aboutsummaryrefslogtreecommitdiff
path: root/drivers/char/hw_random/via-rng.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2008-01-25 08:38:25 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2008-01-25 08:38:25 -0800
commiteba0e319c12fb098d66316a8eafbaaa9174a07c3 (patch)
treeb2703117db9e36bb3510654efd55361f61c54742 /drivers/char/hw_random/via-rng.c
parentdf8dc74e8a383eaf2d9b44b80a71ec6f0e52b42e (diff)
parent15e7b4452b72ae890f2fcb027b4c4fa63a1c9a7a (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (125 commits) [CRYPTO] twofish: Merge common glue code [CRYPTO] hifn_795x: Fixup container_of() usage [CRYPTO] cast6: inline bloat-- [CRYPTO] api: Set default CRYPTO_MINALIGN to unsigned long long [CRYPTO] tcrypt: Make xcbc available as a standalone test [CRYPTO] xcbc: Remove bogus hash/cipher test [CRYPTO] xcbc: Fix algorithm leak when block size check fails [CRYPTO] tcrypt: Zero axbuf in the right function [CRYPTO] padlock: Only reset the key once for each CBC and ECB operation [CRYPTO] api: Include sched.h for cond_resched in scatterwalk.h [CRYPTO] salsa20-asm: Remove unnecessary dependency on CRYPTO_SALSA20 [CRYPTO] tcrypt: Add select of AEAD [CRYPTO] salsa20: Add x86-64 assembly version [CRYPTO] salsa20_i586: Salsa20 stream cipher algorithm (i586 version) [CRYPTO] gcm: Introduce rfc4106 [CRYPTO] api: Show async type [CRYPTO] chainiv: Avoid lock spinning where possible [CRYPTO] seqiv: Add select AEAD in Kconfig [CRYPTO] scatterwalk: Handle zero nbytes in scatterwalk_map_and_copy [CRYPTO] null: Allow setkey on digest_null ...
Diffstat (limited to 'drivers/char/hw_random/via-rng.c')
-rw-r--r--drivers/char/hw_random/via-rng.c19
1 files changed, 12 insertions, 7 deletions
diff --git a/drivers/char/hw_random/via-rng.c b/drivers/char/hw_random/via-rng.c
index ec435cb25c4..868e39fd42e 100644
--- a/drivers/char/hw_random/via-rng.c
+++ b/drivers/char/hw_random/via-rng.c
@@ -27,6 +27,7 @@
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/hw_random.h>
+#include <linux/delay.h>
#include <asm/io.h>
#include <asm/msr.h>
#include <asm/cpufeature.h>
@@ -77,10 +78,11 @@ static inline u32 xstore(u32 *addr, u32 edx_in)
return eax_out;
}
-static int via_rng_data_present(struct hwrng *rng)
+static int via_rng_data_present(struct hwrng *rng, int wait)
{
u32 bytes_out;
u32 *via_rng_datum = (u32 *)(&rng->priv);
+ int i;
/* We choose the recommended 1-byte-per-instruction RNG rate,
* for greater randomness at the expense of speed. Larger
@@ -95,12 +97,15 @@ static int via_rng_data_present(struct hwrng *rng)
* completes.
*/
- *via_rng_datum = 0; /* paranoia, not really necessary */
- bytes_out = xstore(via_rng_datum, VIA_RNG_CHUNK_1);
- bytes_out &= VIA_XSTORE_CNT_MASK;
- if (bytes_out == 0)
- return 0;
- return 1;
+ for (i = 0; i < 20; i++) {
+ *via_rng_datum = 0; /* paranoia, not really necessary */
+ bytes_out = xstore(via_rng_datum, VIA_RNG_CHUNK_1);
+ bytes_out &= VIA_XSTORE_CNT_MASK;
+ if (bytes_out || !wait)
+ break;
+ udelay(10);
+ }
+ return bytes_out ? 1 : 0;
}
static int via_rng_data_read(struct hwrng *rng, u32 *data)