[PATCH 1/2] firmware: qcom: scm: Return -EOPNOTSUPP for unsupported SHM bridge enabling

[Kuldeep Singh]

From: Qingqing Zhou <quic_qqzhou@xxxxxxxxxxx>

Currently for enabling shm bridge, QTEE will return 0 and put error 4 into
result[0] to qcom_scm for unsupported platform, tzmem will consider this
as an unknown error not the unsupported case on the platform.

Error log:
[    0.177224] qcom_scm firmware:scm: error (____ptrval____): Failed to enable the TrustZone memory allocator
[    0.177244] qcom_scm firmware:scm: probe with driver qcom_scm failed with error 4

Change the function call qcom_scm_shm_bridge_enable() to remap this
result[0] into the unsupported error and then tzmem can consider this as
unsupported case instead of reporting an error.

Signed-off-by: Qingqing Zhou <quic_qqzhou@xxxxxxxxxxx>
Co-developed-by: Kuldeep Singh <quic_kuldsing@xxxxxxxxxxx>
Signed-off-by: Kuldeep Singh <quic_kuldsing@xxxxxxxxxxx>
---
 drivers/firmware/qcom/qcom_scm.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
index 10986cb11ec0..620313359042 100644
--- a/drivers/firmware/qcom/qcom_scm.c
+++ b/drivers/firmware/qcom/qcom_scm.c
@@ -111,6 +111,10 @@ enum qcom_scm_qseecom_tz_cmd_info {
 	QSEECOM_TZ_CMD_INFO_VERSION		= 3,
 };
 
+enum qcom_scm_shm_bridge_result {
+	SHMBRIDGE_RESULT_NOTSUPP	= 4,
+};
+
 #define QSEECOM_MAX_APP_NAME_SIZE		64
 
 /* Each bit configures cold/warm boot address for one of the 4 CPUs */
@@ -1361,6 +1365,8 @@ EXPORT_SYMBOL_GPL(qcom_scm_lmh_dcvsh_available);
 
 int qcom_scm_shm_bridge_enable(void)
 {
+	int ret;
+
 	struct qcom_scm_desc desc = {
 		.svc = QCOM_SCM_SVC_MP,
 		.cmd = QCOM_SCM_MP_SHM_BRIDGE_ENABLE,
@@ -1373,7 +1379,11 @@ int qcom_scm_shm_bridge_enable(void)
 					  QCOM_SCM_MP_SHM_BRIDGE_ENABLE))
 		return -EOPNOTSUPP;
 
-	return qcom_scm_call(__scm->dev, &desc, &res) ?: res.result[0];
+	ret = qcom_scm_call(__scm->dev, &desc, &res);
+	if (!ret && res.result[0] == SHMBRIDGE_RESULT_NOTSUPP)
+		return -EOPNOTSUPP;
+
+	return ret ?: res.result[0];
 }
 EXPORT_SYMBOL_GPL(qcom_scm_shm_bridge_enable);
 
-- 
2.34.1