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

[Harald Freudenberger <freude@linux.ibm.com>]

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