summaryrefslogtreecommitdiffstats
path: root/drivers
diff options
context:
space:
mode:
authorAndrey Smirnov <andrew.smirnov@gmail.com>2020-03-19 09:12:30 -0700
committerHerbert Xu <herbert@gondor.apana.org.au>2020-03-30 11:50:49 +1100
commit551ce72a78e2c5493fa987410437e54b5f3fdd34 (patch)
tree765448391f437ff004f71d84fe27d6c2d78a9a3e /drivers
parent32107e43b505de44ebe1917da2c8c6229acbd509 (diff)
downloadlinux-551ce72a78e2c5493fa987410437e54b5f3fdd34.tar.gz
linux-551ce72a78e2c5493fa987410437e54b5f3fdd34.tar.bz2
linux-551ce72a78e2c5493fa987410437e54b5f3fdd34.zip
crypto: caam - invalidate entropy register during RNG initialization
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 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/crypto/caam/ctrl.c11
-rw-r--r--drivers/crypto/caam/regs.h3
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 @@ start_rng:
* 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 */