[PATCH v5 1/3] drivers: tee: optee: remove unused probe local variable

[PATCH v5 1/3] drivers: tee: optee: remove unused probe local variable

[Etienne Carriere]

Removes local variable child in optee_probe() that is not used.

Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
---
- No change since v4

Changes since v3:
- Applied Patrick's R-b tag.

No change since v2.

New change not in v1 series.
---
 drivers/tee/optee/core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index a89d62aaf0..c1f5fc4c7a 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -642,7 +642,6 @@ static int optee_probe(struct udevice *dev)
 {
 	struct optee_pdata *pdata = dev_get_plat(dev);
 	u32 sec_caps;
-	struct udevice *child;
 	int ret;
 
 	if (!is_optee_api(pdata->invoke_fn)) {
@@ -673,7 +672,7 @@ static int optee_probe(struct udevice *dev)
 	 * only bind the drivers associated to the supported OP-TEE TA
 	 */
 	if (IS_ENABLED(CONFIG_RNG_OPTEE)) {
-		ret = device_bind_driver(dev, "optee-rng", "optee-rng", &child);
+		ret = device_bind_driver(dev, "optee-rng", "optee-rng", NULL);
 		if (ret)
 			return ret;
 	}
-- 
2.25.1

[PATCH v5 2/3] drivers: tee: optee: discover OP-TEE services

[Etienne Carriere]

This change defines resources for OP-TEE service drivers to register
themselves for being bound to when OP-TEE firmware reports the related
service is supported. OP-TEE services are discovered during optee
driver probe sequence which mandates optee driver is always probe once
bound.

Discovery of optee services and binding to related U-Boot drivers is
embedded upon configuration switch CONFIG_OPTEE_SERVICE_DISCOVERY.

Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
---
Changes since v4:
- Fix incompatible argument type for __enum_services() reported by 64bit
  builds.

Changes since v3:
- Stub OPTEE_SERVICE_DRIVER() macro when CONFIG_OPTEE_SERVICE_DISCOVERY
  is disable.

Changes since v2:
- Release allocated shared memory from bind_service_drivers() only.
- Remove definition of useless macro OPTEE_SERVICE_DRIVER_GET().

Changes since v1:
- Remove all #ifdef CONFIG_OPTEE_SERVICE_DISCOVERY directives and replace
  with if (IS_ENABLED()) where applicable.
- Incidentally rename local function open_session() to open_enum_session()
  and remove local function close_session() for clarity.
- Update commit log to highlight that "optee driver is always probe once
  bound" when CONFIG_OPTEE_SERVICE_DISCOVERY is enable.
---
 drivers/tee/optee/Kconfig   |   8 ++
 drivers/tee/optee/core.c    | 171 ++++++++++++++++++++++++++++++++++--
 include/tee/optee_service.h |  34 +++++++
 3 files changed, 208 insertions(+), 5 deletions(-)
 create mode 100644 include/tee/optee_service.h

diff --git a/drivers/tee/optee/Kconfig b/drivers/tee/optee/Kconfig
index d03028070b..9dc65b0501 100644
--- a/drivers/tee/optee/Kconfig
+++ b/drivers/tee/optee/Kconfig
@@ -37,6 +37,14 @@ config OPTEE_TA_SCP03
 	help
 	  Enables support for controlling (enabling, provisioning) the
 	  Secure Channel Protocol 03 operation in the OP-TEE SCP03 TA.
+
+config OPTEE_SERVICE_DISCOVERY
+	bool "OP-TEE service discovery"
+	default y
+	help
+	  This implements automated driver binding of OP-TEE service drivers by
+	  requesting OP-TEE firmware to enumerate its hosted services.
+
 endmenu
 
 endif
diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index c1f5fc4c7a..9240277579 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -14,6 +14,7 @@
 #include <linux/arm-smccc.h>
 #include <linux/err.h>
 #include <linux/io.h>
+#include <tee/optee_service.h>
 
 #include "optee_smc.h"
 #include "optee_msg.h"
@@ -22,6 +23,25 @@
 #define PAGELIST_ENTRIES_PER_PAGE \
 	((OPTEE_MSG_NONCONTIG_PAGE_SIZE / sizeof(u64)) - 1)
 
+/*
+ * PTA_DEVICE_ENUM interface exposed by OP-TEE to discover enumerated services
+ */
+#define PTA_DEVICE_ENUM		{ 0x7011a688, 0xddde, 0x4053, \
+				  { 0xa5, 0xa9, 0x7b, 0x3c, 0x4d, 0xdf, 0x13, 0xb8 } }
+/*
+ * PTA_CMD_GET_DEVICES - List services without supplicant dependencies
+ *
+ * [out]    memref[0]: List of the UUIDs of service enumerated by OP-TEE
+ */
+#define PTA_CMD_GET_DEVICES		0x0
+
+/*
+ * PTA_CMD_GET_DEVICES_SUPP - List services depending on tee supplicant
+ *
+ * [out]    memref[0]: List of the UUIDs of service enumerated by OP-TEE
+ */
+#define PTA_CMD_GET_DEVICES_SUPP	0x1
+
 typedef void (optee_invoke_fn)(unsigned long, unsigned long, unsigned long,
 			       unsigned long, unsigned long, unsigned long,
 			       unsigned long, unsigned long,
@@ -42,6 +62,134 @@ struct rpc_param {
 	u32	a7;
 };
 
+static struct optee_service *find_service_driver(const struct tee_optee_ta_uuid *uuid)
+{
+	struct optee_service *service;
+	u8 loc_uuid[TEE_UUID_LEN];
+	size_t service_cnt, idx;
+
+	service_cnt = ll_entry_count(struct optee_service, optee_service);
+	service = ll_entry_start(struct optee_service, optee_service);
+
+	for (idx = 0; idx < service_cnt; idx++, service++) {
+		tee_optee_ta_uuid_to_octets(loc_uuid, &service->uuid);
+		if (!memcmp(uuid, loc_uuid, sizeof(uuid)))
+			return service;
+	}
+
+	return NULL;
+}
+
+static int bind_service_list(struct udevice *dev, struct tee_shm *service_list, size_t count)
+{
+	const struct tee_optee_ta_uuid *service_uuid = (const void *)service_list->addr;
+	struct optee_service *service;
+	size_t idx;
+	int ret;
+
+	for (idx = 0; idx < count; idx++) {
+		service = find_service_driver(service_uuid + idx);
+		if (!service)
+			continue;
+
+		ret = device_bind_driver(dev, service->driver_name, service->driver_name, NULL);
+		if (ret) {
+			dev_warn(dev, "%s was not bound: %d, ignored\n", service->driver_name, ret);
+			continue;
+		}
+	}
+
+	return 0;
+}
+
+static int __enum_services(struct udevice *dev, struct tee_shm *shm, size_t *shm_size, u32 tee_sess)
+{
+	struct tee_invoke_arg arg = { };
+	struct tee_param param = { };
+	int ret = 0;
+
+	arg.func = PTA_CMD_GET_DEVICES;
+	arg.session = tee_sess;
+
+	/* Fill invoke cmd params */
+	param.attr = TEE_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+	param.u.memref.shm = shm;
+	param.u.memref.size = *shm_size;
+
+	ret = tee_invoke_func(dev, &arg, 1, &param);
+	if (ret || (arg.ret && arg.ret != TEE_ERROR_SHORT_BUFFER)) {
+		dev_err(dev, "PTA_CMD_GET_DEVICES invoke function err: 0x%x\n", arg.ret);
+		return -EINVAL;
+	}
+
+	*shm_size = param.u.memref.size;
+
+	return 0;
+}
+
+static int enum_services(struct udevice *dev, struct tee_shm **shm, size_t *count, u32 tee_sess)
+{
+	size_t shm_size = 0;
+	int ret;
+
+	ret = __enum_services(dev, NULL, &shm_size, tee_sess);
+	if (ret)
+		return ret;
+
+	ret = tee_shm_alloc(dev, shm_size, 0, shm);
+	if (ret) {
+		dev_err(dev, "Failed to allocated shared memory: %d\n", ret);
+		return ret;
+	}
+
+	ret = __enum_services(dev, *shm, &shm_size, tee_sess);
+	if (!ret)
+		*count = shm_size / sizeof(struct tee_optee_ta_uuid);
+
+	return ret;
+}
+
+static int open_enum_session(struct udevice *dev, u32 *tee_sess)
+{
+	const struct tee_optee_ta_uuid pta_uuid = PTA_DEVICE_ENUM;
+	struct tee_open_session_arg arg = { };
+	int ret;
+
+	tee_optee_ta_uuid_to_octets(arg.uuid, &pta_uuid);
+
+	ret = tee_open_session(dev, &arg, 0, NULL);
+	if (ret || arg.ret) {
+		if (!ret)
+			ret = -EIO;
+		return ret;
+	}
+
+	*tee_sess = arg.session;
+
+	return 0;
+}
+
+static int bind_service_drivers(struct udevice *dev)
+{
+	struct tee_shm *service_list = NULL;
+	size_t service_count;
+	u32 tee_sess;
+	int ret;
+
+	ret = open_enum_session(dev, &tee_sess);
+	if (ret)
+		return ret;
+
+	ret = enum_services(dev, &service_list, &service_count, tee_sess);
+	if (!ret)
+		ret = bind_service_list(dev, service_list, service_count);
+
+	tee_shm_free(service_list);
+	tee_close_session(dev, tee_sess);
+
+	return ret;
+}
+
 /**
  * reg_pair_to_ptr() - Make a pointer of 2 32-bit values
  * @reg0:	High bits of the pointer
@@ -638,6 +786,14 @@ static int optee_of_to_plat(struct udevice *dev)
 	return 0;
 }
 
+static int optee_bind(struct udevice *dev)
+{
+	if (IS_ENABLED(CONFIG_OPTEE_SERVICE_DISCOVERY))
+		dev_or_flags(dev, DM_FLAG_PROBE_AFTER_BIND);
+
+	return 0;
+}
+
 static int optee_probe(struct udevice *dev)
 {
 	struct optee_pdata *pdata = dev_get_plat(dev);
@@ -667,11 +823,15 @@ static int optee_probe(struct udevice *dev)
 		return -ENOENT;
 	}
 
-	/*
-	 * in U-Boot, the discovery of TA on the TEE bus is not supported:
-	 * only bind the drivers associated to the supported OP-TEE TA
-	 */
-	if (IS_ENABLED(CONFIG_RNG_OPTEE)) {
+	if (IS_ENABLED(CONFIG_OPTEE_SERVICE_DISCOVERY)) {
+		ret = bind_service_drivers(dev);
+		if (ret)
+			return ret;
+	} else if (IS_ENABLED(CONFIG_RNG_OPTEE)) {
+		/*
+		 * Discovery of TAs on the TEE bus is not supported in U-Boot:
+		 * only bind the drivers associated to the supported OP-TEE TA
+		 */
 		ret = device_bind_driver(dev, "optee-rng", "optee-rng", NULL);
 		if (ret)
 			return ret;
@@ -691,6 +851,7 @@ U_BOOT_DRIVER(optee) = {
 	.of_match = optee_match,
 	.of_to_plat = optee_of_to_plat,
 	.probe = optee_probe,
+	.bind = optee_bind,
 	.ops = &optee_ops,
 	.plat_auto	= sizeof(struct optee_pdata),
 	.priv_auto	= sizeof(struct optee_private),
diff --git a/include/tee/optee_service.h b/include/tee/optee_service.h
new file mode 100644
index 0000000000..fca468af7c
--- /dev/null
+++ b/include/tee/optee_service.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * (C) Copyright 2022 Linaro Limited
+ */
+
+#ifndef _OPTEE_SERVICE_H
+#define _OPTEE_SERVICE_H
+
+/*
+ * struct optee_service - Discoverable OP-TEE service
+ *
+ * @driver_name - Name of the related driver
+ * @uuid - UUID of the OP-TEE service related to the driver
+ *
+ * Use macro OPTEE_SERVICE_DRIVER() to register a driver related to an
+ * OP-TEE service discovered when driver asks OP-TEE services enumaration.
+ */
+struct optee_service {
+	const char *driver_name;
+	const struct tee_optee_ta_uuid uuid;
+};
+
+#ifdef CONFIG_OPTEE_SERVICE_DISCOVERY
+#define OPTEE_SERVICE_DRIVER(__name, __uuid, __drv_name) \
+	ll_entry_declare(struct optee_service, __name, optee_service) = { \
+		.uuid = __uuid, \
+		.driver_name = __drv_name, \
+	}
+#else
+#define OPTEE_SERVICE_DRIVER(__name, __uuid, __drv_name) \
+	static int __name##__COUNTER__ __always_unused
+#endif
+
+#endif /* _OPTEE_SERVICE_H */
-- 
2.25.1

[PATCH v5 3/3] drivers: rng: optee_rng: register to CONFIG_OPTEE_SERVICE_DISCOVERY

[Etienne Carriere]

Changes optee_rng driver to register itself has a OP-TEE service so
that a device is bound for the driver when OP-TEE enumerates the
PTA RNG service.

Cc: Sughosh Ganu <sughosh.ganu@linaro.org>
Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
---
No change since v4.

Changes since v3:
- Unconditionally register driver with OPTEE_SERVICE_DRIVER() since the
  macro is now stubbed when CONFIG_OPTEE_SERVICE_DISCOVERY is disable.

No change since v2.

No change since v1.
---
 drivers/rng/Kconfig     | 1 +
 drivers/rng/optee_rng.c | 7 ++++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
index 21a9ff0195..0cbb40add6 100644
--- a/drivers/rng/Kconfig
+++ b/drivers/rng/Kconfig
@@ -41,6 +41,7 @@ config RNG_NPCM
 config RNG_OPTEE
 	bool "OP-TEE based Random Number Generator support"
 	depends on DM_RNG && OPTEE
+	default y if OPTEE_SERVICE_DISCOVERY
 	help
 	  This driver provides support for the OP-TEE based Random Number
 	  Generator on ARM SoCs where hardware entropy sources are not
diff --git a/drivers/rng/optee_rng.c b/drivers/rng/optee_rng.c
index aa8ce864d3..410dfc053f 100644
--- a/drivers/rng/optee_rng.c
+++ b/drivers/rng/optee_rng.c
@@ -11,6 +11,9 @@
 #include <dm/device.h>
 #include <dm/device_compat.h>
 #include <linux/sizes.h>
+#include <tee/optee_service.h>
+
+#define DRIVER_NAME	"optee-rng"
 
 #define TEE_ERROR_HEALTH_TEST_FAIL	0x00000001
 
@@ -35,6 +38,8 @@
 #define TA_HWRNG_UUID { 0xab7a617c, 0xb8e7, 0x4d8f, \
 			{ 0x83, 0x01, 0xd0, 0x9b, 0x61, 0x03, 0x6b, 0x64 } }
 
+OPTEE_SERVICE_DRIVER(optee_rng, TA_HWRNG_UUID, DRIVER_NAME);
+
 /** open_session_ta_hwrng() - Open session with hwrng Trusted App
  *
  * @dev:		device
@@ -177,7 +182,7 @@ static const struct dm_rng_ops optee_rng_ops = {
 };
 
 U_BOOT_DRIVER(optee_rng) = {
-	.name = "optee-rng",
+	.name = DRIVER_NAME,
 	.id = UCLASS_RNG,
 	.ops = &optee_rng_ops,
 	.probe = optee_rng_probe,
-- 
2.25.1

Re: [PATCH v5 1/3] drivers: tee: optee: remove unused probe local variable

[Tom Rini]

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On Tue, Jul 26, 2022 at 04:21:41PM +0200, Etienne Carriere wrote:

> Removes local variable child in optee_probe() that is not used.
> 
> Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
> Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
> Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

Applied to u-boot/next, thanks!

-- 
Tom

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Re: [PATCH v5 2/3] drivers: tee: optee: discover OP-TEE services

[Tom Rini]

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On Tue, Jul 26, 2022 at 04:21:42PM +0200, Etienne Carriere wrote:

> This change defines resources for OP-TEE service drivers to register
> themselves for being bound to when OP-TEE firmware reports the related
> service is supported. OP-TEE services are discovered during optee
> driver probe sequence which mandates optee driver is always probe once
> bound.
> 
> Discovery of optee services and binding to related U-Boot drivers is
> embedded upon configuration switch CONFIG_OPTEE_SERVICE_DISCOVERY.
> 
> Cc: Jens Wiklander <jens.wiklander@linaro.org>
> Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
> Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
> Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>

Applied to u-boot/next, thanks!

-- 
Tom

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Re: [PATCH v5 3/3] drivers: rng: optee_rng: register to CONFIG_OPTEE_SERVICE_DISCOVERY

[Tom Rini]

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On Tue, Jul 26, 2022 at 04:21:43PM +0200, Etienne Carriere wrote:

> Changes optee_rng driver to register itself has a OP-TEE service so
> that a device is bound for the driver when OP-TEE enumerates the
> PTA RNG service.
> 
> Cc: Sughosh Ganu <sughosh.ganu@linaro.org>
> Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
> Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
> Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>

Applied to u-boot/next, thanks!

-- 
Tom

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