Commit bade7e1f authored by Rijo Thomas's avatar Rijo Thomas Committed by Herbert Xu
Browse files

tee: amdtee: check TEE status during driver initialization 



The AMD-TEE driver should check if TEE is available before
registering itself with TEE subsystem. This ensures that
there is a TEE which the driver can talk to before proceeding
with tee device node allocation.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: default avatarJens Wiklander <jens.wiklander@linaro.org>
Co-developed-by: default avatarDevaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: default avatarDevaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: default avatarRijo Thomas <Rijo-john.Thomas@amd.com>
Reviewed-by: default avatarGary R Hook <gary.hook@amd.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 757cc3e9

drivers/crypto/ccp/tee-dev.c

+11 −0
Original line number Diff line number Diff line
@@ -362,3 +362,14 @@ int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf, size_t len, 
	return 0;

}

EXPORT_SYMBOL(psp_tee_process_cmd);



int psp_check_tee_status(void)

{

	struct psp_device *psp = psp_get_master_device();



	if (!psp || !psp->tee_data)

		return -ENODEV;



	return 0;

}

EXPORT_SYMBOL(psp_check_tee_status);

drivers/tee/amdtee/core.c

+6 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/firmware.h>

#include "amdtee_private.h"

#include "../tee_private.h"

#include <linux/psp-tee.h>



static struct amdtee_driver_data *drv_data;

static DEFINE_MUTEX(session_list_mutex);
@@ -438,6 +439,10 @@ static int __init amdtee_driver_init(void) 
	struct tee_shm_pool *pool = ERR_PTR(-EINVAL);

	int rc;



	rc = psp_check_tee_status();

	if (rc)

		goto err_fail;



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

	if (IS_ERR(drv_data))

		return -ENOMEM;
@@ -485,6 +490,7 @@ static int __init amdtee_driver_init(void) 
	kfree(drv_data);

	drv_data = NULL;



err_fail:

	pr_err("amd-tee driver initialization failed\n");

	return rc;

}

include/linux/psp-tee.h

+18 −0
Original line number Diff line number Diff line
@@ -62,6 +62,19 @@ enum tee_cmd_id { 
int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf, size_t len,

			u32 *status);



/**

 * psp_check_tee_status() - Checks whether there is a TEE which a driver can

 * talk to.

 *

 * This function can be used by AMD-TEE driver to query if there is TEE with

 * which it can communicate.

 *

 * Returns:

 * 0          if the device has TEE

 * -%ENODEV   if there is no TEE available

 */

int psp_check_tee_status(void);



#else /* !CONFIG_CRYPTO_DEV_SP_PSP */



static inline int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf,
@@ -69,5 +82,10 @@ static inline int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf, 
{

	return -ENODEV;

}



static inline int psp_check_tee_status(void)

{

	return -ENODEV;

}

#endif /* CONFIG_CRYPTO_DEV_SP_PSP */

#endif /* __PSP_TEE_H_ */