tee: add register user memory

Added new ioctl to allow users register own buffers as a shared memory.

Signed-off-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>
[jw: moved tee_shm_is_registered() declaration]
[jw: added space after __tee_shm_alloc() implementation]
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

2 files changed, 75 insertions, 2 deletions

diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
index e9be4a45ff3e..7c8495607b99 100644
--- a/include/linux/tee_drv.h
+++ b/include/linux/tee_drv.h
@@ -25,8 +25,12 @@
  * specific TEE driver.
  */
 
-#define TEE_SHM_MAPPED		0x1	/* Memory mapped by the kernel */
-#define TEE_SHM_DMA_BUF		0x2	/* Memory with dma-buf handle */
+#define TEE_SHM_MAPPED		BIT(0)	/* Memory mapped by the kernel */
+#define TEE_SHM_DMA_BUF		BIT(1)	/* Memory with dma-buf handle */
+#define TEE_SHM_EXT_DMA_BUF	BIT(2)	/* Memory with dma-buf handle */
+#define TEE_SHM_REGISTER	BIT(3)  /* Memory registered in secure world */
+#define TEE_SHM_USER_MAPPED	BIT(4)  /* Memory mapped in user space */
+#define TEE_SHM_POOL		BIT(5)  /* Memory allocated from pool */
 
 struct device;
 struct tee_device;
@@ -76,6 +80,8 @@ struct tee_param {
  * @cancel_req:		request cancel of an ongoing invoke or open
  * @supp_revc:		called for supplicant to get a command
  * @supp_send:		called for supplicant to send a response
+ * @shm_register:	register shared memory buffer in TEE
+ * @shm_unregister:	unregister shared memory buffer in TEE
  */
 struct tee_driver_ops {
 	void (*get_version)(struct tee_device *teedev,
@@ -94,6 +100,9 @@ struct tee_driver_ops {
 			 struct tee_param *param);
 	int (*supp_send)(struct tee_context *ctx, u32 ret, u32 num_params,
 			 struct tee_param *param);
+	int (*shm_register)(struct tee_context *ctx, struct tee_shm *shm,
+			    struct page **pages, size_t num_pages);
+	int (*shm_unregister)(struct tee_context *ctx, struct tee_shm *shm);
 };
 
 /**
@@ -302,6 +311,40 @@ void *tee_get_drvdata(struct tee_device *teedev);
 struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags);
 
 /**
+ * tee_shm_priv_alloc() - Allocate shared memory privately
+ * @dev:	Device that allocates the shared memory
+ * @size:	Requested size of shared memory
+ *
+ * Allocates shared memory buffer that is not associated with any client
+ * context. Such buffers are owned by TEE driver and used for internal calls.
+ *
+ * @returns a pointer to 'struct tee_shm'
+ */
+struct tee_shm *tee_shm_priv_alloc(struct tee_device *teedev, size_t size);
+
+/**
+ * tee_shm_register() - Register shared memory buffer
+ * @ctx:	Context that registers the shared memory
+ * @addr:	Address is userspace of the shared buffer
+ * @length:	Length of the shared buffer
+ * @flags:	Flags setting properties for the requested shared memory.
+ *
+ * @returns a pointer to 'struct tee_shm'
+ */
+struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
+				 size_t length, u32 flags);
+
+/**
+ * tee_shm_is_registered() - Check if shared memory object in registered in TEE
+ * @shm:	Shared memory handle
+ * @returns true if object is registered in TEE
+ */
+static inline bool tee_shm_is_registered(struct tee_shm *shm)
+{
+	return shm && (shm->flags & TEE_SHM_REGISTER);
+}
+
+/**
  * tee_shm_free() - Free shared memory
  * @shm:	Handle to shared memory to free
  */
diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
index 688782e90140..d41a07afe3fc 100644
--- a/include/uapi/linux/tee.h
+++ b/include/uapi/linux/tee.h
@@ -50,6 +50,7 @@
 
 #define TEE_GEN_CAP_GP		(1 << 0)/* GlobalPlatform compliant TEE */
 #define TEE_GEN_CAP_PRIVILEGED	(1 << 1)/* Privileged device (for supplicant) */
+#define TEE_GEN_CAP_REG_MEM	(1 << 2)/* Supports registering shared memory */
 
 /*
  * TEE Implementation ID
@@ -332,6 +333,35 @@ struct tee_iocl_supp_send_arg {
 #define TEE_IOC_SUPPL_SEND	_IOR(TEE_IOC_MAGIC, TEE_IOC_BASE + 7, \
 				     struct tee_ioctl_buf_data)
 
+/**
+ * struct tee_ioctl_shm_register_data - Shared memory register argument
+ * @addr:      [in] Start address of shared memory to register
+ * @length:    [in/out] Length of shared memory to register
+ * @flags:     [in/out] Flags to/from registration.
+ * @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_REGISTER below.
+ */
+struct tee_ioctl_shm_register_data {
+	__u64 addr;
+	__u64 length;
+	__u32 flags;
+	__s32 id;
+};
+
+/**
+ * TEE_IOC_SHM_REGISTER - Register shared memory argument
+ *
+ * Registers shared memory between the user space process and secure OS.
+ *
+ * Returns a file descriptor on success or < 0 on failure
+ *
+ * The shared memory is unregisterred when the descriptor is closed.
+ */
+#define TEE_IOC_SHM_REGISTER   _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 9, \
+				     struct tee_ioctl_shm_register_data)
 /*
  * Five syscalls are used when communicating with the TEE driver.
  * open(): opens the device associated with the driver