tee: generic TEE subsystem

Initial patch for generic TEE subsystem.
This subsystem provides:
* Registration/un-registration of TEE drivers.
* Shared memory between normal world and secure world.
* Ioctl interface for interaction with user space.
* Sysfs implementation_id of TEE driver

A TEE (Trusted Execution Environment) 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.

This patch builds on other similar implementations trying to solve
the same problem:
* "optee_linuxdriver" by among others
  Jean-michel DELORME<jean-michel.delorme@st.com> and
  Emmanuel MICHEL <emmanuel.michel@st.com>
* "Generic TrustZone Driver" by Javier González <javier@javigon.com>

Acked-by: Andreas Dannenberg <dannenberg@ti.com>
Tested-by: Jerome Forissier <jerome.forissier@linaro.org> (HiKey)
Tested-by: Volodymyr Babchuk <vlad.babchuk@gmail.com> (RCAR H3)
Tested-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Javier González <javier@javigon.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

1 files changed, 346 insertions, 0 deletions

diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
new file mode 100644
index 000000000000..370d8845ab21
--- /dev/null
+++ b/include/uapi/linux/tee.h
@@ -0,0 +1,346 @@
+/*
+ * Copyright (c) 2015-2016, Linaro Limited
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __TEE_H
+#define __TEE_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+/*
+ * This file describes the API provided by a TEE driver to user space.
+ *
+ * Each TEE driver defines a TEE specific protocol which is used for the
+ * data passed back and forth using TEE_IOC_CMD.
+ */
+
+/* Helpers to make the ioctl defines */
+#define TEE_IOC_MAGIC	0xa4
+#define TEE_IOC_BASE	0
+
+/* Flags relating to shared memory */
+#define TEE_IOCTL_SHM_MAPPED	0x1	/* memory mapped in normal world */
+#define TEE_IOCTL_SHM_DMA_BUF	0x2	/* dma-buf handle on shared memory */
+
+#define TEE_MAX_ARG_SIZE	1024
+
+#define TEE_GEN_CAP_GP		(1 << 0)/* GlobalPlatform compliant TEE */
+
+/*
+ * TEE Implementation ID
+ */
+#define TEE_IMPL_ID_OPTEE	1
+
+/*
+ * OP-TEE specific capabilities
+ */
+#define TEE_OPTEE_CAP_TZ	(1 << 0)
+
+/**
+ * struct tee_ioctl_version_data - TEE version
+ * @impl_id:	[out] TEE implementation id
+ * @impl_caps:	[out] Implementation specific capabilities
+ * @gen_caps:	[out] Generic capabilities, defined by TEE_GEN_CAPS_* above
+ *
+ * Identifies the TEE implementation, @impl_id is one of TEE_IMPL_ID_* above.
+ * @impl_caps is implementation specific, for example TEE_OPTEE_CAP_*
+ * is valid when @impl_id == TEE_IMPL_ID_OPTEE.
+ */
+struct tee_ioctl_version_data {
+	__u32 impl_id;
+	__u32 impl_caps;
+	__u32 gen_caps;
+};
+
+/**
+ * TEE_IOC_VERSION - query version of TEE
+ *
+ * Takes a tee_ioctl_version_data struct and returns with the TEE version
+ * data filled in.
+ */
+#define TEE_IOC_VERSION		_IOR(TEE_IOC_MAGIC, TEE_IOC_BASE + 0, \
+				     struct tee_ioctl_version_data)
+
+/**
+ * struct tee_ioctl_shm_alloc_data - Shared memory allocate argument
+ * @size:	[in/out] Size of shared memory to allocate
+ * @flags:	[in/out] Flags to/from allocation.
+ * @id:		[out] Identifier of the shared memory
+ *
+ * The flags field should currently be zero as input. Updated by the call
+ * with actual flags as defined by TEE_IOCTL_SHM_* above.
+ * This structure is used as argument for TEE_IOC_SHM_ALLOC below.
+ */
+struct tee_ioctl_shm_alloc_data {
+	__u64 size;
+	__u32 flags;
+	__s32 id;
+};
+
+/**
+ * TEE_IOC_SHM_ALLOC - allocate shared memory
+ *
+ * Allocates shared memory between the user space process and secure OS.
+ *
+ * Returns a file descriptor on success or < 0 on failure
+ *
+ * The returned file descriptor is used to map the shared memory into user
+ * space. The shared memory is freed when the descriptor is closed and the
+ * memory is unmapped.
+ */
+#define TEE_IOC_SHM_ALLOC	_IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 1, \
+				     struct tee_ioctl_shm_alloc_data)
+
+/**
+ * struct tee_ioctl_buf_data - Variable sized buffer
+ * @buf_ptr:	[in] A __user pointer to a buffer
+ * @buf_len:	[in] Length of the buffer above
+ *
+ * Used as argument for TEE_IOC_OPEN_SESSION, TEE_IOC_INVOKE,
+ * TEE_IOC_SUPPL_RECV, and TEE_IOC_SUPPL_SEND below.
+ */
+struct tee_ioctl_buf_data {
+	__u64 buf_ptr;
+	__u64 buf_len;
+};
+
+/*
+ * Attributes for struct tee_ioctl_param, selects field in the union
+ */
+#define TEE_IOCTL_PARAM_ATTR_TYPE_NONE		0	/* parameter not used */
+
+/*
+ * These defines value parameters (struct tee_ioctl_param_value)
+ */
+#define TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT	1
+#define TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT	2
+#define TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT	3	/* input and output */
+
+/*
+ * These defines shared memory reference parameters (struct
+ * tee_ioctl_param_memref)
+ */
+#define TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT	5
+#define TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT	6
+#define TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT	7	/* input and output */
+
+/*
+ * Mask for the type part of the attribute, leaves room for more types
+ */
+#define TEE_IOCTL_PARAM_ATTR_TYPE_MASK		0xff
+
+/*
+ * Matches TEEC_LOGIN_* in GP TEE Client API
+ * Are only defined for GP compliant TEEs
+ */
+#define TEE_IOCTL_LOGIN_PUBLIC			0
+#define TEE_IOCTL_LOGIN_USER			1
+#define TEE_IOCTL_LOGIN_GROUP			2
+#define TEE_IOCTL_LOGIN_APPLICATION		4
+#define TEE_IOCTL_LOGIN_USER_APPLICATION	5
+#define TEE_IOCTL_LOGIN_GROUP_APPLICATION	6
+
+/**
+ * struct tee_ioctl_param - parameter
+ * @attr: attributes
+ * @a: if a memref, offset into the shared memory object, else a value parameter
+ * @b: if a memref, size of the buffer, else a value parameter
+ * @c: if a memref, shared memory identifier, else a value parameter
+ *
+ * @attr & TEE_PARAM_ATTR_TYPE_MASK indicates if memref or value is used in
+ * the union. TEE_PARAM_ATTR_TYPE_VALUE_* indicates value and
+ * TEE_PARAM_ATTR_TYPE_MEMREF_* indicates memref. TEE_PARAM_ATTR_TYPE_NONE
+ * indicates that none of the members are used.
+ *
+ * Shared memory is allocated with TEE_IOC_SHM_ALLOC which returns an
+ * identifier representing the shared memory object. A memref can reference
+ * a part of a shared memory by specifying an offset (@a) and size (@b) of
+ * the object. To supply the entire shared memory object set the offset
+ * (@a) to 0 and size (@b) to the previously returned size of the object.
+ */
+struct tee_ioctl_param {
+	__u64 attr;
+	__u64 a;
+	__u64 b;
+	__u64 c;
+};
+
+#define TEE_IOCTL_UUID_LEN		16
+
+/**
+ * struct tee_ioctl_open_session_arg - Open session argument
+ * @uuid:	[in] UUID of the Trusted Application
+ * @clnt_uuid:	[in] UUID of client
+ * @clnt_login:	[in] Login class of client, TEE_IOCTL_LOGIN_* above
+ * @cancel_id:	[in] Cancellation id, a unique value to identify this request
+ * @session:	[out] Session id
+ * @ret:	[out] return value
+ * @ret_origin	[out] origin of the return value
+ * @num_params	[in] number of parameters following this struct
+ */
+struct tee_ioctl_open_session_arg {
+	__u8 uuid[TEE_IOCTL_UUID_LEN];
+	__u8 clnt_uuid[TEE_IOCTL_UUID_LEN];
+	__u32 clnt_login;
+	__u32 cancel_id;
+	__u32 session;
+	__u32 ret;
+	__u32 ret_origin;
+	__u32 num_params;
+	/* num_params tells the actual number of element in params */
+	struct tee_ioctl_param params[];
+};
+
+/**
+ * TEE_IOC_OPEN_SESSION - opens a session to a Trusted Application
+ *
+ * Takes a struct tee_ioctl_buf_data which contains a struct
+ * tee_ioctl_open_session_arg followed by any array of struct
+ * tee_ioctl_param
+ */
+#define TEE_IOC_OPEN_SESSION	_IOR(TEE_IOC_MAGIC, TEE_IOC_BASE + 2, \
+				     struct tee_ioctl_buf_data)
+
+/**
+ * struct tee_ioctl_invoke_func_arg - Invokes a function in a Trusted
+ * Application
+ * @func:	[in] Trusted Application function, specific to the TA
+ * @session:	[in] Session id
+ * @cancel_id:	[in] Cancellation id, a unique value to identify this request
+ * @ret:	[out] return value
+ * @ret_origin	[out] origin of the return value
+ * @num_params	[in] number of parameters following this struct
+ */
+struct tee_ioctl_invoke_arg {
+	__u32 func;
+	__u32 session;
+	__u32 cancel_id;
+	__u32 ret;
+	__u32 ret_origin;
+	__u32 num_params;
+	/* num_params tells the actual number of element in params */
+	struct tee_ioctl_param params[];
+};
+
+/**
+ * TEE_IOC_INVOKE - Invokes a function in a Trusted Application
+ *
+ * Takes a struct tee_ioctl_buf_data which contains a struct
+ * tee_invoke_func_arg followed by any array of struct tee_param
+ */
+#define TEE_IOC_INVOKE		_IOR(TEE_IOC_MAGIC, TEE_IOC_BASE + 3, \
+				     struct tee_ioctl_buf_data)
+
+/**
+ * struct tee_ioctl_cancel_arg - Cancels an open session or invoke ioctl
+ * @cancel_id:	[in] Cancellation id, a unique value to identify this request
+ * @session:	[in] Session id, if the session is opened, else set to 0
+ */
+struct tee_ioctl_cancel_arg {
+	__u32 cancel_id;
+	__u32 session;
+};
+
+/**
+ * TEE_IOC_CANCEL - Cancels an open session or invoke
+ */
+#define TEE_IOC_CANCEL		_IOR(TEE_IOC_MAGIC, TEE_IOC_BASE + 4, \
+				     struct tee_ioctl_cancel_arg)
+
+/**
+ * struct tee_ioctl_close_session_arg - Closes an open session
+ * @session:	[in] Session id
+ */
+struct tee_ioctl_close_session_arg {
+	__u32 session;
+};
+
+/**
+ * TEE_IOC_CLOSE_SESSION - Closes a session
+ */
+#define TEE_IOC_CLOSE_SESSION	_IOR(TEE_IOC_MAGIC, TEE_IOC_BASE + 5, \
+				     struct tee_ioctl_close_session_arg)
+
+/**
+ * struct tee_iocl_supp_recv_arg - Receive a request for a supplicant function
+ * @func:	[in] supplicant function
+ * @num_params	[in/out] number of parameters following this struct
+ *
+ * @num_params is the number of params that tee-supplicant has room to
+ * receive when input, @num_params is the number of actual params
+ * tee-supplicant receives when output.
+ */
+struct tee_iocl_supp_recv_arg {
+	__u32 func;
+	__u32 num_params;
+	/* num_params tells the actual number of element in params */
+	struct tee_ioctl_param params[];
+};
+
+/**
+ * TEE_IOC_SUPPL_RECV - Receive a request for a supplicant function
+ *
+ * Takes a struct tee_ioctl_buf_data which contains a struct
+ * tee_iocl_supp_recv_arg followed by any array of struct tee_param
+ */
+#define TEE_IOC_SUPPL_RECV	_IOR(TEE_IOC_MAGIC, TEE_IOC_BASE + 6, \
+				     struct tee_ioctl_buf_data)
+
+/**
+ * struct tee_iocl_supp_send_arg - Send a response to a received request
+ * @ret:	[out] return value
+ * @num_params	[in] number of parameters following this struct
+ */
+struct tee_iocl_supp_send_arg {
+	__u32 ret;
+	__u32 num_params;
+	/* num_params tells the actual number of element in params */
+	struct tee_ioctl_param params[];
+};
+
+/**
+ * TEE_IOC_SUPPL_SEND - Receive a request for a supplicant function
+ *
+ * Takes a struct tee_ioctl_buf_data which contains a struct
+ * tee_iocl_supp_send_arg followed by any array of struct tee_param
+ */
+#define TEE_IOC_SUPPL_SEND	_IOR(TEE_IOC_MAGIC, TEE_IOC_BASE + 7, \
+				     struct tee_ioctl_buf_data)
+
+/*
+ * Five syscalls are used when communicating with the TEE driver.
+ * open(): opens the device associated with the driver
+ * ioctl(): as described above operating on the file descriptor from open()
+ * close(): two cases
+ *   - closes the device file descriptor
+ *   - closes a file descriptor connected to allocated shared memory
+ * mmap(): maps shared memory into user space using information from struct
+ *	   tee_ioctl_shm_alloc_data
+ * munmap(): unmaps previously shared memory
+ */
+
+#endif /*__TEE_H*/