Patch "firmware: qcom: scm: Return -EOPNOTSUPP for unsupported SHM bridge enabling" has been added to the 6.11-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    firmware: qcom: scm: Return -EOPNOTSUPP for unsupported SHM bridge enabling

to the 6.11-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     firmware-qcom-scm-return-eopnotsupp-for-unsupported-.patch
and it can be found in the queue-6.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 25da4f84535c6698a22603b6e7d1445cd7699475
Author: Qingqing Zhou <quic_qqzhou@xxxxxxxxxxx>
Date:   Wed Oct 23 00:51:48 2024 +0530

    firmware: qcom: scm: Return -EOPNOTSUPP for unsupported SHM bridge enabling
    
    [ Upstream commit f489f6c6eb26482010470d77bad3901a3de1b166 ]
    
    When enabling SHM bridge, QTEE returns 0 and sets error 4 in result to
    qcom_scm for unsupported platforms. Currently, tzmem interprets this as
    an unknown error rather than recognizing it as an unsupported 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
    
    To address this, modify the function call qcom_scm_shm_bridge_enable()
    to remap result to indicate an unsupported error. This way, tzmem will
    correctly identify it as an unsupported platform case instead of
    reporting it as an error.
    
    Fixes: 178e19c0df1b ("firmware: qcom: scm: add support for SHM bridge operations")
    Signed-off-by: Qingqing Zhou <quic_qqzhou@xxxxxxxxxxx>
    Co-developed-by: Kuldeep Singh <quic_kuldsing@xxxxxxxxxxx>
    Signed-off-by: Kuldeep Singh <quic_kuldsing@xxxxxxxxxxx>
    Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
    Reviewed-by: Mukesh Ojha <quic_mojha@xxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20241022192148.1626633-1-quic_kuldsing@xxxxxxxxxxx
    Signed-off-by: Bjorn Andersson <andersson@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
index a50d8e8d0f1b8..6436bd09587a5 100644
--- a/drivers/firmware/qcom/qcom_scm.c
+++ b/drivers/firmware/qcom/qcom_scm.c
@@ -112,6 +112,7 @@ enum qcom_scm_qseecom_tz_cmd_info {
 };
 
 #define QSEECOM_MAX_APP_NAME_SIZE		64
+#define SHMBRIDGE_RESULT_NOTSUPP		4
 
 /* Each bit configures cold/warm boot address for one of the 4 CPUs */
 static const u8 qcom_scm_cpu_cold_bits[QCOM_SCM_BOOT_MAX_CPUS] = {
@@ -1353,6 +1354,8 @@ 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,
@@ -1365,7 +1368,15 @@ 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)
+		return ret;
+
+	if (res.result[0] == SHMBRIDGE_RESULT_NOTSUPP)
+		return -EOPNOTSUPP;
+
+	return res.result[0];
 }
 EXPORT_SYMBOL_GPL(qcom_scm_shm_bridge_enable);