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Commit 6301566e authored by Miaoqing Pan's avatar Miaoqing Pan Committed by Kalle Valo
Browse files

ath9k: export HW random number generator 



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: default avatarMiaoqing Pan <miaoqing@qca.qualcomm.com>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
parent fa5b8c8a

drivers/net/wireless/ath/ath9k/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -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.

drivers/net/wireless/ath/ath9k/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/net/wireless/ath/ath9k/ath9k.h

+23 −0
Original line number Diff line number Diff line
@@ -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);

drivers/net/wireless/ath/ath9k/main.c

+4 −0
Original line number Diff line number Diff line
@@ -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);

drivers/net/wireless/ath/ath9k/rng.c

0 → 100644
+75 −0
Original line number Diff line number Diff line 
/*

 * 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;

	}

}