s390/zcrypt: Rework zcrypt function zcrypt_device_status_mask_ext

Rework the existing function zcrypt_device_status_mask_ext():
Add two new parameters to provide upper limits for
cards and queues. The existing implementation needed an
array of 256 * 256 * 4 = 256 KB which is really huge. The
reworked function is more flexible in the sense that the
caller can decide the upper limit for cards and domains to
be stored into the status array. So for example a caller may
decide to only query for cards 0...127 and queues 0...127
and thus only an array of size 128 * 128 * 4 = 64 KB is needed.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Link: https://lore.kernel.org/r/20250424133619.16495-9-freude@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

4 files changed, 33 insertions, 13 deletions

diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 88bf719b4c58..89baa87a13fc 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -1304,19 +1304,25 @@ static void zcrypt_device_status_mask(struct zcrypt_device_status *devstatus)
 	spin_unlock(&zcrypt_list_lock);
 }
 
-void zcrypt_device_status_mask_ext(struct zcrypt_device_status_ext *devstatus)
+void zcrypt_device_status_mask_ext(struct zcrypt_device_status_ext *devstatus,
+				   int maxcard, int maxqueue)
 {
 	struct zcrypt_card *zc;
 	struct zcrypt_queue *zq;
 	struct zcrypt_device_status_ext *stat;
 	int card, queue;
 
+	maxcard = min_t(int, maxcard, MAX_ZDEV_CARDIDS_EXT);
+	maxqueue = min_t(int, maxqueue, MAX_ZDEV_DOMAINS_EXT);
+
 	spin_lock(&zcrypt_list_lock);
 	for_each_zcrypt_card(zc) {
 		for_each_zcrypt_queue(zq, zc) {
 			card = AP_QID_CARD(zq->queue->qid);
 			queue = AP_QID_QUEUE(zq->queue->qid);
-			stat = &devstatus[card * AP_DOMAINS + queue];
+			if (card >= maxcard || queue >= maxqueue)
+				continue;
+			stat = &devstatus[card * maxqueue + queue];
 			stat->hwtype = zc->card->ap_dev.device_type;
 			stat->functions = zc->card->hwinfo.fac >> 26;
 			stat->qid = zq->queue->qid;
@@ -1622,7 +1628,9 @@ static long zcrypt_unlocked_ioctl(struct file *filp, unsigned int cmd,
 					 GFP_KERNEL);
 		if (!device_status)
 			return -ENOMEM;
-		zcrypt_device_status_mask_ext(device_status);
+		zcrypt_device_status_mask_ext(device_status,
+					      MAX_ZDEV_CARDIDS_EXT,
+					      MAX_ZDEV_DOMAINS_EXT);
 		if (copy_to_user((char __user *)arg, device_status,
 				 total_size))
 			rc = -EFAULT;
diff --git a/drivers/s390/crypto/zcrypt_api.h b/drivers/s390/crypto/zcrypt_api.h
index 14ed3e4e8e56..6ef8850a42df 100644
--- a/drivers/s390/crypto/zcrypt_api.h
+++ b/drivers/s390/crypto/zcrypt_api.h
@@ -172,7 +172,8 @@ int zcrypt_api_init(void);
 void zcrypt_api_exit(void);
 long zcrypt_send_cprb(struct ica_xcRB *xcRB, u32 xflags);
 long zcrypt_send_ep11_cprb(struct ep11_urb *urb, u32 xflags);
-void zcrypt_device_status_mask_ext(struct zcrypt_device_status_ext *devstatus);
+void zcrypt_device_status_mask_ext(struct zcrypt_device_status_ext *devstatus,
+				   int maxcard, int maxqueue);
 int zcrypt_device_status_ext(int card, int queue,
 			     struct zcrypt_device_status_ext *devstatus);
 
diff --git a/drivers/s390/crypto/zcrypt_ccamisc.c b/drivers/s390/crypto/zcrypt_ccamisc.c
index d51ab5a0c58f..bbc804d632a4 100644
--- a/drivers/s390/crypto/zcrypt_ccamisc.c
+++ b/drivers/s390/crypto/zcrypt_ccamisc.c
@@ -1806,7 +1806,10 @@ static int findcard(u64 mkvp, u16 *pcardnr, u16 *pdomain,
 				 GFP_KERNEL);
 	if (!device_status)
 		return -ENOMEM;
-	zcrypt_device_status_mask_ext(device_status);
+
+	zcrypt_device_status_mask_ext(device_status,
+				      MAX_ZDEV_CARDIDS_EXT,
+				      MAX_ZDEV_DOMAINS_EXT);
 
 	/* walk through all crypto cards */
 	for (i = 0; i < MAX_ZDEV_ENTRIES_EXT; i++) {
@@ -1913,7 +1916,7 @@ int cca_findcard2(u32 **apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
 {
 	struct zcrypt_device_status_ext *device_status;
 	u32 *_apqns = NULL, _nr_apqns = 0;
-	int i, card, dom, curmatch, oldmatch, rc = 0;
+	int i, card, dom, curmatch, oldmatch, rc;
 	struct cca_info ci;
 
 	/* fetch status of all crypto cards */
@@ -1922,13 +1925,16 @@ int cca_findcard2(u32 **apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
 				 GFP_KERNEL);
 	if (!device_status)
 		return -ENOMEM;
-	zcrypt_device_status_mask_ext(device_status);
+
+	zcrypt_device_status_mask_ext(device_status,
+				      MAX_ZDEV_CARDIDS_EXT,
+				      MAX_ZDEV_DOMAINS_EXT);
 
 	/* allocate 1k space for up to 256 apqns */
 	_apqns = kmalloc_array(256, sizeof(u32), GFP_KERNEL);
 	if (!_apqns) {
-		kvfree(device_status);
-		return -ENOMEM;
+		rc = -ENOMEM;
+		goto out;
 	}
 
 	/* walk through all the crypto apqnss */
@@ -1993,6 +1999,7 @@ int cca_findcard2(u32 **apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
 		rc = 0;
 	}
 
+out:
 	kvfree(device_status);
 	return rc;
 }
diff --git a/drivers/s390/crypto/zcrypt_ep11misc.c b/drivers/s390/crypto/zcrypt_ep11misc.c
index 048582851f25..af6582a6ca48 100644
--- a/drivers/s390/crypto/zcrypt_ep11misc.c
+++ b/drivers/s390/crypto/zcrypt_ep11misc.c
@@ -1598,7 +1598,7 @@ int ep11_findcard2(u32 **apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
 {
 	struct zcrypt_device_status_ext *device_status;
 	u32 *_apqns = NULL, _nr_apqns = 0;
-	int i, card, dom, rc = -ENOMEM;
+	int i, card, dom, rc;
 	struct ep11_domain_info edi;
 	struct ep11_card_info eci;
 
@@ -1608,13 +1608,16 @@ int ep11_findcard2(u32 **apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
 				 GFP_KERNEL);
 	if (!device_status)
 		return -ENOMEM;
-	zcrypt_device_status_mask_ext(device_status);
+
+	zcrypt_device_status_mask_ext(device_status,
+				      MAX_ZDEV_CARDIDS_EXT,
+				      MAX_ZDEV_DOMAINS_EXT);
 
 	/* allocate 1k space for up to 256 apqns */
 	_apqns = kmalloc_array(256, sizeof(u32), GFP_KERNEL);
 	if (!_apqns) {
-		kvfree(device_status);
-		return -ENOMEM;
+		rc = -ENOMEM;
+		goto out;
 	}
 
 	/* walk through all the crypto apqnss */
@@ -1668,6 +1671,7 @@ int ep11_findcard2(u32 **apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
 		rc = 0;
 	}
 
+out:
 	kvfree(device_status);
 	return rc;
 }