1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Hypervisor filesystem for Linux on s390.
4 * Set Partition-Resource Parameter interface.
5 *
6 * Copyright IBM Corp. 2013
7 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
8 */
9
10#include <linux/errno.h>
11#include <linux/gfp.h>
12#include <linux/string.h>
13#include <linux/types.h>
14#include <linux/uaccess.h>
15#include <asm/diag.h>
16#include <asm/sclp.h>
17#include "hypfs.h"
18
19#define DIAG304_SET_WEIGHTS 0
20#define DIAG304_QUERY_PRP 1
21#define DIAG304_SET_CAPPING 2
22
23#define DIAG304_CMD_MAX 2
24
25static inline unsigned long __hypfs_sprp_diag304(void *data, unsigned long cmd)
26{
27 union register_pair r1 = { .even = virt_to_phys(data), };
28
29 asm volatile("diag %[r1],%[r3],0x304"
30 : [r1] "+&d" (r1.pair)
31 : [r3] "d" (cmd)
32 : "memory");
33 return r1.odd;
34}
35
36static unsigned long hypfs_sprp_diag304(void *data, unsigned long cmd)
37{
38 diag_stat_inc(DIAG_STAT_X304);
39 return __hypfs_sprp_diag304(data, cmd);
40}
41
42static void hypfs_sprp_free(const void *data)
43{
44 free_page((unsigned long) data);
45}
46
47static int hypfs_sprp_create(void **data_ptr, void **free_ptr, size_t *size)
48{
49 unsigned long rc;
50 void *data;
51
52 data = (void *) get_zeroed_page(GFP_KERNEL);
53 if (!data)
54 return -ENOMEM;
55 rc = hypfs_sprp_diag304(data, DIAG304_QUERY_PRP);
56 if (rc != 1) {
57 *data_ptr = *free_ptr = NULL;
58 *size = 0;
59 free_page((unsigned long) data);
60 return -EIO;
61 }
62 *data_ptr = *free_ptr = data;
63 *size = PAGE_SIZE;
64 return 0;
65}
66
67static int __hypfs_sprp_ioctl(void __user *user_area)
68{
69 struct hypfs_diag304 *diag304;
70 unsigned long cmd;
71 void __user *udata;
72 void *data;
73 int rc;
74
75 rc = -ENOMEM;
76 data = (void *)get_zeroed_page(GFP_KERNEL);
77 diag304 = kzalloc(sizeof(*diag304), GFP_KERNEL);
78 if (!data || !diag304)
79 goto out;
80
81 rc = -EFAULT;
82 if (copy_from_user(diag304, user_area, sizeof(*diag304)))
83 goto out;
84 rc = -EINVAL;
85 if ((diag304->args[0] >> 8) != 0 || diag304->args[1] > DIAG304_CMD_MAX)
86 goto out;
87
88 rc = -EFAULT;
89 udata = (void __user *)(unsigned long) diag304->data;
90 if (diag304->args[1] == DIAG304_SET_WEIGHTS ||
91 diag304->args[1] == DIAG304_SET_CAPPING)
92 if (copy_from_user(to: data, from: udata, PAGE_SIZE))
93 goto out;
94
95 cmd = *(unsigned long *) &diag304->args[0];
96 diag304->rc = hypfs_sprp_diag304(data, cmd);
97
98 if (diag304->args[1] == DIAG304_QUERY_PRP)
99 if (copy_to_user(to: udata, from: data, PAGE_SIZE)) {
100 rc = -EFAULT;
101 goto out;
102 }
103
104 rc = copy_to_user(user_area, diag304, sizeof(*diag304)) ? -EFAULT : 0;
105out:
106 kfree(objp: diag304);
107 free_page((unsigned long) data);
108 return rc;
109}
110
111static long hypfs_sprp_ioctl(struct file *file, unsigned int cmd,
112 unsigned long arg)
113{
114 void __user *argp;
115
116 if (!capable(CAP_SYS_ADMIN))
117 return -EACCES;
118 argp = (void __user *)arg;
119 switch (cmd) {
120 case HYPFS_DIAG304:
121 return __hypfs_sprp_ioctl(user_area: argp);
122 default: /* unknown ioctl number */
123 return -ENOTTY;
124 }
125 return 0;
126}
127
128static struct hypfs_dbfs_file hypfs_sprp_file = {
129 .name = "diag_304",
130 .data_create = hypfs_sprp_create,
131 .data_free = hypfs_sprp_free,
132 .unlocked_ioctl = hypfs_sprp_ioctl,
133};
134
135void hypfs_sprp_init(void)
136{
137 if (!sclp.has_sprp)
138 return;
139 hypfs_dbfs_create_file(df: &hypfs_sprp_file);
140}
141
142void hypfs_sprp_exit(void)
143{
144 if (!sclp.has_sprp)
145 return;
146 hypfs_dbfs_remove_file(df: &hypfs_sprp_file);
147}
148

source code of linux/arch/s390/hypfs/hypfs_sprp.c