mirror-linux/drivers/tee/qcomtee/qcomtee_object.h

317 lines
10 KiB
C

/* 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 */