optee: add experimental support for /dev/tee0

Userspace accesses OP-TEE via ioctls and mmaps of the /dev/tee0
device. Replicating this in barebox is useful for verifying proper
operation of CONFIG_OPTEE by hacking libteeclient + optee_tests to
run under barebox.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20231127063559.2205776-8-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 33 insertions, 0 deletions

diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
index e5f0344d4d..4a5cb0f0a5 100644
--- a/include/linux/tee_drv.h
+++ b/include/linux/tee_drv.h
@@ -182,6 +182,9 @@ int tee_session_calc_client_uuid(uuid_t *uuid, u32 connection_method,
  * @refcount:	reference counter
  * @flags:	defined by TEE_SHM_* in tee_drv.h
  * @link:	list head for registering object globally
+ * @fd:		file descriptor for use in userspace
+ * @dev:	device for registering shared memory
+ * @res:	resource to be associated with device
  *
  * This pool is only supposed to be accessed directly from the TEE
  * subsystem and from drivers that implements their own shm pool manager.
@@ -194,6 +197,11 @@ struct tee_shm {
 	refcount_t refcount;
 	u32 flags;
 	struct list_head link;
+
+	int fd;
+	struct device_d dev;
+	struct cdev cdev;
+	struct resource res;
 };
 
 /**
@@ -205,6 +213,10 @@ void *tee_get_drvdata(struct tee_device *teedev);
 struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size);
 struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size);
 
+struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size);
+struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
+					  unsigned long addr, size_t length);
+
 /**
  * tee_shm_is_dynamic() - Check if shared memory object is of the dynamic kind
  * @shm:	Shared memory handle
@@ -257,6 +269,27 @@ static inline size_t tee_shm_get_size(struct tee_shm *shm)
 }
 
 /**
+ * tee_shm_get_id() - Get id of a shared memory object
+ * @shm:	Shared memory handle
+ * @returns id
+ */
+static inline int tee_shm_get_id(struct tee_shm *shm)
+{
+	/* Only call on non-private SHMs */
+	BUG_ON(shm->dev.id < 0);
+	return shm->dev.id;
+}
+
+/**
+ * tee_shm_get_from_id() - Find shared memory object and increase reference
+ * count
+ * @ctx:	Context owning the shared memory
+ * @id:		Id of shared memory object
+ * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
+ */
+struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id);
+
+/**
  * tee_client_open_context() - Open a TEE context
  * @start:	if not NULL, continue search after this context
  * @match:	function to check TEE device