linux_kernel/drivers/pci/hotplug/rpadlpar_sysfs.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Interface for Dynamic Logical Partitioning of I/O Slots on
 * RPA-compliant PPC64 platform.
 *
 * John Rose <johnrose@austin.ibm.com>
 * October 2003
 *
 * Copyright (C) 2003 IBM.
 */
#include <linux/kobject.h>
#include <linux/string.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include "rpaphp.h"
#include "rpadlpar.h"
#include "../pci.h"

#define DLPAR_KOBJ_NAME       "control"

/* Those two have no quotes because they are passed to __ATTR() which
 * stringifies the argument (yuck !)
 */
#define ADD_SLOT_ATTR_NAME    add_slot
#define REMOVE_SLOT_ATTR_NAME remove_slot

static ssize_t add_slot_store(struct kobject *kobj, struct kobj_attribute *attr,
			      const char *buf, size_t nbytes)
{
	char drc_name[MAX_DRC_NAME_LEN];
	char *end;
	int rc;

	if (nbytes >= MAX_DRC_NAME_LEN)
		return 0;

	memcpy(drc_name, buf, nbytes);

	end = strchr(drc_name, '\n');
	if (!end)
		end = &drc_name[nbytes];
	*end = '\0';

	rc = dlpar_add_slot(drc_name);
	if (rc)
		return rc;

	return nbytes;
}

static ssize_t add_slot_show(struct kobject *kobj,
			     struct kobj_attribute *attr, char *buf)
{
	return sprintf(buf, "0\n");
}

static ssize_t remove_slot_store(struct kobject *kobj,
				 struct kobj_attribute *attr,
				 const char *buf, size_t nbytes)
{
	char drc_name[MAX_DRC_NAME_LEN];
	int rc;
	char *end;

	if (nbytes >= MAX_DRC_NAME_LEN)
		return 0;

	memcpy(drc_name, buf, nbytes);

	end = strchr(drc_name, '\n');
	if (!end)
		end = &drc_name[nbytes];
	*end = '\0';

	rc = dlpar_remove_slot(drc_name);
	if (rc)
		return rc;

	return nbytes;
}

static ssize_t remove_slot_show(struct kobject *kobj,
				struct kobj_attribute *attr, char *buf)
{
	return sprintf(buf, "0\n");
}

static struct kobj_attribute add_slot_attr =
	__ATTR(ADD_SLOT_ATTR_NAME, 0644, add_slot_show, add_slot_store);

static struct kobj_attribute remove_slot_attr =
	__ATTR(REMOVE_SLOT_ATTR_NAME, 0644, remove_slot_show, remove_slot_store);

static struct attribute *default_attrs[] = {
	&add_slot_attr.attr,
	&remove_slot_attr.attr,
	NULL,
};

static const struct attribute_group dlpar_attr_group = {
	.attrs = default_attrs,
};

static struct kobject *dlpar_kobj;

int dlpar_sysfs_init(void)
{
	int error;

	dlpar_kobj = kobject_create_and_add(DLPAR_KOBJ_NAME,
					    &pci_slots_kset->kobj);
	if (!dlpar_kobj)
		return -EINVAL;

	error = sysfs_create_group(dlpar_kobj, &dlpar_attr_group);
	if (error)
		kobject_put(dlpar_kobj);
	return error;
}

void dlpar_sysfs_exit(void)
{
	sysfs_remove_group(dlpar_kobj, &dlpar_attr_group);
	kobject_put(dlpar_kobj);
}