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: Jens Wiklander jens.wiklander@linaro.org Co-developed-by: Devaraj Rangasamy Devaraj.Rangasamy@amd.com Signed-off-by: Devaraj Rangasamy Devaraj.Rangasamy@amd.com Signed-off-by: Rijo Thomas Rijo-john.Thomas@amd.com --- drivers/crypto/ccp/tee-dev.c | 11 +++++++++++ drivers/tee/amdtee/core.c | 6 ++++++ include/linux/psp-tee.h | 18 ++++++++++++++++++ 3 files changed, 35 insertions(+)
diff --git a/drivers/crypto/ccp/tee-dev.c b/drivers/crypto/ccp/tee-dev.c index 555c8a7..5e697a9 100644 --- a/drivers/crypto/ccp/tee-dev.c +++ b/drivers/crypto/ccp/tee-dev.c @@ -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); diff --git a/drivers/tee/amdtee/core.c b/drivers/tee/amdtee/core.c index dd360f3..9d0cee1 100644 --- a/drivers/tee/amdtee/core.c +++ b/drivers/tee/amdtee/core.c @@ -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; } diff --git a/include/linux/psp-tee.h b/include/linux/psp-tee.h index 63bb221..cb0c95d 100644 --- a/include/linux/psp-tee.h +++ b/include/linux/psp-tee.h @@ -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_ */