Staging
v0.7.0
v0.7.0
https://github.com/torvalds/linux
Tip revision: ce522ba9ef7e2d9fb22a39eb3371c0c64e2a433e authored by Linus Torvalds on 11 April 2022, 00:21:36 UTC
Linux 5.18-rc2
Linux 5.18-rc2
Tip revision: ce522ba
hypfs_sprp.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)
{
union register_pair r1 = { .even = (unsigned long)data, };
asm volatile("diag %[r1],%[r3],0x304\n"
: [r1] "+&d" (r1.pair)
: [r3] "d" (cmd)
: "memory");
return r1.odd;
}
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);
}