summaryrefslogtreecommitdiff
path: root/arch/s390/hypfs/hypfs_sprp.c
blob: 601b70786dc857804d5fe263a9ef2e7c9b710502 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
// 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,
};

int hypfs_sprp_init(void)
{
	if (!sclp.has_sprp)
		return 0;
	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);
}