v4.19.13 snapshot.
diff --git a/arch/s390/pci/pci_debug.c b/arch/s390/pci/pci_debug.c
new file mode 100644
index 0000000..04388a2
--- /dev/null
+++ b/arch/s390/pci/pci_debug.c
@@ -0,0 +1,217 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright IBM Corp. 2012,2015
+ *
+ *  Author(s):
+ *    Jan Glauber <jang@linux.vnet.ibm.com>
+ */
+
+#define KMSG_COMPONENT "zpci"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
+#include <linux/export.h>
+#include <linux/pci.h>
+#include <asm/debug.h>
+
+#include <asm/pci_dma.h>
+
+static struct dentry *debugfs_root;
+debug_info_t *pci_debug_msg_id;
+EXPORT_SYMBOL_GPL(pci_debug_msg_id);
+debug_info_t *pci_debug_err_id;
+EXPORT_SYMBOL_GPL(pci_debug_err_id);
+
+static char *pci_common_names[] = {
+	"Load operations",
+	"Store operations",
+	"Store block operations",
+	"Refresh operations",
+};
+
+static char *pci_fmt0_names[] = {
+	"DMA read bytes",
+	"DMA write bytes",
+};
+
+static char *pci_fmt1_names[] = {
+	"Received bytes",
+	"Received packets",
+	"Transmitted bytes",
+	"Transmitted packets",
+};
+
+static char *pci_fmt2_names[] = {
+	"Consumed work units",
+	"Maximum work units",
+};
+
+static char *pci_fmt3_names[] = {
+	"Transmitted bytes",
+};
+
+static char *pci_sw_names[] = {
+	"Allocated pages",
+	"Mapped pages",
+	"Unmapped pages",
+};
+
+static void pci_fmb_show(struct seq_file *m, char *name[], int length,
+			 u64 *data)
+{
+	int i;
+
+	for (i = 0; i < length; i++, data++)
+		seq_printf(m, "%26s:\t%llu\n", name[i], *data);
+}
+
+static void pci_sw_counter_show(struct seq_file *m)
+{
+	struct zpci_dev *zdev = m->private;
+	atomic64_t *counter = &zdev->allocated_pages;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(pci_sw_names); i++, counter++)
+		seq_printf(m, "%26s:\t%lu\n", pci_sw_names[i],
+			   atomic64_read(counter));
+}
+
+static int pci_perf_show(struct seq_file *m, void *v)
+{
+	struct zpci_dev *zdev = m->private;
+
+	if (!zdev)
+		return 0;
+
+	mutex_lock(&zdev->lock);
+	if (!zdev->fmb) {
+		mutex_unlock(&zdev->lock);
+		seq_puts(m, "FMB statistics disabled\n");
+		return 0;
+	}
+
+	/* header */
+	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);
+
+	pci_fmb_show(m, pci_common_names, ARRAY_SIZE(pci_common_names),
+		     &zdev->fmb->ld_ops);
+
+	switch (zdev->fmb->format) {
+	case 0:
+		if (!(zdev->fmb->fmt_ind & ZPCI_FMB_DMA_COUNTER_VALID))
+			break;
+		pci_fmb_show(m, pci_fmt0_names, ARRAY_SIZE(pci_fmt0_names),
+			     &zdev->fmb->fmt0.dma_rbytes);
+		break;
+	case 1:
+		pci_fmb_show(m, pci_fmt1_names, ARRAY_SIZE(pci_fmt1_names),
+			     &zdev->fmb->fmt1.rx_bytes);
+		break;
+	case 2:
+		pci_fmb_show(m, pci_fmt2_names, ARRAY_SIZE(pci_fmt2_names),
+			     &zdev->fmb->fmt2.consumed_work_units);
+		break;
+	case 3:
+		pci_fmb_show(m, pci_fmt3_names, ARRAY_SIZE(pci_fmt3_names),
+			     &zdev->fmb->fmt3.tx_bytes);
+		break;
+	default:
+		seq_puts(m, "Unknown format\n");
+	}
+
+	pci_sw_counter_show(m);
+	mutex_unlock(&zdev->lock);
+	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;
+
+	mutex_lock(&zdev->lock);
+	switch (val) {
+	case 0:
+		rc = zpci_fmb_disable_device(zdev);
+		break;
+	case 1:
+		rc = zpci_fmb_enable_device(zdev);
+		break;
+	}
+	mutex_unlock(&zdev->lock);
+	return rc ? rc : count;
+}
+
+static int pci_perf_seq_open(struct inode *inode, struct file *filp)
+{
+	return single_open(filp, pci_perf_show,
+			   file_inode(filp)->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,
+};
+
+void zpci_debug_init_device(struct zpci_dev *zdev, const char *name)
+{
+	zdev->debugfs_dev = debugfs_create_dir(name, 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;
+}
+
+void zpci_debug_exit_device(struct zpci_dev *zdev)
+{
+	debugfs_remove(zdev->debugfs_perf);
+	debugfs_remove(zdev->debugfs_dev);
+}
+
+int __init zpci_debug_init(void)
+{
+	/* event trace buffer */
+	pci_debug_msg_id = debug_register("pci_msg", 8, 1, 8 * 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);
+
+	/* 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);
+
+	debugfs_root = debugfs_create_dir("pci", NULL);
+	return 0;
+}
+
+void zpci_debug_exit(void)
+{
+	debug_unregister(pci_debug_msg_id);
+	debug_unregister(pci_debug_err_id);
+	debugfs_remove(debugfs_root);
+}