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Commit c3fa24af authored by Sumit Garg's avatar Sumit Garg Committed by Jens Wiklander
Browse files

tee: optee: add TEE bus device enumeration support 



OP-TEE provides a pseudo TA to enumerate TAs which can act as devices/
services for TEE bus. So implement device enumeration using invoke
function: PTA_CMD_GET_DEVICES provided by pseudo TA to fetch array of
device UUIDs. Also register these enumerated devices with TEE bus as
"optee-clntX" device.

Signed-off-by: default avatarSumit Garg <sumit.garg@linaro.org>
Reviewed-by: default avatarDaniel Thompson <daniel.thompson@linaro.org>
[jw: fix optee_enumerate_devices() with no devices found]
Signed-off-by: default avatarJens Wiklander <jens.wiklander@linaro.org>
parent 0fc1db9d

drivers/tee/optee/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -5,3 +5,4 @@ optee-objs += call.o 
optee-objs += rpc.o

optee-objs += supp.o

optee-objs += shm_pool.o

optee-objs += device.o

drivers/tee/optee/core.c

+4 −0
Original line number Diff line number Diff line
@@ -634,6 +634,10 @@ static struct optee *optee_probe(struct device_node *np) 
	if (optee->sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)

		pr_info("dynamic shared memory is enabled\n");



	rc = optee_enumerate_devices();

	if (rc)

		goto err;



	pr_info("initialized driver\n");

	return optee;

err:

drivers/tee/optee/device.c

0 → 100644
+155 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Copyright (C) 2019 Linaro Ltd.

 */



#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt



#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/tee_drv.h>

#include <linux/uuid.h>

#include "optee_private.h"



/*

 * Get device UUIDs

 *

 * [out]     memref[0]        Array of device UUIDs

 *

 * Return codes:

 * TEE_SUCCESS - Invoke command success

 * TEE_ERROR_BAD_PARAMETERS - Incorrect input param

 * TEE_ERROR_SHORT_BUFFER - Output buffer size less than required

 */

#define PTA_CMD_GET_DEVICES		0x0



static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)

{

	if (ver->impl_id == TEE_IMPL_ID_OPTEE)

		return 1;

	else

		return 0;

}



static int get_devices(struct tee_context *ctx, u32 session,

		       struct tee_shm *device_shm, u32 *shm_size)

{

	u32 ret = 0;

	struct tee_ioctl_invoke_arg inv_arg = {0};

	struct tee_param param[4] = {0};



	/* Invoke PTA_CMD_GET_DEVICES function */

	inv_arg.func = PTA_CMD_GET_DEVICES;

	inv_arg.session = session;

	inv_arg.num_params = 4;



	/* Fill invoke cmd params */

	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;

	param[0].u.memref.shm = device_shm;

	param[0].u.memref.size = *shm_size;

	param[0].u.memref.shm_offs = 0;



	ret = tee_client_invoke_func(ctx, &inv_arg, param);

	if ((ret < 0) || ((inv_arg.ret != TEEC_SUCCESS) &&

			  (inv_arg.ret != TEEC_ERROR_SHORT_BUFFER))) {

		pr_err("PTA_CMD_GET_DEVICES invoke function err: %x\n",

		       inv_arg.ret);

		return -EINVAL;

	}



	*shm_size = param[0].u.memref.size;



	return 0;

}



static int optee_register_device(const uuid_t *device_uuid, u32 device_id)

{

	struct tee_client_device *optee_device = NULL;

	int rc;



	optee_device = kzalloc(sizeof(*optee_device), GFP_KERNEL);

	if (!optee_device)

		return -ENOMEM;



	optee_device->dev.bus = &tee_bus_type;

	dev_set_name(&optee_device->dev, "optee-clnt%u", device_id);

	uuid_copy(&optee_device->id.uuid, device_uuid);



	rc = device_register(&optee_device->dev);

	if (rc) {

		pr_err("device registration failed, err: %d\n", rc);

		kfree(optee_device);

	}



	return rc;

}



int optee_enumerate_devices(void)

{

	const uuid_t pta_uuid =

		UUID_INIT(0x7011a688, 0xddde, 0x4053,

			  0xa5, 0xa9, 0x7b, 0x3c, 0x4d, 0xdf, 0x13, 0xb8);

	struct tee_ioctl_open_session_arg sess_arg = {0};

	struct tee_shm *device_shm = NULL;

	const uuid_t *device_uuid = NULL;

	struct tee_context *ctx = NULL;

	u32 shm_size = 0, idx, num_devices = 0;

	int rc;



	/* Open context with OP-TEE driver */

	ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL);

	if (IS_ERR(ctx))

		return -ENODEV;



	/* Open session with device enumeration pseudo TA */

	memcpy(sess_arg.uuid, pta_uuid.b, TEE_IOCTL_UUID_LEN);

	sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;

	sess_arg.num_params = 0;



	rc = tee_client_open_session(ctx, &sess_arg, NULL);

	if ((rc < 0) || (sess_arg.ret != TEEC_SUCCESS)) {

		/* Device enumeration pseudo TA not found */

		rc = 0;

		goto out_ctx;

	}



	rc = get_devices(ctx, sess_arg.session, NULL, &shm_size);

	if (rc < 0 || !shm_size)

		goto out_sess;



	device_shm = tee_shm_alloc(ctx, shm_size,

				   TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);

	if (IS_ERR(device_shm)) {

		pr_err("tee_shm_alloc failed\n");

		rc = PTR_ERR(device_shm);

		goto out_sess;

	}



	rc = get_devices(ctx, sess_arg.session, device_shm, &shm_size);

	if (rc < 0)

		goto out_shm;



	device_uuid = tee_shm_get_va(device_shm, 0);

	if (IS_ERR(device_uuid)) {

		pr_err("tee_shm_get_va failed\n");

		rc = PTR_ERR(device_uuid);

		goto out_shm;

	}



	num_devices = shm_size / sizeof(uuid_t);



	for (idx = 0; idx < num_devices; idx++) {

		rc = optee_register_device(&device_uuid[idx], idx);

		if (rc)

			goto out_shm;

	}



out_shm:

	tee_shm_free(device_shm);

out_sess:

	tee_client_close_session(ctx, sess_arg.session);

out_ctx:

	tee_client_close_context(ctx);



	return rc;

}

drivers/tee/optee/optee_private.h

+3 −0
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#define TEEC_ERROR_BAD_PARAMETERS	0xFFFF0006

#define TEEC_ERROR_COMMUNICATION	0xFFFF000E

#define TEEC_ERROR_OUT_OF_MEMORY	0xFFFF000C

#define TEEC_ERROR_SHORT_BUFFER		0xFFFF0010



#define TEEC_ORIGIN_COMMS		0x00000002
@@ -181,6 +182,8 @@ void optee_free_pages_list(void *array, size_t num_entries); 
void optee_fill_pages_list(u64 *dst, struct page **pages, int num_pages,

			   size_t page_offset);



int optee_enumerate_devices(void);



/*

 * Small helpers

 */