[PATCH 5.13 114/175] optee: fix tee out of memory failure seen during kexec reboot

[Greg Kroah-Hartman]

From: Allen Pais <apais@xxxxxxxxxxxxxxxxxxx>

commit f25889f93184db8b07a543cc2bbbb9a8fcaf4333 upstream.

The following out of memory errors are seen on kexec reboot
from the optee core.

[    0.368428] tee_bnxt_fw optee-clnt0: tee_shm_alloc failed
[    0.368461] tee_bnxt_fw: probe of optee-clnt0 failed with error -22

tee_shm_release() is not invoked on dma shm buffer.

Implement .shutdown() method to handle the release of the buffers
correctly.

More info:
https://github.com/OP-TEE/optee_os/issues/3637

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Allen Pais <apais@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
Reviewed-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/tee/optee/core.c |   20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -574,6 +574,13 @@ static optee_invoke_fn *get_invoke_func(
 	return ERR_PTR(-EINVAL);
 }
 
+/* optee_remove - Device Removal Routine
+ * @pdev: platform device information struct
+ *
+ * optee_remove is called by platform subsystem to alert the driver
+ * that it should release the device
+ */
+
 static int optee_remove(struct platform_device *pdev)
 {
 	struct optee *optee = platform_get_drvdata(pdev);
@@ -604,6 +611,18 @@ static int optee_remove(struct platform_
 	return 0;
 }
 
+/* optee_shutdown - Device Removal Routine
+ * @pdev: platform device information struct
+ *
+ * platform_shutdown is called by the platform subsystem to alert
+ * the driver that a shutdown, reboot, or kexec is happening and
+ * device must be disabled.
+ */
+static void optee_shutdown(struct platform_device *pdev)
+{
+	optee_disable_shm_cache(platform_get_drvdata(pdev));
+}
+
 static int optee_probe(struct platform_device *pdev)
 {
 	optee_invoke_fn *invoke_fn;
@@ -749,6 +768,7 @@ MODULE_DEVICE_TABLE(of, optee_dt_match);
 static struct platform_driver optee_driver = {
 	.probe  = optee_probe,
 	.remove = optee_remove,
+	.shutdown = optee_shutdown,
 	.driver = {
 		.name = "optee",
 		.of_match_table = optee_dt_match,