[PATCH] lib: utils/mailbox: Allow service group version lower than RPMI spec version

[Rahul Pathak]

RPMI specfication defines the version of the
service group as the specification version that
service group complies with.

Its possible that group version may not changed
but spec version has due to other changes.

Allow RPMI mailbox driver to check for every service
group version including base to not be greater than
the reported RPMI spec version.

Signed-off-by: Rahul Pathak <rahul.pathak at oss.qualcomm.com>
---
 lib/utils/mailbox/fdt_mailbox_rpmi_shmem.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/lib/utils/mailbox/fdt_mailbox_rpmi_shmem.c b/lib/utils/mailbox/fdt_mailbox_rpmi_shmem.c
index 21330c4b..7eded2fd 100644
--- a/lib/utils/mailbox/fdt_mailbox_rpmi_shmem.c
+++ b/lib/utils/mailbox/fdt_mailbox_rpmi_shmem.c
@@ -562,8 +562,14 @@ static struct mbox_chan *rpmi_shmem_mbox_request_chan(
 		ret = smq_base_get_two_u32(mctl,
 					   RPMI_BASE_SRV_PROBE_SERVICE_GROUP,
 					   chan_args, tval);
-		if (ret || !tval[1])
+		/*
+		 * The service group version must not be greater than the
+		 * RPMI specification version implemented by the platform
+		 * microcontroller.
+		 */
+		if (ret || !tval[1] || tval[1] > mctl->spec_version)
 			return NULL;
+
 	}
 
 	srvgrp_chan = sbi_zalloc(sizeof(*srvgrp_chan));
@@ -773,8 +779,14 @@ static int rpmi_shmem_mbox_init(const void *fdt, int nodeoff,
 	if (ret)
 		goto fail_free_chan;
 	mctl->spec_version = tval[1];
+
+	/*
+	 * Spec version must not be lower than the Base service group
+	 * version. Spec allows the group version lower then the spec
+	 * version which is implemented by the platform microcontroller.
+	 */
 	if (mctl->spec_version < RPMI_BASE_VERSION_MIN ||
-	    mctl->spec_version != base_srvgrp->servicegroup_version) {
+	    base_srvgrp->servicegroup_version > mctl->spec_version) {
 		ret = SBI_EINVAL;
 		goto fail_free_chan;
 	}
-- 
2.43.0