From db490cb9aeb77b392f4bdaad3ebe96ea1d5c7bfe Mon Sep 17 00:00:00 2001 From: Ingo Tuchscherer Date: Tue, 17 Mar 2015 16:02:20 +0100 Subject: s390/zcrypt: enable s390 hwrng to seed kernel entropy Set the 'quality' property in the zcrypt rng device structure to enable the zcrypt hwrng device to take part in the kernel entropy seeding process. A module parameter named hwrng_seed will be introduced to disable the participation. By default this parameter is set to 1 (enabled). Signed-off-by: Ingo Tuchscherer Signed-off-by: Harald Freudenberger Signed-off-by: Martin Schwidefsky --- drivers/s390/crypto/zcrypt_api.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/s390') diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c index 08f1830cbfc4..01bf1f5cf2e9 100644 --- a/drivers/s390/crypto/zcrypt_api.c +++ b/drivers/s390/crypto/zcrypt_api.c @@ -54,6 +54,10 @@ MODULE_DESCRIPTION("Cryptographic Coprocessor interface, " \ "Copyright IBM Corp. 2001, 2012"); MODULE_LICENSE("GPL"); +static int zcrypt_hwrng_seed = 1; +module_param_named(hwrng_seed, zcrypt_hwrng_seed, int, S_IRUSR|S_IRGRP); +MODULE_PARM_DESC(hwrng_seed, "Turn on/off hwrng auto seed, default is 1 (on)."); + static DEFINE_SPINLOCK(zcrypt_device_lock); static LIST_HEAD(zcrypt_device_list); static int zcrypt_device_count = 0; @@ -1373,6 +1377,7 @@ static int zcrypt_rng_data_read(struct hwrng *rng, u32 *data) static struct hwrng zcrypt_rng_dev = { .name = "zcrypt", .data_read = zcrypt_rng_data_read, + .quality = 990, }; static int zcrypt_rng_device_add(void) @@ -1387,6 +1392,8 @@ static int zcrypt_rng_device_add(void) goto out; } zcrypt_rng_buffer_index = 0; + if (!zcrypt_hwrng_seed) + zcrypt_rng_dev.quality = 0; rc = hwrng_register(&zcrypt_rng_dev); if (rc) goto out_free; -- cgit v1.2.3