s390/pci: performance statistics and debug infrastructure

Add support for reading the PCI function measurement block counters
provided by the hypervisor. Add two s390 debug features, one for
critical errors and one for tracing and provide wrappers to log data.

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

1 files changed, 193 insertions, 0 deletions

diff --git a/arch/s390/pci/pci_debug.c b/arch/s390/pci/pci_debug.c
new file mode 100644
index 0000000..a303c95
--- /dev/null
+++ b/arch/s390/pci/pci_debug.c
@@ -0,0 +1,193 @@
+/*
+ *  Copyright IBM Corp. 2012
+ *
+ *  Author(s):
+ *    Jan Glauber <jang@linux.vnet.ibm.com>
+ */
+
+#define COMPONENT "zPCI"
+#define pr_fmt(fmt) COMPONENT ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
+#include <linux/pci.h>
+#include <asm/debug.h>
+
+#include <asm/pci_dma.h>
+
+static struct dentry *debugfs_root;
+
+static char *pci_perf_names[] = {
+	/* hardware counters */
+	"Load operations",
+	"Store operations",
+	"Store block operations",
+	"Refresh operations",
+	"DMA read bytes",
+	"DMA write bytes",
+	/* software counters */
+	"Allocated pages",
+	"Mapped pages",
+	"Unmapped pages",
+};
+
+static int pci_perf_show(struct seq_file *m, void *v)
+{
+	struct zpci_dev *zdev = m->private;
+	u64 *stat;
+	int i;
+
+	if (!zdev)
+		return 0;
+	if (!zdev->fmb)
+		return seq_printf(m, "FMB statistics disabled\n");
+
+	/* header */
+	seq_printf(m, "FMB @ %p\n", zdev->fmb);
+	seq_printf(m, "Update interval: %u ms\n", zdev->fmb_update);
+	seq_printf(m, "Samples: %u\n", zdev->fmb->samples);
+	seq_printf(m, "Last update TOD: %Lx\n", zdev->fmb->last_update);
+
+	/* hardware counters */
+	stat = (u64 *) &zdev->fmb->ld_ops;
+	for (i = 0; i < 4; i++)
+		seq_printf(m, "%26s:\t%llu\n",
+			   pci_perf_names[i], *(stat + i));
+	if (zdev->fmb->dma_valid)
+		for (i = 4; i < 6; i++)
+			seq_printf(m, "%26s:\t%llu\n",
+				   pci_perf_names[i], *(stat + i));
+	/* software counters */
+	for (i = 6; i < ARRAY_SIZE(pci_perf_names); i++)
+		seq_printf(m, "%26s:\t%llu\n",
+			   pci_perf_names[i],
+			   atomic64_read((atomic64_t *) (stat + i)));
+
+	return 0;
+}
+
+static ssize_t pci_perf_seq_write(struct file *file, const char __user *ubuf,
+				  size_t count, loff_t *off)
+{
+	struct zpci_dev *zdev = ((struct seq_file *) file->private_data)->private;
+	unsigned long val;
+	int rc;
+
+	if (!zdev)
+		return 0;
+
+	rc = kstrtoul_from_user(ubuf, count, 10, &val);
+	if (rc)
+		return rc;
+
+	switch (val) {
+	case 0:
+		rc = zpci_fmb_disable_device(zdev);
+		if (rc)
+			return rc;
+		break;
+	case 1:
+		rc = zpci_fmb_enable_device(zdev);
+		if (rc)
+			return rc;
+		break;
+	}
+	return count;
+}
+
+static int pci_perf_seq_open(struct inode *inode, struct file *filp)
+{
+	return single_open(filp, pci_perf_show,
+			   filp->f_path.dentry->d_inode->i_private);
+}
+
+static const struct file_operations debugfs_pci_perf_fops = {
+	.open	 = pci_perf_seq_open,
+	.read	 = seq_read,
+	.write	 = pci_perf_seq_write,
+	.llseek  = seq_lseek,
+	.release = single_release,
+};
+
+static int pci_debug_show(struct seq_file *m, void *v)
+{
+	struct zpci_dev *zdev = m->private;
+
+	zpci_debug_info(zdev, m);
+	return 0;
+}
+
+static int pci_debug_seq_open(struct inode *inode, struct file *filp)
+{
+	return single_open(filp, pci_debug_show,
+			   filp->f_path.dentry->d_inode->i_private);
+}
+
+static const struct file_operations debugfs_pci_debug_fops = {
+	.open	 = pci_debug_seq_open,
+	.read	 = seq_read,
+	.llseek  = seq_lseek,
+	.release = single_release,
+};
+
+void zpci_debug_init_device(struct zpci_dev *zdev)
+{
+	zdev->debugfs_dev = debugfs_create_dir(dev_name(&zdev->pdev->dev),
+					       debugfs_root);
+	if (IS_ERR(zdev->debugfs_dev))
+		zdev->debugfs_dev = NULL;
+
+	zdev->debugfs_perf = debugfs_create_file("statistics",
+				S_IFREG | S_IRUGO | S_IWUSR,
+				zdev->debugfs_dev, zdev,
+				&debugfs_pci_perf_fops);
+	if (IS_ERR(zdev->debugfs_perf))
+		zdev->debugfs_perf = NULL;
+
+	zdev->debugfs_debug = debugfs_create_file("debug",
+				S_IFREG | S_IRUGO | S_IWUSR,
+				zdev->debugfs_dev, zdev,
+				&debugfs_pci_debug_fops);
+	if (IS_ERR(zdev->debugfs_debug))
+		zdev->debugfs_debug = NULL;
+}
+
+void zpci_debug_exit_device(struct zpci_dev *zdev)
+{
+	debugfs_remove(zdev->debugfs_perf);
+	debugfs_remove(zdev->debugfs_debug);
+	debugfs_remove(zdev->debugfs_dev);
+}
+
+int __init zpci_debug_init(void)
+{
+	/* event trace buffer */
+	pci_debug_msg_id = debug_register("pci_msg", 16, 1, 16 * sizeof(long));
+	if (!pci_debug_msg_id)
+		return -EINVAL;
+	debug_register_view(pci_debug_msg_id, &debug_sprintf_view);
+	debug_set_level(pci_debug_msg_id, 3);
+	zpci_dbg("Debug view initialized\n");
+
+	/* error log */
+	pci_debug_err_id = debug_register("pci_error", 2, 1, 16);
+	if (!pci_debug_err_id)
+		return -EINVAL;
+	debug_register_view(pci_debug_err_id, &debug_hex_ascii_view);
+	debug_set_level(pci_debug_err_id, 6);
+	zpci_err("Debug view initialized\n");
+
+	debugfs_root = debugfs_create_dir("pci", NULL);
+	return 0;
+}
+
+void zpci_debug_exit(void)
+{
+	if (pci_debug_msg_id)
+		debug_unregister(pci_debug_msg_id);
+	if (pci_debug_err_id)
+		debug_unregister(pci_debug_err_id);
+
+	debugfs_remove(debugfs_root);
+}