diff mbox series

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

Message ID 1516969484-19409-2-git-send-email-bryan.odonoghue@linaro.org
State Superseded
Headers show
Series Fix CAAM for TrustZone enable for warp7 | expand

Commit Message

Bryan O'Donoghue Jan. 26, 2018, 12:24 p.m. UTC 
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@linaro.org>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Alex Porosanu <alexandru.porosanu@nxp.com>
Cc: Ruchika Gupta <ruchika.gupta@nxp.com>
Cc: Aneesh Bansal <aneesh.bansal@nxp.com>
Link: https://github.com/OP-TEE/optee_os/issues/1408
Link: https://tinyurl.com/yam5gv9a
Tested-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
---
 drivers/crypto/fsl/jr.c | 9 +++++++++
 drivers/crypto/fsl/jr.h | 2 ++
 2 files changed, 11 insertions(+)

Comments

Ruchika Gupta Feb. 8, 2018, 6:02 p.m. UTC | #1 
>-----Original Message-----
>From: Bryan O'Donoghue [mailto:bryan.odonoghue@linaro.org]
>Sent: Friday, January 26, 2018 5:55 PM
>To: u-boot@lists.denx.de; trini@konsulko.com
>Cc: Peng Fan <peng.fan@nxp.com>; Fabio Estevam <fabio.estevam@nxp.com>;
>lukas.auer@aisec.fraunhofer.de; Bryan O'Donoghue
><bryan.odonoghue@linaro.org>; Alexandru Porosanu
><alexandru.porosanu@nxp.com>; Ruchika Gupta <ruchika.gupta@nxp.com>;
>Aneesh Bansal <aneesh.bansal@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@linaro.org>
>Cc: Fabio Estevam <fabio.estevam@nxp.com>
>Cc: Peng Fan <peng.fan@nxp.com>
>Cc: Alex Porosanu <alexandru.porosanu@nxp.com>
>Cc: Ruchika Gupta <ruchika.gupta@nxp.com>
>Cc: Aneesh Bansal <aneesh.bansal@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@aisec.fraunhofer.de>

Reviewed-by: Ruchika Gupta <ruchika.gupta@nxp.com>
diff mbox series

Patch

diff --git a/drivers/crypto/fsl/jr.c b/drivers/crypto/fsl/jr.c
index a6dad01..34bd070 100644
--- a/drivers/crypto/fsl/jr.c
+++ b/drivers/crypto/fsl/jr.c
@@ -579,6 +579,8 @@  int sec_init_idx(uint8_t sec_idx)
 {
 	ccsr_sec_t *sec = (void *)SEC_ADDR(sec_idx);
 	uint32_t mcr = sec_in32(&sec->mcfgr);
+	uint32_t jrown_ns;
+	int i;
 	int ret = 0;
 
 #ifdef CONFIG_FSL_CORENET
@@ -634,6 +636,13 @@  int sec_init_idx(uint8_t sec_idx)
 #endif
 #endif
 
+	/* Set ownership of job rings to non-TrustZone mode by default */
+	for (i = 0; i < ARRAY_SIZE(sec->jrliodnr); i++) {
+		jrown_ns = sec_in32(&sec->jrliodnr[i].ms);
+		jrown_ns |= JROWN_NS | JRMID_NS;
+		sec_out32(&sec->jrliodnr[i].ms, jrown_ns);
+	}
+
 	ret = jr_init(sec_idx);
 	if (ret < 0) {
 		printf("SEC initialization failed\n");
diff --git a/drivers/crypto/fsl/jr.h b/drivers/crypto/fsl/jr.h
index f546226..ef515e7 100644
--- a/drivers/crypto/fsl/jr.h
+++ b/drivers/crypto/fsl/jr.h
@@ -34,6 +34,8 @@ 
 #define JRNSLIODN_MASK		0x0fff0000
 #define JRSLIODN_SHIFT		0
 #define JRSLIODN_MASK		0x00000fff
+#define JROWN_NS		0x00000008
+#define JRMID_NS		0x00000001
 
 #define JQ_DEQ_ERR		-1
 #define JQ_DEQ_TO_ERR		-2