[PATCH v5 06/11] crypto: ccp: Add support for setting user ID for dynamic boost control

From: Mario Limonciello
Date: Fri Jun 23 2023 - 14:32:10 EST


As part of the authentication flow for Dynamic Boost Control, the calling
software will need to send a uid used in all of its future
communications.

Add support for another IOCTL call to let userspace software set this up.

Acked-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
v4->v5:
* Pick up tag
v1->v2:
* Update commit message
---
drivers/crypto/ccp/dbc.c | 18 ++++++++++++++++++
drivers/crypto/ccp/dbc.h | 6 ++++++
include/linux/psp-platform-access.h | 1 +
include/uapi/linux/psp-dbc.h | 20 ++++++++++++++++++++
4 files changed, 45 insertions(+)

diff --git a/drivers/crypto/ccp/dbc.c b/drivers/crypto/ccp/dbc.c
index f65e93a81e53f..c6f5fb3658ca3 100644
--- a/drivers/crypto/ccp/dbc.c
+++ b/drivers/crypto/ccp/dbc.c
@@ -117,6 +117,24 @@ static long dbc_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
goto unlock;
}
break;
+ case DBCIOCUID:
+ dbc_dev->mbox->req.header.payload_size = sizeof(dbc_dev->mbox->dbc_set_uid);
+ if (copy_from_user(&dbc_dev->mbox->dbc_set_uid.user, argp,
+ sizeof(struct dbc_user_setuid))) {
+ ret = -EFAULT;
+ goto unlock;
+ }
+
+ ret = send_dbc_cmd(dbc_dev, PSP_DYNAMIC_BOOST_SET_UID);
+ if (ret)
+ goto unlock;
+
+ if (copy_to_user(argp, &dbc_dev->mbox->dbc_set_uid.user,
+ sizeof(struct dbc_user_setuid))) {
+ ret = -EFAULT;
+ goto unlock;
+ }
+ break;
default:
ret = -EINVAL;

diff --git a/drivers/crypto/ccp/dbc.h b/drivers/crypto/ccp/dbc.h
index 1c3a0a078d156..1564351000761 100644
--- a/drivers/crypto/ccp/dbc.h
+++ b/drivers/crypto/ccp/dbc.h
@@ -33,9 +33,15 @@ struct dbc_nonce {
struct dbc_user_nonce user;
} __packed;

+struct dbc_set_uid {
+ struct psp_req_buffer_hdr header;
+ struct dbc_user_setuid user;
+} __packed;
+
union dbc_buffer {
struct psp_request req;
struct dbc_nonce dbc_nonce;
+ struct dbc_set_uid dbc_set_uid;
};

void dbc_dev_destroy(struct psp_device *psp);
diff --git a/include/linux/psp-platform-access.h b/include/linux/psp-platform-access.h
index 53b4a1df51806..18b9e0f0cb03b 100644
--- a/include/linux/psp-platform-access.h
+++ b/include/linux/psp-platform-access.h
@@ -9,6 +9,7 @@ enum psp_platform_access_msg {
PSP_CMD_NONE = 0x0,
PSP_I2C_REQ_BUS_CMD = 0x64,
PSP_DYNAMIC_BOOST_GET_NONCE,
+ PSP_DYNAMIC_BOOST_SET_UID,
};

struct psp_req_buffer_hdr {
diff --git a/include/uapi/linux/psp-dbc.h b/include/uapi/linux/psp-dbc.h
index d032f78934e27..7443c78ede199 100644
--- a/include/uapi/linux/psp-dbc.h
+++ b/include/uapi/linux/psp-dbc.h
@@ -18,6 +18,7 @@

#define DBC_NONCE_SIZE 16
#define DBC_SIG_SIZE 32
+#define DBC_UID_SIZE 16

/**
* struct dbc_user_nonce - Nonce exchange structure (input/output).
@@ -34,6 +35,16 @@ struct dbc_user_nonce {
__u8 signature[DBC_SIG_SIZE];
} __packed;

+/**
+ * struct dbc_user_setuid - UID exchange structure (input).
+ * @uid: 16 byte value representing software identity
+ * @signature: 32 byte signature created by software using a previous nonce
+ */
+struct dbc_user_setuid {
+ __u8 uid[DBC_UID_SIZE];
+ __u8 signature[DBC_SIG_SIZE];
+} __packed;
+
/**
* Dynamic Boost Control (DBC) IOC
*
@@ -64,4 +75,13 @@ struct dbc_user_nonce {
*/
#define DBCIOCNONCE _IOWR(DBC_IOC_TYPE, 0x1, struct dbc_user_nonce)

+/**
+ * DBCIOCUID - Set the user ID (UID) of a calling process.
+ * The user ID is 8 bytes long. It must be programmed using a
+ * 32 byte signature built using the nonce fetched from
+ * DBCIOCNONCE.
+ * The UID can only be set once until the system is rebooted.
+ */
+#define DBCIOCUID _IOW(DBC_IOC_TYPE, 0x2, struct dbc_user_setuid)
+
#endif /* __PSP_DBC_USER_H__ */
--
2.34.1