crypto: caam - fix i.MX6SX entropy delay value
Subsystems (3)
PATCH v4 1/1 crypto: caam - fix i.MX6SX entropy delay value
From: Fabio Estevam <[email protected]>
Since commit 358ba762d9f1 ("crypto: caam - enable prediction resistance in HRWNG") the following CAAM errors can be seen on i.MX6SX:
caam_jr 2101000.jr: 20003c5b: CCB: desc idx 60: RNG: Hardware error
hwrng: no data available
This error is due to an incorrect entropy delay for i.MX6SX.
Fix it by increasing the minimum entropy delay for i.MX6SX as done in U-Boot:
https://patchwork.ozlabs.org/project/uboot/patch/[email protected]/
---
Changes since v3:
- Add a needs_extended_entropy_delay() function
- Assign the 'ent_delay' inside the the RNG initialization area. (Horia)
- Change the terminology as per Horia's explanation.
drivers/crypto/caam/ctrl.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
drivers/crypto/caam/ctrl.c +18 -0
@@ -609,6 +609,13 @@ static bool check_version(struct fsl_mc_version *mc_version, u32 major, }#endif +static bool needs_extended_entropy_delay (void ) +{ +if (of_machine_is_compatible ("fsl,imx6sx" )) +return true; +return false; +} +/* Probe routine for CAAM top (controller) level */ static int caam_probe (struct platform_device *pdev) {
@@ -855,6 +862,8 @@ static int caam_probe(struct platform_device *pdev)* Also, if a handle was instantiated, do not change * the TRNG parameters. */ +if (needs_extended_entropy_delay ()) + ent_delay =12000 ;if (!(ctrlpriv->rng4_sh_init || inst_handles)) { dev_info(dev, "Entropy delay = %u\n",
@@ -871,6 +880,15 @@ static int caam_probe(struct platform_device *pdev)*/ ret =instantiate_rng (dev, inst_handles, gen_sk); +/* +* Entropy delay is determined via TRNG characterization. +* TRNG characterization is run across different voltages +* and temperatures. +* If worst case value for ent_dly is identified, +* the loop can be skipped for that platform. +*/ +if (needs_extended_entropy_delay ()) +break ;if (ret == -EAGAIN )/* * if here, the loop will rerun,
Signature · 1 line
2.25.1
Quoted 10 lines · Fabio Estevam
From: Fabio Estevam <[email protected]>
Since commit
358ba762d9f1("crypto: caam - enable prediction resistance in HRWNG") the following CAAM errors can be seen on i.MX6SX:
caam_jr2101000.jr:20003c5b: CCB: desc idx 60: RNG: Hardware error
hwrng: no data availableThis error is due to an incorrect entropy delay for i.MX6SX.
Quoted 7 lines
Fix it by increasing the minimum entropy delay for i.MX6SX as done in U-Boot:
https://patchwork.ozlabs.org/project/uboot/patch/[email protected]/Cc <[email protected]>Fixes 358ba762d9f1 ("crypto: caam - enable prediction resistance in HRWNG")Signed-off-by Fabio Estevam <[email protected]>
Thanks,
Horia
A message that is not in the archive (sent off-list or not yet received): VI1PR04MB5342FB22BDAF3163C7C8ECD9E7F59@VI1PR04MB5342.eurprd04.prod.outlook.com
Quoted 67 lines
-----Original Message-----
From: Fabio Estevam <[email protected]>
Sent: Tuesday, April 19, 2022 5:15 PM
To: [email protected]
Cc: Horia Geanta <[email protected]>; Gaurav Jain <[email protected]>; Varun Sethi <[email protected]>; linux- [email protected]; Fabio Estevam <[email protected]>; [email protected]
Subject: [EXT] [PATCH v4] crypto: caam - fix i.MX6SX entropy delay valueCaution: EXT Email
From: Fabio Estevam <[email protected]>
Since commit
358ba762d9f1("crypto: caam - enable prediction resistance in HRWNG") the following CAAM errors can be seen on i.MX6SX:
caam_jr2101000.jr:20003c5b: CCB: desc idx 60: RNG: Hardware error
hwrng: no data availableThis error is due to an incorrect entropy delay for i.MX6SX.
Fix it by increasing the minimum entropy delay for i.MX6SX as done in U-Boot:
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatch
work.ozlabs.org%2Fproject%2Fuboot%2Fpatch%2F20220415111049.2565744- 1- gaurav.jain%40nxp.com%2F&data=05%7C01%7Cgaurav.jain%40nxp.co m%7C9016fe4b6bb8402de08f08da21fa0703%7C686ea1d3bc2b4c6fa92cd99c5c 301635%7C0%7C0%7C637859655100732358%7CUnknown%7CTWFpbGZsb3d8 eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3 D%7C3000%7C%7C%7C&sdata=wglpvZBmQUKn7sLRx5xpdwdgFMOc6LE qIMqUU0h4UZE%3D&reserved=0Cc <[email protected]>Fixes 358ba762d9f1 ("crypto: caam - enable prediction resistance in HRWNG")Signed-off-by Fabio Estevam <[email protected]>---
Changes since v3:
- Add aneeds_extended_entropy_delay()function
- Assign the 'ent_delay' inside the the RNG initialization area. (Horia)
- Change the terminology as per Horia's explanation.drivers/crypto/caam/ctrl.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)drivers/crypto/caam/ctrl.c index renamed from drivers/crypto/caam/ctrl.c +0
-0
ca0361b2dbb0..5b989a842ee9100644drivers/crypto/caam/ctrl.c +7
-0@@ -609,6 +609,13 @@ static bool check_version(struct fsl_mc_version *mc_version, u32 major, } #endif +static bool needs_extended_entropy_delay (void ) +{ +if (of_machine_is_compatible ("fsl,imx6sx" )) +return true; +return false; +} + /* Probe routine for CAAM top (controller) level */ static int
caam_probe(struct platform_device *pdev){ @@ -855,6 +862,8 @@ static intcaam_probe(struct platform_device *pdev)
* Also, if a handle was instantiated, do not change
* the TRNG parameters.
*/
drivers/crypto/caam/ctrl.c static int caam_probe(struct platform_device *pdev) · line 867
Quoted 3 lines
drivers/crypto/caam/ctrl.c +2
-0+if (needs_extended_entropy_delay ()) + ent_delay =12000 ;if (!(ctrlpriv->rng4_sh_init || inst_handles)) {
Please note if TRNG state handles are already instantiated e.g. by U-Boot bootloader, It is assumed that entropy is set correctly and kick_trng() will be skipped Kindly pick the U-Boot changes as detailed in commit message.
Quoted 6 lines
dev_info(dev,
"Entropy delay = %u\n", @@ -871,6 +880,15 @@ static
int caam_probe(struct platform_device *pdev)
*/
ret = instantiate_rng(dev, inst_handles,
gen_sk);drivers/crypto/caam/ctrl.c static int caam_probe(struct platform_device *pdev) · line 890
Quoted 8 lines
drivers/crypto/caam/ctrl.c +8
-0+/* +* Entropy delay is determined via TRNG characterization. +* TRNG characterization is run across different voltages +* and temperatures. +* If worst case value for ent_dly is identified, +* the loop can be skipped for that platform. +*/ +if (needs_extended_entropy_delay ())
There is nothing like extended entropy delay and function name seems to be incorrect, The software test were run offline across ranges of temperature, voltage and process to determine the correct entropy delay. However, value of 12000 is determined by running said test across voltage and temperature only for iMX6SX.
Quoted 6 lines
+ break; if (ret == -EAGAIN) /* * if here, the loop will rerun,--
2.25.1
Hi Vabhav,
Quoted 2 lines · Vabhav Sharma
There is nothing like extended entropy delay and function name seems to be incorrect, The software test were run offline across ranges of temperature, voltage and process to determine the correct entropy delay. However, value of 12000 is determined by running said test across voltage and temperature only for iMX6SX.
Ok, I did as you suggested and sent a v5.
Just realized that I forgot to add you on Cc. Sorry about that.
Thanks