[PATCH] s390: qeth driver fixes [4/6]

[PATCH 7/9] s390: qeth driver fixes [4/6]

From: Frank Pavlic <fpavlic@de.ibm.com>
	- fix kernel crash due to race,
	  set card->state to SOFTSETUP after
	  card and card->dev are initialized properly.
	- remove CONFIG_QETH_PERF_STATS, use sysfs attribute instead,
	  as we want to have the ability to turn on/off the
	  statistics at runtime.
Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/s390/net/Kconfig

@@ -92,15 +92,6 @@ config QETH_VLAN
 	  If CONFIG_QETH is switched on, this option will include IEEE
 	  802.1q VLAN support in the qeth device driver.
 
-config QETH_PERF_STATS
-	bool "Performance statistics in /proc"
-	depends on QETH
-	help
-	  When switched on, this option will add a file in the proc-fs
-	  (/proc/qeth_perf_stats) containing performance statistics. It
-	  may slightly impact performance, so this is only recommended for
-	  internal tuning of the device driver.
-
 config CCWGROUP
  	tristate
 	default (LCS || CTC || QETH)

drivers/s390/net/qeth.h

@@ -176,7 +176,6 @@ extern struct ccwgroup_driver qeth_ccwgroup_driver;
 /**
  * card stuff
  */
-#ifdef CONFIG_QETH_PERF_STATS
 struct qeth_perf_stats {
 	unsigned int bufs_rec;
 	unsigned int bufs_sent;
@@ -211,8 +210,10 @@ struct qeth_perf_stats {
 	unsigned int large_send_cnt;
 	unsigned int sg_skbs_sent;
 	unsigned int sg_frags_sent;
+	/* initial values when measuring starts */
+	unsigned long initial_rx_packets;
+	unsigned long initial_tx_packets;
 };
-#endif /* CONFIG_QETH_PERF_STATS */
 
 /* Routing stuff */
 struct qeth_routing_info {
@@ -767,6 +768,7 @@ struct qeth_card_options {
 	int fake_ll;
 	int layer2;
 	enum qeth_large_send_types large_send;
+	int performance_stats;
 };
 
 /*
@@ -819,9 +821,7 @@ struct qeth_card {
 	struct list_head cmd_waiter_list;
 	/* QDIO buffer handling */
 	struct qeth_qdio_info qdio;
-#ifdef CONFIG_QETH_PERF_STATS
 	struct qeth_perf_stats perf_stats;
-#endif /* CONFIG_QETH_PERF_STATS */
 	int use_hard_stop;
 	int (*orig_hard_header)(struct sk_buff *,struct net_device *,
 				unsigned short,void *,void *,unsigned);
@@ -1049,13 +1049,11 @@ qeth_get_arphdr_type(int cardtype, int linktype)
 	}
 }
 
-#ifdef CONFIG_QETH_PERF_STATS
 static inline int
 qeth_get_micros(void)
 {
 	return (int) (get_clock() >> 12);
 }
-#endif
 
 static inline int
 qeth_get_qdio_q_format(struct qeth_card *card)

drivers/s390/net/qeth_eddp.c

@@ -179,9 +179,8 @@ qeth_eddp_fill_buffer(struct qeth_qdio_out_q *queue,
 			flush_cnt++;
 		}
 	} else {
-#ifdef CONFIG_QETH_PERF_STATS
-		queue->card->perf_stats.skbs_sent_pack++;
-#endif
+		if (queue->card->options.performance_stats)
+			queue->card->perf_stats.skbs_sent_pack++;
 		QETH_DBF_TEXT(trace, 6, "fillbfpa");
 		if (buf->next_element_to_fill >=
 				QETH_MAX_BUFFER_ELEMENTS(queue->card)) {

drivers/s390/net/qeth_proc.c

@@ -173,7 +173,6 @@ static struct file_operations qeth_procfile_fops = {
 #define QETH_PERF_PROCFILE_NAME "qeth_perf"
 static struct proc_dir_entry *qeth_perf_procfile;
 
-#ifdef CONFIG_QETH_PERF_STATS
 static int
 qeth_perf_procfile_seq_show(struct seq_file *s, void *it)
 {
@@ -192,14 +191,21 @@ qeth_perf_procfile_seq_show(struct seq_file *s, void *it)
 			CARD_DDEV_ID(card),
 			QETH_CARD_IFNAME(card)
 		  );
+	if (!card->options.performance_stats)
+		seq_printf(s, "Performance statistics are deactivated.\n");
 	seq_printf(s, "  Skb's/buffers received                 : %lu/%u\n"
 		      "  Skb's/buffers sent                     : %lu/%u\n\n",
-		        card->stats.rx_packets, card->perf_stats.bufs_rec,
-		        card->stats.tx_packets, card->perf_stats.bufs_sent
+		        card->stats.rx_packets -
+				card->perf_stats.initial_rx_packets,
+			card->perf_stats.bufs_rec,
+		        card->stats.tx_packets -
+				card->perf_stats.initial_tx_packets,
+			card->perf_stats.bufs_sent
 		  );
 	seq_printf(s, "  Skb's/buffers sent without packing     : %lu/%u\n"
 		      "  Skb's/buffers sent with packing        : %u/%u\n\n",
-		   card->stats.tx_packets - card->perf_stats.skbs_sent_pack,
+		   card->stats.tx_packets - card->perf_stats.initial_tx_packets
+					  - card->perf_stats.skbs_sent_pack,
 		   card->perf_stats.bufs_sent - card->perf_stats.bufs_sent_pack,
 		   card->perf_stats.skbs_sent_pack,
 		   card->perf_stats.bufs_sent_pack
@@ -275,11 +281,6 @@ static struct file_operations qeth_perf_procfile_fops = {
 	.release = seq_release,
 };
 
-#define qeth_perf_procfile_created qeth_perf_procfile
-#else
-#define qeth_perf_procfile_created 1
-#endif /* CONFIG_QETH_PERF_STATS */
-
 int __init
 qeth_create_procfs_entries(void)
 {
@@ -288,15 +289,13 @@ qeth_create_procfs_entries(void)
 	if (qeth_procfile)
 		qeth_procfile->proc_fops = &qeth_procfile_fops;
 
-#ifdef CONFIG_QETH_PERF_STATS
 	qeth_perf_procfile = create_proc_entry(QETH_PERF_PROCFILE_NAME,
 					   S_IFREG | 0444, NULL);
 	if (qeth_perf_procfile)
 		qeth_perf_procfile->proc_fops = &qeth_perf_procfile_fops;
-#endif /* CONFIG_QETH_PERF_STATS */
 
 	if (qeth_procfile &&
-	    qeth_perf_procfile_created)
+	    qeth_perf_procfile)
 		return 0;
 	else
 		return -ENOMEM;

drivers/s390/net/qeth_sys.c

@@ -742,6 +742,47 @@ qeth_dev_layer2_store(struct device *dev, struct device_attribute *attr, const c
 static DEVICE_ATTR(layer2, 0644, qeth_dev_layer2_show,
 		   qeth_dev_layer2_store);
 
+static ssize_t
+qeth_dev_performance_stats_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct qeth_card *card = dev->driver_data;
+
+	if (!card)
+		return -EINVAL;
+
+	return sprintf(buf, "%i\n", card->options.performance_stats ? 1:0);
+}
+
+static ssize_t
+qeth_dev_performance_stats_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct qeth_card *card = dev->driver_data;
+	char *tmp;
+	int i;
+
+	if (!card)
+		return -EINVAL;
+
+	i = simple_strtoul(buf, &tmp, 16);
+	if ((i == 0) || (i == 1)) {
+		if (i == card->options.performance_stats)
+			return count;
+		card->options.performance_stats = i;
+		if (i == 0)
+			memset(&card->perf_stats, 0,
+				sizeof(struct qeth_perf_stats));
+		card->perf_stats.initial_rx_packets = card->stats.rx_packets;
+		card->perf_stats.initial_tx_packets = card->stats.tx_packets;
+	} else {
+		PRINT_WARN("performance_stats: write 0 or 1 to this file!\n");
+		return -EINVAL;
+	}
+	return count;
+}
+
+static DEVICE_ATTR(performance_stats, 0644, qeth_dev_performance_stats_show,
+		   qeth_dev_performance_stats_store);
+
 static ssize_t
 qeth_dev_large_send_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
@@ -928,6 +969,7 @@ static struct device_attribute * qeth_device_attrs[] = {
 	&dev_attr_canonical_macaddr,
 	&dev_attr_layer2,
 	&dev_attr_large_send,
+	&dev_attr_performance_stats,
 	NULL,
 };