v4.19.13 snapshot.
diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
new file mode 100644
index 0000000..1c77617
--- /dev/null
+++ b/drivers/w1/w1_int.c
@@ -0,0 +1,254 @@
+/*
+ * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+#include <linux/export.h>
+#include <linux/moduleparam.h>
+
+#include "w1_internal.h"
+#include "w1_netlink.h"
+
+static int w1_search_count = -1; /* Default is continual scan */
+module_param_named(search_count, w1_search_count, int, 0);
+
+static int w1_enable_pullup = 1;
+module_param_named(enable_pullup, w1_enable_pullup, int, 0);
+
+static struct w1_master *w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
+ struct device_driver *driver,
+ struct device *device)
+{
+ struct w1_master *dev;
+ int err;
+
+ /*
+ * We are in process context(kernel thread), so can sleep.
+ */
+ dev = kzalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
+ if (!dev) {
+ pr_err("Failed to allocate %zd bytes for new w1 device.\n",
+ sizeof(struct w1_master));
+ return NULL;
+ }
+
+
+ dev->bus_master = (struct w1_bus_master *)(dev + 1);
+
+ dev->owner = THIS_MODULE;
+ dev->max_slave_count = slave_count;
+ dev->slave_count = 0;
+ dev->attempts = 0;
+ dev->initialized = 0;
+ dev->id = id;
+ dev->slave_ttl = slave_ttl;
+ dev->search_count = w1_search_count;
+ dev->enable_pullup = w1_enable_pullup;
+
+ /* 1 for w1_process to decrement
+ * 1 for __w1_remove_master_device to decrement
+ */
+ atomic_set(&dev->refcnt, 2);
+
+ INIT_LIST_HEAD(&dev->slist);
+ INIT_LIST_HEAD(&dev->async_list);
+ mutex_init(&dev->mutex);
+ mutex_init(&dev->bus_mutex);
+ mutex_init(&dev->list_mutex);
+
+ memcpy(&dev->dev, device, sizeof(struct device));
+ dev_set_name(&dev->dev, "w1_bus_master%u", dev->id);
+ snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id);
+ dev->dev.init_name = dev->name;
+
+ dev->driver = driver;
+
+ dev->seq = 1;
+
+ err = device_register(&dev->dev);
+ if (err) {
+ pr_err("Failed to register master device. err=%d\n", err);
+ put_device(&dev->dev);
+ dev = NULL;
+ }
+
+ return dev;
+}
+
+static void w1_free_dev(struct w1_master *dev)
+{
+ device_unregister(&dev->dev);
+}
+
+/**
+ * w1_add_master_device() - registers a new master device
+ * @master: master bus device to register
+ */
+int w1_add_master_device(struct w1_bus_master *master)
+{
+ struct w1_master *dev, *entry;
+ int retval = 0;
+ struct w1_netlink_msg msg;
+ int id, found;
+
+ /* validate minimum functionality */
+ if (!(master->touch_bit && master->reset_bus) &&
+ !(master->write_bit && master->read_bit) &&
+ !(master->write_byte && master->read_byte && master->reset_bus)) {
+ pr_err("w1_add_master_device: invalid function set\n");
+ return(-EINVAL);
+ }
+
+ /* Lock until the device is added (or not) to w1_masters. */
+ mutex_lock(&w1_mlock);
+ /* Search for the first available id (starting at 1). */
+ id = 0;
+ do {
+ ++id;
+ found = 0;
+ list_for_each_entry(entry, &w1_masters, w1_master_entry) {
+ if (entry->id == id) {
+ found = 1;
+ break;
+ }
+ }
+ } while (found);
+
+ dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl,
+ &w1_master_driver, &w1_master_device);
+ if (!dev) {
+ mutex_unlock(&w1_mlock);
+ return -ENOMEM;
+ }
+
+ retval = w1_create_master_attributes(dev);
+ if (retval) {
+ mutex_unlock(&w1_mlock);
+ goto err_out_free_dev;
+ }
+
+ memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
+
+ dev->initialized = 1;
+
+ dev->thread = kthread_run(&w1_process, dev, "%s", dev->name);
+ if (IS_ERR(dev->thread)) {
+ retval = PTR_ERR(dev->thread);
+ dev_err(&dev->dev,
+ "Failed to create new kernel thread. err=%d\n",
+ retval);
+ mutex_unlock(&w1_mlock);
+ goto err_out_rm_attr;
+ }
+
+ list_add(&dev->w1_master_entry, &w1_masters);
+ mutex_unlock(&w1_mlock);
+
+ memset(&msg, 0, sizeof(msg));
+ msg.id.mst.id = dev->id;
+ msg.type = W1_MASTER_ADD;
+ w1_netlink_send(dev, &msg);
+
+ return 0;
+
+#if 0 /* Thread cleanup code, not required currently. */
+err_out_kill_thread:
+ set_bit(W1_ABORT_SEARCH, &dev->flags);
+ kthread_stop(dev->thread);
+#endif
+err_out_rm_attr:
+ w1_destroy_master_attributes(dev);
+err_out_free_dev:
+ w1_free_dev(dev);
+
+ return retval;
+}
+EXPORT_SYMBOL(w1_add_master_device);
+
+void __w1_remove_master_device(struct w1_master *dev)
+{
+ struct w1_netlink_msg msg;
+ struct w1_slave *sl, *sln;
+
+ mutex_lock(&w1_mlock);
+ list_del(&dev->w1_master_entry);
+ mutex_unlock(&w1_mlock);
+
+ set_bit(W1_ABORT_SEARCH, &dev->flags);
+ kthread_stop(dev->thread);
+
+ mutex_lock(&dev->mutex);
+ mutex_lock(&dev->list_mutex);
+ list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
+ mutex_unlock(&dev->list_mutex);
+ w1_slave_detach(sl);
+ mutex_lock(&dev->list_mutex);
+ }
+ w1_destroy_master_attributes(dev);
+ mutex_unlock(&dev->list_mutex);
+ mutex_unlock(&dev->mutex);
+ atomic_dec(&dev->refcnt);
+
+ while (atomic_read(&dev->refcnt)) {
+ dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",
+ dev->name, atomic_read(&dev->refcnt));
+
+ if (msleep_interruptible(1000))
+ flush_signals(current);
+ mutex_lock(&dev->list_mutex);
+ w1_process_callbacks(dev);
+ mutex_unlock(&dev->list_mutex);
+ }
+ mutex_lock(&dev->list_mutex);
+ w1_process_callbacks(dev);
+ mutex_unlock(&dev->list_mutex);
+
+ memset(&msg, 0, sizeof(msg));
+ msg.id.mst.id = dev->id;
+ msg.type = W1_MASTER_REMOVE;
+ w1_netlink_send(dev, &msg);
+
+ w1_free_dev(dev);
+}
+
+/**
+ * w1_remove_master_device() - unregister a master device
+ * @bm: master bus device to remove
+ */
+void w1_remove_master_device(struct w1_bus_master *bm)
+{
+ struct w1_master *dev, *found = NULL;
+
+ list_for_each_entry(dev, &w1_masters, w1_master_entry) {
+ if (!dev->initialized)
+ continue;
+
+ if (dev->bus_master->data == bm->data) {
+ found = dev;
+ break;
+ }
+ }
+
+ if (!found) {
+ pr_err("Device doesn't exist.\n");
+ return;
+ }
+
+ __w1_remove_master_device(found);
+}
+EXPORT_SYMBOL(w1_remove_master_device);