[v4,06/11] crypto: ccp: Add support for setting user ID for dynamic boost control

Commit Message

Mario Limonciello June 8, 2023, 11:17 a.m. UTC

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.

Signed-off-by: Mario Limonciello <[e-mail]>
---
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(+)

Patch

diff --git a/drivers/crypto/ccp/dbc.c b/drivers/crypto/ccp/dbc.c
index 7afeca903136..ca7ec528536b 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 1c3a0a078d15..156435100076 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 53b4a1df5180..18b9e0f0cb03 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 d032f78934e2..7443c78ede19 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__ */