linux/drivers/pci/hotplug/rpadlpar_sysfs.c
Krzysztof Wilczyński f8cf6e513e PCI/sysfs: Use sysfs_emit() and sysfs_emit_at() in "show" functions
The sysfs_emit() and sysfs_emit_at() functions were introduced to make
it less ambiguous which function is preferred when writing to the output
buffer in a device attribute's "show" callback [1].

Convert the PCI sysfs object "show" functions from sprintf(), snprintf()
and scnprintf() to sysfs_emit() and sysfs_emit_at() accordingly, as the
latter is aware of the PAGE_SIZE buffer and correctly returns the number
of bytes written into the buffer.

No functional change intended.

[1] Documentation/filesystems/sysfs.rst

Related commit: ad025f8e46 ("PCI/sysfs: Use sysfs_emit() and
sysfs_emit_at() in "show" functions").

Link: https://lore.kernel.org/r/20210603000112.703037-2-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
2021-06-03 22:14:47 -05:00

124 lines
2.5 KiB
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;
strscpy(drc_name, buf, nbytes + 1);
end = strchr(drc_name, '\n');
if (end)
*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 sysfs_emit(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;
strscpy(drc_name, buf, nbytes + 1);
end = strchr(drc_name, '\n');
if (end)
*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 sysfs_emit(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);
}