4 files changed, 131 insertions, 67 deletions

diff --git a/drivers/nubus/Makefile b/drivers/nubus/Makefile
index 21bda2031e7e..6d063cde39d1 100644
--- a/drivers/nubus/Makefile
+++ b/drivers/nubus/Makefile
@@ -2,6 +2,6 @@
 # Makefile for the nubus specific drivers.
 #
 
-obj-y   := nubus.o
+obj-y := nubus.o bus.o
 
 obj-$(CONFIG_PROC_FS) += proc.o
diff --git a/drivers/nubus/bus.c b/drivers/nubus/bus.c
new file mode 100644
index 000000000000..d306c348c857
--- /dev/null
+++ b/drivers/nubus/bus.c
@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Bus implementation for the NuBus subsystem.
+//
+// Copyright (C) 2017 Finn Thain
+
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/nubus.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+
+#define to_nubus_board(d)       container_of(d, struct nubus_board, dev)
+#define to_nubus_driver(d)      container_of(d, struct nubus_driver, driver)
+
+static int nubus_bus_match(struct device *dev, struct device_driver *driver)
+{
+	return 1;
+}
+
+static int nubus_device_probe(struct device *dev)
+{
+	struct nubus_driver *ndrv = to_nubus_driver(dev->driver);
+	int err = -ENODEV;
+
+	if (ndrv->probe)
+		err = ndrv->probe(to_nubus_board(dev));
+	return err;
+}
+
+static int nubus_device_remove(struct device *dev)
+{
+	struct nubus_driver *ndrv = to_nubus_driver(dev->driver);
+	int err = -ENODEV;
+
+	if (dev->driver && ndrv->remove)
+		err = ndrv->remove(to_nubus_board(dev));
+	return err;
+}
+
+struct bus_type nubus_bus_type = {
+	.name		= "nubus",
+	.match		= nubus_bus_match,
+	.probe		= nubus_device_probe,
+	.remove		= nubus_device_remove,
+};
+EXPORT_SYMBOL(nubus_bus_type);
+
+int nubus_driver_register(struct nubus_driver *ndrv)
+{
+	ndrv->driver.bus = &nubus_bus_type;
+	return driver_register(&ndrv->driver);
+}
+EXPORT_SYMBOL(nubus_driver_register);
+
+void nubus_driver_unregister(struct nubus_driver *ndrv)
+{
+	driver_unregister(&ndrv->driver);
+}
+EXPORT_SYMBOL(nubus_driver_unregister);
+
+static struct device nubus_parent = {
+	.init_name	= "nubus",
+};
+
+int __init nubus_bus_register(void)
+{
+	int err;
+
+	err = device_register(&nubus_parent);
+	if (err)
+		return err;
+
+	err = bus_register(&nubus_bus_type);
+	if (!err)
+		return 0;
+
+	device_unregister(&nubus_parent);
+	return err;
+}
+
+static void nubus_device_release(struct device *dev)
+{
+	struct nubus_board *board = to_nubus_board(dev);
+	struct nubus_rsrc *fres, *tmp;
+
+	list_for_each_entry_safe(fres, tmp, &nubus_func_rsrcs, list)
+		if (fres->board == board) {
+			list_del(&fres->list);
+			kfree(fres);
+		}
+	kfree(board);
+}
+
+int nubus_device_register(struct nubus_board *board)
+{
+	board->dev.parent = &nubus_parent;
+	board->dev.release = nubus_device_release;
+	board->dev.bus = &nubus_bus_type;
+	dev_set_name(&board->dev, "slot.%X", board->slot);
+	return device_register(&board->dev);
+}
+
+static int nubus_print_device_name_fn(struct device *dev, void *data)
+{
+	struct nubus_board *board = to_nubus_board(dev);
+	struct seq_file *m = data;
+
+	seq_printf(m, "Slot %X: %s\n", board->slot, board->name);
+	return 0;
+}
+
+int nubus_proc_show(struct seq_file *m, void *data)
+{
+	return bus_for_each_dev(&nubus_bus_type, NULL, m,
+				nubus_print_device_name_fn);
+}
diff --git a/drivers/nubus/nubus.c b/drivers/nubus/nubus.c
index 0bb54ccd7a1a..4621ff98138c 100644
--- a/drivers/nubus/nubus.c
+++ b/drivers/nubus/nubus.c
@@ -33,7 +33,6 @@
 /* Globals */
 
 LIST_HEAD(nubus_func_rsrcs);
-struct nubus_board *nubus_boards;
 
 /* Meaning of "bytelanes":
 
@@ -715,10 +714,9 @@ static int __init nubus_get_board_resource(struct nubus_board *board, int slot,
 	return 0;
 }
 
-static struct nubus_board * __init nubus_add_board(int slot, int bytelanes)
+static void __init nubus_add_board(int slot, int bytelanes)
 {
 	struct nubus_board *board;
-	struct nubus_board **boardp;
 	unsigned char *rp;
 	unsigned long dpat;
 	struct nubus_dir dir;
@@ -731,7 +729,7 @@ static struct nubus_board * __init nubus_add_board(int slot, int bytelanes)
 
 	/* Actually we should probably panic if this fails */
 	if ((board = kzalloc(sizeof(*board), GFP_ATOMIC)) == NULL)
-		return NULL;
+		return;
 	board->fblock = rp;
 
 	/* Dump the format block for debugging purposes */
@@ -794,7 +792,8 @@ static struct nubus_board * __init nubus_add_board(int slot, int bytelanes)
 	if (nubus_readdir(&dir, &ent) == -1) {
 		/* We can't have this! */
 		pr_err("Slot %X: Board resource not found!\n", slot);
-		return NULL;
+		kfree(board);
+		return;
 	}
 
 	if (ent.type < 1 || ent.type > 127)
@@ -823,14 +822,8 @@ static struct nubus_board * __init nubus_add_board(int slot, int bytelanes)
 		list_add_tail(&fres->list, &nubus_func_rsrcs);
 	}
 
-	/* Put it on the global NuBus board chain. Keep entries in order. */
-	for (boardp = &nubus_boards; *boardp != NULL;
-	     boardp = &((*boardp)->next))
-		/* spin */;
-	*boardp = board;
-	board->next = NULL;
-
-	return board;
+	if (nubus_device_register(board))
+		put_device(&board->dev);
 }
 
 static void __init nubus_probe_slot(int slot)
@@ -876,10 +869,15 @@ static void __init nubus_scan_bus(void)
 
 static int __init nubus_init(void)
 {
+	int err;
+
 	if (!MACH_IS_MAC)
 		return 0;
 
 	nubus_proc_init();
+	err = nubus_bus_register();
+	if (err)
+		return err;
 	nubus_scan_bus();
 	return 0;
 }
diff --git a/drivers/nubus/proc.c b/drivers/nubus/proc.c
index 60c0f40b4d5e..c2e5a7e6bd3e 100644
--- a/drivers/nubus/proc.c
+++ b/drivers/nubus/proc.c
@@ -198,68 +198,17 @@ void nubus_proc_add_rsrc(struct proc_dir_entry *procdir,
 /*
  * /proc/nubus stuff
  */
-static int nubus_proc_show(struct seq_file *m, void *v)
-{
-	const struct nubus_board *board = v;
-
-	/* Display header on line 1 */
-	if (v == SEQ_START_TOKEN)
-		seq_puts(m, "Nubus devices found:\n");
-	else
-		seq_printf(m, "Slot %X: %s\n", board->slot, board->name);
-	return 0;
-}
-
-static void *nubus_proc_start(struct seq_file *m, loff_t *_pos)
-{
-	struct nubus_board *board;
-	unsigned pos;
-
-	if (*_pos > LONG_MAX)
-		return NULL;
-	pos = *_pos;
-	if (pos == 0)
-		return SEQ_START_TOKEN;
-	for (board = nubus_boards; board; board = board->next)
-		if (--pos == 0)
-			break;
-	return board;
-}
-
-static void *nubus_proc_next(struct seq_file *p, void *v, loff_t *_pos)
-{
-	/* Walk the list of NuBus boards */
-	struct nubus_board *board = v;
-
-	++*_pos;
-	if (v == SEQ_START_TOKEN)
-		board = nubus_boards;
-	else if (board)
-		board = board->next;
-	return board;
-}
-
-static void nubus_proc_stop(struct seq_file *p, void *v)
-{
-}
-
-static const struct seq_operations nubus_proc_seqops = {
-	.start	= nubus_proc_start,
-	.next	= nubus_proc_next,
-	.stop	= nubus_proc_stop,
-	.show	= nubus_proc_show,
-};
 
 static int nubus_proc_open(struct inode *inode, struct file *file)
 {
-	return seq_open(file, &nubus_proc_seqops);
+	return single_open(file, nubus_proc_show, NULL);
 }
 
 static const struct file_operations nubus_proc_fops = {
 	.open		= nubus_proc_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
-	.release	= seq_release,
+	.release	= single_release,
 };
 
 void __init nubus_proc_init(void)