bybrooklyn/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-04-18 14:53:58 -04:00
Code Issues Packages Projects Releases Wiki Activity

s390/zcrypt: Introduce cprb mempool for cca misc functions

Browse Source 
Introduce a new module parameter "zcrypt_mempool_threshold"
for the zcrypt module. This parameter controls the minimal
amount of mempool items which are pre-allocated for urgent
requests/replies and will be used with the support for the
new xflag ZCRYPT_XFLAG_NOMEMALLOC. The default value of 5
shall provide enough memory items to support up to 5 requests
(and their associated reply) in parallel. The minimum value
is 1 and is checked in zcrypt module init().

If the mempool is depleted upon one cca misc functions is called
with the named xflag set, the function will fail with -ENOMEM
and the caller is responsible for taking further actions.

For CCA each mempool item is 16KB, as a CCA CPRB needs to
hold the request and the reply. The pool items only support
requests/replies with a limit of about 8KB.
So by default the CCA mempool consumes
  5 * 16KB = 80KB

This is only part of an rework to support a new xflag
ZCRYPT_XFLAG_NOMEMALLOC but not yet complete.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Link: https://lore.kernel.org/r/20250424133619.16495-7-freude@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Harald Freudenberger
2025-04-24 15:36:00 +02:00
committed by Heiko Carstens
parent 80c20b2c6d
commit 9bdb5f7e83
4 changed files with 103 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
drivers/s390/crypto/zcrypt_api.c
View File

@@ -50,6 +50,10 @@ MODULE_DESCRIPTION("Cryptographic Coprocessor interface, " \
"Copyright IBM Corp. 2001, 2012");
MODULE_LICENSE("GPL");
unsigned int zcrypt_mempool_threshold = 5;
module_param_named(mempool_threshold, zcrypt_mempool_threshold, uint, 0440);
MODULE_PARM_DESC(mempool_threshold, "CCA and EP11 request/reply mempool minimal items (min: 1)");
/*
* zcrypt tracepoint functions
*/
@@ -2144,13 +2148,23 @@ int __init zcrypt_api_init(void)
{
int rc;
/* make sure the mempool threshold is >= 1 */
if (zcrypt_mempool_threshold < 1) {
rc = -EINVAL;
goto out;
}
rc = zcrypt_debug_init();
if (rc)
goto out;
rc = zcdn_init();
if (rc)
goto out;
goto out_zcdn_init_failed;
rc = zcrypt_ccamisc_init();
if (rc)
goto out_ccamisc_init_failed;
/* Register the request sprayer. */
rc = misc_register(&zcrypt_misc_device);
@@ -2163,7 +2177,10 @@ int __init zcrypt_api_init(void)
return 0;
out_misc_register_failed:
zcrypt_ccamisc_exit();
out_ccamisc_init_failed:
zcdn_exit();
out_zcdn_init_failed:
zcrypt_debug_exit();
out:
return rc;