[EXT] RE: [PATCH v5 01/16] crypto/fsl: Add support for CAAM Job ring driver model

[Gaurav Jain]

Hello Andrey

> -----Original Message-----
> From: ZHIZHIKIN Andrey <andrey.zhizhikin at leica-geosystems.com>
> Sent: Wednesday, November 17, 2021 6:33 PM
> To: Gaurav Jain <gaurav.jain at nxp.com>; u-boot at lists.denx.de
> Cc: Stefano Babic <sbabic at denx.de>; Fabio Estevam <festevam at gmail.com>;
> Peng Fan <peng.fan at nxp.com>; Simon Glass <sjg at chromium.org>; Priyanka
> Jain <priyanka.jain at nxp.com>; Ye Li <ye.li at nxp.com>; Horia Geanta
> <horia.geanta at nxp.com>; Ji Luo <ji.luo at nxp.com>; Franck Lenormand
> <franck.lenormand at nxp.com>; Silvano Di Ninno
> <silvano.dininno at nxp.com>; Sahil Malhotra <sahil.malhotra at nxp.com>;
> Pankaj Gupta <pankaj.gupta at nxp.com>; Varun Sethi <V.Sethi at nxp.com>;
> dl-uboot-imx <uboot-imx at nxp.com>; Shengzhou Liu
> <shengzhou.liu at nxp.com>; Mingkai Hu <mingkai.hu at nxp.com>; Rajesh
> Bhagat <rajesh.bhagat at nxp.com>; Meenakshi Aggarwal
> <meenakshi.aggarwal at nxp.com>; Wasim Khan <wasim.khan at nxp.com>;
> Alison Wang <alison.wang at nxp.com>; Pramod Kumar
> <pramod.kumar_1 at nxp.com>; Andy Tang <andy.tang at nxp.com>; Adrian
> Alonso <adrian.alonso at nxp.com>; Vladimir Oltean <olteanv at gmail.com>
> Subject: RE: [EXT] RE: [PATCH v5 01/16] crypto/fsl: Add support for CAAM Job
> ring driver model
> 
> Caution: EXT Email
> 
> Hello Gaurav,
> 
> > -----Original Message-----
> > From: Gaurav Jain <gaurav.jain at nxp.com>
> > Sent: Wednesday, November 17, 2021 12:26 PM
> > To: ZHIZHIKIN Andrey <andrey.zhizhikin at leica-geosystems.com>; u-
> > boot at lists.denx.de
> > Cc: Stefano Babic <sbabic at denx.de>; Fabio Estevam
> > <festevam at gmail.com>; Peng Fan <peng.fan at nxp.com>; Simon Glass
> > <sjg at chromium.org>; Priyanka Jain <priyanka.jain at nxp.com>; Ye Li
> > <ye.li at nxp.com>; Horia Geanta <horia.geanta at nxp.com>; Ji Luo
> > <ji.luo at nxp.com>; Franck Lenormand <franck.lenormand at nxp.com>;
> Silvano
> > Di Ninno <silvano.dininno at nxp.com>; Sahil Malhotra
> > <sahil.malhotra at nxp.com>; Pankaj Gupta <pankaj.gupta at nxp.com>;
> Varun
> > Sethi <V.Sethi at nxp.com>; dl-uboot-imx <uboot-imx at nxp.com>;
> Shengzhou
> > Liu <shengzhou.liu at nxp.com>; Mingkai Hu <mingkai.hu at nxp.com>;
> Rajesh
> > Bhagat <rajesh.bhagat at nxp.com>; Meenakshi Aggarwal
> > <meenakshi.aggarwal at nxp.com>; Wasim Khan <wasim.khan at nxp.com>;
> Alison
> > Wang <alison.wang at nxp.com>; Pramod Kumar
> <pramod.kumar_1 at nxp.com>;
> > Andy Tang <andy.tang at nxp.com>; Adrian Alonso
> <adrian.alonso at nxp.com>;
> > Vladimir Oltean <olteanv at gmail.com>
> > Subject: RE: [EXT] RE: [PATCH v5 01/16] crypto/fsl: Add support for
> > CAAM Job ring driver model
> >
> >
> > Hello Andrey
> >
> > > -----Original Message-----
> > > From: ZHIZHIKIN Andrey <andrey.zhizhikin at leica-geosystems.com>
> > > Sent: Tuesday, November 16, 2021 9:24 PM
> > > To: Gaurav Jain <gaurav.jain at nxp.com>; u-boot at lists.denx.de
> > > Cc: Stefano Babic <sbabic at denx.de>; Fabio Estevam
> > > <festevam at gmail.com>; Peng Fan <peng.fan at nxp.com>; Simon Glass
> > > <sjg at chromium.org>; Priyanka Jain <priyanka.jain at nxp.com>; Ye Li
> > > <ye.li at nxp.com>; Horia Geanta <horia.geanta at nxp.com>; Ji Luo
> > > <ji.luo at nxp.com>; Franck Lenormand <franck.lenormand at nxp.com>;
> > > Silvano Di Ninno <silvano.dininno at nxp.com>; Sahil Malhotra
> > > <sahil.malhotra at nxp.com>; Pankaj Gupta <pankaj.gupta at nxp.com>;
> Varun
> > > Sethi <V.Sethi at nxp.com>; dl-uboot-imx <uboot-imx at nxp.com>;
> Shengzhou
> > > Liu <shengzhou.liu at nxp.com>; Mingkai Hu <mingkai.hu at nxp.com>;
> Rajesh
> > > Bhagat <rajesh.bhagat at nxp.com>; Meenakshi Aggarwal
> > > <meenakshi.aggarwal at nxp.com>; Wasim Khan <wasim.khan at nxp.com>;
> > > Alison Wang <alison.wang at nxp.com>; Pramod Kumar
> > > <pramod.kumar_1 at nxp.com>; Andy Tang <andy.tang at nxp.com>;
> Adrian
> > > Alonso <adrian.alonso at nxp.com>; Vladimir Oltean <olteanv at gmail.com>
> > > Subject: [EXT] RE: [PATCH v5 01/16] crypto/fsl: Add support for CAAM
> > > Job ring driver model
> > >
> > > Caution: EXT Email
> > >
> > > Hello Gaurav,
> > >
> > > > -----Original Message-----
> > > > From: U-Boot <u-boot-bounces at lists.denx.de> On Behalf Of Gaurav
> > > > Jain
> > > > Sent: Monday, November 15, 2021 8:00 AM
> > > > To: u-boot at lists.denx.de
> > > > Cc: Stefano Babic <sbabic at denx.de>; Fabio Estevam
> > > > <festevam at gmail.com>; Peng Fan <peng.fan at nxp.com>; Simon Glass
> > > > <sjg at chromium.org>; Priyanka Jain <priyanka.jain at nxp.com>; Ye Li
> > > > <ye.li at nxp.com>; Horia Geanta <horia.geanta at nxp.com>; Ji Luo
> > > > <ji.luo at nxp.com>; Franck Lenormand <franck.lenormand at nxp.com>;
> > > > Silvano Di Ninno <silvano.dininno at nxp.com>; Sahil malhotra
> > > > <sahil.malhotra at nxp.com>; Pankaj Gupta <pankaj.gupta at nxp.com>;
> > > > Varun Sethi <V.Sethi at nxp.com>; NXP i . MX U-Boot Team
> > > > <uboot-imx at nxp.com>; Shengzhou Liu <Shengzhou.Liu at nxp.com>;
> > > > Mingkai Hu <mingkai.hu at nxp.com>; Rajesh Bhagat
> > > > <rajesh.bhagat at nxp.com>;
> > > Meenakshi
> > > > Aggarwal <meenakshi.aggarwal at nxp.com>; Wasim Khan
> > > > <wasim.khan at nxp.com>; Alison Wang <alison.wang at nxp.com>;
> Pramod
> > > Kumar
> > > > <pramod.kumar_1 at nxp.com>; Tang Yuantian <andy.tang at nxp.com>;
> > > > Adrian Alonso <adrian.alonso at nxp.com>; Vladimir Oltean
> > > > <olteanv at gmail.com>; Gaurav Jain <gaurav.jain at nxp.com>
> > > > Subject: [PATCH v5 01/16] crypto/fsl: Add support for CAAM Job
> > > > ring driver model
> > > >
> > > >
> > > > added device tree support for job ring driver.
> > > > sec is initialized based on job ring information processed from
> > > > device tree.
> > > >
> > > > Signed-off-by: Gaurav Jain <gaurav.jain at nxp.com>
> > > > Reviewed-by: Ye Li <ye.li at nxp.com>
> > > > ---
> > > >  cmd/Kconfig                 |   1 +
> > > >  drivers/crypto/fsl/Kconfig  |   7 +
> > > >  drivers/crypto/fsl/Makefile |   4 +-
> > > >  drivers/crypto/fsl/jr.c     | 316 +++++++++++++++++++++++-------------
> > > >  drivers/crypto/fsl/jr.h     |  14 ++
> > > >  5 files changed, 232 insertions(+), 110 deletions(-)
> > > >
> 
> [snip]
> 
> > > >         sec_out32(&sec->mcfgr, mcr);
> > > > +#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_IMX8M)
> > >
> > > This would effectively reserve the JR0 on _all_ i.MX8M derivatives is S
> World.
> > This code is to set any JR DID in SPL so that the job ring can be configured.
> >
> > >
> > > Current implementation only has JR0 reserved in S World on imx8mm
> > > derivative, but this new addition extends this to imx8mn, imx8mp and
> imx8mq.
> > Current implementation do not initialize CAAM for i.MX8M derivatives.
> > It is not based on driver model approach and only using JR0.
> 
> OK, but then I do not have on explanation on why do I see following results
> from reading JRaDID_MS registers on imx8m derivatives:
> - imx8mm:
>         JR0DID_MS = 0x8011
>         JR1DID_MS = 0x0
>         JR2DID_MS = 0x0
> - imx8mn:
>         JR0DID_MS = 0x0
>         JR1DID_MS = 0x0
>         JR2DID_MS = 0x0
> - imx8mp:
>         JR0DID_MS = 0x0
>         JR1DID_MS = 0x0
>         JR2DID_MS = 0x0
> 
> This readout is taken at Kernel boot, and it clearly shows that only JR0 has
> TZ_OWN, PRIM_TZ and PRIM_DID bits set, and it is only done on imx8mm.

HAB is a code that is part of the ROM code which set the JR DID for all i.mx8M.
I took the dumps on SPL boot which actually shows the JR DID set by HAB.
Dump taken by you on kernel boot does not show the values set by ROM.
IMX8MM
JR0DID_MS = 0x8011
JR1DID_MS = 0x8011
JR2DID_MS = 0x0

IMX8MN
JR0DID_MS = 0x8011
JR1DID_MS = 0x8011
JR2DID_MS = 0x0

IMX8MP
JR0DID_MS = 0x8011
JR1DID_MS = 0x8011
JR2DID_MS = 0x0
> 
> > With New implementation CAAM is enabled for i.MX8M derivative. Any JR
> > whose DID is written in ATF, can be used in Uboot.
> > JR0 is reserved for HAB so JR1 will be used for all i.MX8M derivatives.
> >
> > >
> > > I'm wondering about several points here:
> > > 1. Why does current implementation on have this reservation done on
> > > imx8mm and
> > >    where does this happen? None of the code pieces suggests that it is
> done in
> > >    U-Boot, is it performed in BootROM?
> >
> > I cannot see if current implementation(SPL/Uboot) has reservation done
> > for imx8mm.
> > In ATF, we are reserving the JR0.
> 
> I was not able to identify which part of ATF code is responsible to program
> JR0DID_MS on imx8mm, the only thing I saw was the part where the JR0 is
> held in S World *if* the JR0DID_MS is set to 0x8011. Can you point out where
> is this performed in ATF code?
> 
> If it is not in the ATF, then my question above still stands: which component
> (HW or SW) programs JR0DID_MS, and why is it only done on imx8mm
> derivative?
HAB which is part of the ROM code sets the JR DID for all i.mx8M.
> 
> >
> > > 2. What is the intention of having JR0 reserved for all derivatives? Is this
> > >    the part of a bigger change that stretches across different SW
> components
> > >    (e.g. ATF, OP-TEE, etc.)? If that is the case - then a more detailed
> > >    description would be appreciated here.
> > >
> > > ATF code already accounts for this reservation in commit:
> > > a83a7c65e ("TEE-639 plat: imx8m: Do not release JR0 to NS if HAB is
> > > using it") [1], but there is no description on why is this required though.
> > >
> > > If this is required for HAB feature, then the question is: should it
> > > be kept in
> > S
> > > World when U-Boot starts, or SPL can release it after the binary is
> > > verified
> > and
> > > crypto facilities are not in use anymore?
> >
> > Commit: a83a7c65e reserves JR0 for HAB and not released to NS but JR1,
> > JR2 are released to NS.
> 
> Then I believe this change should be in-sync with ATF implementation,
> because of the fact that your change can have any arbitrary JR to be held in S
> World.
> 
> What would happen if for example JR1 is programmed with TZ_OWN, but
> ATF releases it to NS world? Can it be used by Kernel afterwards? Or should
> the node be disabled here so that Kernel does not even see JR1 during boot?
>
Since JR0 is marked as disabled in DT, so SPL is only accessing single job ring and setting the JR1 DID as 0x8011.
After SPL boots successfully, ATF is releasing JR1 and JR2 to NS by modifying the JRDID_MS as 0x1.
Uboot is also accessing single jobring which is JR1.
JR0 is only reserved for secure boot.

> So far, ATF only examines the JR0DID_MS content, and not all the others...
> 
> > HAB uses JR0 for secure boot on all i.MX8M derivatives. Uboot calls
> > HAB API for authenticating kernel.
> 
> This implies then that the JR0 is permanently held in S World and stays there
> for entire device powercycle and cannot be reclaimed in NS World?
Yes JR0 is held in S world.

 In this
> case, the DT node should be completely removed from DTB file so no SW
> entity can even see it (as it is in a total possession of HW mechanisms).
> 
We can consider this change after this patch series is merged.
Currently I have disabled the JR0 in device tree.

> >
> > >
> > > > +       jrdid_ms = JRDID_MS_TZ_OWN | JRDID_MS_PRIM_TZ |
> > > > + JRDID_MS_PRIM_DID;
> > >
> > > What is the intention of setting JRDID_MS_PRIM_TZ? Isn't setting
> > > JRDID_MS_TZ_OWN would be sufficient here?
> >
> > PRIM_TZ bit is set to 1 to indicate that only SecureWorld can access
> > registers in that Job Ring's register page
> 
> But would it not be enough just to set TZ_OWN? If I read SRM correct: only
> TZ_OWN is enough to hold the JR in S World.
> 
HAB is also setting 0x8011 as JR DID. It is better to be in sync with HAB.

Regards
Gaurav Jain

> >
> 
> [snip]
> 
> > >
> 
> -- andrey