RE: [EXT] [RFC PATCH] crypto: caam - restore retry count after HW RNG failure

From: Gaurav Jain
Date: Tue Jan 18 2022 - 04:05:03 EST

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Hi Petr

Recently I have sent patches in upstream uboot for adding caam driver support.
http://patchwork.ozlabs.org/project/uboot/list/?series=280725

if possible pls add this series in uboot and try to reproduce the problem.

Problem with armv8:
ERROR: modpost: "caam_reinstantiate_rng" [drivers/crypto/caam/caam_jr.ko] undefined!
make[1]: *** [scripts/Makefile.modpost:134: modules-only.symvers] Error 1
make[1]: *** Deleting file 'modules-only.symvers'
make: *** [Makefile:1755: modules] Error 2

Regards
Gaurav Jain

> -----Original Message-----
> From: Petr Benes <petrben@xxxxxxxxx>
> Sent: Monday, January 17, 2022 7:39 PM
> To: Gaurav Jain <gaurav.jain@xxxxxxx>
> Cc: Horia Geanta <horia.geanta@xxxxxxx>; Pankaj Gupta
> <pankaj.gupta@xxxxxxx>; Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>; Michal
> Vokáč <michal.vokac@xxxxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>;
> Petr Benes <petr.benes@xxxxxxxxx>; l.stach@xxxxxxxxxxxxxx;
> robert.hancock@xxxxxxxxxx; linux-crypto@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; Varun Sethi <V.Sethi@xxxxxxx>; Vabhav Sharma
> <vabhav.sharma@xxxxxxx>
> Subject: Re: [EXT] [RFC PATCH] crypto: caam - restore retry count after HW RNG
> failure
>
> Caution: EXT Email
>
> Hi Gaurav,
>
> I've resumed work on this issue. I hope I'll get RTSTATUS and RTMCTL soon.
> Meanwhile, what is the problem with armv8? I'll try some build for armv8, but it
> will take time.
>
> Regards,
> Petr
>
> On Thu, 13 Jan 2022 at 08:23, Gaurav Jain <gaurav.jain@xxxxxxx> wrote:
> >
> > Hello Michal
> >
> > >
> > > -----Original Message-----
> > > From: Michal Vokáč <michal.vokac@xxxxxxxxx>
> > > Sent: Friday, November 12, 2021 8:57 PM
> > > To: Horia Geanta <horia.geanta@xxxxxxx>; Pankaj Gupta
> > > <pankaj.gupta@xxxxxxx>; Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> > > Cc: David S. Miller <davem@xxxxxxxxxxxxx>;
> > > linux-crypto@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> > > l.stach@xxxxxxxxxxxxxx; robert.hancock@xxxxxxxxxx; Petr Benes
> > > <petr.benes@xxxxxxxxx>; petrben@xxxxxxxxx; Michal Vokáč
> > > <michal.vokac@xxxxxxxxx>
> > > Subject: [EXT] [RFC PATCH] crypto: caam - restore retry count after
> > > HW RNG failure
> > >
> > > Caution: EXT Email
> > >
> > > From: Petr Benes <petr.benes@xxxxxxxxx>
> > >
> > > Each time TRNG generates entropy, statistical tests are run.
> > > If they fail, RETRY_COUNT value is decremented. Once it reaches 0,
> > > HW RNG returns an error, and needs to be reset.
> >
> > The least-significant 16 bits of the RTSTATUS register reflect the result of each
> of statistical tests.
> > Can you dump RTSTATUS to see which test has failed? Please dump RTMCTL as
> well.
> >
> > Have you tried to build this patch for armv8? For me it is failing.
> >
> > Regards
> > Gaurav Jain
> >
> > > RETRY_COUNT could be programmed in RTSCMISC register and is set to 1
> > > by default. Hence, we are left without hwrng after the first error,
> > > which could happen even under normal conditions.
> > >
> > > Cc: petrben@xxxxxxxxx
> > > Signed-off-by: Petr Benes <petr.benes@xxxxxxxxx>
> > > Signed-off-by: Michal Vokáč <michal.vokac@xxxxxxxxx>
> > > ---
> > > Hi,
> > > we are also experiencing this issue:
> > >
> > > caam_jr 2101000.jr0: 20003c5b: CCB: desc idx 60: RNG: Hardware error.
> > >
> > > It is happening on both i.MX6S and i.MX6DL SoCs we use.
> > > On Solo I can reproduce it really fast. Sometimes it happens right
> > > after the board is NFS booted, sometimes I need to stress the HWRNG
> > > for a while (generate few hundred KBs of random data). On some
> > > DualLite SoCs it is happening at least once a day.
> > >
> > > We are using the v5.10 LTS branch but I can confirm that this is
> > > happening on all kernels since v5.7 to the latest linux-next.
> > >
> > > We also tried to increase the RTSDCTL_ENT_DLY_MIN delay as suggested
> > > in this thread [1]. It helped and the issue never occurred since
> > > then but we are looking for more universal and permanent solution
> > > suitable for upstream, hence we came up with this patch.
> > >
> > > Any comments will be appreciated.
> > > Thanks, Michal
> > >
> > > [1]
> > > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flk
> > >
> ml.org%2F&data=04%7C01%7Cgaurav.jain%40nxp.com%7Cbda11e9702e1
> 428
> > >
> 1fc3608d9d9c2e529%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C6
> 3778
> > >
> 0253361778015%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQ
> IjoiV2
> > >
> luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=Pe0skMXk%2F
> epS
> > > AnqjZRZ6tLKqO4SKbDvX3ysA0w7W6y4%3D&reserved=0
> > > %2Flkml%2F2021%2F8%2F30%2F296&data=04%7C01%7Cpankaj.gupta
> %40
> > >
> nxp.com%7C5d6bf460b260415aeda008d9a5f0ffab%7C686ea1d3bc2b4c6fa92cd
> > >
> 99c5c301635%7C0%7C0%7C637723276775699794%7CUnknown%7CTWFpbGZs
> > >
> b3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0
> > > %3D%7C1000&sdata=VxN9MqDFbISptW3OX9XTtZ%2FwQTsEbF6dETxX
> B%2
> > > BHrywg%3D&reserved=0
> > >
> > > drivers/crypto/caam/caamrng.c | 42
> ++++++++++++++++++++++++++++++++---
> > > drivers/crypto/caam/ctrl.c | 13 +++++++++++
> > > drivers/crypto/caam/ctrl.h | 2 ++
> > > 3 files changed, 54 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/crypto/caam/caamrng.c
> > > b/drivers/crypto/caam/caamrng.c index 77d048dfe5d0..2be5584ae591
> > > 100644
> > > --- a/drivers/crypto/caam/caamrng.c
> > > +++ b/drivers/crypto/caam/caamrng.c
> > > @@ -21,6 +21,7 @@
> > > #include "desc_constr.h"
> > > #include "jr.h"
> > > #include "error.h"
> > > +#include "ctrl.h"
> > >
> > > #define CAAM_RNG_MAX_FIFO_STORE_SIZE 16
> > >
> > > @@ -113,6 +114,35 @@ static int caam_rng_read_one(struct device *jrdev,
> > > return err ?: (ret ?: len);
> > > }
> > >
> > > +static void caam_rng_retry_reset(struct caam_rng_ctx *context) {
> > > + struct device *ctrldev = context->ctrldev;
> > > + struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev);
> > > + struct caam_ctrl __iomem *ctrl;
> > > + struct rng4tst __iomem *r4tst;
> > > + u32 __iomem *rtstatus;
> > > + u32 retry_count;
> > > +
> > > + ctrl = (struct caam_ctrl __iomem *)ctrlpriv->ctrl;
> > > + r4tst = &ctrl->r4tst[0];
> > > +
> > > + /*
> > > + * There is unfortunately no member for RTSTATUS register in
> > > + * struct rng4tst and the structure doesn't look stable
> > > + */
> > > + rtstatus = (u32 *)((char *)&ctrl->r4tst[0] + 0x3C);
> > > + retry_count = (rd_reg32(rtstatus) >> 16) & 0xf;
> > > + dev_dbg(ctrldev, "CAAM RNG retry count %d\n", retry_count);
> > > + if (retry_count == 0) {
> > > + dev_err(ctrldev, "CAAM RNG resetting retry count to 1\n");
> > > + clrsetbits_32(&r4tst->rtmctl, 0, RTMCTL_PRGM | RTMCTL_ACC);
> > > + wr_reg32(&r4tst->rtscmisc,
> > > + (rd_reg32(&r4tst->rtscmisc) & 0x7f) | (1 <<
> > > 16));
> > > + clrsetbits_32(&r4tst->rtmctl, RTMCTL_PRGM | RTMCTL_ACC,
> > > + RTMCTL_SAMP_MODE_RAW_ES_SC);
> > > + caam_reinstantiate_rng(ctrldev);
> > > + }
> > > +}
> > > +
> > > static void caam_rng_fill_async(struct caam_rng_ctx *ctx) {
> > > struct scatterlist sg[1];
> > > @@ -129,8 +159,10 @@ static void caam_rng_fill_async(struct
> > > caam_rng_ctx
> > > *ctx)
> > > sg[0].length,
> > > ctx->desc_async,
> > > &done);
> > > - if (len < 0)
> > > + if (len < 0) {
> > > + caam_rng_retry_reset(ctx);
> > > return;
> > > + }
> > >
> > > kfifo_dma_in_finish(&ctx->fifo, len); } @@ -145,13 +177,17
> > > @@ static void caam_rng_worker(struct work_struct *work) static int
> > > caam_read(struct hwrng *rng, void *dst, size_t max, bool wait) {
> > > struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);
> > > - int out;
> > > + int out, ret;
> > >
> > > if (wait) {
> > > struct completion done;
> > >
> > > - return caam_rng_read_one(ctx->jrdev, dst, max,
> > > + ret = caam_rng_read_one(ctx->jrdev, dst, max,
> > > ctx->desc_sync, &done);
> > > + if (ret < 0)
> > > + caam_rng_retry_reset(ctx);
> > > +
> > > + return ret;
> > > }
> > >
> > > out = kfifo_out(&ctx->fifo, dst, max); diff --git
> > > a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c index
> > > ca0361b2dbb0..e421f8d1982b 100644
> > > --- a/drivers/crypto/caam/ctrl.c
> > > +++ b/drivers/crypto/caam/ctrl.c
> > > @@ -339,6 +339,19 @@ static int instantiate_rng(struct device
> > > *ctrldev, int state_handle_mask,
> > > return devm_add_action_or_reset(ctrldev,
> > > devm_deinstantiate_rng, ctrldev); }
> > >
> > > +/*
> > > + * caam_reinstantiate_rng - reinstantiates RNG. Intended for a case
> > > +when RNG
> > > falls into
> > > + * HW error condition. That happens if TRNG fails statistical
> > > + * check and RTY_CNT value set in RTSCMISC decrements to
> zero.
> > > + * It is exported to caamrng.c
> > > + * @ctrldev - pointer to device
> > > + */
> > > +
> > > +int caam_reinstantiate_rng(struct device *ctrldev) {
> > > + return instantiate_rng(ctrldev, 0, 0); }
> > > +
> > > /*
> > > * kick_trng - sets the various parameters for enabling the initialization
> > > * of the RNG4 block in CAAM
> > > diff --git a/drivers/crypto/caam/ctrl.h b/drivers/crypto/caam/ctrl.h
> > > index
> > > f3ecd67922a7..26ff5a49a865 100644
> > > --- a/drivers/crypto/caam/ctrl.h
> > > +++ b/drivers/crypto/caam/ctrl.h
> > > @@ -8,6 +8,8 @@
> > > #ifndef CTRL_H
> > > #define CTRL_H
> > >
> > > +int caam_reinstantiate_rng(struct device *ctrldev);
> > > +
> > > /* Prototypes for backend-level services exposed to APIs */ extern
> > > bool caam_dpaa2;
> > >
> > > --
> > > 2.25.1
> >

Next message: Asil Ajwad: "Greetings,"
Previous message: Lukas Czerner: "Re: [PATCH AUTOSEL 5.10 116/116] ext4: allow to change s_last_trim_minblks via sysfs"
In reply to: Petr Benes: "Re: [EXT] [RFC PATCH] crypto: caam - restore retry count after HW RNG failure"
Next in thread: Petr Benes: "Re: [EXT] [RFC PATCH] crypto: caam - restore retry count after HW RNG failure"
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