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Diffstat (limited to 'drivers/tee/qcomtee/qcomtee_object.h')
| -rw-r--r-- | drivers/tee/qcomtee/qcomtee_object.h | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/drivers/tee/qcomtee/qcomtee_object.h b/drivers/tee/qcomtee/qcomtee_object.h new file mode 100644 index 000000000000..5221449be7db --- /dev/null +++ b/drivers/tee/qcomtee/qcomtee_object.h @@ -0,0 +1,316 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. + */ + +#ifndef QCOMTEE_OBJECT_H +#define QCOMTEE_OBJECT_H + +#include <linux/completion.h> +#include <linux/kref.h> +#include <linux/slab.h> +#include <linux/workqueue.h> + +struct qcomtee_object; + +/** + * DOC: Overview + * + * qcomtee_object provides object refcounting, ID allocation for objects hosted + * in the kernel, and necessary message marshaling for Qualcomm TEE (QTEE). + * + * To invoke an object in QTEE, the user calls qcomtee_object_do_invoke() + * while passing an instance of &struct qcomtee_object and the requested + * operation + arguments. + * + * After boot, QTEE provides a static object %ROOT_QCOMTEE_OBJECT (type of + * %QCOMTEE_OBJECT_TYPE_ROOT). The root object is invoked to pass the user's + * credentials and obtain other instances of &struct qcomtee_object (type of + * %QCOMTEE_OBJECT_TYPE_TEE) that represent services and TAs in QTEE; + * see &enum qcomtee_object_type. + * + * The objects received from QTEE are refcounted. So the owner of these objects + * can issue qcomtee_object_get() to increase the refcount and pass objects + * to other clients, or issue qcomtee_object_put() to decrease the refcount + * and release the resources in QTEE. + * + * The kernel can host services accessible to QTEE. A driver should embed + * an instance of &struct qcomtee_object in the struct it wants to export to + * QTEE (this is called a callback object). It issues qcomtee_object_user_init() + * to set the dispatch() operation for the callback object and set its type + * to %QCOMTEE_OBJECT_TYPE_CB. + * + * core.c holds an object table for callback objects. An object ID is assigned + * to each callback object, which is an index to the object table. QTEE uses + * these IDs to reference or invoke callback objects. + * + * If QTEE invokes a callback object in the kernel, the dispatch() operation is + * called in the context of the thread that originally called + * qcomtee_object_do_invoke(). + */ + +/** + * enum qcomtee_object_type - Object types. + * @QCOMTEE_OBJECT_TYPE_TEE: object hosted on QTEE. + * @QCOMTEE_OBJECT_TYPE_CB: object hosted on kernel. + * @QCOMTEE_OBJECT_TYPE_ROOT: 'primordial' object. + * @QCOMTEE_OBJECT_TYPE_NULL: NULL object. + * + * The primordial object is used for bootstrapping the IPC connection between + * the kernel and QTEE. It is invoked by the kernel when it wants to get a + * 'client env'. + */ +enum qcomtee_object_type { + QCOMTEE_OBJECT_TYPE_TEE, + QCOMTEE_OBJECT_TYPE_CB, + QCOMTEE_OBJECT_TYPE_ROOT, + QCOMTEE_OBJECT_TYPE_NULL, +}; + +/** + * enum qcomtee_arg_type - Type of QTEE argument. + * @QCOMTEE_ARG_TYPE_INV: invalid type. + * @QCOMTEE_ARG_TYPE_OB: output buffer (OB). + * @QCOMTEE_ARG_TYPE_OO: output object (OO). + * @QCOMTEE_ARG_TYPE_IB: input buffer (IB). + * @QCOMTEE_ARG_TYPE_IO: input object (IO). + * + * Use the invalid type to specify the end of the argument array. + */ +enum qcomtee_arg_type { + QCOMTEE_ARG_TYPE_INV = 0, + QCOMTEE_ARG_TYPE_OB, + QCOMTEE_ARG_TYPE_OO, + QCOMTEE_ARG_TYPE_IB, + QCOMTEE_ARG_TYPE_IO, + QCOMTEE_ARG_TYPE_NR, +}; + +/** + * define QCOMTEE_ARGS_PER_TYPE - Maximum arguments of a specific type. + * + * The QTEE transport protocol limits the maximum number of arguments of + * a specific type (i.e., IB, OB, IO, and OO). + */ +#define QCOMTEE_ARGS_PER_TYPE 16 + +/* Maximum arguments that can fit in a QTEE message, ignoring the type. */ +#define QCOMTEE_ARGS_MAX (QCOMTEE_ARGS_PER_TYPE * (QCOMTEE_ARG_TYPE_NR - 1)) + +struct qcomtee_buffer { + union { + void *addr; + void __user *uaddr; + }; + size_t size; +}; + +/** + * struct qcomtee_arg - Argument for QTEE object invocation. + * @type: type of argument as &enum qcomtee_arg_type. + * @flags: extra flags. + * @b: address and size if the type of argument is a buffer. + * @o: object instance if the type of argument is an object. + * + * &qcomtee_arg.flags only accepts %QCOMTEE_ARG_FLAGS_UADDR for now, which + * states that &qcomtee_arg.b contains a userspace address in uaddr. + */ +struct qcomtee_arg { + enum qcomtee_arg_type type; +/* 'b.uaddr' holds a __user address. */ +#define QCOMTEE_ARG_FLAGS_UADDR BIT(0) + unsigned int flags; + union { + struct qcomtee_buffer b; + struct qcomtee_object *o; + }; +}; + +static inline int qcomtee_args_len(struct qcomtee_arg *args) +{ + int i = 0; + + while (args[i].type != QCOMTEE_ARG_TYPE_INV) + i++; + return i; +} + +/* Context is busy (callback is in progress). */ +#define QCOMTEE_OIC_FLAG_BUSY BIT(1) +/* Context needs to notify the current object. */ +#define QCOMTEE_OIC_FLAG_NOTIFY BIT(2) +/* Context has shared state with QTEE. */ +#define QCOMTEE_OIC_FLAG_SHARED BIT(3) + +/** + * struct qcomtee_object_invoke_ctx - QTEE context for object invocation. + * @ctx: TEE context for this invocation. + * @flags: flags for the invocation context. + * @errno: error code for the invocation. + * @object: current object invoked in this callback context. + * @u: array of arguments for the current invocation (+1 for ending arg). + * @in_msg: inbound buffer shared with QTEE. + * @out_msg: outbound buffer shared with QTEE. + * @in_shm: TEE shm allocated for inbound buffer. + * @out_shm: TEE shm allocated for outbound buffer. + * @data: extra data attached to this context. + */ +struct qcomtee_object_invoke_ctx { + struct tee_context *ctx; + unsigned long flags; + int errno; + + struct qcomtee_object *object; + struct qcomtee_arg u[QCOMTEE_ARGS_MAX + 1]; + + struct qcomtee_buffer in_msg; + struct qcomtee_buffer out_msg; + struct tee_shm *in_shm; + struct tee_shm *out_shm; + + void *data; +}; + +static inline struct qcomtee_object_invoke_ctx * +qcomtee_object_invoke_ctx_alloc(struct tee_context *ctx) +{ + struct qcomtee_object_invoke_ctx *oic; + + oic = kzalloc(sizeof(*oic), GFP_KERNEL); + if (oic) + oic->ctx = ctx; + return oic; +} + +/** + * qcomtee_object_do_invoke() - Submit an invocation for an object. + * @oic: context to use for the current invocation. + * @object: object being invoked. + * @op: requested operation on the object. + * @u: array of arguments for the current invocation. + * @result: result returned from QTEE. + * + * The caller is responsible for keeping track of the refcount for each object, + * including @object. On return, the caller loses ownership of all input + * objects of type %QCOMTEE_OBJECT_TYPE_CB. + * + * @object can be of %QCOMTEE_OBJECT_TYPE_ROOT or %QCOMTEE_OBJECT_TYPE_TEE. + * + * Return: On success, returns 0; on failure, returns < 0. + */ +int qcomtee_object_do_invoke(struct qcomtee_object_invoke_ctx *oic, + struct qcomtee_object *object, u32 op, + struct qcomtee_arg *u, int *result); + +/** + * struct qcomtee_object_operations - Callback object operations. + * @release: release the object if QTEE is not using it. + * @dispatch: dispatch the operation requested by QTEE. + * @notify: report the status of any pending response submitted by @dispatch. + */ +struct qcomtee_object_operations { + void (*release)(struct qcomtee_object *object); + int (*dispatch)(struct qcomtee_object_invoke_ctx *oic, + struct qcomtee_object *object, u32 op, + struct qcomtee_arg *args); + void (*notify)(struct qcomtee_object_invoke_ctx *oic, + struct qcomtee_object *object, int err); +}; + +/** + * struct qcomtee_object - QTEE or kernel object. + * @name: object name. + * @refcount: reference counter. + * @object_type: object type as &enum qcomtee_object_type. + * @info: extra information for the object. + * @ops: callback operations for objects of type %QCOMTEE_OBJECT_TYPE_CB. + * @work: work for async operations on the object. + * + * @work is used for releasing objects of %QCOMTEE_OBJECT_TYPE_TEE type. + */ +struct qcomtee_object { + const char *name; + struct kref refcount; + + enum qcomtee_object_type object_type; + struct object_info { + unsigned long qtee_id; + /* TEE context for QTEE object async requests. */ + struct tee_context *qcomtee_async_ctx; + } info; + + struct qcomtee_object_operations *ops; + struct work_struct work; +}; + +/* Static instances of qcomtee_object objects. */ +#define NULL_QCOMTEE_OBJECT ((struct qcomtee_object *)(0)) +extern struct qcomtee_object qcomtee_object_root; +#define ROOT_QCOMTEE_OBJECT (&qcomtee_object_root) + +static inline enum qcomtee_object_type +typeof_qcomtee_object(struct qcomtee_object *object) +{ + if (object == NULL_QCOMTEE_OBJECT) + return QCOMTEE_OBJECT_TYPE_NULL; + return object->object_type; +} + +static inline const char *qcomtee_object_name(struct qcomtee_object *object) +{ + if (object == NULL_QCOMTEE_OBJECT) + return "null"; + + if (!object->name) + return "no-name"; + return object->name; +} + +/** + * qcomtee_object_user_init() - Initialize an object for the user. + * @object: object to initialize. + * @ot: type of object as &enum qcomtee_object_type. + * @ops: instance of callbacks. + * @fmt: name assigned to the object. + * + * Return: On success, returns 0; on failure, returns < 0. + */ +int qcomtee_object_user_init(struct qcomtee_object *object, + enum qcomtee_object_type ot, + struct qcomtee_object_operations *ops, + const char *fmt, ...) __printf(4, 5); + +/* Object release is RCU protected. */ +int qcomtee_object_get(struct qcomtee_object *object); +void qcomtee_object_put(struct qcomtee_object *object); + +#define qcomtee_arg_for_each(i, args) \ + for (i = 0; args[i].type != QCOMTEE_ARG_TYPE_INV; i++) + +/* Next argument of type @type after index @i. */ +int qcomtee_next_arg_type(struct qcomtee_arg *u, int i, + enum qcomtee_arg_type type); + +/* Iterate over argument of given type. */ +#define qcomtee_arg_for_each_type(i, args, at) \ + for (i = qcomtee_next_arg_type(args, 0, at); \ + args[i].type != QCOMTEE_ARG_TYPE_INV; \ + i = qcomtee_next_arg_type(args, i + 1, at)) + +#define qcomtee_arg_for_each_input_buffer(i, args) \ + qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_IB) +#define qcomtee_arg_for_each_output_buffer(i, args) \ + qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_OB) +#define qcomtee_arg_for_each_input_object(i, args) \ + qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_IO) +#define qcomtee_arg_for_each_output_object(i, args) \ + qcomtee_arg_for_each_type(i, args, QCOMTEE_ARG_TYPE_OO) + +struct qcomtee_object * +qcomtee_object_get_client_env(struct qcomtee_object_invoke_ctx *oic); + +struct qcomtee_object * +qcomtee_object_get_service(struct qcomtee_object_invoke_ctx *oic, + struct qcomtee_object *client_env, u32 uid); + +#endif /* QCOMTEE_OBJECT_H */ |