crypto: ccp - Add GET_ID SEV command

The GET_ID command, added as of SEV API v0.16, allows the SEV firmware
to be queried about a unique CPU ID. This unique ID can then be used
to obtain the public certificate containing the Chip Endorsement Key
(CEK) public key signed by the AMD SEV Signing Key (ASK).

For more information please refer to "Section 5.12 GET_ID" of
https://support.amd.com/TechDocs/55766_SEV-KM%20API_Specification.pdf

Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
index 1d24962..827c601 100644
--- a/include/linux/psp-sev.h
+++ b/include/linux/psp-sev.h
@@ -55,6 +55,7 @@
 	SEV_CMD_PDH_GEN			= 0x009,
 	SEV_CMD_DF_FLUSH		= 0x00A,
 	SEV_CMD_DOWNLOAD_FIRMWARE	= 0x00B,
+	SEV_CMD_GET_ID			= 0x00C,
 
 	/* Guest commands */
 	SEV_CMD_DECOMMISSION		= 0x020,
@@ -142,6 +143,16 @@
 } __packed;
 
 /**
+ * struct sev_data_get_id - GET_ID command parameters
+ *
+ * @address: physical address of region to place unique CPU ID(s)
+ * @len: len of the region
+ */
+struct sev_data_get_id {
+	u64 address;				/* In */
+	u32 len;				/* In/Out */
+} __packed;
+/**
  * struct sev_data_pdh_cert_export - PDH_CERT_EXPORT command parameters
  *
  * @pdh_address: PDH certificate address