[v4,2/2] firmware: arm_scmi: optee: use optee system invocation
Commit Message
Changes SCMI optee transport to request an OP-TEE system invocation
context per SCMI channel. This prevents possible deadlock when many
Linux clients invoke OP-TEE are all suspended waiting for an OP-TEE
RPC request access an SCMI resource through the SCMI OP-TEE PTA service.
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
---
No change since v3
Changes since v2:
- Fixed syntax issues (missing ';' chars), reported by kernel test robot.
Changes since v1:
- Updated to use new tee API functions tee_client_request_system_context()
and tee_client_release_system_context().
---
drivers/firmware/arm_scmi/optee.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
@@ -119,6 +119,7 @@ struct scmi_optee_channel {
u32 tee_session;
u32 caps;
u32 rx_len;
+ bool sys_thread;
struct mutex mu;
struct scmi_chan_info *cinfo;
union {
@@ -432,9 +433,15 @@ static int scmi_optee_chan_setup(struct scmi_chan_info *cinfo, struct device *de
channel->channel_id = channel_id;
mutex_init(&channel->mu);
+ ret = tee_client_request_system_context(scmi_optee_private->tee_ctx);
+ if (ret)
+ dev_warn(dev, "Couldn't provision an OP-TEE system context\n");
+ else
+ channel->sys_thread = true;
+
ret = setup_shmem(dev, cinfo, channel);
if (ret)
- return ret;
+ goto err_release_sysctx;
ret = open_session(scmi_optee_private, &channel->tee_session);
if (ret)
@@ -458,6 +465,9 @@ static int scmi_optee_chan_setup(struct scmi_chan_info *cinfo, struct device *de
err_free_shm:
if (channel->tee_shm)
tee_shm_free(channel->tee_shm);
+err_release_sysctx:
+ if (channel->sys_thread)
+ tee_client_release_system_context(scmi_optee_private->tee_ctx);
return ret;
}
@@ -483,6 +493,9 @@ static int scmi_optee_chan_free(int id, void *p, void *data)
scmi_free_channel(cinfo, data, id);
+ if (channel->sys_thread)
+ tee_client_release_system_context(scmi_optee_private->tee_ctx);
+
return 0;
}