linux-brain/arch/s390/hypfs/hypfs_sprp.c
Greg Kroah-Hartman f36108c462 s390/hypfs: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-01-28 15:58:54 +01:00

153 lines
3.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Hypervisor filesystem for Linux on s390.
* Set Partition-Resource Parameter interface.
*
* Copyright IBM Corp. 2013
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
*/
#include <linux/compat.h>
#include <linux/errno.h>
#include <linux/gfp.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <asm/diag.h>
#include <asm/sclp.h>
#include "hypfs.h"
#define DIAG304_SET_WEIGHTS 0
#define DIAG304_QUERY_PRP 1
#define DIAG304_SET_CAPPING 2
#define DIAG304_CMD_MAX 2
static inline unsigned long __hypfs_sprp_diag304(void *data, unsigned long cmd)
{
register unsigned long _data asm("2") = (unsigned long) data;
register unsigned long _rc asm("3");
register unsigned long _cmd asm("4") = cmd;
asm volatile("diag %1,%2,0x304\n"
: "=d" (_rc) : "d" (_data), "d" (_cmd) : "memory");
return _rc;
}
static unsigned long hypfs_sprp_diag304(void *data, unsigned long cmd)
{
diag_stat_inc(DIAG_STAT_X304);
return __hypfs_sprp_diag304(data, cmd);
}
static void hypfs_sprp_free(const void *data)
{
free_page((unsigned long) data);
}
static int hypfs_sprp_create(void **data_ptr, void **free_ptr, size_t *size)
{
unsigned long rc;
void *data;
data = (void *) get_zeroed_page(GFP_KERNEL);
if (!data)
return -ENOMEM;
rc = hypfs_sprp_diag304(data, DIAG304_QUERY_PRP);
if (rc != 1) {
*data_ptr = *free_ptr = NULL;
*size = 0;
free_page((unsigned long) data);
return -EIO;
}
*data_ptr = *free_ptr = data;
*size = PAGE_SIZE;
return 0;
}
static int __hypfs_sprp_ioctl(void __user *user_area)
{
struct hypfs_diag304 *diag304;
unsigned long cmd;
void __user *udata;
void *data;
int rc;
rc = -ENOMEM;
data = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
diag304 = kzalloc(sizeof(*diag304), GFP_KERNEL);
if (!data || !diag304)
goto out;
rc = -EFAULT;
if (copy_from_user(diag304, user_area, sizeof(*diag304)))
goto out;
rc = -EINVAL;
if ((diag304->args[0] >> 8) != 0 || diag304->args[1] > DIAG304_CMD_MAX)
goto out;
rc = -EFAULT;
udata = (void __user *)(unsigned long) diag304->data;
if (diag304->args[1] == DIAG304_SET_WEIGHTS ||
diag304->args[1] == DIAG304_SET_CAPPING)
if (copy_from_user(data, udata, PAGE_SIZE))
goto out;
cmd = *(unsigned long *) &diag304->args[0];
diag304->rc = hypfs_sprp_diag304(data, cmd);
if (diag304->args[1] == DIAG304_QUERY_PRP)
if (copy_to_user(udata, data, PAGE_SIZE)) {
rc = -EFAULT;
goto out;
}
rc = copy_to_user(user_area, diag304, sizeof(*diag304)) ? -EFAULT : 0;
out:
kfree(diag304);
free_page((unsigned long) data);
return rc;
}
static long hypfs_sprp_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (is_compat_task())
argp = compat_ptr(arg);
else
argp = (void __user *) arg;
switch (cmd) {
case HYPFS_DIAG304:
return __hypfs_sprp_ioctl(argp);
default: /* unknown ioctl number */
return -ENOTTY;
}
return 0;
}
static struct hypfs_dbfs_file hypfs_sprp_file = {
.name = "diag_304",
.data_create = hypfs_sprp_create,
.data_free = hypfs_sprp_free,
.unlocked_ioctl = hypfs_sprp_ioctl,
};
void hypfs_sprp_init(void)
{
if (!sclp.has_sprp)
return;
hypfs_dbfs_create_file(&hypfs_sprp_file);
}
void hypfs_sprp_exit(void)
{
if (!sclp.has_sprp)
return;
hypfs_dbfs_remove_file(&hypfs_sprp_file);
}