Merge tag 'optee-cleanup-for-v6.8' of https://git.linaro.org/people/jens.wiklander/linux-tee into soc/drivers

OP-TEE cleanup

- Remove a redundant custom workqueue in the OP-TEE driver.
- Fix a missing description of an argument to optee_handle_rpc().

* tag 'optee-cleanup-for-v6.8' of https://git.linaro.org/people/jens.wiklander/linux-tee:
  optee: add missing description of RPC argument reference
  tee: optee: Remove redundant custom workqueue
  tee: optee: Fix supplicant based device enumeration

Link: https://lore.kernel.org/r/20231214132237.GA3092763@rayden
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Documentation/ABI/testing/sysfs-bus-optee-devices

@@ -6,3 +6,12 @@ Description:
 		OP-TEE bus provides reference to registered drivers under this directory. The <uuid>
 		matches Trusted Application (TA) driver and corresponding TA in secure OS. Drivers
 		are free to create needed API under optee-ta-<uuid> directory.
+
+What:		/sys/bus/tee/devices/optee-ta-<uuid>/need_supplicant
+Date:		November 2023
+KernelVersion:	6.7
+Contact:	op-tee@lists.trustedfirmware.org
+Description:
+		Allows to distinguish whether an OP-TEE based TA/device requires user-space
+		tee-supplicant to function properly or not. This attribute will be present for
+		devices which depend on tee-supplicant to be running.

drivers/tee/optee/core.c

@@ -15,7 +15,6 @@
 #include <linux/string.h>
 #include <linux/tee_drv.h>
 #include <linux/types.h>
-#include <linux/workqueue.h>
 #include "optee_private.h"
 
 int optee_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
@@ -112,12 +111,7 @@ int optee_open(struct tee_context *ctx, bool cap_memref_null)
 
 		if (!optee->scan_bus_done) {
 			INIT_WORK(&optee->scan_bus_work, optee_bus_scan);
-			optee->scan_bus_wq = create_workqueue("optee_bus_scan");
-			if (!optee->scan_bus_wq) {
-				kfree(ctxdata);
-				return -ECHILD;
-			}
-			queue_work(optee->scan_bus_wq, &optee->scan_bus_work);
+			schedule_work(&optee->scan_bus_work);
 			optee->scan_bus_done = true;
 		}
 	}
@@ -161,10 +155,7 @@ void optee_release_supp(struct tee_context *ctx)
 	struct optee *optee = tee_get_drvdata(ctx->teedev);
 
 	optee_release_helper(ctx, optee_close_session_helper);
-	if (optee->scan_bus_wq) {
-		destroy_workqueue(optee->scan_bus_wq);
-		optee->scan_bus_wq = NULL;
-	}
+
 	optee_supp_release(&optee->supp);
 }
 

drivers/tee/optee/device.c

@@ -60,7 +60,16 @@ static void optee_release_device(struct device *dev)
 	kfree(optee_device);
 }
 
-static int optee_register_device(const uuid_t *device_uuid)
+static ssize_t need_supplicant_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	return 0;
+}
+
+static DEVICE_ATTR_RO(need_supplicant);
+
+static int optee_register_device(const uuid_t *device_uuid, u32 func)
 {
 	struct tee_client_device *optee_device = NULL;
 	int rc;
@@ -83,6 +92,10 @@ static int optee_register_device(const uuid_t *device_uuid)
 		put_device(&optee_device->dev);
 	}
 
+	if (func == PTA_CMD_GET_DEVICES_SUPP)
+		device_create_file(&optee_device->dev,
+				   &dev_attr_need_supplicant);
+
 	return rc;
 }
 
@@ -142,7 +155,7 @@ static int __optee_enumerate_devices(u32 func)
 	num_devices = shm_size / sizeof(uuid_t);
 
 	for (idx = 0; idx < num_devices; idx++) {
-		rc = optee_register_device(&device_uuid[idx]);
+		rc = optee_register_device(&device_uuid[idx], func);
 		if (rc)
 			goto out_shm;
 	}

drivers/tee/optee/optee_private.h

@@ -199,7 +199,6 @@ struct optee_ops {
  * @pool:		shared memory pool
  * @rpc_param_count:	If > 0 number of RPC parameters to make room for
  * @scan_bus_done	flag if device registation was already done.
- * @scan_bus_wq		workqueue to scan optee bus and register optee drivers
  * @scan_bus_work	workq to scan optee bus and register optee drivers
  */
 struct optee {
@@ -218,7 +217,6 @@ struct optee {
 	struct tee_shm_pool *pool;
 	unsigned int rpc_param_count;
 	bool   scan_bus_done;
-	struct workqueue_struct *scan_bus_wq;
 	struct work_struct scan_bus_work;
 };
 

drivers/tee/optee/smc_abi.c

@@ -803,6 +803,7 @@ static void handle_rpc_func_cmd(struct tee_context *ctx, struct optee *optee,
 /**
  * optee_handle_rpc() - handle RPC from secure world
  * @ctx:	context doing the RPC
+ * @rpc_arg:	pointer to RPC arguments if any, or NULL if none
  * @param:	value of registers for the RPC
  * @call_ctx:	call context. Preserved during one OP-TEE invocation
  *