Re: [PATCH 2/2] ath9k: export HW random number generator

[Oleksij Rempel <linux@rempel-privat.de>]

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Hi all,

i did rngtest on top of this patch. The results are incredibly bad,
right now it is more a pattern generator not random number generator. Is
it possible to fix it?

/home/lex# cat /dev/hwrng | rngtest -c 1000
rngtest 5
Copyright (c) 2004 by Henrique de Moraes Holschuh
This is free software; see the source for copying conditions.  There is
NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE.

rngtest: starting FIPS tests...
rngtest: bits received from input: 20000032
rngtest: FIPS 140-2 successes: 0
rngtest: FIPS 140-2 failures: 1000
rngtest: FIPS 140-2(2001-10-10) Monobit: 27
rngtest: FIPS 140-2(2001-10-10) Poker: 1000
rngtest: FIPS 140-2(2001-10-10) Runs: 1000
rngtest: FIPS 140-2(2001-10-10) Long run: 2
rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
rngtest: input channel speed: (min=1.879; avg=871.897;
max=19531250.000)Kibits/s
rngtest: FIPS tests speed: (min=19.443; avg=48.374; max=70.123)Mibits/s
rngtest: Program run time: 23423736 microseconds



Am 15.07.2015 um 09:54 schrieb miaoqing@qti.qualcomm.com:
> From: Miaoqing Pan <miaoqing@qca.qualcomm.com>
> 
> We measured the FFT-based entropy in 3 ways, Shannon entropy,
> collision entropy, and directly measured min-entropy. Just to
> be conservative, we recommend the estimated min-Entropy to be
> 10 bits per 16-bit value.
> 
> Analysis was done by Jacobson,David(djacobso@qti.qualcomm.com).
> 
> Signed-off-by: Miaoqing Pan <miaoqing@qca.qualcomm.com>
> ---
>  drivers/net/wireless/ath/ath9k/Kconfig  |  7 +++
>  drivers/net/wireless/ath/ath9k/Makefile |  1 +
>  drivers/net/wireless/ath/ath9k/ath9k.h  | 23 ++++++++++
>  drivers/net/wireless/ath/ath9k/main.c   |  4 ++
>  drivers/net/wireless/ath/ath9k/rng.c    | 75 +++++++++++++++++++++++++++++++++
>  5 files changed, 110 insertions(+)
>  create mode 100644 drivers/net/wireless/ath/ath9k/rng.c
> 
> diff --git a/drivers/net/wireless/ath/ath9k/Kconfig b/drivers/net/wireless/ath/ath9k/Kconfig
> index fee0cad..bde62ec9 100644
> --- a/drivers/net/wireless/ath/ath9k/Kconfig
> +++ b/drivers/net/wireless/ath/ath9k/Kconfig
> @@ -176,3 +176,10 @@ config ATH9K_HTC_DEBUGFS
>  	depends on ATH9K_HTC && DEBUG_FS
>  	---help---
>  	  Say Y, if you need access to ath9k_htc's statistics.
> +
> +config ATH9K_HWRNG
> +	bool "Random number generator support"
> +	depends on ATH9K && (HW_RANDOM = y || HW_RANDOM = ATH9K)
> +	default y
> +	---help---
> +	  Provides a hardware random number generator to the kernel.
> diff --git a/drivers/net/wireless/ath/ath9k/Makefile b/drivers/net/wireless/ath/ath9k/Makefile
> index ecda613..76f9dc3 100644
> --- a/drivers/net/wireless/ath/ath9k/Makefile
> +++ b/drivers/net/wireless/ath/ath9k/Makefile
> @@ -15,6 +15,7 @@ ath9k-$(CONFIG_ATH9K_DFS_DEBUGFS) += dfs_debug.o
>  ath9k-$(CONFIG_ATH9K_DFS_CERTIFIED) += dfs.o
>  ath9k-$(CONFIG_ATH9K_TX99) += tx99.o
>  ath9k-$(CONFIG_ATH9K_WOW) += wow.o
> +ath9k-$(CONFIG_ATH9K_HWRNG) += rng.o
>  
>  ath9k-$(CONFIG_ATH9K_DEBUGFS) += debug.o
>  
> diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
> index a7a81b3..45596e5 100644
> --- a/drivers/net/wireless/ath/ath9k/ath9k.h
> +++ b/drivers/net/wireless/ath/ath9k/ath9k.h
> @@ -23,6 +23,7 @@
>  #include <linux/leds.h>
>  #include <linux/completion.h>
>  #include <linux/time.h>
> +#include <linux/hw_random.h>
>  
>  #include "common.h"
>  #include "debug.h"
> @@ -1041,6 +1042,12 @@ struct ath_softc {
>  	u32 wow_intr_before_sleep;
>  	bool force_wow;
>  #endif
> +
> +#ifdef CONFIG_ATH9K_HWRNG
> +	struct hwrng rng;
> +	bool rng_initialized;
> +	u32 rng_last;
> +#endif
>  };
>  
>  /********/
> @@ -1063,6 +1070,22 @@ static inline int ath9k_tx99_send(struct ath_softc *sc,
>  }
>  #endif /* CONFIG_ATH9K_TX99 */
>  
> +/***************************/
> +/* Random Number Generator */
> +/***************************/
> +#ifdef CONFIG_ATH9K_HWRNG
> +void ath9k_rng_register(struct ath_softc *sc);
> +void ath9k_rng_unregister(struct ath_softc *sc);
> +#else
> +static inline void ath9k_rng_register(struct ath_softc *sc)
> +{
> +}
> +
> +static inline void ath9k_rng_unregister(struct ath_softc *sc)
> +{
> +}
> +#endif
> +
>  static inline void ath_read_cachesize(struct ath_common *common, int *csz)
>  {
>  	common->bus_ops->read_cachesize(common, csz);
> diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
> index cfd45cb..5916ab2 100644
> --- a/drivers/net/wireless/ath/ath9k/main.c
> +++ b/drivers/net/wireless/ath/ath9k/main.c
> @@ -739,6 +739,8 @@ static int ath9k_start(struct ieee80211_hw *hw)
>  
>  	ath9k_ps_restore(sc);
>  
> +	ath9k_rng_register(sc);
> +
>  	return 0;
>  }
>  
> @@ -828,6 +830,8 @@ static void ath9k_stop(struct ieee80211_hw *hw)
>  
>  	ath9k_deinit_channel_context(sc);
>  
> +	ath9k_rng_unregister(sc);
> +
>  	mutex_lock(&sc->mutex);
>  
>  	ath_cancel_work(sc);
> diff --git a/drivers/net/wireless/ath/ath9k/rng.c b/drivers/net/wireless/ath/ath9k/rng.c
> new file mode 100644
> index 0000000..d8fa7a5
> --- /dev/null
> +++ b/drivers/net/wireless/ath/ath9k/rng.c
> @@ -0,0 +1,75 @@
> +/*
> + * Copyright (c) 2015 Qualcomm Atheros, Inc.
> + *
> + * Permission to use, copy, modify, and/or distribute this software for any
> + * purpose with or without fee is hereby granted, provided that the above
> + * copyright notice and this permission notice appear in all copies.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
> + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
> + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
> + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
> + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
> + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
> + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
> + */
> +
> +#include "ath9k.h"
> +#include "hw.h"
> +#include "ar9003_phy.h"
> +
> +static int ath9k_rng_data_read(struct hwrng *rng, u32 *data)
> +{
> +	u32 v1, v2;
> +	struct ath_softc *sc = (struct ath_softc *)rng->priv;
> +	struct ath_hw *ah = sc->sc_ah;
> +
> +	ath9k_ps_wakeup(sc);
> +
> +	REG_RMW_FIELD(ah, AR_PHY_TEST, AR_PHY_TEST_BBB_OBS_SEL, 5);
> +	REG_CLR_BIT(ah, AR_PHY_TEST, AR_PHY_TEST_RX_OBS_SEL_BIT5);
> +	REG_RMW_FIELD(ah, AR_PHY_TEST_CTL_STATUS, AR_PHY_TEST_CTL_RX_OBS_SEL, 0);
> +
> +	v1 = REG_READ(ah, AR_PHY_TST_ADC);
> +	v2 = REG_READ(ah, AR_PHY_TST_ADC);
> +
> +	ath9k_ps_restore(sc);
> +
> +	/* wait for data ready */
> +	if (v1 && v2 && sc->rng_last != v1 && v1 != v2) {
> +		*data = (v1 & 0xffff) | (v2 << 16);
> +		sc->rng_last = v2;
> +
> +		return sizeof(u32);
> +	}
> +
> +	sc->rng_last = v2;
> +
> +	return 0;
> +}
> +
> +void ath9k_rng_register(struct ath_softc *sc)
> +{
> +	struct ath_hw *ah = sc->sc_ah;
> +
> +	if (WARN_ON(sc->rng_initialized))
> +		return;
> +
> +	if (!AR_SREV_9300_20_OR_LATER(ah))
> +		return;
> +
> +	sc->rng.name = "ath9k";
> +	sc->rng.data_read = ath9k_rng_data_read;
> +	sc->rng.priv = (unsigned long)sc;
> +
> +	if (!hwrng_register(&sc->rng))
> +		sc->rng_initialized = true;
> +}
> +
> +void ath9k_rng_unregister(struct ath_softc *sc)
> +{
> +	if (sc->rng_initialized) {
> +		hwrng_unregister(&sc->rng);
> +		sc->rng_initialized = false;
> +	}
> +}
> 


-- 
Regards,
Oleksij


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