PCI: hotplug: Delete skeleton driver

Ten years ago, commit 58319b802a61 ("PCI: Hotplug core: remove 'name'")
dropped the name element from struct hotplug_slot but neglected to update
the skeleton driver.

That same year, commit f46753c5e354 ("PCI: introduce pci_slot") raised the
number of arguments to pci_hp_register() from one to four.

Fourteen years ago, historic commit 7ab60fc1b8e7 ("PCI Hotplug skeleton:
final cleanups") removed all usages of the retval variable from
pcihp_skel_init() but not the variable itself, provoking a compiler
warning: https://git.kernel.org/tglx/history/c/7ab60fc1b8e7

It seems fair to assume the driver hasn't been used as a template for a new
driver in a while.  Per Bjorn's and Christoph's preference, delete it.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Christoph Hellwig <hch@lst.de>

drivers/pci/hotplug/pcihp_skeleton.c

@@ -1,348 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * PCI Hot Plug Controller Skeleton Driver - 0.3
- *
- * Copyright (C) 2001,2003 Greg Kroah-Hartman (greg@kroah.com)
- * Copyright (C) 2001,2003 IBM Corp.
- *
- * All rights reserved.
- *
- * This driver is to be used as a skeleton driver to show how to interface
- * with the pci hotplug core easily.
- *
- * Send feedback to <greg@kroah.com>
- *
- */
-
-#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/kernel.h>
-#include <linux/slab.h>
-#include <linux/pci.h>
-#include <linux/pci_hotplug.h>
-#include <linux/init.h>
-
-#define SLOT_NAME_SIZE	10
-struct slot {
-	u8 number;
-	struct hotplug_slot *hotplug_slot;
-	struct list_head slot_list;
-	char name[SLOT_NAME_SIZE];
-};
-
-static LIST_HEAD(slot_list);
-
-#define MY_NAME	"pcihp_skeleton"
-
-#define dbg(format, arg...)					\
-	do {							\
-		if (debug)					\
-			printk(KERN_DEBUG "%s: " format "\n",	\
-				MY_NAME, ## arg);		\
-	} while (0)
-#define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME, ## arg)
-#define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME, ## arg)
-#define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME, ## arg)
-
-/* local variables */
-static bool debug;
-static int num_slots;
-
-#define DRIVER_VERSION	"0.3"
-#define DRIVER_AUTHOR	"Greg Kroah-Hartman <greg@kroah.com>"
-#define DRIVER_DESC	"Hot Plug PCI Controller Skeleton Driver"
-
-MODULE_AUTHOR(DRIVER_AUTHOR);
-MODULE_DESCRIPTION(DRIVER_DESC);
-MODULE_LICENSE("GPL");
-module_param(debug, bool, 0644);
-MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
-
-static int enable_slot(struct hotplug_slot *slot);
-static int disable_slot(struct hotplug_slot *slot);
-static int set_attention_status(struct hotplug_slot *slot, u8 value);
-static int hardware_test(struct hotplug_slot *slot, u32 value);
-static int get_power_status(struct hotplug_slot *slot, u8 *value);
-static int get_attention_status(struct hotplug_slot *slot, u8 *value);
-static int get_latch_status(struct hotplug_slot *slot, u8 *value);
-static int get_adapter_status(struct hotplug_slot *slot, u8 *value);
-
-static struct hotplug_slot_ops skel_hotplug_slot_ops = {
-	.enable_slot =		enable_slot,
-	.disable_slot =		disable_slot,
-	.set_attention_status =	set_attention_status,
-	.hardware_test =	hardware_test,
-	.get_power_status =	get_power_status,
-	.get_attention_status =	get_attention_status,
-	.get_latch_status =	get_latch_status,
-	.get_adapter_status =	get_adapter_status,
-};
-
-static int enable_slot(struct hotplug_slot *hotplug_slot)
-{
-	struct slot *slot = hotplug_slot->private;
-	int retval = 0;
-
-	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
-
-	/*
-	 * Fill in code here to enable the specified slot
-	 */
-
-	return retval;
-}
-
-static int disable_slot(struct hotplug_slot *hotplug_slot)
-{
-	struct slot *slot = hotplug_slot->private;
-	int retval = 0;
-
-	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
-
-	/*
-	 * Fill in code here to disable the specified slot
-	 */
-
-	return retval;
-}
-
-static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
-{
-	struct slot *slot = hotplug_slot->private;
-	int retval = 0;
-
-	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
-
-	switch (status) {
-	case 0:
-		/*
-		 * Fill in code here to turn light off
-		 */
-		break;
-
-	case 1:
-	default:
-		/*
-		 * Fill in code here to turn light on
-		 */
-		break;
-	}
-
-	return retval;
-}
-
-static int hardware_test(struct hotplug_slot *hotplug_slot, u32 value)
-{
-	struct slot *slot = hotplug_slot->private;
-	int retval = 0;
-
-	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
-
-	switch (value) {
-	case 0:
-		/* Specify a test here */
-		break;
-	case 1:
-		/* Specify another test here */
-		break;
-	}
-
-	return retval;
-}
-
-static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
-{
-	struct slot *slot = hotplug_slot->private;
-	int retval = 0;
-
-	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
-
-	/*
-	 * Fill in logic to get the current power status of the specific
-	 * slot and store it in the *value location.
-	 */
-
-	return retval;
-}
-
-static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
-{
-	struct slot *slot = hotplug_slot->private;
-	int retval = 0;
-
-	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
-
-	/*
-	 * Fill in logic to get the current attention status of the specific
-	 * slot and store it in the *value location.
-	 */
-
-	return retval;
-}
-
-static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
-{
-	struct slot *slot = hotplug_slot->private;
-	int retval = 0;
-
-	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
-
-	/*
-	 * Fill in logic to get the current latch status of the specific
-	 * slot and store it in the *value location.
-	 */
-
-	return retval;
-}
-
-static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
-{
-	struct slot *slot = hotplug_slot->private;
-	int retval = 0;
-
-	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
-
-	/*
-	 * Fill in logic to get the current adapter status of the specific
-	 * slot and store it in the *value location.
-	 */
-
-	return retval;
-}
-
-static void release_slot(struct hotplug_slot *hotplug_slot)
-{
-	struct slot *slot = hotplug_slot->private;
-
-	dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
-	kfree(slot->hotplug_slot->info);
-	kfree(slot->hotplug_slot);
-	kfree(slot);
-}
-
-static void make_slot_name(struct slot *slot)
-{
-	/*
-	 * Stupid way to make a filename out of the slot name.
-	 * replace this if your hardware provides a better way to name slots.
-	 */
-	snprintf(slot->hotplug_slot->name, SLOT_NAME_SIZE, "%d", slot->number);
-}
-
-/**
- * init_slots - initialize 'struct slot' structures for each slot
- *
- */
-static int __init init_slots(void)
-{
-	struct slot *slot;
-	struct hotplug_slot *hotplug_slot;
-	struct hotplug_slot_info *info;
-	int retval;
-	int i;
-
-	/*
-	 * Create a structure for each slot, and register that slot
-	 * with the pci_hotplug subsystem.
-	 */
-	for (i = 0; i < num_slots; ++i) {
-		slot = kzalloc(sizeof(*slot), GFP_KERNEL);
-		if (!slot) {
-			retval = -ENOMEM;
-			goto error;
-		}
-
-		hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
-		if (!hotplug_slot) {
-			retval = -ENOMEM;
-			goto error_slot;
-		}
-		slot->hotplug_slot = hotplug_slot;
-
-		info = kzalloc(sizeof(*info), GFP_KERNEL);
-		if (!info) {
-			retval = -ENOMEM;
-			goto error_hpslot;
-		}
-		hotplug_slot->info = info;
-
-		slot->number = i;
-
-		hotplug_slot->name = slot->name;
-		hotplug_slot->private = slot;
-		hotplug_slot->release = &release_slot;
-		make_slot_name(slot);
-		hotplug_slot->ops = &skel_hotplug_slot_ops;
-
-		/*
-		 * Initialize the slot info structure with some known
-		 * good values.
-		 */
-		get_power_status(hotplug_slot, &info->power_status);
-		get_attention_status(hotplug_slot, &info->attention_status);
-		get_latch_status(hotplug_slot, &info->latch_status);
-		get_adapter_status(hotplug_slot, &info->adapter_status);
-
-		dbg("registering slot %d\n", i);
-		retval = pci_hp_register(slot->hotplug_slot);
-		if (retval) {
-			err("pci_hp_register failed with error %d\n", retval);
-			goto error_info;
-		}
-
-		/* add slot to our internal list */
-		list_add(&slot->slot_list, &slot_list);
-	}
-
-	return 0;
-error_info:
-	kfree(info);
-error_hpslot:
-	kfree(hotplug_slot);
-error_slot:
-	kfree(slot);
-error:
-	return retval;
-}
-
-static void __exit cleanup_slots(void)
-{
-	struct slot *slot, *next;
-
-	/*
-	 * Unregister all of our slots with the pci_hotplug subsystem.
-	 * Memory will be freed in release_slot() callback after slot's
-	 * lifespan is finished.
-	 */
-	list_for_each_entry_safe(slot, next, &slot_list, slot_list) {
-		list_del(&slot->slot_list);
-		pci_hp_deregister(slot->hotplug_slot);
-	}
-}
-
-static int __init pcihp_skel_init(void)
-{
-	int retval;
-
-	info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
-	/*
-	 * Do specific initialization stuff for your driver here
-	 * like initializing your controller hardware (if any) and
-	 * determining the number of slots you have in the system
-	 * right now.
-	 */
-	num_slots = 5;
-
-	return init_slots();
-}
-
-static void __exit pcihp_skel_exit(void)
-{
-	/*
-	 * Clean everything up.
-	 */
-	cleanup_slots();
-}
-
-module_init(pcihp_skel_init);
-module_exit(pcihp_skel_exit);