diff options
| author | Patrick McHardy <kaber@trash.net> | 2007-11-21 07:24:45 +0300 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2008-01-11 00:16:16 +0300 |
| commit | 984e976f5382ff09351ddd3b023937611396d739 (patch) | |
| tree | 2fcce0de19b06547772f015b8409efc3d2c8d52a /drivers/char/hw_random/via-rng.c | |
| parent | 2407d60872dd2a95404c6048f775f3b64d438f4b (diff) | |
| download | linux-984e976f5382ff09351ddd3b023937611396d739.tar.xz | |
[HWRNG]: move status polling loop to data_present callbacks
Handle waiting for new random within the drivers themselves, this allows to
use better suited timeouts for the individual rngs.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/char/hw_random/via-rng.c')
| -rw-r--r-- | drivers/char/hw_random/via-rng.c | 19 |
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 ec435cb25c4f..868e39fd42e4 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) |