Function crypto_get_driverid

freebsd/opencrypto/crypto.c:989–1049

* Return a new driver id. Registers a driver with the system so that * it can be probed by subsequent sessions. */

 * it can be probed by subsequent sessions.
 */
int32_t
crypto_get_driverid(device_t dev, size_t sessionsize, int flags)
{
	struct cryptocap *cap, **newdrv;
	int i;

	if ((flags & (CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE)) == 0) {
		device_printf(dev,
		    "no flags specified when registering driver\n");
		return -1;
	}

	cap = malloc(sizeof(*cap), M_CRYPTO_DATA, M_WAITOK | M_ZERO);
	cap->cc_dev = dev;
	cap->cc_session_size = sessionsize;
	cap->cc_flags = flags;
	refcount_init(&cap->cc_refs, 1);

	CRYPTO_DRIVER_LOCK();
	for (;;) {
		for (i = 0; i < crypto_drivers_size; i++) {
			if (crypto_drivers[i] == NULL)
				break;
		}

		if (i < crypto_drivers_size)
			break;

		/* Out of entries, allocate some more. */

		if (2 * crypto_drivers_size <= crypto_drivers_size) {
			CRYPTO_DRIVER_UNLOCK();
			printf("crypto: driver count wraparound!\n");
			cap_rele(cap);
			return (-1);
		}
		CRYPTO_DRIVER_UNLOCK();

		newdrv = malloc(2 * crypto_drivers_size *
		    sizeof(*crypto_drivers), M_CRYPTO_DATA, M_WAITOK | M_ZERO);

		CRYPTO_DRIVER_LOCK();
		memcpy(newdrv, crypto_drivers,
		    crypto_drivers_size * sizeof(*crypto_drivers));

		crypto_drivers_size *= 2;

		free(crypto_drivers, M_CRYPTO_DATA);
		crypto_drivers = newdrv;
	}

	cap->cc_hid = i;
	crypto_drivers[i] = cap;
	CRYPTO_DRIVER_UNLOCK();

	if (bootverbose)
		printf("crypto: assign %s driver id %u, flags 0x%x\n",
		    device_get_nameunit(dev), i, flags);