[PW_SID:1163446] tee: optee: add RISC-V RPMI TEE transport

Documentation/devicetree/bindings/tee/riscv,rpmi-mpxy-tee.yaml

@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/tee/riscv,rpmi-mpxy-tee.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V RPMI TEE service group based message proxy
+
+maintainers:
+  - Amirreza Zarrabi <amirreza.zarrabi@oss.qualcomm.com>
+
+description: |
+  The RISC-V Platform Management Interface (RPMI) [1] defines a messaging
+  protocol which is modular and extensible. The supervisor software can
+  send/receive RPMI messages via the SBI MPXY extension [2] or some dedicated
+  supervisor-mode RPMI transport.
+
+  The RPMI specification [1] defines a TEE service group which is the RISC-V
+  analog of Arm FF-A: OP-TEE and the rich execution environment (REE, i.e.
+  Linux) are peer endpoints and the RPMI framework (machine mode firmware)
+  mediates every message. Entering OP-TEE on a hart runs it on that hart until
+  it responds, so the SBI implementation provides one SBI MPXY channel per
+  hart; all of them are listed, in hart order, on a single node.
+
+  ===========================================
+  References
+  ===========================================
+
+  [1] RISC-V Platform Management Interface (RPMI) v1.0 (or higher)
+      https://github.com/riscv-non-isa/riscv-rpmi/releases
+
+  [2] RISC-V Supervisor Binary Interface (SBI) v3.0 (or higher)
+      https://github.com/riscv-non-isa/riscv-sbi-doc/releases
+
+properties:
+  compatible:
+    const: riscv,rpmi-mpxy-tee
+
+  mboxes:
+    minItems: 1
+    description:
+      One SBI MPXY channel implementing the RPMI TEE service group per hart,
+      listed in the same order as the CPU nodes.
+
+  interrupts:
+    maxItems: 1
+    description:
+      Availability doorbell raised by OP-TEE to signal asynchronous
+      notifications over the RPMI TEE signal bus. Optional; when absent
+      asynchronous notification is disabled.
+
+required:
+  - compatible
+  - mboxes
+
+additionalProperties: false
+
+examples:
+  - |
+    tee {
+        compatible = "riscv,rpmi-mpxy-tee";
+        mboxes = <&mpxy_mbox 0x10 0x0>, <&mpxy_mbox 0x11 0x0>;
+    };
+...

MAINTAINERS

@@ -20420,6 +20420,7 @@ M:	Jens Wiklander <jenswi@kernel.org>
 L:	op-tee@lists.trustedfirmware.org (moderated for non-subscribers)
 S:	Maintained
 F:	Documentation/ABI/testing/sysfs-bus-optee-devices
+F:	Documentation/devicetree/bindings/tee/riscv,rpmi-mpxy-tee.yaml
 F:	drivers/tee/optee/
 
 OP-TEE RANDOM NUMBER GENERATOR (RNG) DRIVER

drivers/tee/optee/Makefile

@@ -9,6 +9,7 @@ optee-objs += supp.o
 optee-objs += device.o
 optee-objs += smc_abi.o
 optee-objs += ffa_abi.o
+optee-$(CONFIG_RISCV_SBI_MPXY_MBOX) += optee_riscv.o
 
 # for tracing framework to find optee_trace.h
 CFLAGS_smc_abi.o := -I$(src)

drivers/tee/optee/core.c

@@ -220,6 +220,7 @@ void optee_remove_common(struct optee *optee)
 
 static int smc_abi_rc;
 static int ffa_abi_rc;
+static int riscv_abi_rc;
 static bool intf_is_regged;
 
 static int __init optee_core_init(void)
@@ -245,9 +246,10 @@ static int __init optee_core_init(void)
 
 	smc_abi_rc = optee_smc_abi_register();
 	ffa_abi_rc = optee_ffa_abi_register();
+	riscv_abi_rc = optee_riscv_abi_register();
 
-	/* If both failed there's no point with this module */
-	if (smc_abi_rc && ffa_abi_rc) {
+	/* If all failed there's no point with this module */
+	if (smc_abi_rc && ffa_abi_rc && riscv_abi_rc) {
 		if (IS_REACHABLE(CONFIG_RPMB)) {
 			rpmb_interface_unregister(&rpmb_class_intf);
 			intf_is_regged = false;
@@ -270,6 +272,8 @@ static void __exit optee_core_exit(void)
 		optee_smc_abi_unregister();
 	if (!ffa_abi_rc)
 		optee_ffa_abi_unregister();
+	if (!riscv_abi_rc)
+		optee_riscv_abi_unregister();
 }
 module_exit(optee_core_exit);
 

drivers/tee/optee/optee_private.h

@@ -171,6 +171,44 @@ struct optee_ffa {
 	struct work_struct notif_work;
 };
 
+/**
+ * struct optee_riscv - RPMI TEE communication struct
+ * @chan:		per-hart RPMI TEE service group mailbox channels
+ * @client:		RPMI mailbox client used to request @chan
+ * @dev:		device backing the RPMI TEE mailbox client
+ * @nr_chan:		number of entries in @chan
+ * @max_msg_data_size:	maximum RPMI message data size of the TEE channel
+ * @next_nonce:		monotonic nonce source for memory parcel creation
+ * @mutex:		serializes access to @global_ids
+ * @global_ids:		memory parcel id to tee_shm translation table
+ * @notif_wq:		workqueue for signal-bus asynchronous notification
+ * @notif_work:		work for signal-bus asynchronous notification
+ * @signal_irq:		availability doorbell IRQ, or 0 if async notif unused
+ * @sender_signals:	number of signals OP-TEE may raise to the REE
+ * @bottom_half_value:	signal value that requests an RPC bottom half, or
+ *			U32_MAX if async notif is unused
+ *
+ * This is the RISC-V analog of struct optee_ffa: communication with secure
+ * world OP-TEE OS rides the RPMI TEE service group (RPMI spec section 4.16)
+ * over the SBI MPXY mailbox instead of Arm FF-A.
+ */
+struct optee_riscv {
+	struct mbox_chan **chan;
+	struct mbox_client *client;
+	struct device *dev;
+	unsigned int nr_chan;
+	u32 max_msg_data_size;
+	atomic_t next_nonce;
+	/* Serializes access to @global_ids */
+	struct mutex mutex;
+	struct rhashtable global_ids;
+	struct workqueue_struct *notif_wq;
+	struct work_struct notif_work;
+	unsigned int signal_irq;
+	u32 sender_signals;
+	u32 bottom_half_value;
+};
+
 struct optee;
 
 /**
@@ -231,6 +269,7 @@ struct optee_ops {
  * @ctx:			driver internal TEE context
  * @smc:			specific to SMC ABI
  * @ffa:			specific to FF-A ABI
+ * @riscv:			specific to RPMI TEE ABI
  * @shm_arg_cache:		shared memory cache argument
  * @call_queue:			queue of threads waiting to call @invoke_fn
  * @notif:			notification synchronization struct
@@ -259,6 +298,7 @@ struct optee {
 	union {
 		struct optee_smc smc;
 		struct optee_ffa ffa;
+		struct optee_riscv riscv;
 	};
 	struct optee_shm_arg_cache shm_arg_cache;
 	struct optee_call_queue call_queue;
@@ -426,5 +466,12 @@ int optee_smc_abi_register(void);
 void optee_smc_abi_unregister(void);
 int optee_ffa_abi_register(void);
 void optee_ffa_abi_unregister(void);
+#ifdef CONFIG_RISCV_SBI_MPXY_MBOX
+int optee_riscv_abi_register(void);
+void optee_riscv_abi_unregister(void);
+#else
+static inline int optee_riscv_abi_register(void) { return -EOPNOTSUPP; }
+static inline void optee_riscv_abi_unregister(void) { }
+#endif
 
 #endif /*OPTEE_PRIVATE_H*/