v4.19.13 snapshot.
diff --git a/net/atm/proc.c b/net/atm/proc.c
new file mode 100644
index 0000000..0b0495a
--- /dev/null
+++ b/net/atm/proc.c
@@ -0,0 +1,400 @@
+// SPDX-License-Identifier: GPL-2.0
+/* net/atm/proc.c - ATM /proc interface
+ *
+ * Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA
+ *
+ * seq_file api usage by romieu@fr.zoreil.com
+ *
+ * Evaluating the efficiency of the whole thing if left as an exercise to
+ * the reader.
+ */
+
+#include <linux/module.h> /* for EXPORT_SYMBOL */
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/stat.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/errno.h>
+#include <linux/atm.h>
+#include <linux/atmdev.h>
+#include <linux/netdevice.h>
+#include <linux/atmclip.h>
+#include <linux/init.h> /* for __init */
+#include <linux/slab.h>
+#include <net/net_namespace.h>
+#include <net/atmclip.h>
+#include <linux/uaccess.h>
+#include <linux/param.h> /* for HZ */
+#include <linux/atomic.h>
+#include "resources.h"
+#include "common.h" /* atm_proc_init prototype */
+#include "signaling.h" /* to get sigd - ugly too */
+
+static ssize_t proc_dev_atm_read(struct file *file, char __user *buf,
+				 size_t count, loff_t *pos);
+
+static const struct file_operations proc_atm_dev_ops = {
+	.read =		proc_dev_atm_read,
+	.llseek =	noop_llseek,
+};
+
+static void add_stats(struct seq_file *seq, const char *aal,
+  const struct k_atm_aal_stats *stats)
+{
+	seq_printf(seq, "%s ( %d %d %d %d %d )", aal,
+		   atomic_read(&stats->tx), atomic_read(&stats->tx_err),
+		   atomic_read(&stats->rx), atomic_read(&stats->rx_err),
+		   atomic_read(&stats->rx_drop));
+}
+
+static void atm_dev_info(struct seq_file *seq, const struct atm_dev *dev)
+{
+	int i;
+
+	seq_printf(seq, "%3d %-8s", dev->number, dev->type);
+	for (i = 0; i < ESI_LEN; i++)
+		seq_printf(seq, "%02x", dev->esi[i]);
+	seq_puts(seq, "  ");
+	add_stats(seq, "0", &dev->stats.aal0);
+	seq_puts(seq, "  ");
+	add_stats(seq, "5", &dev->stats.aal5);
+	seq_printf(seq, "\t[%d]", refcount_read(&dev->refcnt));
+	seq_putc(seq, '\n');
+}
+
+struct vcc_state {
+	int bucket;
+	struct sock *sk;
+};
+
+static inline int compare_family(struct sock *sk, int family)
+{
+	return !family || (sk->sk_family == family);
+}
+
+static int __vcc_walk(struct sock **sock, int family, int *bucket, loff_t l)
+{
+	struct sock *sk = *sock;
+
+	if (sk == SEQ_START_TOKEN) {
+		for (*bucket = 0; *bucket < VCC_HTABLE_SIZE; ++*bucket) {
+			struct hlist_head *head = &vcc_hash[*bucket];
+
+			sk = hlist_empty(head) ? NULL : __sk_head(head);
+			if (sk)
+				break;
+		}
+		l--;
+	}
+try_again:
+	for (; sk; sk = sk_next(sk)) {
+		l -= compare_family(sk, family);
+		if (l < 0)
+			goto out;
+	}
+	if (!sk && ++*bucket < VCC_HTABLE_SIZE) {
+		sk = sk_head(&vcc_hash[*bucket]);
+		goto try_again;
+	}
+	sk = SEQ_START_TOKEN;
+out:
+	*sock = sk;
+	return (l < 0);
+}
+
+static inline void *vcc_walk(struct seq_file *seq, loff_t l)
+{
+	struct vcc_state *state = seq->private;
+	int family = (uintptr_t)(PDE_DATA(file_inode(seq->file)));
+
+	return __vcc_walk(&state->sk, family, &state->bucket, l) ?
+	       state : NULL;
+}
+
+static void *vcc_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(vcc_sklist_lock)
+{
+	struct vcc_state *state = seq->private;
+	loff_t left = *pos;
+
+	read_lock(&vcc_sklist_lock);
+	state->sk = SEQ_START_TOKEN;
+	return left ? vcc_walk(seq, left) : SEQ_START_TOKEN;
+}
+
+static void vcc_seq_stop(struct seq_file *seq, void *v)
+	__releases(vcc_sklist_lock)
+{
+	read_unlock(&vcc_sklist_lock);
+}
+
+static void *vcc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	v = vcc_walk(seq, 1);
+	*pos += !!PTR_ERR(v);
+	return v;
+}
+
+static void pvc_info(struct seq_file *seq, struct atm_vcc *vcc)
+{
+	static const char *const class_name[] = {
+		"off", "UBR", "CBR", "VBR", "ABR"};
+	static const char *const aal_name[] = {
+		"---",	"1",	"2",	"3/4",	/*  0- 3 */
+		"???",	"5",	"???",	"???",	/*  4- 7 */
+		"???",	"???",	"???",	"???",	/*  8-11 */
+		"???",	"0",	"???",	"???"};	/* 12-15 */
+
+	seq_printf(seq, "%3d %3d %5d %-3s %7d %-5s %7d %-6s",
+		   vcc->dev->number, vcc->vpi, vcc->vci,
+		   vcc->qos.aal >= ARRAY_SIZE(aal_name) ? "err" :
+		   aal_name[vcc->qos.aal], vcc->qos.rxtp.min_pcr,
+		   class_name[vcc->qos.rxtp.traffic_class],
+		   vcc->qos.txtp.min_pcr,
+		   class_name[vcc->qos.txtp.traffic_class]);
+	if (test_bit(ATM_VF_IS_CLIP, &vcc->flags)) {
+		struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
+		struct net_device *dev;
+
+		dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : NULL;
+		seq_printf(seq, "CLIP, Itf:%s, Encap:",
+		    dev ? dev->name : "none?");
+		seq_printf(seq, "%s", clip_vcc->encap ? "LLC/SNAP" : "None");
+	}
+	seq_putc(seq, '\n');
+}
+
+static const char *vcc_state(struct atm_vcc *vcc)
+{
+	static const char *const map[] = { ATM_VS2TXT_MAP };
+
+	return map[ATM_VF2VS(vcc->flags)];
+}
+
+static void vcc_info(struct seq_file *seq, struct atm_vcc *vcc)
+{
+	struct sock *sk = sk_atm(vcc);
+
+	seq_printf(seq, "%pK ", vcc);
+	if (!vcc->dev)
+		seq_printf(seq, "Unassigned    ");
+	else
+		seq_printf(seq, "%3d %3d %5d ", vcc->dev->number, vcc->vpi,
+			vcc->vci);
+	switch (sk->sk_family) {
+	case AF_ATMPVC:
+		seq_printf(seq, "PVC");
+		break;
+	case AF_ATMSVC:
+		seq_printf(seq, "SVC");
+		break;
+	default:
+		seq_printf(seq, "%3d", sk->sk_family);
+	}
+	seq_printf(seq, " %04lx  %5d %7d/%7d %7d/%7d [%d]\n",
+		   vcc->flags, sk->sk_err,
+		   sk_wmem_alloc_get(sk), sk->sk_sndbuf,
+		   sk_rmem_alloc_get(sk), sk->sk_rcvbuf,
+		   refcount_read(&sk->sk_refcnt));
+}
+
+static void svc_info(struct seq_file *seq, struct atm_vcc *vcc)
+{
+	if (!vcc->dev)
+		seq_printf(seq, sizeof(void *) == 4 ?
+			   "N/A@%pK%10s" : "N/A@%pK%2s", vcc, "");
+	else
+		seq_printf(seq, "%3d %3d %5d         ",
+			   vcc->dev->number, vcc->vpi, vcc->vci);
+	seq_printf(seq, "%-10s ", vcc_state(vcc));
+	seq_printf(seq, "%s%s", vcc->remote.sas_addr.pub,
+	    *vcc->remote.sas_addr.pub && *vcc->remote.sas_addr.prv ? "+" : "");
+	if (*vcc->remote.sas_addr.prv) {
+		int i;
+
+		for (i = 0; i < ATM_ESA_LEN; i++)
+			seq_printf(seq, "%02x", vcc->remote.sas_addr.prv[i]);
+	}
+	seq_putc(seq, '\n');
+}
+
+static int atm_dev_seq_show(struct seq_file *seq, void *v)
+{
+	static char atm_dev_banner[] =
+		"Itf Type    ESI/\"MAC\"addr "
+		"AAL(TX,err,RX,err,drop) ...               [refcnt]\n";
+
+	if (v == &atm_devs)
+		seq_puts(seq, atm_dev_banner);
+	else {
+		struct atm_dev *dev = list_entry(v, struct atm_dev, dev_list);
+
+		atm_dev_info(seq, dev);
+	}
+	return 0;
+}
+
+static const struct seq_operations atm_dev_seq_ops = {
+	.start	= atm_dev_seq_start,
+	.next	= atm_dev_seq_next,
+	.stop	= atm_dev_seq_stop,
+	.show	= atm_dev_seq_show,
+};
+
+static int pvc_seq_show(struct seq_file *seq, void *v)
+{
+	static char atm_pvc_banner[] =
+		"Itf VPI VCI   AAL RX(PCR,Class) TX(PCR,Class)\n";
+
+	if (v == SEQ_START_TOKEN)
+		seq_puts(seq, atm_pvc_banner);
+	else {
+		struct vcc_state *state = seq->private;
+		struct atm_vcc *vcc = atm_sk(state->sk);
+
+		pvc_info(seq, vcc);
+	}
+	return 0;
+}
+
+static const struct seq_operations pvc_seq_ops = {
+	.start	= vcc_seq_start,
+	.next	= vcc_seq_next,
+	.stop	= vcc_seq_stop,
+	.show	= pvc_seq_show,
+};
+
+static int vcc_seq_show(struct seq_file *seq, void *v)
+{
+	if (v == SEQ_START_TOKEN) {
+		seq_printf(seq, sizeof(void *) == 4 ? "%-8s%s" : "%-16s%s",
+			"Address ", "Itf VPI VCI   Fam Flags Reply "
+			"Send buffer     Recv buffer      [refcnt]\n");
+	} else {
+		struct vcc_state *state = seq->private;
+		struct atm_vcc *vcc = atm_sk(state->sk);
+
+		vcc_info(seq, vcc);
+	}
+	return 0;
+}
+
+static const struct seq_operations vcc_seq_ops = {
+	.start	= vcc_seq_start,
+	.next	= vcc_seq_next,
+	.stop	= vcc_seq_stop,
+	.show	= vcc_seq_show,
+};
+
+static int svc_seq_show(struct seq_file *seq, void *v)
+{
+	static const char atm_svc_banner[] =
+		"Itf VPI VCI           State      Remote\n";
+
+	if (v == SEQ_START_TOKEN)
+		seq_puts(seq, atm_svc_banner);
+	else {
+		struct vcc_state *state = seq->private;
+		struct atm_vcc *vcc = atm_sk(state->sk);
+
+		svc_info(seq, vcc);
+	}
+	return 0;
+}
+
+static const struct seq_operations svc_seq_ops = {
+	.start	= vcc_seq_start,
+	.next	= vcc_seq_next,
+	.stop	= vcc_seq_stop,
+	.show	= svc_seq_show,
+};
+
+static ssize_t proc_dev_atm_read(struct file *file, char __user *buf,
+				 size_t count, loff_t *pos)
+{
+	struct atm_dev *dev;
+	unsigned long page;
+	int length;
+
+	if (count == 0)
+		return 0;
+	page = get_zeroed_page(GFP_KERNEL);
+	if (!page)
+		return -ENOMEM;
+	dev = PDE_DATA(file_inode(file));
+	if (!dev->ops->proc_read)
+		length = -EINVAL;
+	else {
+		length = dev->ops->proc_read(dev, pos, (char *)page);
+		if (length > count)
+			length = -EINVAL;
+	}
+	if (length >= 0) {
+		if (copy_to_user(buf, (char *)page, length))
+			length = -EFAULT;
+		(*pos)++;
+	}
+	free_page(page);
+	return length;
+}
+
+struct proc_dir_entry *atm_proc_root;
+EXPORT_SYMBOL(atm_proc_root);
+
+
+int atm_proc_dev_register(struct atm_dev *dev)
+{
+	int error;
+
+	/* No proc info */
+	if (!dev->ops->proc_read)
+		return 0;
+
+	error = -ENOMEM;
+	dev->proc_name = kasprintf(GFP_KERNEL, "%s:%d", dev->type, dev->number);
+	if (!dev->proc_name)
+		goto err_out;
+
+	dev->proc_entry = proc_create_data(dev->proc_name, 0, atm_proc_root,
+					   &proc_atm_dev_ops, dev);
+	if (!dev->proc_entry)
+		goto err_free_name;
+	return 0;
+
+err_free_name:
+	kfree(dev->proc_name);
+err_out:
+	return error;
+}
+
+void atm_proc_dev_deregister(struct atm_dev *dev)
+{
+	if (!dev->ops->proc_read)
+		return;
+
+	remove_proc_entry(dev->proc_name, atm_proc_root);
+	kfree(dev->proc_name);
+}
+
+int __init atm_proc_init(void)
+{
+	atm_proc_root = proc_net_mkdir(&init_net, "atm", init_net.proc_net);
+	if (!atm_proc_root)
+		return -ENOMEM;
+	proc_create_seq("devices", 0444, atm_proc_root, &atm_dev_seq_ops);
+	proc_create_seq_private("pvc", 0444, atm_proc_root, &pvc_seq_ops,
+			sizeof(struct vcc_state), (void *)(uintptr_t)PF_ATMPVC);
+	proc_create_seq_private("svc", 0444, atm_proc_root, &svc_seq_ops,
+			sizeof(struct vcc_state), (void *)(uintptr_t)PF_ATMSVC);
+	proc_create_seq_private("vc", 0444, atm_proc_root, &vcc_seq_ops,
+			sizeof(struct vcc_state), NULL);
+	return 0;
+}
+
+void atm_proc_exit(void)
+{
+	remove_proc_subtree("atm", init_net.proc_net);
+}