crypto: ccp - Add support for getting and setting DBC parameters

After software has authenticated a dynamic boost control request,
it can fetch and set supported parameters using a selection of messages.

Add support for these messages and export the ability to do this to
userspace.
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/ccp/dbc.c

@@ -74,6 +74,30 @@ static int send_dbc_nonce(struct psp_dbc_device *dbc_dev)
 	return ret;
 }
 
+static int send_dbc_parameter(struct psp_dbc_device *dbc_dev)
+{
+	dbc_dev->mbox->req.header.payload_size = sizeof(dbc_dev->mbox->dbc_param);
+
+	switch (dbc_dev->mbox->dbc_param.user.msg_index) {
+	case PARAM_SET_FMAX_CAP:
+	case PARAM_SET_PWR_CAP:
+	case PARAM_SET_GFX_MODE:
+		return send_dbc_cmd(dbc_dev, PSP_DYNAMIC_BOOST_SET_PARAMETER);
+	case PARAM_GET_FMAX_CAP:
+	case PARAM_GET_PWR_CAP:
+	case PARAM_GET_CURR_TEMP:
+	case PARAM_GET_FMAX_MAX:
+	case PARAM_GET_FMAX_MIN:
+	case PARAM_GET_SOC_PWR_MAX:
+	case PARAM_GET_SOC_PWR_MIN:
+	case PARAM_GET_SOC_PWR_CUR:
+	case PARAM_GET_GFX_MODE:
+		return send_dbc_cmd(dbc_dev, PSP_DYNAMIC_BOOST_GET_PARAMETER);
+	}
+
+	return -EINVAL;
+}
+
 void dbc_dev_destroy(struct psp_device *psp)
 {
 	struct psp_dbc_device *dbc_dev = psp->dbc_data;
@@ -135,6 +159,23 @@ static long dbc_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 			goto unlock;
 		}
 		break;
+	case DBCIOCPARAM:
+		if (copy_from_user(&dbc_dev->mbox->dbc_param.user, argp,
+				   sizeof(struct dbc_user_param))) {
+			ret = -EFAULT;
+			goto unlock;
+		}
+
+		ret = send_dbc_parameter(dbc_dev);
+		if (ret)
+			goto unlock;
+
+		if (copy_to_user(argp, &dbc_dev->mbox->dbc_param.user,
+				 sizeof(struct dbc_user_param)))  {
+			ret = -EFAULT;
+			goto unlock;
+		}
+		break;
 	default:
 		ret = -EINVAL;
 

drivers/crypto/ccp/dbc.h

@@ -38,10 +38,16 @@ struct dbc_set_uid {
 	struct dbc_user_setuid		user;
 } __packed;
 
+struct dbc_param {
+	struct psp_req_buffer_hdr	header;
+	struct dbc_user_param		user;
+} __packed;
+
 union dbc_buffer {
 	struct psp_request		req;
 	struct dbc_nonce		dbc_nonce;
 	struct dbc_set_uid		dbc_set_uid;
+	struct dbc_param		dbc_param;
 };
 
 void dbc_dev_destroy(struct psp_device *psp);

include/linux/psp-platform-access.h

@@ -10,6 +10,8 @@ enum psp_platform_access_msg {
 	PSP_I2C_REQ_BUS_CMD = 0x64,
 	PSP_DYNAMIC_BOOST_GET_NONCE,
 	PSP_DYNAMIC_BOOST_SET_UID,
+	PSP_DYNAMIC_BOOST_GET_PARAMETER,
+	PSP_DYNAMIC_BOOST_SET_PARAMETER,
 };
 
 struct psp_req_buffer_hdr {

include/uapi/linux/psp-dbc.h

@@ -45,6 +45,23 @@ struct dbc_user_setuid {
 	__u8	signature[DBC_SIG_SIZE];
 } __packed;
 
+/**
+ * struct dbc_user_param - Parameter exchange structure (input/output).
+ * @msg_index: Message indicating what parameter to set or get (input)
+ * @param:     4 byte parameter, units are message specific. (input/output)
+ * @signature: 32 byte signature.
+ *             - When sending a message this is to be created by software
+ *               using a previous nonce (input)
+ *             - For interpreting results, this signature is updated by the
+ *               PSP to allow software to validate the authenticity of the
+ *               results.
+ */
+struct dbc_user_param {
+	__u32	msg_index;
+	__u32	param;
+	__u8	signature[DBC_SIG_SIZE];
+} __packed;
+
 /**
  * Dynamic Boost Control (DBC) IOC
  *
@@ -84,4 +101,47 @@ struct dbc_user_setuid {
  */
 #define DBCIOCUID	_IOW(DBC_IOC_TYPE, 0x2, struct dbc_user_setuid)
 
+/**
+ * DBCIOCPARAM - Set or get a parameter from the PSP.
+ *               This request will only work after DBCIOCUID has successfully
+ *               set the UID of the calling process.
+ *               Whether the parameter is set or get is controlled by the
+ *               message ID in the request.
+ *               This command must be sent using a 32 byte signature built
+ *               using the nonce fetched from DBCIOCNONCE.
+ *               When the command succeeds, the 32 byte signature will be
+ *               updated by the PSP for software to authenticate the results.
+ */
+#define DBCIOCPARAM	_IOWR(DBC_IOC_TYPE, 0x3, struct dbc_user_param)
+
+/**
+ * enum dbc_cmd_msg - Messages utilized by DBCIOCPARAM
+ * @PARAM_GET_FMAX_CAP:		Get frequency cap (MHz)
+ * @PARAM_SET_FMAX_CAP:		Set frequency cap (MHz)
+ * @PARAM_GET_PWR_CAP:		Get socket power cap (mW)
+ * @PARAM_SET_PWR_CAP:		Set socket power cap (mW)
+ * @PARAM_GET_GFX_MODE:		Get graphics mode (0/1)
+ * @PARAM_SET_GFX_MODE:		Set graphics mode (0/1)
+ * @PARAM_GET_CURR_TEMP:	Get current temperature (degrees C)
+ * @PARAM_GET_FMAX_MAX:		Get maximum allowed value for frequency (MHz)
+ * @PARAM_GET_FMAX_MIN:		Get minimum allowed value for frequency (MHz)
+ * @PARAM_GET_SOC_PWR_MAX:	Get maximum allowed value for SoC power (mw)
+ * @PARAM_GET_SOC_PWR_MIN:	Get minimum allowed value for SoC power (mw)
+ * @PARAM_GET_SOC_PWR_CUR:	Get current value for SoC Power (mW)
+ */
+enum dbc_cmd_msg {
+	PARAM_GET_FMAX_CAP	= 0x3,
+	PARAM_SET_FMAX_CAP	= 0x4,
+	PARAM_GET_PWR_CAP	= 0x5,
+	PARAM_SET_PWR_CAP	= 0x6,
+	PARAM_GET_GFX_MODE	= 0x7,
+	PARAM_SET_GFX_MODE	= 0x8,
+	PARAM_GET_CURR_TEMP	= 0x9,
+	PARAM_GET_FMAX_MAX	= 0xA,
+	PARAM_GET_FMAX_MIN	= 0xB,
+	PARAM_GET_SOC_PWR_MAX	= 0xC,
+	PARAM_GET_SOC_PWR_MIN	= 0xD,
+	PARAM_GET_SOC_PWR_CUR	= 0xE,
+};
+
 #endif /* __PSP_DBC_USER_H__ */