[U-Boot] [RESEND PATCH v3 1/2] drivers/crypto/fsl: assign job-rings to non-TrustZone

[Ruchika Gupta]

>-----Original Message-----
>From: Bryan O'Donoghue [mailto:bryan.odonoghue at linaro.org]
>Sent: Friday, January 26, 2018 5:55 PM
>To: u-boot at lists.denx.de; trini at konsulko.com
>Cc: Peng Fan <peng.fan at nxp.com>; Fabio Estevam <fabio.estevam at nxp.com>;
>lukas.auer at aisec.fraunhofer.de; Bryan O'Donoghue
><bryan.odonoghue at linaro.org>; Alexandru Porosanu
><alexandru.porosanu at nxp.com>; Ruchika Gupta <ruchika.gupta at nxp.com>;
>Aneesh Bansal <aneesh.bansal at nxp.com>
>Subject: [RESEND PATCH v3 1/2] drivers/crypto/fsl: assign job-rings to non-
>TrustZone
>
>After enabling TrustZone various parts of the CAAM silicon become inaccessible
>to non TrustZone contexts. The job-ring registers are designed to allow non
>TrustZone contexts like Linux to still submit jobs to CAAM even after TrustZone
>has been enabled.
>
>The default job-ring permissions after the BootROM look like this for job-ring
>zero.
>
>ms=0x00008001 ls=0x00008001
>
>The MS field is JRaMIDR_MS (job ring MID most significant).
>
>Referring to "Security Reference Manual for i.MX 7Dual and 7Solo Applications
>Processors, Rev. 0, 03/2017" section 8.10.4 we see that JROWN_NS controls
>whether or not a job-ring is accessible from non TrustZone.
>
>Bit 15 (TrustZone) is the logical inverse of bit 3 hence the above value of
>0x8001 shows that JROWN_NS=0 and TrustZone=1.
>
>Clearly then as soon as TrustZone becomes active the job-ring registers are no
>longer accessible from Linux, which is not what we want.
>
>This patch explicitly sets all job-ring registers to JROWN_NS=1 (non
>TrustZone) by default and to the Non-Secure MID 001. Both settings are required
>to successfully assign a job-ring to non-secure mode. If a piece of TrustZone
>firmware requires ownership of job-ring registers it can unset the JROWN_NS bit
>itself.
>
>This patch in conjunction with a modification of the Linux kernel to skip HWRNG
>initialisation makes CAAM usable to Linux with TrustZone enabled.
>
>Signed-off-by: Bryan O'Donoghue <bryan.odonoghue at linaro.org>
>Cc: Fabio Estevam <fabio.estevam at nxp.com>
>Cc: Peng Fan <peng.fan at nxp.com>
>Cc: Alex Porosanu <alexandru.porosanu at nxp.com>
>Cc: Ruchika Gupta <ruchika.gupta at nxp.com>
>Cc: Aneesh Bansal <aneesh.bansal at nxp.com>
>Link:
>https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.c
>om%2FOP-
>TEE%2Foptee_os%2Fissues%2F1408&data=02%7C01%7Cruchika.gupta%40nxp.c
>om%7C1fe21d0a12d34d7722c008d564b7cb4d%7C686ea1d3bc2b4c6fa92cd99c5
>c301635%7C0%7C0%7C636525662918265016&sdata=Nt5Fu2LYXDq95Rlv7N5Ns
>w45tO%2Fw3nDcbQF%2BOPRP7PI%3D&reserved=0
>Link:
>https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftinyurl.c
>om%2Fyam5gv9a&data=02%7C01%7Cruchika.gupta%40nxp.com%7C1fe21d0a12
>d34d7722c008d564b7cb4d%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C1
>%7C636525662918265016&sdata=BypstfduS%2FVyPaeEQCj1hyx5RRSF690SbLaxZ
>j74KPo%3D&reserved=0
>Tested-by: Lukas Auer <lukas.auer at aisec.fraunhofer.de>

Reviewed-by: Ruchika Gupta <ruchika.gupta at nxp.com>