[S390] qdio: convert global statistics to per-device stats

Revamp the qdio performance statistics and move them from procfs to
debugfs using the seq_file interface. Since the statistics are not
intended for the general user the removal of /proc/qdio_perf should
not surprise anyone.

The per device statistics are disabled by default, writing 1 to
/<debugfs mountpoint>/qdio/<device bus ID>/statistics enables the
statistics for the given device.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 106 insertions, 8 deletions

diff --git a/drivers/s390/cio/qdio_debug.c b/drivers/s390/cio/qdio_debug.c
index 76769978285f..f49761ff9a00 100644
--- a/drivers/s390/cio/qdio_debug.c
+++ b/drivers/s390/cio/qdio_debug.c
@@ -55,13 +55,11 @@ static int qstat_show(struct seq_file *m, void *v)
         if (!q)
                 return 0;
 
-        seq_printf(m, "device state indicator: %d\n", *(u32 *)q->irq_ptr->dsci);
-        seq_printf(m, "nr_used: %d\n", atomic_read(&q->nr_buf_used));
-        seq_printf(m, "ftc: %d\n", q->first_to_check);
-        seq_printf(m, "last_move: %d\n", q->last_move);
-        seq_printf(m, "polling: %d\n", q->u.in.polling);
-        seq_printf(m, "ack start: %d\n", q->u.in.ack_start);
-        seq_printf(m, "ack count: %d\n", q->u.in.ack_count);
+        seq_printf(m, "DSCI: %d   nr_used: %d\n",
+                   *(u32 *)q->irq_ptr->dsci, atomic_read(&q->nr_buf_used));
+        seq_printf(m, "ftc: %d  last_move: %d\n", q->first_to_check, q->last_move);
+        seq_printf(m, "polling: %d  ack start: %d  ack count: %d\n",
+                   q->u.in.polling, q->u.in.ack_start, q->u.in.ack_count);
         seq_printf(m, "slsb buffer states:\n");
         seq_printf(m, "|0      |8      |16     |24     |32     |40     |48     |56  63|\n");
 
@@ -110,7 +108,6 @@ static ssize_t qstat_seq_write(struct file *file, const char __user *buf,
 
         if (!q)
                 return 0;
-
         if (q->is_input_q)
                 xchg(q->irq_ptr->dsci, 1);
         local_bh_disable();
@@ -134,6 +131,98 @@ static const struct file_operations debugfs_fops = {
         .release = single_release,
 };
 
+static char *qperf_names[] = {
+        "Assumed adapter interrupts",
+        "QDIO interrupts",
+        "Requested PCIs",
+        "Inbound tasklet runs",
+        "Inbound tasklet resched",
+        "Inbound tasklet resched2",
+        "Outbound tasklet runs",
+        "SIGA read",
+        "SIGA write",
+        "SIGA sync",
+        "Inbound calls",
+        "Inbound handler",
+        "Inbound stop_polling",
+        "Inbound queue full",
+        "Outbound calls",
+        "Outbound handler",
+        "Outbound fast_requeue",
+        "Outbound target_full",
+        "QEBSM eqbs",
+        "QEBSM eqbs partial",
+        "QEBSM sqbs",
+        "QEBSM sqbs partial"
+};
+
+static int qperf_show(struct seq_file *m, void *v)
+{
+        struct qdio_irq *irq_ptr = m->private;
+        unsigned int *stat;
+        int i;
+
+        if (!irq_ptr)
+                return 0;
+        if (!irq_ptr->perf_stat_enabled) {
+                seq_printf(m, "disabled\n");
+                return 0;
+        }
+        stat = (unsigned int *)&irq_ptr->perf_stat;
+
+        for (i = 0; i < ARRAY_SIZE(qperf_names); i++)
+                seq_printf(m, "%26s:\t%u\n",
+                           qperf_names[i], *(stat + i));
+        return 0;
+}
+
+static ssize_t qperf_seq_write(struct file *file, const char __user *ubuf,
+                               size_t count, loff_t *off)
+{
+        struct seq_file *seq = file->private_data;
+        struct qdio_irq *irq_ptr = seq->private;
+        unsigned long val;
+        char buf[8];
+        int ret;
+
+        if (!irq_ptr)
+                return 0;
+        if (count >= sizeof(buf))
+                return -EINVAL;
+        if (copy_from_user(&buf, ubuf, count))
+                return -EFAULT;
+        buf[count] = 0;
+
+        ret = strict_strtoul(buf, 10, &val);
+        if (ret < 0)
+                return ret;
+
+        switch (val) {
+        case 0:
+                irq_ptr->perf_stat_enabled = 0;
+                memset(&irq_ptr->perf_stat, 0, sizeof(irq_ptr->perf_stat));
+                break;
+        case 1:
+                irq_ptr->perf_stat_enabled = 1;
+                break;
+        }
+        return count;
+}
+
+static int qperf_seq_open(struct inode *inode, struct file *filp)
+{
+        return single_open(filp, qperf_show,
+                           filp->f_path.dentry->d_inode->i_private);
+}
+
+static struct file_operations debugfs_perf_fops = {
+        .owner   = THIS_MODULE,
+        .open    = qperf_seq_open,
+        .read    = seq_read,
+        .write   = qperf_seq_write,
+        .llseek  = seq_lseek,
+        .release = single_release,
+};
 static void setup_debugfs_entry(struct qdio_q *q, struct ccw_device *cdev)
 {
         char name[QDIO_DEBUGFS_NAME_LEN];
@@ -156,6 +245,14 @@ void qdio_setup_debug_entries(struct qdio_irq *irq_ptr, struct ccw_device *cdev)
                                                   debugfs_root);
         if (IS_ERR(irq_ptr->debugfs_dev))
                 irq_ptr->debugfs_dev = NULL;
+
+        irq_ptr->debugfs_perf = debugfs_create_file("statistics",
+                                S_IFREG | S_IRUGO | S_IWUSR,
+                                irq_ptr->debugfs_dev, irq_ptr,
+                                &debugfs_perf_fops);
+        if (IS_ERR(irq_ptr->debugfs_perf))
+                irq_ptr->debugfs_perf = NULL;
+
         for_each_input_queue(irq_ptr, q, i)
                 setup_debugfs_entry(q, cdev);
         for_each_output_queue(irq_ptr, q, i)
@@ -171,6 +268,7 @@ void qdio_shutdown_debug_entries(struct qdio_irq *irq_ptr, struct ccw_device *cd
                 debugfs_remove(q->debugfs_q);
         for_each_output_queue(irq_ptr, q, i)
                 debugfs_remove(q->debugfs_q);
+        debugfs_remove(irq_ptr->debugfs_perf);
         debugfs_remove(irq_ptr->debugfs_dev);
 }