[U-Boot] [PATCH 04/10] Add UCLASS_TEE for Trusted Execution Environment

[Jens Wiklander <jens.wiklander@linaro.org>]

Adds a uclass to interface with a TEE (Trusted Execution Environment).

A TEE driver is a driver that interfaces with a trusted OS running in
some secure environment, for example, TrustZone on ARM cpus, or a
separate secure co-processor etc.

The TEE subsystem can serve a TEE driver for a Global Platform compliant
TEE, but it's not limited to only Global Platform TEEs.

The over all design is based on the TEE subsystem in the Linux kernel,
tailored for U-boot.

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
---
 MAINTAINERS              |   6 ++
 drivers/Kconfig          |   2 +
 drivers/Makefile         |   1 +
 drivers/tee/Kconfig      |   8 ++
 drivers/tee/Makefile     |   3 +
 drivers/tee/tee-uclass.c | 180 +++++++++++++++++++++++++++++++++++++++
 include/dm/uclass-id.h   |   1 +
 include/tee.h            | 134 +++++++++++++++++++++++++++++
 8 files changed, 335 insertions(+)
 create mode 100644 drivers/tee/Kconfig
 create mode 100644 drivers/tee/Makefile
 create mode 100644 drivers/tee/tee-uclass.c
 create mode 100644 include/tee.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 58b61ac05882..7458c606ee92 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -571,6 +571,12 @@ TQ GROUP
 S:	Orphaned (Since 2016-02)
 T:	git git://git.denx.de/u-boot-tq-group.git
 
+TEE
+M:	Jens Wiklander <jens.wiklander@linaro.org>
+S:	Maintained
+F:	drivers/tee/
+F:	include/tee.h
+
 UBI
 M:	Kyungmin Park <kmpark@infradead.org>
 M:	Heiko Schocher <hs@denx.de>
diff --git a/drivers/Kconfig b/drivers/Kconfig
index c72abf893297..f3249ab1d143 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -94,6 +94,8 @@ source "drivers/spmi/Kconfig"
 
 source "drivers/sysreset/Kconfig"
 
+source "drivers/tee/Kconfig"
+
 source "drivers/thermal/Kconfig"
 
 source "drivers/timer/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index d53208540ea6..0fcae36f50f7 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -103,6 +103,7 @@ obj-y += smem/
 obj-y += soc/
 obj-$(CONFIG_REMOTEPROC) += remoteproc/
 obj-y += thermal/
+obj-$(CONFIG_TEE) += tee/
 
 obj-$(CONFIG_MACH_PIC32) += ddr/microchip/
 endif
diff --git a/drivers/tee/Kconfig b/drivers/tee/Kconfig
new file mode 100644
index 000000000000..817ab331b0f8
--- /dev/null
+++ b/drivers/tee/Kconfig
@@ -0,0 +1,8 @@
+# Generic Trusted Execution Environment Configuration
+config TEE
+	bool "Trusted Execution Environment support"
+	depends on ARM && (ARM64 || CPU_V7A)
+	select ARM_SMCCC
+	help
+	  This implements a generic interface towards a Trusted Execution
+	  Environment (TEE).
diff --git a/drivers/tee/Makefile b/drivers/tee/Makefile
new file mode 100644
index 000000000000..b6d8e16e6211
--- /dev/null
+++ b/drivers/tee/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0+
+
+obj-y += tee-uclass.o
diff --git a/drivers/tee/tee-uclass.c b/drivers/tee/tee-uclass.c
new file mode 100644
index 000000000000..f0243a0f2e4e
--- /dev/null
+++ b/drivers/tee/tee-uclass.c
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2018 Linaro Limited
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <tee.h>
+
+struct tee_uclass_priv {
+	struct list_head list_shm;
+};
+
+static const struct tee_driver_ops *tee_get_ops(struct udevice *dev)
+{
+	return device_get_ops(dev);
+}
+
+void tee_get_version(struct udevice *dev, struct tee_version_data *vers)
+{
+	tee_get_ops(dev)->get_version(dev, vers);
+}
+
+int tee_open_session(struct udevice *dev, struct tee_open_session_arg *arg,
+		     ulong num_param, struct tee_param *param)
+{
+	return tee_get_ops(dev)->open_session(dev, arg, num_param, param);
+}
+
+int tee_close_session(struct udevice *dev, u32 session)
+{
+	return tee_get_ops(dev)->close_session(dev, session);
+}
+
+int tee_invoke_func(struct udevice *dev, struct tee_invoke_arg *arg,
+		    ulong num_param, struct tee_param *param)
+{
+	return tee_get_ops(dev)->invoke_func(dev, arg, num_param, param);
+}
+
+struct tee_shm *__tee_shm_add(struct udevice *dev, ulong align, void *addr,
+			      ulong size, u32 flags)
+{
+	struct tee_shm *shm;
+	void *p = addr;
+
+	if (flags & TEE_SHM_ALLOC) {
+		if (align)
+			p = memalign(align, size);
+		else
+			p = malloc(size);
+	}
+	if (!p)
+		return NULL;
+
+	shm = calloc(1, sizeof(*shm));
+	if (!shm)
+		goto err;
+
+	shm->dev = dev;
+	shm->addr = p;
+	shm->size = size;
+	shm->flags = flags;
+
+	if ((flags & TEE_SHM_SEC_REGISTER) &&
+	    tee_get_ops(dev)->shm_register(dev, shm))
+		goto err;
+
+	if (flags & TEE_SHM_REGISTER) {
+		struct tee_uclass_priv *priv = dev_get_uclass_priv(dev);
+
+		list_add(&shm->link, &priv->list_shm);
+	}
+	return shm;
+err:
+	free(shm);
+	if (flags & TEE_SHM_ALLOC)
+		free(p);
+	return NULL;
+}
+
+struct tee_shm *tee_shm_alloc(struct udevice *dev, ulong size,
+			      u32 flags)
+{
+	u32 f = flags;
+
+	f |= TEE_SHM_SEC_REGISTER | TEE_SHM_REGISTER | TEE_SHM_ALLOC;
+	return __tee_shm_add(dev, 0, NULL, size, f);
+}
+
+struct tee_shm *tee_shm_register(struct udevice *dev, void *addr,
+				 ulong size, u32 flags)
+{
+	u32 f = flags & ~TEE_SHM_ALLOC;
+
+	f |= TEE_SHM_SEC_REGISTER | TEE_SHM_REGISTER;
+	return __tee_shm_add(dev, 0, addr, size, f);
+}
+
+void tee_shm_free(struct tee_shm *shm)
+{
+	if (!shm)
+		return;
+
+	if (shm->flags & TEE_SHM_SEC_REGISTER)
+		tee_get_ops(shm->dev)->shm_unregister(shm->dev, shm);
+
+	if (shm->flags & TEE_SHM_REGISTER)
+		list_del(&shm->link);
+
+	if (shm->flags & TEE_SHM_ALLOC)
+		free(shm->addr);
+
+	free(shm);
+}
+
+bool tee_shm_is_registered(struct tee_shm *shm, struct udevice *dev)
+{
+	struct tee_uclass_priv *priv = dev_get_uclass_priv(dev);
+	struct tee_shm *s;
+
+	list_for_each_entry(s, &priv->list_shm, link)
+		if (s == shm)
+			return true;
+
+	return false;
+}
+
+struct udevice *tee_find_device(struct udevice *start,
+				int (*match)(struct tee_version_data *vers,
+					     const void *data),
+				const void *data,
+				struct tee_version_data *vers)
+{
+	struct udevice *dev = start;
+	struct tee_version_data lv;
+	struct tee_version_data *v = vers ? vers : &lv;
+
+	if (!dev)
+		uclass_first_device(UCLASS_TEE, &dev);
+
+	for (; dev; uclass_next_device(&dev)) {
+		tee_get_ops(dev)->get_version(dev, v);
+		if (!match || match(v, data))
+			return dev;
+	}
+
+	return NULL;
+}
+
+static int tee_pre_probe(struct udevice *dev)
+{
+	struct tee_uclass_priv *priv = dev_get_uclass_priv(dev);
+
+	INIT_LIST_HEAD(&priv->list_shm);
+	return 0;
+}
+
+static int tee_pre_remove(struct udevice *dev)
+{
+	struct tee_uclass_priv *priv = dev_get_uclass_priv(dev);
+	struct tee_shm *shm;
+
+	while (!list_empty(&priv->list_shm)) {
+		shm = list_first_entry(&priv->list_shm, struct tee_shm, link);
+		debug("%s: freeing leftover shm %p (size %lu, flags %#x)\n",
+		      __func__, (void *)shm, shm->size, shm->flags);
+		tee_shm_free(shm);
+	}
+
+	return 0;
+}
+
+UCLASS_DRIVER(tee) = {
+	.id = UCLASS_TEE,
+	.name = "tee",
+	.per_device_auto_alloc_size = sizeof(struct tee_uclass_priv),
+	.pre_probe = tee_pre_probe,
+	.pre_remove = tee_pre_remove,
+};
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index a39643ec5eef..955e0a915b87 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -81,6 +81,7 @@ enum uclass_id {
 	UCLASS_SPI_GENERIC,	/* Generic SPI flash target */
 	UCLASS_SYSCON,		/* System configuration device */
 	UCLASS_SYSRESET,	/* System reset device */
+	UCLASS_TEE,		/* Trusted Execution Environment device */
 	UCLASS_THERMAL,		/* Thermal sensor */
 	UCLASS_TIMER,		/* Timer device */
 	UCLASS_TPM,		/* Trusted Platform Module TIS interface */
diff --git a/include/tee.h b/include/tee.h
new file mode 100644
index 000000000000..c2ac13e34128
--- /dev/null
+++ b/include/tee.h
@@ -0,0 +1,134 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2018 Linaro Limited
+ */
+
+#ifndef __TEE_H
+#define __TEE_H
+
+#include <common.h>
+#include <dm.h>
+
+#define TEE_UUID_LEN		16
+
+#define TEE_GEN_CAP_GP          BIT(0)	/* GlobalPlatform compliant TEE */
+#define TEE_GEN_CAP_REG_MEM     BIT(1)	/* Supports registering shared memory */
+
+#define TEE_SHM_REGISTER	BIT(0)
+#define TEE_SHM_SEC_REGISTER	BIT(1)
+#define TEE_SHM_ALLOC		BIT(2)
+
+#define TEE_PARAM_ATTR_TYPE_NONE		0	/* parameter not used */
+#define TEE_PARAM_ATTR_TYPE_VALUE_INPUT		1
+#define TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT	2
+#define TEE_PARAM_ATTR_TYPE_VALUE_INOUT		3	/* input and output */
+#define TEE_PARAM_ATTR_TYPE_MEMREF_INPUT	5
+#define TEE_PARAM_ATTR_TYPE_MEMREF_OUTPUT	6
+#define TEE_PARAM_ATTR_TYPE_MEMREF_INOUT	7	/* input and output */
+#define TEE_PARAM_ATTR_TYPE_MASK		0xff
+#define TEE_PARAM_ATTR_META			0x100
+#define TEE_PARAM_ATTR_MASK			(TEE_PARAM_ATTR_TYPE_MASK | \
+						 TEE_PARAM_ATTR_META)
+
+/*
+ * Some Global Platform error codes which has a meaning if the
+ * TEE_GEN_CAP_GP bit is returned by the driver.
+ */
+#define TEE_SUCCESS			0x00000000
+#define TEE_ERROR_GENERIC		0xffff0000
+#define TEE_ERROR_BAD_PARAMETERS	0xffff0006
+#define TEE_ERROR_ITEM_NOT_FOUND	0xffff0008
+#define TEE_ERROR_NOT_IMPLEMENTED	0xffff0009
+#define TEE_ERROR_NOT_SUPPORTED		0xffff000a
+#define TEE_ERROR_COMMUNICATION		0xffff000e
+#define TEE_ERROR_OUT_OF_MEMORY		0xffff000c
+#define TEE_ERROR_TARGET_DEAD		0xffff3024
+
+#define TEE_ORIGIN_COMMS		0x00000002
+
+struct tee_driver_ops;
+
+struct tee_shm {
+	struct udevice *dev;
+	struct list_head link;
+	void *addr;
+	ulong size;
+	u32 flags;
+};
+
+struct tee_param_memref {
+	ulong shm_offs;
+	ulong size;
+	struct tee_shm *shm;
+};
+
+struct tee_param_value {
+	u64 a;
+	u64 b;
+	u64 c;
+};
+
+struct tee_param {
+	u64 attr;
+	union {
+		struct tee_param_memref memref;
+		struct tee_param_value value;
+	} u;
+};
+
+struct tee_open_session_arg {
+	u8 uuid[TEE_UUID_LEN];
+	u8 clnt_uuid[TEE_UUID_LEN];
+	u32 clnt_login;
+	u32 session;
+	u32 ret;
+	u32 ret_origin;
+};
+
+struct tee_invoke_arg {
+	u32 func;
+	u32 session;
+	u32 ret;
+	u32 ret_origin;
+};
+
+struct tee_version_data {
+	u32 gen_caps;
+};
+
+struct tee_driver_ops {
+	void (*get_version)(struct udevice *dev, struct tee_version_data *vers);
+	int (*open_session)(struct udevice *dev,
+			    struct tee_open_session_arg *arg, ulong num_param,
+			    struct tee_param *param);
+	int (*close_session)(struct udevice *dev, u32 session);
+	int (*invoke_func)(struct udevice *dev, struct tee_invoke_arg *arg,
+			   ulong num_param, struct tee_param *param);
+	int (*shm_register)(struct udevice *dev, struct tee_shm *shm);
+	int (*shm_unregister)(struct udevice *dev, struct tee_shm *shm);
+};
+
+struct tee_shm *__tee_shm_add(struct udevice *dev, ulong align, void *addr,
+			      ulong size, u32 flags);
+struct tee_shm *tee_shm_alloc(struct udevice *dev, ulong size, u32 flags);
+struct tee_shm *tee_shm_register(struct udevice *dev, void *addr,
+				 ulong length, u32 flags);
+void tee_shm_free(struct tee_shm *shm);
+bool tee_shm_is_registered(struct tee_shm *shm, struct udevice *dev);
+
+struct udevice *tee_find_device(struct udevice *start,
+				int (*match)(struct tee_version_data *vers,
+					     const void *data),
+				const void *data,
+				struct tee_version_data *vers);
+
+void tee_get_version(struct udevice *dev, struct tee_version_data *vers);
+int tee_open_session(struct udevice *dev, struct tee_open_session_arg *arg,
+		     ulong num_param, struct tee_param *param);
+
+int tee_close_session(struct udevice *dev, u32 session);
+
+int tee_invoke_func(struct udevice *dev, struct tee_invoke_arg *arg,
+		    ulong num_param, struct tee_param *param);
+
+#endif /*__TEE_H*/
-- 
2.17.1