[PATCH v2 13/20] s390/zcrypt: Add small mempool for cca info list entries

Harald Freudenberger
2025-03-04T17:21:31Z

Add a small memory pool for (pre-)allocating cca info list
entries. These entries are rather small and the pool is a simple
way to support the xflag ZCRYPT_XFLAG_NOMEMALLOC to avoid mallocs.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
---
drivers/s390/crypto/zcrypt_ccamisc.c | 67 ++++++++++++++++++++--------
drivers/s390/crypto/zcrypt_ccamisc.h | 3 +-
drivers/s390/crypto/zcrypt_cex4.c | 4 +-
3 files changed, 53 insertions(+), 21 deletions(-)

diff --git a/drivers/s390/crypto/zcrypt_ccamisc.c b/drivers/s390/crypto/zcrypt_ccamisc.c
index ff7ba2622484..e4ec922aae0d 100644
--- a/drivers/s390/crypto/zcrypt_ccamisc.c
+++ b/drivers/s390/crypto/zcrypt_ccamisc.c
@@ -41,6 +41,10 @@ struct cca_info_list_entry {
static LIST_HEAD(cca_info_list);
static DEFINE_SPINLOCK(cca_info_list_lock);

+/* memory pool for cca_info_list entries */
+#define INFO_ENTRY_MEMPOOL_MIN_ITEMS 8
+static mempool_t *info_mempool;
+
/*
* Cprb memory pool held for urgent cases where no memory
* can be allocated via kmalloc. This pool is only used
@@ -1662,7 +1666,7 @@ static int cca_info_cache_fetch(u16 cardnr, u16 domain, struct cca_info *ci)
}

static void cca_info_cache_update(u16 cardnr, u16 domain,
- const struct cca_info *ci)
+ const struct cca_info *ci, u32 xflags)
{
int found = 0;
struct cca_info_list_entry *ptr;
@@ -1677,7 +1681,9 @@ static void cca_info_cache_update(u16 cardnr, u16 domain,
}
}
if (!found) {
- ptr = kmalloc(sizeof(*ptr), GFP_ATOMIC);
+ ptr = (xflags & ZCRYPT_XFLAG_NOMEMALLOC) ?
+ mempool_alloc_preallocated(info_mempool) :
+ mempool_alloc(info_mempool, GFP_ATOMIC);
if (!ptr) {
spin_unlock_bh(&cca_info_list_lock);
return;
@@ -1699,7 +1705,7 @@ static void cca_info_cache_scrub(u16 cardnr, u16 domain)
if (ptr->cardnr == cardnr &&
ptr->domain == domain) {
list_del(&ptr->list);
- kfree(ptr);
+ mempool_free(ptr, info_mempool);
break;
}
}
@@ -1713,7 +1719,7 @@ static void __exit mkvp_cache_free(void)
spin_lock_bh(&cca_info_list_lock);
list_for_each_entry_safe(ptr, pnext, &cca_info_list, list) {
list_del(&ptr->list);
- kfree(ptr);
+ mempool_free(ptr, info_mempool);
}
spin_unlock_bh(&cca_info_list_lock);
}
@@ -1721,14 +1727,14 @@ static void __exit mkvp_cache_free(void)
/*
* Fetch cca_info values via query_crypto_facility from adapter.
*/
-static int fetch_cca_info(u16 cardnr, u16 domain, struct cca_info *ci)
+static int fetch_cca_info(u16 cardnr, u16 domain,
+ struct cca_info *ci, u32 xflags)
{
void *mem;
int rc, found = 0;
size_t rlen, vlen;
u8 *rarray, *varray;
struct zcrypt_device_status_ext devstat;
- u32 xflags = 0;

memset(ci, 0, sizeof(*ci));

@@ -1802,15 +1808,15 @@ static int fetch_cca_info(u16 cardnr, u16 domain, struct cca_info *ci)
/*
* Fetch cca information about a CCA queue.
*/
-int cca_get_info(u16 card, u16 dom, struct cca_info *ci, int verify)
+int cca_get_info(u16 card, u16 dom, struct cca_info *ci, int verify, u32 xflags)
{
int rc;

rc = cca_info_cache_fetch(card, dom, ci);
if (rc || verify) {
- rc = fetch_cca_info(card, dom, ci);
+ rc = fetch_cca_info(card, dom, ci, xflags);
if (rc == 0)
- cca_info_cache_update(card, dom, ci);
+ cca_info_cache_update(card, dom, ci, xflags);
}

return rc;
@@ -1828,6 +1834,7 @@ static int findcard(u64 mkvp, u16 *pcardnr, u16 *pdomain,
u16 card, dom;
struct cca_info ci;
int i, rc, oi = -1;
+ u32 xflg = 0; /* xflags */

/* mkvp must not be zero, minhwtype needs to be >= 0 */
if (mkvp == 0 || minhwtype < 0)
@@ -1859,8 +1866,8 @@ static int findcard(u64 mkvp, u16 *pcardnr, u16 *pdomain,
if (!verify)
break;
/* verify: refresh card info */
- if (fetch_cca_info(card, dom, &ci) == 0) {
- cca_info_cache_update(card, dom, &ci);
+ if (fetch_cca_info(card, dom, &ci, xflg) == 0) {
+ cca_info_cache_update(card, dom, &ci, xflg);
if (ci.hwtype >= minhwtype &&
ci.cur_aes_mk_state == '2' &&
ci.cur_aes_mkvp == mkvp)
@@ -1882,8 +1889,8 @@ static int findcard(u64 mkvp, u16 *pcardnr, u16 *pdomain,
card = AP_QID_CARD(device_status[i].qid);
dom = AP_QID_QUEUE(device_status[i].qid);
/* fresh fetch mkvp from adapter */
- if (fetch_cca_info(card, dom, &ci) == 0) {
- cca_info_cache_update(card, dom, &ci);
+ if (fetch_cca_info(card, dom, &ci, xflg) == 0) {
+ cca_info_cache_update(card, dom, &ci, xflg);
if (ci.hwtype >= minhwtype &&
ci.cur_aes_mk_state == '2' &&
ci.cur_aes_mkvp == mkvp)
@@ -1955,6 +1962,7 @@ int cca_findcard2(u32 *apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
int i, card, dom, curmatch, oldmatch, rc;
struct cca_info ci;
u32 _nr_apqns = 0;
+ u32 xflags = 0;

/* occupy the device status memory */
mutex_lock(&dev_status_mem_mutex);
@@ -1985,7 +1993,7 @@ int cca_findcard2(u32 *apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
if (domain != 0xFFFF && dom != domain)
continue;
/* get cca info on this apqn */
- if (cca_get_info(card, dom, &ci, verify))
+ if (cca_get_info(card, dom, &ci, verify, xflags))
continue;
/* current master key needs to be valid */
if (mktype == AES_MK_SET && ci.cur_aes_mk_state != '2')
@@ -2037,6 +2045,8 @@ EXPORT_SYMBOL(cca_findcard2);

int __init zcrypt_ccamisc_init(void)
{
+ int rc = -ENOMEM;
+
/* Pre-allocate a small memory pool for cca cprbs. */
cprb_mempool = mempool_create_kmalloc_pool(zcrypt_cca_cprbpool_min_items,
CPRB_MEMPOOL_ITEM_SIZE);
@@ -2044,19 +2054,39 @@ int __init zcrypt_ccamisc_init(void)
ZCRYPT_DBF_ERR("%s mempool_create(%d,%d) failed: %ld\n",
__func__, zcrypt_cca_cprbpool_min_items,
CPRB_MEMPOOL_ITEM_SIZE, PTR_ERR(cprb_mempool));
+ rc = PTR_ERR(cprb_mempool);
cprb_mempool = NULL;
- return -ENOMEM;
+ goto out;
+ }
+
+ /* Pre-allocate a small memory pool for cca info list entries */
+ info_mempool = mempool_create_kmalloc_pool(INFO_ENTRY_MEMPOOL_MIN_ITEMS,
+ sizeof(struct cca_info_list_entry));
+ if (IS_ERR(info_mempool)) {
+ ZCRYPT_DBF_ERR("%s info entry mempool_create(%d,%d) failed: %ld\n",
+ __func__, INFO_ENTRY_MEMPOOL_MIN_ITEMS,
+ (int)sizeof(struct cca_info_list_entry),
+ PTR_ERR(info_mempool));
+ rc = PTR_ERR(info_mempool);
+ info_mempool = NULL;
+ goto out;
}

/* Pre-allocate one crypto status card struct used in findcard() */
dev_status_mem = kvmalloc(ZCRYPT_DEV_STATUS_EXT_SIZE, GFP_KERNEL);
if (!dev_status_mem) {
ZCRYPT_DBF_ERR("%s allocation of dev_status_mem failed\n", __func__);
- mempool_destroy(cprb_mempool);
- return -ENOMEM;
+ goto out;
}

- return 0;
+ rc = 0;
+
+out:
+ if (rc) {
+ mempool_destroy(cprb_mempool);
+ mempool_destroy(info_mempool);
+ }
+ return rc;
}

void zcrypt_ccamisc_exit(void)
@@ -2064,4 +2094,5 @@ void zcrypt_ccamisc_exit(void)
mkvp_cache_free();
kvfree(dev_status_mem);
mempool_destroy(cprb_mempool);
+ mempool_destroy(info_mempool);
}
diff --git a/drivers/s390/crypto/zcrypt_ccamisc.h b/drivers/s390/crypto/zcrypt_ccamisc.h
index bed647a42eb2..966f0eaf3c4c 100644
--- a/drivers/s390/crypto/zcrypt_ccamisc.h
+++ b/drivers/s390/crypto/zcrypt_ccamisc.h
@@ -268,7 +268,8 @@ struct cca_info {
/*
* Fetch cca information about an CCA queue.
*/
-int cca_get_info(u16 card, u16 dom, struct cca_info *ci, int verify);
+int cca_get_info(u16 card, u16 dom, struct cca_info *ci,
+ int verify, u32 xflags);

int zcrypt_ccamisc_init(void);
void zcrypt_ccamisc_exit(void);
diff --git a/drivers/s390/crypto/zcrypt_cex4.c b/drivers/s390/crypto/zcrypt_cex4.c
index 64df7d2f6266..49a638d373fa 100644
--- a/drivers/s390/crypto/zcrypt_cex4.c
+++ b/drivers/s390/crypto/zcrypt_cex4.c
@@ -86,7 +86,7 @@ static ssize_t cca_serialnr_show(struct device *dev,
memset(&ci, 0, sizeof(ci));

if (ap_domain_index >= 0)
- cca_get_info(ac->id, ap_domain_index, &ci, zc->online);
+ cca_get_info(ac->id, ap_domain_index, &ci, zc->online, 0);

return sysfs_emit(buf, "%s\n", ci.serial);
}
@@ -120,7 +120,7 @@ static ssize_t cca_mkvps_show(struct device *dev,

cca_get_info(AP_QID_CARD(zq->queue->qid),
AP_QID_QUEUE(zq->queue->qid),
- &ci, zq->online);
+ &ci, zq->online, 0);

if (ci.new_aes_mk_state >= '1' && ci.new_aes_mk_state <= '3')
n += sysfs_emit_at(buf, n, "AES NEW: %s 0x%016llx\n",
--
2.43.0