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authorIngo Tuchscherer <ingo.tuchscherer@de.ibm.com>2015-03-17 18:02:20 +0300
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2015-07-01 10:34:37 +0300
commitdb490cb9aeb77b392f4bdaad3ebe96ea1d5c7bfe (patch)
treef9f0b64173f679f17ce6c8f6500be0d0f0195d31 /drivers/s390
parent05a8256c586ab75bcd6b793737b2022a1a98cb1e (diff)
downloadlinux-db490cb9aeb77b392f4bdaad3ebe96ea1d5c7bfe.tar.xz
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 <ingo.tuchscherer@de.ibm.com> Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/crypto/zcrypt_api.c7
1 files changed, 7 insertions, 0 deletions
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;