drivers: tee: sandbox: add rpc test ta emulation

This adds support for RPC test trusted application emulation, which
permits to test reverse RPC calls to TEE supplicant. Currently it covers
requests to the I2C bus from TEE.

Signed-off-by: Igor Opaniuk <igor.opaniuk@foundries.io>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Acked-by: Etienne Carriere <etienne.carriere@linaro.org>

4 files changed, 179 insertions, 4 deletions

diff --git a/drivers/tee/Makefile b/drivers/tee/Makefile
index 5c8ffdbce8c..ff844195ae1 100644
--- a/drivers/tee/Makefile
+++ b/drivers/tee/Makefile
@@ -2,5 +2,7 @@
 
 obj-y += tee-uclass.o
 obj-$(CONFIG_SANDBOX) += sandbox.o
+obj-$(CONFIG_OPTEE_TA_RPC_TEST) += optee/supplicant.o
+obj-$(CONFIG_OPTEE_TA_RPC_TEST) += optee/i2c.o
 obj-$(CONFIG_OPTEE) += optee/
 obj-y += broadcom/
diff --git a/drivers/tee/optee/Kconfig b/drivers/tee/optee/Kconfig
index d489834df92..65622f30b1e 100644
--- a/drivers/tee/optee/Kconfig
+++ b/drivers/tee/optee/Kconfig
@@ -22,6 +22,15 @@ config OPTEE_TA_AVB
 	  The TA can support the "avb" subcommands "read_rb", "write"rb"
 	  and "is_unlocked".
 
+config OPTEE_TA_RPC_TEST
+	bool "Support RPC TEST TA"
+	depends on SANDBOX_TEE
+	default y
+	help
+	  Enables support for RPC test trusted application emulation, which
+	  permits to test reverse RPC calls to TEE supplicant. Should
+	  be used only in sandbox env.
+
 endmenu
 
 endif
diff --git a/drivers/tee/sandbox.c b/drivers/tee/sandbox.c
index e1ba027fd6e..3a1d34d6fc0 100644
--- a/drivers/tee/sandbox.c
+++ b/drivers/tee/sandbox.c
@@ -7,11 +7,15 @@
 #include <sandboxtee.h>
 #include <tee.h>
 #include <tee/optee_ta_avb.h>
+#include <tee/optee_ta_rpc_test.h>
+
+#include "optee/optee_msg.h"
+#include "optee/optee_private.h"
 
 /*
  * The sandbox tee driver tries to emulate a generic Trusted Exectution
- * Environment (TEE) with the Trusted Application (TA) OPTEE_TA_AVB
- * available.
+ * Environment (TEE) with the Trusted Applications (TA) OPTEE_TA_AVB and
+ * OPTEE_TA_RPC_TEST available.
  */
 
 static const u32 pstorage_max = 16;
@@ -32,7 +36,38 @@ struct ta_entry {
 			   struct tee_param *params);
 };
 
-#ifdef CONFIG_OPTEE_TA_AVB
+static int get_msg_arg(struct udevice *dev, uint num_params,
+		       struct tee_shm **shmp, struct optee_msg_arg **msg_arg)
+{
+	int rc;
+	struct optee_msg_arg *ma;
+
+	rc = __tee_shm_add(dev, OPTEE_MSG_NONCONTIG_PAGE_SIZE, NULL,
+			   OPTEE_MSG_GET_ARG_SIZE(num_params), TEE_SHM_ALLOC,
+			   shmp);
+	if (rc)
+		return rc;
+
+	ma = (*shmp)->addr;
+	memset(ma, 0, OPTEE_MSG_GET_ARG_SIZE(num_params));
+	ma->num_params = num_params;
+	*msg_arg = ma;
+
+	return 0;
+}
+
+void *optee_alloc_and_init_page_list(void *buf, ulong len,
+				     u64 *phys_buf_ptr)
+{
+	/*
+	 * An empty stub is added just to fix linking issues.
+	 * This function isn't supposed to be called in sandbox
+	 * setup, otherwise replace this with a proper
+	 * implementation from optee/core.c
+	 */
+	return NULL;
+}
+
 static u32 get_attr(uint n, uint num_params, struct tee_param *params)
 {
 	if (n >= num_params)
@@ -63,6 +98,7 @@ bad_params:
 	return TEE_ERROR_BAD_PARAMETERS;
 }
 
+#ifdef CONFIG_OPTEE_TA_AVB
 static u32 ta_avb_open_session(struct udevice *dev, uint num_params,
 			       struct tee_param *params)
 {
@@ -214,7 +250,99 @@ static u32 ta_avb_invoke_func(struct udevice *dev, u32 func, uint num_params,
 		return TEE_ERROR_NOT_SUPPORTED;
 	}
 }
-#endif /*OPTEE_TA_AVB*/
+#endif /* OPTEE_TA_AVB */
+
+#ifdef CONFIG_OPTEE_TA_RPC_TEST
+static u32 ta_rpc_test_open_session(struct udevice *dev, uint num_params,
+				    struct tee_param *params)
+{
+	/*
+	 * We don't expect additional parameters when opening a session to
+	 * this TA.
+	 */
+	return check_params(TEE_PARAM_ATTR_TYPE_NONE, TEE_PARAM_ATTR_TYPE_NONE,
+			    TEE_PARAM_ATTR_TYPE_NONE, TEE_PARAM_ATTR_TYPE_NONE,
+			    num_params, params);
+}
+
+static void fill_i2c_rpc_params(struct optee_msg_arg *msg_arg, u64 bus_num,
+				u64 chip_addr, u64 xfer_flags, u64 op,
+				struct tee_param_memref memref)
+{
+	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
+	msg_arg->params[1].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
+	msg_arg->params[2].attr = OPTEE_MSG_ATTR_TYPE_RMEM_INOUT;
+	msg_arg->params[3].attr = OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT;
+
+	/* trigger I2C services of TEE supplicant */
+	msg_arg->cmd = OPTEE_MSG_RPC_CMD_I2C_TRANSFER;
+
+	msg_arg->params[0].u.value.a = op;
+	msg_arg->params[0].u.value.b = bus_num;
+	msg_arg->params[0].u.value.c = chip_addr;
+	msg_arg->params[1].u.value.a = xfer_flags;
+
+	/* buffer to read/write data */
+	msg_arg->params[2].u.rmem.shm_ref = (ulong)memref.shm;
+	msg_arg->params[2].u.rmem.size = memref.size;
+	msg_arg->params[2].u.rmem.offs = memref.shm_offs;
+
+	msg_arg->num_params = 4;
+}
+
+static u32 ta_rpc_test_invoke_func(struct udevice *dev, u32 func,
+				   uint num_params,
+				   struct tee_param *params)
+{
+	struct tee_shm *shm;
+	struct tee_param_memref memref_data;
+	struct optee_msg_arg *msg_arg;
+	int chip_addr, bus_num, op, xfer_flags;
+	int res;
+
+	res = check_params(TEE_PARAM_ATTR_TYPE_VALUE_INPUT,
+			   TEE_PARAM_ATTR_TYPE_MEMREF_INOUT,
+			   TEE_PARAM_ATTR_TYPE_NONE,
+			   TEE_PARAM_ATTR_TYPE_NONE,
+			   num_params, params);
+	if (res)
+		return TEE_ERROR_BAD_PARAMETERS;
+
+	bus_num = params[0].u.value.a;
+	chip_addr = params[0].u.value.b;
+	xfer_flags = params[0].u.value.c;
+	memref_data = params[1].u.memref;
+
+	switch (func) {
+	case TA_RPC_TEST_CMD_I2C_READ:
+		op = OPTEE_MSG_RPC_CMD_I2C_TRANSFER_RD;
+		break;
+	case TA_RPC_TEST_CMD_I2C_WRITE:
+		op = OPTEE_MSG_RPC_CMD_I2C_TRANSFER_WR;
+		break;
+	default:
+		return TEE_ERROR_NOT_SUPPORTED;
+	}
+
+	/*
+	 * Fill params for an RPC call to tee supplicant
+	 */
+	res = get_msg_arg(dev, 4, &shm, &msg_arg);
+	if (res)
+		goto out;
+
+	fill_i2c_rpc_params(msg_arg, bus_num, chip_addr, xfer_flags, op,
+			    memref_data);
+
+	/* Make an RPC call to tee supplicant */
+	optee_suppl_cmd(dev, shm, 0);
+	res = msg_arg->ret;
+out:
+	tee_shm_free(shm);
+
+	return res;
+}
+#endif /* CONFIG_OPTEE_TA_RPC_TEST */
 
 static const struct ta_entry ta_entries[] = {
 #ifdef CONFIG_OPTEE_TA_AVB
@@ -223,6 +351,12 @@ static const struct ta_entry ta_entries[] = {
 	  .invoke_func = ta_avb_invoke_func,
 	},
 #endif
+#ifdef CONFIG_OPTEE_TA_RPC_TEST
+	{ .uuid = TA_RPC_TEST_UUID,
+	  .open_session = ta_rpc_test_open_session,
+	  .invoke_func = ta_rpc_test_invoke_func,
+	},
+#endif
 };
 
 static void sandbox_tee_get_version(struct udevice *dev,
diff --git a/include/tee/optee_ta_rpc_test.h b/include/tee/optee_ta_rpc_test.h
new file mode 100644
index 00000000000..9491fbab1d8
--- /dev/null
+++ b/include/tee/optee_ta_rpc_test.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/* Copyright (c) 2020 Foundries Ltd */
+
+#ifndef __TA_RPC_TEST_H
+#define __TA_RPC_TEST_H
+
+#define TA_RPC_TEST_UUID { 0x48420575, 0x96ca, 0x401a, \
+		      { 0x89, 0x91, 0x1e, 0xfd, 0xce, 0xbd, 0x7d, 0x04 } }
+
+/*
+ * Does a reverse RPC call for I2C read
+ *
+ * in		params[0].value.a:	bus number
+ * in		params[0].value.b:	chip address
+ * in		params[0].value.c:	control flags
+ * inout	params[1].u.memref:	buffer to read data
+ */
+#define TA_RPC_TEST_CMD_I2C_READ	0
+
+/*
+ * Does a reverse RPC call for I2C write
+ *
+ * in		params[0].value.a:	bus number
+ * in		params[0].value.b:	chip address
+ * in		params[0].value.c:	control flags
+ * inout	params[1].u.memref:	buffer with data to write
+ */
+#define TA_RPC_TEST_CMD_I2C_WRITE	1
+
+#endif /* __TA_RPC_TEST_H */