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From: Andrey Smirnov <andrew.smirnov@gmail.com>
To: linux-crypto@vger.kernel.org
Cc: "Andrey Smirnov" <andrew.smirnov@gmail.com>,
	"Aymen Sghaier" <aymen.sghaier@nxp.com>,
	"Vipul Kumar" <vipul_kumar@mentor.com>,
	"Horia Geantă" <horia.geanta@nxp.com>,
	"Chris Healy" <cphealy@gmail.com>,
	"Lucas Stach" <l.stach@pengutronix.de>,
	"Herbert Xu" <herbert@gondor.apana.org.au>,
	"Iuliana Prodan" <iuliana.prodan@nxp.com>,
	linux-kernel@vger.kernel.org, linux-imx@nxp.com
Subject: [PATCH v8 6/8] crypto: caam - invalidate entropy register during RNG initialization
Date: Mon, 16 Mar 2020 08:00:45 -0700	[thread overview]
Message-ID: <20200316150047.30828-7-andrew.smirnov@gmail.com> (raw)
In-Reply-To: <20200316150047.30828-1-andrew.smirnov@gmail.com>

In order to make sure that we always use non-stale entropy data, change
the code to invalidate entropy register during RNG initialization.

Signed-off-by: Aymen Sghaier <aymen.sghaier@nxp.com>
Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>
[andrew.smirnov@gmail.com ported to upstream kernel, rewrote commit msg]
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Horia Geantă <horia.geanta@nxp.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Iuliana Prodan <iuliana.prodan@nxp.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-imx@nxp.com
---
 drivers/crypto/caam/ctrl.c | 11 ++++++++---
 drivers/crypto/caam/regs.h |  3 ++-
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c
index 7f7f2960b0cc..b278471f4013 100644
--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -341,8 +341,12 @@ static void kick_trng(struct platform_device *pdev, int ent_delay)
 	ctrl = (struct caam_ctrl __iomem *)ctrlpriv->ctrl;
 	r4tst = &ctrl->r4tst[0];
 
-	/* put RNG4 into program mode */
-	clrsetbits_32(&r4tst->rtmctl, 0, RTMCTL_PRGM);
+	/*
+	 * Setting both RTMCTL:PRGM and RTMCTL:TRNG_ACC causes TRNG to
+	 * properly invalidate the entropy in the entropy register and
+	 * force re-generation.
+	 */
+	clrsetbits_32(&r4tst->rtmctl, 0, RTMCTL_PRGM | RTMCTL_ACC);
 
 	/*
 	 * Performance-wise, it does not make sense to
@@ -372,7 +376,8 @@ static void kick_trng(struct platform_device *pdev, int ent_delay)
 	 * select raw sampling in both entropy shifter
 	 * and statistical checker; ; put RNG4 into run mode
 	 */
-	clrsetbits_32(&r4tst->rtmctl, RTMCTL_PRGM, RTMCTL_SAMP_MODE_RAW_ES_SC);
+	clrsetbits_32(&r4tst->rtmctl, RTMCTL_PRGM | RTMCTL_ACC,
+		      RTMCTL_SAMP_MODE_RAW_ES_SC);
 }
 
 static int caam_get_era_from_hw(struct caam_ctrl __iomem *ctrl)
diff --git a/drivers/crypto/caam/regs.h b/drivers/crypto/caam/regs.h
index 05127b70527d..c191e8fd0fa7 100644
--- a/drivers/crypto/caam/regs.h
+++ b/drivers/crypto/caam/regs.h
@@ -487,7 +487,8 @@ struct rngtst {
 
 /* RNG4 TRNG test registers */
 struct rng4tst {
-#define RTMCTL_PRGM	0x00010000	/* 1 -> program mode, 0 -> run mode */
+#define RTMCTL_ACC  BIT(5)  /* TRNG access mode */
+#define RTMCTL_PRGM BIT(16) /* 1 -> program mode, 0 -> run mode */
 #define RTMCTL_SAMP_MODE_VON_NEUMANN_ES_SC	0 /* use von Neumann data in
 						     both entropy shifter and
 						     statistical checker */
-- 
2.21.0


  parent reply	other threads:[~2020-03-16 15:01 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-16 15:00 [PATCH v8 0/8] enable CAAM's HWRNG as default Andrey Smirnov
2020-03-16 15:00 ` [PATCH v8 1/8] crypto: caam - allocate RNG instantiation descriptor with GFP_DMA Andrey Smirnov
2020-03-17 15:22   ` Horia Geantă
2020-03-16 15:00 ` [PATCH v8 2/8] crypto: caam - use struct hwrng's .init for initialization Andrey Smirnov
2020-03-16 15:00 ` [PATCH v8 3/8] crypto: caam - drop global context pointer and init_done Andrey Smirnov
2020-03-17 16:45   ` Horia Geantă
2020-03-19 13:00     ` Andrey Smirnov
2020-03-16 15:00 ` [PATCH v8 4/8] crypto: caam - simplify RNG implementation Andrey Smirnov
2020-03-17 21:37   ` Horia Geantă
2020-03-17 21:58   ` Horia Geantă
2020-03-19 13:07     ` Andrey Smirnov
2020-03-16 15:00 ` [PATCH v8 5/8] crypto: caam - check if RNG job failed Andrey Smirnov
2020-03-17 17:09   ` Horia Geantă
2020-03-16 15:00 ` Andrey Smirnov [this message]
2020-03-16 15:00 ` [PATCH v8 7/8] crypto: caam - enable prediction resistance in HRWNG Andrey Smirnov
2020-03-17 17:41   ` Horia Geantă
2020-03-17 17:59   ` Horia Geantă
2020-03-16 15:00 ` [PATCH v8 8/8] crypto: caam - limit single JD RNG output to maximum of 16 bytes Andrey Smirnov
2020-03-17 21:56   ` Horia Geantă
2020-03-17 11:16 ` [PATCH v8 0/8] enable CAAM's HWRNG as default Horia Geantă

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