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| author | Jorge Ramirez-Ortiz <jorge.ramirez@oss.qualcomm.com> | 2026-08-31 17:48:01 +0200 |
|---|---|---|
| committer | Martin K. Petersen (Oracle) <mkp@kernel.org> | 2026-09-09 21:53:11 -0400 |
| commit | 657eff806d38abd73e0002cda070c4cf14eb9882 (patch) | |
| tree | e67b69eb19df12316f5a5417ed37d93a8c6265ae | |
| parent | a8a34238e5e65609a434fc13aa1d64fcf2df1d23 (diff) | |
| download | linux-next-657eff806d38abd73e0002cda070c4cf14eb9882.tar.gz linux-next-657eff806d38abd73e0002cda070c4cf14eb9882.zip | |
scsi: ufs: rpmb: Use a fixed-length RPMB dev_id
The RPMB authentication key is derived from the dev_id handed to the RPMB
subsystem. OP-TEE implements the eMMC RPMB flow, where the dev_id is the
eMMC CID: a fixed 16-byte value the key derivation depends on.
The UFS RPMB id is "<device_id>-R<region>", which is variable length and
longer than 16 bytes. Handing it to the RPMB subsystem as-is would tie the
derived key to a length OP-TEE does not expect and diverge from the
fixed-CID eMMC ABI, forcing OP-TEE to be taught about variable-length UFS
ids.
A fixed 16-byte dev_id is needed so the derived key stays stable and unique
per region while matching the eMMC CID layout OP-TEE relies on, keeping the
key-derivation ABI identical with no OP-TEE change. The reduction to a
fixed 16 bytes must also be reproducible by the bootloaders (such as
U-Boot) that derive the same dev_id.
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez@oss.qualcomm.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Stanley Jhu <stanleyjhu@google.com>
Link: https://patch.msgid.link/20260831154804.719528-3-jorge.ramirez@oss.qualcomm.com
Signed-off-by: Martin K. Petersen (Oracle) <mkp@kernel.org>
| -rw-r--r-- | drivers/ufs/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/ufs/core/ufs-rpmb.c | 9 |
2 files changed, 8 insertions, 2 deletions
diff --git a/drivers/ufs/Kconfig b/drivers/ufs/Kconfig index f662e7ce71f1..b62c00e7ff06 100644 --- a/drivers/ufs/Kconfig +++ b/drivers/ufs/Kconfig @@ -7,6 +7,7 @@ menuconfig SCSI_UFSHCD tristate "Universal Flash Storage Controller" depends on SCSI && SCSI_DMA depends on RPMB || !RPMB + select CRYPTO_LIB_BLAKE2B if RPMB select PM_DEVFREQ select DEVFREQ_GOV_SIMPLE_ONDEMAND select NLS diff --git a/drivers/ufs/core/ufs-rpmb.c b/drivers/ufs/core/ufs-rpmb.c index 00ba4f3b842b..783ecfc7581d 100644 --- a/drivers/ufs/core/ufs-rpmb.c +++ b/drivers/ufs/core/ufs-rpmb.c @@ -10,6 +10,7 @@ * Can Guo <can.guo@oss.qualcomm.com> */ +#include <crypto/blake2b.h> #include <linux/module.h> #include <linux/device.h> #include <linux/kernel.h> @@ -21,6 +22,7 @@ #include <linux/unaligned.h> #include "ufshcd-priv.h" +#define UFS_RPMB_ID_LEN 16 /* Match eMMC CID Length */ #define UFS_RPMB_UA_RETRIES 3 /* Retries for the power-on UNIT ATTENTION */ #define UFS_RPMB_SEC_PROTOCOL 0xEC /* JEDEC UFS application */ #define UFS_RPMB_SEC_PROTOCOL_ID 0x01 /* JEDEC UFS RPMB protocol ID, CDB byte3 */ @@ -157,6 +159,7 @@ static void ufs_rpmb_device_release(struct device *dev) int ufs_rpmb_probe(struct ufs_hba *hba) { struct ufs_rpmb_dev *ufs_rpmb, *it, *tmp; + u8 dev_id[UFS_RPMB_ID_LEN]; struct rpmb_dev *rdev; char *cid = NULL; int region; @@ -215,8 +218,10 @@ int ufs_rpmb_probe(struct ufs_hba *hba) goto err_out; } - descr.dev_id = cid; - descr.dev_id_len = strlen(cid); + blake2b(NULL, 0, cid, strlen(cid), dev_id, UFS_RPMB_ID_LEN); + + descr.dev_id = dev_id; + descr.dev_id_len = UFS_RPMB_ID_LEN; descr.capacity = cap; /* Register RPMB device */ |