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 <[email protected]>
Signed-off-by: Vipul Kumar <[email protected]>
[[email protected] ported to upstream kernel, rewrote commit msg]
Signed-off-by: Andrey Smirnov <[email protected]>
Reviewed-by: Horia Geantă <[email protected]>
Cc: Chris Healy <[email protected]>
Cc: Lucas Stach <[email protected]>
Cc: Horia Geantă <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Iuliana Prodan <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
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