tee: add AMD-TEE driver

Adds AMD-TEE driver.
* targets AMD APUs which has AMD Secure Processor with software-based
  Trusted Execution Environment (TEE) support
* registers with TEE subsystem
* defines tee_driver_ops function callbacks
* kernel allocated memory is used as shared memory between normal
  world and secure world.
* acts as REE (Rich Execution Environment) communication agent, which
  uses the services of AMD Secure Processor driver to submit commands
  for processing in TEE environment

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Co-developed-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Reviewed-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/tee/Kconfig

@@ -14,7 +14,7 @@ if TEE
 menu "TEE drivers"
 
 source "drivers/tee/optee/Kconfig"
-
+source "drivers/tee/amdtee/Kconfig"
 endmenu
 
 endif

drivers/tee/Makefile

@@ -4,3 +4,4 @@ tee-objs += tee_core.o
 tee-objs += tee_shm.o
 tee-objs += tee_shm_pool.o
 obj-$(CONFIG_OPTEE) += optee/
+obj-$(CONFIG_AMDTEE) += amdtee/

drivers/tee/amdtee/Kconfig

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: MIT
+# AMD-TEE Trusted Execution Environment Configuration
+config AMDTEE
+	tristate "AMD-TEE"
+	default m
+	depends on CRYPTO_DEV_SP_PSP
+	help
+	  This implements AMD's Trusted Execution Environment (TEE) driver.

drivers/tee/amdtee/Makefile

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: MIT
+obj-$(CONFIG_AMDTEE) += amdtee.o
+amdtee-objs += core.o
+amdtee-objs += call.o
+amdtee-objs += shm_pool.o

drivers/tee/amdtee/amdtee_if.h

@@ -0,0 +1,183 @@
+/* SPDX-License-Identifier: MIT */
+
+/*
+ * Copyright 2019 Advanced Micro Devices, Inc.
+ */
+
+/*
+ * This file has definitions related to Host and AMD-TEE Trusted OS interface.
+ * These definitions must match the definitions on the TEE side.
+ */
+
+#ifndef AMDTEE_IF_H
+#define AMDTEE_IF_H
+
+#include <linux/types.h>
+
+/*****************************************************************************
+ ** TEE Param
+ ******************************************************************************/
+#define TEE_MAX_PARAMS		4
+
+/**
+ * struct memref - memory reference structure
+ * @buf_id:    buffer ID of the buffer mapped by TEE_CMD_ID_MAP_SHARED_MEM
+ * @offset:    offset in bytes from beginning of the buffer
+ * @size:      data size in bytes
+ */
+struct memref {
+	u32 buf_id;
+	u32 offset;
+	u32 size;
+};
+
+struct value {
+	u32 a;
+	u32 b;
+};
+
+/*
+ * Parameters passed to open_session or invoke_command
+ */
+union tee_op_param {
+	struct memref mref;
+	struct value val;
+};
+
+struct tee_operation {
+	u32 param_types;
+	union tee_op_param params[TEE_MAX_PARAMS];
+};
+
+/* Must be same as in GP TEE specification */
+#define TEE_OP_PARAM_TYPE_NONE                  0
+#define TEE_OP_PARAM_TYPE_VALUE_INPUT           1
+#define TEE_OP_PARAM_TYPE_VALUE_OUTPUT          2
+#define TEE_OP_PARAM_TYPE_VALUE_INOUT           3
+#define TEE_OP_PARAM_TYPE_INVALID               4
+#define TEE_OP_PARAM_TYPE_MEMREF_INPUT          5
+#define TEE_OP_PARAM_TYPE_MEMREF_OUTPUT         6
+#define TEE_OP_PARAM_TYPE_MEMREF_INOUT          7
+
+#define TEE_PARAM_TYPE_GET(t, i)        (((t) >> ((i) * 4)) & 0xF)
+#define TEE_PARAM_TYPES(t0, t1, t2, t3) \
+	((t0) | ((t1) << 4) | ((t2) << 8) | ((t3) << 12))
+
+/*****************************************************************************
+ ** TEE Commands
+ *****************************************************************************/
+
+/*
+ * The shared memory between rich world and secure world may be physically
+ * non-contiguous. Below structures are meant to describe a shared memory region
+ * via scatter/gather (sg) list
+ */
+
+/**
+ * struct tee_sg_desc - sg descriptor for a physically contiguous buffer
+ * @low_addr: [in] bits[31:0] of buffer's physical address. Must be 4KB aligned
+ * @hi_addr:  [in] bits[63:32] of the buffer's physical address
+ * @size:     [in] size in bytes (must be multiple of 4KB)
+ */
+struct tee_sg_desc {
+	u32 low_addr;
+	u32 hi_addr;
+	u32 size;
+};
+
+/**
+ * struct tee_sg_list - structure describing a scatter/gather list
+ * @count:   [in] number of sg descriptors
+ * @size:    [in] total size of all buffers in the list. Must be multiple of 4KB
+ * @buf:     [in] list of sg buffer descriptors
+ */
+#define TEE_MAX_SG_DESC 64
+struct tee_sg_list {
+	u32 count;
+	u32 size;
+	struct tee_sg_desc buf[TEE_MAX_SG_DESC];
+};
+
+/**
+ * struct tee_cmd_map_shared_mem - command to map shared memory
+ * @buf_id:    [out] return buffer ID value
+ * @sg_list:   [in] list describing memory to be mapped
+ */
+struct tee_cmd_map_shared_mem {
+	u32 buf_id;
+	struct tee_sg_list sg_list;
+};
+
+/**
+ * struct tee_cmd_unmap_shared_mem - command to unmap shared memory
+ * @buf_id:    [in] buffer ID of memory to be unmapped
+ */
+struct tee_cmd_unmap_shared_mem {
+	u32 buf_id;
+};
+
+/**
+ * struct tee_cmd_load_ta - load Trusted Application (TA) binary into TEE
+ * @low_addr:    [in] bits [31:0] of the physical address of the TA binary
+ * @hi_addr:     [in] bits [63:32] of the physical address of the TA binary
+ * @size:        [in] size of TA binary in bytes
+ * @ta_handle:   [out] return handle of the loaded TA
+ */
+struct tee_cmd_load_ta {
+	u32 low_addr;
+	u32 hi_addr;
+	u32 size;
+	u32 ta_handle;
+};
+
+/**
+ * struct tee_cmd_unload_ta - command to unload TA binary from TEE environment
+ * @ta_handle:    [in] handle of the loaded TA to be unloaded
+ */
+struct tee_cmd_unload_ta {
+	u32 ta_handle;
+};
+
+/**
+ * struct tee_cmd_open_session - command to call TA_OpenSessionEntryPoint in TA
+ * @ta_handle:      [in] handle of the loaded TA
+ * @session_info:   [out] pointer to TA allocated session data
+ * @op:             [in/out] operation parameters
+ * @return_origin:  [out] origin of return code after TEE processing
+ */
+struct tee_cmd_open_session {
+	u32 ta_handle;
+	u32 session_info;
+	struct tee_operation op;
+	u32 return_origin;
+};
+
+/**
+ * struct tee_cmd_close_session - command to call TA_CloseSessionEntryPoint()
+ *                                in TA
+ * @ta_handle:      [in] handle of the loaded TA
+ * @session_info:   [in] pointer to TA allocated session data
+ */
+struct tee_cmd_close_session {
+	u32 ta_handle;
+	u32 session_info;
+};
+
+/**
+ * struct tee_cmd_invoke_cmd - command to call TA_InvokeCommandEntryPoint() in
+ *                             TA
+ * @ta_handle:     [in] handle of the loaded TA
+ * @cmd_id:        [in] TA command ID
+ * @session_info:  [in] pointer to TA allocated session data
+ * @op:            [in/out] operation parameters
+ * @return_origin: [out] origin of return code after TEE processing
+ */
+struct tee_cmd_invoke_cmd {
+	u32 ta_handle;
+	u32 cmd_id;
+	u32 session_info;
+	struct tee_operation op;
+	u32 return_origin;
+};
+
+#endif /*AMDTEE_IF_H*/

drivers/tee/amdtee/amdtee_private.h

@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: MIT */
+
+/*
+ * Copyright 2019 Advanced Micro Devices, Inc.
+ */
+
+#ifndef AMDTEE_PRIVATE_H
+#define AMDTEE_PRIVATE_H
+
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/tee_drv.h>
+#include <linux/kref.h>
+#include <linux/types.h>
+#include "amdtee_if.h"
+
+#define DRIVER_NAME	"amdtee"
+#define DRIVER_AUTHOR   "AMD-TEE Linux driver team"
+
+/* Some GlobalPlatform error codes used in this driver */
+#define TEEC_SUCCESS			0x00000000
+#define TEEC_ERROR_GENERIC		0xFFFF0000
+#define TEEC_ERROR_BAD_PARAMETERS	0xFFFF0006
+#define TEEC_ERROR_COMMUNICATION	0xFFFF000E
+
+#define TEEC_ORIGIN_COMMS		0x00000002
+
+/* Maximum number of sessions which can be opened with a Trusted Application */
+#define TEE_NUM_SESSIONS			32
+
+#define TA_LOAD_PATH				"/amdtee"
+#define TA_PATH_MAX				60
+
+/**
+ * struct amdtee - main service struct
+ * @teedev:		client device
+ * @pool:		shared memory pool
+ */
+struct amdtee {
+	struct tee_device *teedev;
+	struct tee_shm_pool *pool;
+};
+
+/**
+ * struct amdtee_session - Trusted Application (TA) session related information.
+ * @ta_handle:     handle to Trusted Application (TA) loaded in TEE environment
+ * @refcount:      counter to keep track of sessions opened for the TA instance
+ * @session_info:  an array pointing to TA allocated session data.
+ * @sess_mask:     session usage bit-mask. If a particular bit is set, then the
+ *                 corresponding @session_info entry is in use or valid.
+ *
+ * Session structure is updated on open_session and this information is used for
+ * subsequent operations with the Trusted Application.
+ */
+struct amdtee_session {
+	struct list_head list_node;
+	u32 ta_handle;
+	struct kref refcount;
+	u32 session_info[TEE_NUM_SESSIONS];
+	DECLARE_BITMAP(sess_mask, TEE_NUM_SESSIONS);
+	spinlock_t lock;	/* synchronizes access to @sess_mask */
+};
+
+/**
+ * struct amdtee_context_data - AMD-TEE driver context data
+ * @sess_list:    Keeps track of sessions opened in current TEE context
+ */
+struct amdtee_context_data {
+	struct list_head sess_list;
+};
+
+struct amdtee_driver_data {
+	struct amdtee *amdtee;
+};
+
+struct shmem_desc {
+	void *kaddr;
+	u64 size;
+};
+
+/**
+ * struct amdtee_shm_data - Shared memory data
+ * @kaddr:	Kernel virtual address of shared memory
+ * @buf_id:	Buffer id of memory mapped by TEE_CMD_ID_MAP_SHARED_MEM
+ */
+struct amdtee_shm_data {
+	struct  list_head shm_node;
+	void    *kaddr;
+	u32     buf_id;
+};
+
+struct amdtee_shm_context {
+	struct list_head shmdata_list;
+};
+
+#define LOWER_TWO_BYTE_MASK	0x0000FFFF
+
+/**
+ * set_session_id() - Sets the session identifier.
+ * @ta_handle:      [in] handle of the loaded Trusted Application (TA)
+ * @session_index:  [in] Session index. Range: 0 to (TEE_NUM_SESSIONS - 1).
+ * @session:        [out] Pointer to session id
+ *
+ * Lower two bytes of the session identifier represents the TA handle and the
+ * upper two bytes is session index.
+ */
+static inline void set_session_id(u32 ta_handle, u32 session_index,
+				  u32 *session)
+{
+	*session = (session_index << 16) | (LOWER_TWO_BYTE_MASK & ta_handle);
+}
+
+static inline u32 get_ta_handle(u32 session)
+{
+	return session & LOWER_TWO_BYTE_MASK;
+}
+
+static inline u32 get_session_index(u32 session)
+{
+	return (session >> 16) & LOWER_TWO_BYTE_MASK;
+}
+
+int amdtee_open_session(struct tee_context *ctx,
+			struct tee_ioctl_open_session_arg *arg,
+			struct tee_param *param);
+
+int amdtee_close_session(struct tee_context *ctx, u32 session);
+
+int amdtee_invoke_func(struct tee_context *ctx,
+		       struct tee_ioctl_invoke_arg *arg,
+		       struct tee_param *param);
+
+int amdtee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session);
+
+int amdtee_map_shmem(struct tee_shm *shm);
+
+void amdtee_unmap_shmem(struct tee_shm *shm);
+
+int handle_load_ta(void *data, u32 size,
+		   struct tee_ioctl_open_session_arg *arg);
+
+int handle_unload_ta(u32 ta_handle);
+
+int handle_open_session(struct tee_ioctl_open_session_arg *arg, u32 *info,
+			struct tee_param *p);
+
+int handle_close_session(u32 ta_handle, u32 info);
+
+int handle_map_shmem(u32 count, struct shmem_desc *start, u32 *buf_id);
+
+void handle_unmap_shmem(u32 buf_id);
+
+int handle_invoke_cmd(struct tee_ioctl_invoke_arg *arg, u32 sinfo,
+		      struct tee_param *p);
+
+struct tee_shm_pool *amdtee_config_shm(void);
+
+u32 get_buffer_id(struct tee_shm *shm);
+#endif /*AMDTEE_PRIVATE_H*/