_initcall(omap_feed_randpool);
+
void __init omap2xxx_check_revision(void)
{
int i, j;
--
1.8.1.4
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