diff options
Diffstat (limited to 'drivers/s390/crypto/zcrypt_api.c')
| -rw-r--r-- | drivers/s390/crypto/zcrypt_api.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c index f60f9fb25214..10206e4498d0 100644 --- a/drivers/s390/crypto/zcrypt_api.c +++ b/drivers/s390/crypto/zcrypt_api.c @@ -1992,6 +1992,72 @@ void zcrypt_rng_device_remove(void) mutex_unlock(&zcrypt_rng_mutex); } +/* + * Wait until the zcrypt api is operational. + * The AP bus scan and the binding of ap devices to device drivers is + * an asynchronous job. This function waits until these initial jobs + * are done and so the zcrypt api should be ready to serve crypto + * requests - if there are resources available. The function uses an + * internal timeout of 60s. The very first caller will either wait for + * ap bus bindings complete or the timeout happens. This state will be + * remembered for further callers which will only be blocked until a + * decision is made (timeout or bindings complete). + * On timeout -ETIME is returned, on success the return value is 0. + */ +int zcrypt_wait_api_operational(void) +{ + static DEFINE_MUTEX(zcrypt_wait_api_lock); + static int zcrypt_wait_api_state; + int rc; + + rc = mutex_lock_interruptible(&zcrypt_wait_api_lock); + if (rc) + return rc; + + switch (zcrypt_wait_api_state) { + case 0: + /* initial state, invoke wait for the ap bus complete */ + rc = ap_wait_init_apqn_bindings_complete( + msecs_to_jiffies(60 * 1000)); + switch (rc) { + case 0: + /* ap bus bindings are complete */ + zcrypt_wait_api_state = 1; + break; + case -EINTR: + /* interrupted, go back to caller */ + break; + case -ETIME: + /* timeout */ + ZCRYPT_DBF(DBF_WARN, + "%s ap_wait_init_apqn_bindings_complete() returned with ETIME\n", + __func__); + zcrypt_wait_api_state = -ETIME; + break; + default: + /* other failure */ + ZCRYPT_DBF(DBF_DEBUG, + "%s ap_wait_init_apqn_bindings_complete() failure rc=%d\n", + __func__, rc); + break; + } + break; + case 1: + /* a previous caller already found ap bus bindings complete */ + rc = 0; + break; + default: + /* a previous caller had timeout or other failure */ + rc = zcrypt_wait_api_state; + break; + } + + mutex_unlock(&zcrypt_wait_api_lock); + + return rc; +} +EXPORT_SYMBOL(zcrypt_wait_api_operational); + int __init zcrypt_debug_init(void) { zcrypt_dbf_info = debug_register("zcrypt", 1, 1, |