s390/qeth: dynamically allocate simple IPA cmds

This patch reduces the usage of the write channel's static cmd buffers,
by dynamically allocating all simple IPA cmds (eg. STARTLAN, SETVMAC).
It also converts the OSN path.

Doing so requires some changes to how we calculate the cmd length.
Currently when building IPA cmds, we're quite generous in how much data
we send down to the device (basically the size of the biggest cmd we
know). This is no real concern at the moment, since the static cmd
buffers are backed with zeroed pages. But for dynamic allocations, the
exact length matters. So this patch also adds the needed length
calculations to each cmd path.

Commands that have multiple subtypes (eg. SETADP) of differing length
will be converted with follow-up patches.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 56 insertions, 18 deletions

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index 5bcdede5e955..42aa4a21a4c2 100644
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -551,6 +551,7 @@ enum qeth_card_states {
  * Protocol versions
  */
 enum qeth_prot_versions {
+	QETH_PROT_NONE = 0x0000,
 	QETH_PROT_IPV4 = 0x0004,
 	QETH_PROT_IPV6 = 0x0006,
 };
@@ -995,6 +996,14 @@ int qeth_send_ipa_cmd(struct qeth_card *, struct qeth_cmd_buffer *,
 		  void *);
 struct qeth_cmd_buffer *qeth_get_ipacmd_buffer(struct qeth_card *,
 			enum qeth_ipa_cmds, enum qeth_prot_versions);
+struct qeth_cmd_buffer *qeth_ipa_alloc_cmd(struct qeth_card *card,
+					   enum qeth_ipa_cmds cmd_code,
+					   enum qeth_prot_versions prot,
+					   unsigned int data_length);
+struct qeth_cmd_buffer *qeth_alloc_cmd(struct qeth_channel *channel,
+				       unsigned int length, unsigned int ccws,
+				       long timeout);
+
 struct sk_buff *qeth_core_get_next_skb(struct qeth_card *,
 		struct qeth_qdio_buffer *, struct qdio_buffer_element **, int *,
 		struct qeth_hdr **);
@@ -1012,7 +1021,6 @@ void qeth_release_buffer(struct qeth_cmd_buffer *iob);
 void qeth_notify_reply(struct qeth_reply *reply, int reason);
 void qeth_prepare_ipa_cmd(struct qeth_card *card, struct qeth_cmd_buffer *iob,
 			  u16 cmd_length);
-struct qeth_cmd_buffer *qeth_get_buffer(struct qeth_channel *channel);
 int qeth_query_switch_attributes(struct qeth_card *card,
 				  struct qeth_switch_info *sw_info);
 int qeth_query_card_info(struct qeth_card *card,
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index fe3dfeaf5ceb..84ed772bbfbd 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -756,7 +756,7 @@ static void qeth_cancel_cmd(struct qeth_cmd_buffer *iob, int rc)
 	qeth_release_buffer(iob);
 }
 
-struct qeth_cmd_buffer *qeth_get_buffer(struct qeth_channel *channel)
+static struct qeth_cmd_buffer *qeth_get_buffer(struct qeth_channel *channel)
 {
 	struct qeth_cmd_buffer *buffer = NULL;
 	unsigned long flags;
@@ -766,11 +766,10 @@ struct qeth_cmd_buffer *qeth_get_buffer(struct qeth_channel *channel)
 	spin_unlock_irqrestore(&channel->iob_lock, flags);
 	return buffer;
 }
-EXPORT_SYMBOL_GPL(qeth_get_buffer);
 
-static struct qeth_cmd_buffer *qeth_alloc_cmd(struct qeth_channel *channel,
-					      unsigned int length,
-					      unsigned int ccws, long timeout)
+struct qeth_cmd_buffer *qeth_alloc_cmd(struct qeth_channel *channel,
+				       unsigned int length, unsigned int ccws,
+				       long timeout)
 {
 	struct qeth_cmd_buffer *iob;
 
@@ -795,6 +794,7 @@ static struct qeth_cmd_buffer *qeth_alloc_cmd(struct qeth_channel *channel,
 	iob->length = length;
 	return iob;
 }
+EXPORT_SYMBOL_GPL(qeth_alloc_cmd);
 
 void qeth_clear_cmd_buffers(struct qeth_channel *channel)
 {
@@ -2804,6 +2804,25 @@ struct qeth_cmd_buffer *qeth_get_ipacmd_buffer(struct qeth_card *card,
 }
 EXPORT_SYMBOL_GPL(qeth_get_ipacmd_buffer);
 
+struct qeth_cmd_buffer *qeth_ipa_alloc_cmd(struct qeth_card *card,
+					   enum qeth_ipa_cmds cmd_code,
+					   enum qeth_prot_versions prot,
+					   unsigned int data_length)
+{
+	struct qeth_cmd_buffer *iob;
+
+	data_length += offsetof(struct qeth_ipa_cmd, data);
+	iob = qeth_alloc_cmd(&card->write, IPA_PDU_HEADER_SIZE + data_length, 1,
+			     QETH_IPA_TIMEOUT);
+	if (!iob)
+		return NULL;
+
+	qeth_prepare_ipa_cmd(card, iob, data_length);
+	qeth_fill_ipacmd_header(card, __ipa_cmd(iob), cmd_code, prot);
+	return iob;
+}
+EXPORT_SYMBOL_GPL(qeth_ipa_alloc_cmd);
+
 static int qeth_send_ipa_cmd_cb(struct qeth_card *card,
 				struct qeth_reply *reply, unsigned long data)
 {
@@ -2862,7 +2881,7 @@ static int qeth_send_startlan(struct qeth_card *card)
 
 	QETH_CARD_TEXT(card, 2, "strtlan");
 
-	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_STARTLAN, 0);
+	iob = qeth_ipa_alloc_cmd(card, IPA_CMD_STARTLAN, QETH_PROT_NONE, 0);
 	if (!iob)
 		return -ENOMEM;
 	return qeth_send_ipa_cmd(card, iob, qeth_send_startlan_cb, NULL);
@@ -2971,7 +2990,7 @@ static int qeth_query_ipassists(struct qeth_card *card,
 	struct qeth_cmd_buffer *iob;
 
 	QETH_CARD_TEXT_(card, 2, "qipassi%i", prot);
-	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_QIPASSIST, prot);
+	iob = qeth_ipa_alloc_cmd(card, IPA_CMD_QIPASSIST, prot, 0);
 	if (!iob)
 		return -ENOMEM;
 	rc = qeth_send_ipa_cmd(card, iob, qeth_query_ipassists_cb, NULL);
diff --git a/drivers/s390/net/qeth_core_mpc.h b/drivers/s390/net/qeth_core_mpc.h
index fadafdc0e8e4..e84249f8803e 100644
--- a/drivers/s390/net/qeth_core_mpc.h
+++ b/drivers/s390/net/qeth_core_mpc.h
@@ -806,6 +806,8 @@ struct qeth_ipa_cmd {
 	} data;
 } __attribute__ ((packed));
 
+#define IPA_DATA_SIZEOF(field)	FIELD_SIZEOF(struct qeth_ipa_cmd, data.field)
+
 /*
  * special command for ARP processing.
  * this is not included in setassparms command before, because we get
diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 9565ef9747c1..1dd8d22299c2 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -85,7 +85,8 @@ static int qeth_l2_send_setdelmac(struct qeth_card *card, __u8 *mac,
 	struct qeth_cmd_buffer *iob;
 
 	QETH_CARD_TEXT(card, 2, "L2sdmac");
-	iob = qeth_get_ipacmd_buffer(card, ipacmd, QETH_PROT_IPV4);
+	iob = qeth_ipa_alloc_cmd(card, ipacmd, QETH_PROT_IPV4,
+				 IPA_DATA_SIZEOF(setdelmac));
 	if (!iob)
 		return -ENOMEM;
 	cmd = __ipa_cmd(iob);
@@ -240,7 +241,8 @@ static int qeth_l2_send_setdelvlan(struct qeth_card *card, __u16 i,
 	struct qeth_cmd_buffer *iob;
 
 	QETH_CARD_TEXT_(card, 4, "L2sdv%x", ipacmd);
-	iob = qeth_get_ipacmd_buffer(card, ipacmd, QETH_PROT_IPV4);
+	iob = qeth_ipa_alloc_cmd(card, ipacmd, QETH_PROT_IPV4,
+				 IPA_DATA_SIZEOF(setdelvlan));
 	if (!iob)
 		return -ENOMEM;
 	cmd = __ipa_cmd(iob);
@@ -1040,6 +1042,8 @@ int qeth_osn_assist(struct net_device *dev, void *data, int data_len)
 	struct qeth_cmd_buffer *iob;
 	struct qeth_card *card;
 
+	if (data_len < 0)
+		return -EINVAL;
 	if (!dev)
 		return -ENODEV;
 	card = dev->ml_priv;
@@ -1048,7 +1052,9 @@ int qeth_osn_assist(struct net_device *dev, void *data, int data_len)
 	QETH_CARD_TEXT(card, 2, "osnsdmc");
 	if (!qeth_card_hw_is_reachable(card))
 		return -ENODEV;
-	iob = qeth_get_buffer(&card->write);
+
+	iob = qeth_alloc_cmd(&card->write, IPA_PDU_HEADER_SIZE + data_len, 1,
+			     QETH_IPA_TIMEOUT);
 	if (!iob)
 		return -ENOMEM;
 
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 4d66f9556451..81312be8a36b 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -377,7 +377,8 @@ static int qeth_l3_send_setdelmc(struct qeth_card *card,
 
 	QETH_CARD_TEXT(card, 4, "setdelmc");
 
-	iob = qeth_get_ipacmd_buffer(card, ipacmd, addr->proto);
+	iob = qeth_ipa_alloc_cmd(card, ipacmd, addr->proto,
+				 IPA_DATA_SIZEOF(setdelipm));
 	if (!iob)
 		return -ENOMEM;
 	cmd = __ipa_cmd(iob);
@@ -429,7 +430,8 @@ static int qeth_l3_send_setdelip(struct qeth_card *card,
 
 	QETH_CARD_TEXT(card, 4, "setdelip");
 
-	iob = qeth_get_ipacmd_buffer(card, ipacmd, addr->proto);
+	iob = qeth_ipa_alloc_cmd(card, ipacmd, addr->proto,
+				 IPA_DATA_SIZEOF(setdelip6));
 	if (!iob)
 		return -ENOMEM;
 	cmd = __ipa_cmd(iob);
@@ -461,7 +463,8 @@ static int qeth_l3_send_setrouting(struct qeth_card *card,
 	struct qeth_cmd_buffer *iob;
 
 	QETH_CARD_TEXT(card, 4, "setroutg");
-	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_SETRTG, prot);
+	iob = qeth_ipa_alloc_cmd(card, IPA_CMD_SETRTG, prot,
+				 IPA_DATA_SIZEOF(setrtg));
 	if (!iob)
 		return -ENOMEM;
 	cmd = __ipa_cmd(iob);
@@ -981,8 +984,8 @@ static int qeth_l3_iqd_read_initial_mac(struct qeth_card *card)
 
 	QETH_CARD_TEXT(card, 2, "hsrmac");
 
-	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_CREATE_ADDR,
-				     QETH_PROT_IPV6);
+	iob = qeth_ipa_alloc_cmd(card, IPA_CMD_CREATE_ADDR, QETH_PROT_IPV6,
+				 IPA_DATA_SIZEOF(create_destroy_addr));
 	if (!iob)
 		return -ENOMEM;
 	cmd = __ipa_cmd(iob);
@@ -1025,8 +1028,8 @@ static int qeth_l3_get_unique_id(struct qeth_card *card)
 		return 0;
 	}
 
-	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_CREATE_ADDR,
-				     QETH_PROT_IPV6);
+	iob = qeth_ipa_alloc_cmd(card, IPA_CMD_CREATE_ADDR, QETH_PROT_IPV6,
+				 IPA_DATA_SIZEOF(create_destroy_addr));
 	if (!iob)
 		return -ENOMEM;
 	cmd = __ipa_cmd(iob);