390/qeth: Fix locking warning during qeth device setup

Do not wait for channel command buffers in IPA commands.
The potential wait could be done while holding a spin lock and causes
in recent kernels such a bug if kernel lock debugging is enabled:

kernel: BUG: sleeping function called from invalid context at drivers/s390/net/qeth_core_main.c:
794
kernel: in_atomic(): 1, irqs_disabled(): 0, pid: 2031, name: NetworkManager
kernel: 2 locks held by NetworkManager/2031:
kernel:  #0:  (rtnl_mutex){+.+.+.}, at: [<00000000006e0d7a>] rtnetlink_rcv+0x32/0x50
kernel:  #1:  (_xmit_ETHER){+.....}, at: [<00000000006cfe90>] dev_set_rx_mode+0x30/0x50
kernel: CPU: 0 PID: 2031 Comm: NetworkManager Not tainted 3.18.0-rc5-next-20141124 #1
kernel:        00000000275fb1f0 00000000275fb280 0000000000000002 0000000000000000
               00000000275fb320 00000000275fb298 00000000275fb298 00000000007e326a
               0000000000000000 000000000099ce2c 00000000009b4988 000000000000000b
               00000000275fb2e0 00000000275fb280 0000000000000000 0000000000000000
               0000000000000000 00000000001129c8 00000000275fb280 00000000275fb2e0
kernel: Call Trace:
kernel: ([<00000000001128b0>] show_trace+0xf8/0x158)
kernel:  [<000000000011297a>] show_stack+0x6a/0xe8
kernel:  [<00000000007e995a>] dump_stack+0x82/0xb0
kernel:  [<000000000017d668>] ___might_sleep+0x170/0x228
kernel:  [<000003ff80026f0e>] qeth_wait_for_buffer+0x36/0xd0 [qeth]
kernel:  [<000003ff80026fe2>] qeth_get_ipacmd_buffer+0x3a/0xc0 [qeth]
kernel:  [<000003ff80105078>] qeth_l3_send_setdelmc+0x58/0xf8 [qeth_l3]
kernel:  [<000003ff8010b1fe>] qeth_l3_set_ip_addr_list+0x2c6/0x848 [qeth_l3]
kernel:  [<000003ff8010bbb4>] qeth_l3_set_multicast_list+0x434/0xc48 [qeth_l3]
kernel:  [<00000000006cfe9a>] dev_set_rx_mode+0x3a/0x50
kernel:  [<00000000006cff90>] __dev_open+0xe0/0x140
kernel:  [<00000000006d02a0>] __dev_change_flags+0xa0/0x178
kernel:  [<00000000006d03a8>] dev_change_flags+0x30/0x70
kernel:  [<00000000006e14ee>] do_setlink+0x346/0x9a0
...

The device driver has plenty of command buffers available
per channel for channel command communication.
In the extremely rare case when there is no command buffer
available, return a NULL pointer and issue a warning
in the kernel log. The caller handles the case when
a NULL pointer is encountered and returns an error.

In the case the wait for command buffer is possible
(because no lock is held as in the OSN case), still wait
until a channel command buffer is available.

Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Reviewed-by: Eugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 39 insertions, 11 deletions

diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 625227ad16ee..e2a0ee845399 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -549,6 +549,8 @@ 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);
+	if (!iob)
+		return -ENOMEM;
 	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
 	memcpy(&cmd->data.setdelipm.mac, addr->mac, OSA_ADDR_LEN);
 	if (addr->proto == QETH_PROT_IPV6)
@@ -588,6 +590,8 @@ static int qeth_l3_send_setdelip(struct qeth_card *card,
 	QETH_CARD_TEXT_(card, 4, "flags%02X", flags);
 
 	iob = qeth_get_ipacmd_buffer(card, ipacmd, addr->proto);
+	if (!iob)
+		return -ENOMEM;
 	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
 	if (addr->proto == QETH_PROT_IPV6) {
 		memcpy(cmd->data.setdelip6.ip_addr, &addr->u.a6.addr,
@@ -616,6 +620,8 @@ static int qeth_l3_send_setrouting(struct qeth_card *card,
 
 	QETH_CARD_TEXT(card, 4, "setroutg");
 	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_SETRTG, prot);
+	if (!iob)
+		return -ENOMEM;
 	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
 	cmd->data.setrtg.type = (type);
 	rc = qeth_send_ipa_cmd(card, iob, NULL, NULL);
@@ -1049,12 +1055,14 @@ static struct qeth_cmd_buffer *qeth_l3_get_setassparms_cmd(
 	QETH_CARD_TEXT(card, 4, "getasscm");
 	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_SETASSPARMS, prot);
 
-	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
-	cmd->data.setassparms.hdr.assist_no = ipa_func;
-	cmd->data.setassparms.hdr.length = 8 + len;
-	cmd->data.setassparms.hdr.command_code = cmd_code;
-	cmd->data.setassparms.hdr.return_code = 0;
-	cmd->data.setassparms.hdr.seq_no = 0;
+	if (iob) {
+		cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
+		cmd->data.setassparms.hdr.assist_no = ipa_func;
+		cmd->data.setassparms.hdr.length = 8 + len;
+		cmd->data.setassparms.hdr.command_code = cmd_code;
+		cmd->data.setassparms.hdr.return_code = 0;
+		cmd->data.setassparms.hdr.seq_no = 0;
+	}
 
 	return iob;
 }
@@ -1090,6 +1098,8 @@ static int qeth_l3_send_simple_setassparms_ipv6(struct qeth_card *card,
 	QETH_CARD_TEXT(card, 4, "simassp6");
 	iob = qeth_l3_get_setassparms_cmd(card, ipa_func, cmd_code,
 				       0, QETH_PROT_IPV6);
+	if (!iob)
+		return -ENOMEM;
 	rc = qeth_l3_send_setassparms(card, iob, 0, 0,
 				   qeth_l3_default_setassparms_cb, NULL);
 	return rc;
@@ -1108,6 +1118,8 @@ static int qeth_l3_send_simple_setassparms(struct qeth_card *card,
 		length = sizeof(__u32);
 	iob = qeth_l3_get_setassparms_cmd(card, ipa_func, cmd_code,
 				       length, QETH_PROT_IPV4);
+	if (!iob)
+		return -ENOMEM;
 	rc = qeth_l3_send_setassparms(card, iob, length, data,
 				   qeth_l3_default_setassparms_cb, NULL);
 	return rc;
@@ -1494,6 +1506,8 @@ static int qeth_l3_iqd_read_initial_mac(struct qeth_card *card)
 
 	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_CREATE_ADDR,
 				     QETH_PROT_IPV6);
+	if (!iob)
+		return -ENOMEM;
 	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
 	*((__u16 *) &cmd->data.create_destroy_addr.unique_id[6]) =
 			card->info.unique_id;
@@ -1537,6 +1551,8 @@ static int qeth_l3_get_unique_id(struct qeth_card *card)
 
 	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_CREATE_ADDR,
 				     QETH_PROT_IPV6);
+	if (!iob)
+		return -ENOMEM;
 	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
 	*((__u16 *) &cmd->data.create_destroy_addr.unique_id[6]) =
 			card->info.unique_id;
@@ -1611,6 +1627,8 @@ qeth_diags_trace(struct qeth_card *card, enum qeth_diags_trace_cmds diags_cmd)
 	QETH_DBF_TEXT(SETUP, 2, "diagtrac");
 
 	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_SET_DIAG_ASS, 0);
+	if (!iob)
+		return -ENOMEM;
 	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
 	cmd->data.diagass.subcmd_len = 16;
 	cmd->data.diagass.subcmd = QETH_DIAGS_CMD_TRACE;
@@ -2442,6 +2460,8 @@ static int qeth_l3_query_arp_cache_info(struct qeth_card *card,
 			IPA_CMD_ASS_ARP_QUERY_INFO,
 			sizeof(struct qeth_arp_query_data) - sizeof(char),
 			prot);
+	if (!iob)
+		return -ENOMEM;
 	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
 	cmd->data.setassparms.data.query_arp.request_bits = 0x000F;
 	cmd->data.setassparms.data.query_arp.reply_bits = 0;
@@ -2535,6 +2555,8 @@ static int qeth_l3_arp_add_entry(struct qeth_card *card,
 				       IPA_CMD_ASS_ARP_ADD_ENTRY,
 				       sizeof(struct qeth_arp_cache_entry),
 				       QETH_PROT_IPV4);
+	if (!iob)
+		return -ENOMEM;
 	rc = qeth_l3_send_setassparms(card, iob,
 				   sizeof(struct qeth_arp_cache_entry),
 				   (unsigned long) entry,
@@ -2574,6 +2596,8 @@ static int qeth_l3_arp_remove_entry(struct qeth_card *card,
 				       IPA_CMD_ASS_ARP_REMOVE_ENTRY,
 				       12,
 				       QETH_PROT_IPV4);
+	if (!iob)
+		return -ENOMEM;
 	rc = qeth_l3_send_setassparms(card, iob,
 				   12, (unsigned long)buf,
 				   qeth_l3_default_setassparms_cb, NULL);
@@ -3262,6 +3286,8 @@ static const struct net_device_ops qeth_l3_osa_netdev_ops = {
 
 static int qeth_l3_setup_netdev(struct qeth_card *card)
 {
+	int rc;
+
 	if (card->info.type == QETH_CARD_TYPE_OSD ||
 	    card->info.type == QETH_CARD_TYPE_OSX) {
 		if ((card->info.link_type == QETH_LINK_TYPE_LANE_TR) ||
@@ -3293,7 +3319,9 @@ static int qeth_l3_setup_netdev(struct qeth_card *card)
 			return -ENODEV;
 		card->dev->flags |= IFF_NOARP;
 		card->dev->netdev_ops = &qeth_l3_netdev_ops;
-		qeth_l3_iqd_read_initial_mac(card);
+		rc = qeth_l3_iqd_read_initial_mac(card);
+		if (rc)
+			return rc;
 		if (card->options.hsuid[0])
 			memcpy(card->dev->perm_addr, card->options.hsuid, 9);
 	} else
@@ -3360,7 +3388,7 @@ static int __qeth_l3_set_online(struct ccwgroup_device *gdev, int recovery_mode)
 	recover_flag = card->state;
 	rc = qeth_core_hardsetup_card(card);
 	if (rc) {
-		QETH_DBF_TEXT_(SETUP, 2, "2err%d", rc);
+		QETH_DBF_TEXT_(SETUP, 2, "2err%04x", rc);
 		rc = -ENODEV;
 		goto out_remove;
 	}
@@ -3401,7 +3429,7 @@ static int __qeth_l3_set_online(struct ccwgroup_device *gdev, int recovery_mode)
 contin:
 	rc = qeth_l3_setadapter_parms(card);
 	if (rc)
-		QETH_DBF_TEXT_(SETUP, 2, "2err%d", rc);
+		QETH_DBF_TEXT_(SETUP, 2, "2err%04x", rc);
 	if (!card->options.sniffer) {
 		rc = qeth_l3_start_ipassists(card);
 		if (rc) {
@@ -3410,10 +3438,10 @@ contin:
 		}
 		rc = qeth_l3_setrouting_v4(card);
 		if (rc)
-			QETH_DBF_TEXT_(SETUP, 2, "4err%d", rc);
+			QETH_DBF_TEXT_(SETUP, 2, "4err%04x", rc);
 		rc = qeth_l3_setrouting_v6(card);
 		if (rc)
-			QETH_DBF_TEXT_(SETUP, 2, "5err%d", rc);
+			QETH_DBF_TEXT_(SETUP, 2, "5err%04x", rc);
 	}
 	netif_tx_disable(card->dev);