[PATCH v2 07/20] s390/zcrypt: Rework zcrypt function zcrypt_device_status_mask_ext

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

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.
* Instead of void the reworked function now returns an int.
  The currently only way to have the function return != 0
  is by providing card or domains limits beyond 256.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
---
 drivers/s390/crypto/zcrypt_api.c      | 20 +++++++++++++++-----
 drivers/s390/crypto/zcrypt_api.h      |  3 ++-
 drivers/s390/crypto/zcrypt_ccamisc.c  | 22 +++++++++++++++++-----
 drivers/s390/crypto/zcrypt_ep11misc.c | 14 ++++++++++----
 4 files changed, 44 insertions(+), 15 deletions(-)

diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 62cc05881b13..bd2738e3792a 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -1317,19 +1317,25 @@ 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)
+int 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;
 
+	if (maxcard > MAX_ZDEV_CARDIDS_EXT || maxqueue > MAX_ZDEV_DOMAINS_EXT)
+		return -EINVAL;
+
 	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;
@@ -1337,6 +1343,8 @@ void zcrypt_device_status_mask_ext(struct zcrypt_device_status_ext *devstatus)
 		}
 	}
 	spin_unlock(&zcrypt_list_lock);
+
+	return 0;
 }
 EXPORT_SYMBOL(zcrypt_device_status_mask_ext);
 
@@ -1635,9 +1643,11 @@ 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);
-		if (copy_to_user((char __user *)arg, device_status,
-				 total_size))
+		rc = zcrypt_device_status_mask_ext(device_status,
+						   MAX_ZDEV_CARDIDS_EXT,
+						   MAX_ZDEV_DOMAINS_EXT);
+		if (!rc && copy_to_user((char __user *)arg, device_status,
+					total_size))
 			rc = -EFAULT;
 		kvfree(device_status);
 		return rc;
diff --git a/drivers/s390/crypto/zcrypt_api.h b/drivers/s390/crypto/zcrypt_api.h
index 25a339ef52c3..3b57e7437f3d 100644
--- a/drivers/s390/crypto/zcrypt_api.h
+++ b/drivers/s390/crypto/zcrypt_api.h
@@ -178,7 +178,8 @@ 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);
+int 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 2c2ca2d67e2d..420895df70f0 100644
--- a/drivers/s390/crypto/zcrypt_ccamisc.c
+++ b/drivers/s390/crypto/zcrypt_ccamisc.c
@@ -1807,7 +1807,12 @@ static int findcard(u64 mkvp, u16 *pcardnr, u16 *pdomain,
 				 GFP_KERNEL);
 	if (!device_status)
 		return -ENOMEM;
-	zcrypt_device_status_mask_ext(device_status);
+
+	rc = zcrypt_device_status_mask_ext(device_status,
+					   MAX_ZDEV_CARDIDS_EXT,
+					   MAX_ZDEV_DOMAINS_EXT);
+	if (rc)
+		goto out;
 
 	/* walk through all crypto cards */
 	for (i = 0; i < MAX_ZDEV_ENTRIES_EXT; i++) {
@@ -1875,6 +1880,7 @@ static int findcard(u64 mkvp, u16 *pcardnr, u16 *pdomain,
 		rc = -ENODEV;
 	}
 
+out:
 	kvfree(device_status);
 	return rc;
 }
@@ -1914,7 +1920,7 @@ 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 */
@@ -1923,13 +1929,18 @@ 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);
+
+	rc = zcrypt_device_status_mask_ext(device_status,
+					   MAX_ZDEV_CARDIDS_EXT,
+					   MAX_ZDEV_DOMAINS_EXT);
+	if (rc)
+		goto out;
 
 	/* 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 */
@@ -1994,6 +2005,7 @@ 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 86578a95b140..df16294eff9e 100644
--- a/drivers/s390/crypto/zcrypt_ep11misc.c
+++ b/drivers/s390/crypto/zcrypt_ep11misc.c
@@ -1603,7 +1603,7 @@ 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;
 
@@ -1613,13 +1613,18 @@ 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);
+
+	rc = zcrypt_device_status_mask_ext(device_status,
+					   MAX_ZDEV_CARDIDS_EXT,
+					   MAX_ZDEV_DOMAINS_EXT);
+	if (rc)
+		goto out;
 
 	/* 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 */
@@ -1673,6 +1678,7 @@ int ep11_findcard2(u32 **apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
 		rc = 0;
 	}
 
+out:
 	kvfree(device_status);
 	return rc;
 }
-- 
2.43.0