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/compat.h>
11#include <linux/errno.h>
12#include <linux/gfp.h>
13#include <linux/string.h>
14#include <linux/types.h>
15#include <linux/uaccess.h>
16#include <asm/diag.h>
17#include <asm/sclp.h>
18#include "hypfs.h"
19
20#define DIAG304_SET_WEIGHTS 0
21#define DIAG304_QUERY_PRP 1
22#define DIAG304_SET_CAPPING 2
23
24#define DIAG304_CMD_MAX 2
25
26static inline unsigned long __hypfs_sprp_diag304(void *data, unsigned long cmd)
27{
28 union register_pair r1 = { .even = virt_to_phys(data), };
29
30 asm volatile("diag %[r1],%[r3],0x304\n"
31 : [r1] "+&d" (r1.pair)
32 : [r3] "d" (cmd)
33 : "memory");
34 return r1.odd;
35}
36
37static unsigned long hypfs_sprp_diag304(void *data, unsigned long cmd)
38{
39 diag_stat_inc(DIAG_STAT_X304);
40 return __hypfs_sprp_diag304(data, cmd);
41}
42
43static void hypfs_sprp_free(const void *data)
44{
45 free_page((unsigned long) data);
46}
47
48static int hypfs_sprp_create(void **data_ptr, void **free_ptr, size_t *size)
49{
50 unsigned long rc;
51 void *data;
52
53 data = (void *) get_zeroed_page(GFP_KERNEL);
54 if (!data)
55 return -ENOMEM;
56 rc = hypfs_sprp_diag304(data, DIAG304_QUERY_PRP);
57 if (rc != 1) {
58 *data_ptr = *free_ptr = NULL;
59 *size = 0;
60 free_page((unsigned long) data);
61 return -EIO;
62 }
63 *data_ptr = *free_ptr = data;
64 *size = PAGE_SIZE;
65 return 0;
66}
67
68static int __hypfs_sprp_ioctl(void __user *user_area)
69{
70 struct hypfs_diag304 *diag304;
71 unsigned long cmd;
72 void __user *udata;
73 void *data;
74 int rc;
75
76 rc = -ENOMEM;
77 data = (void *)get_zeroed_page(GFP_KERNEL);
78 diag304 = kzalloc(sizeof(*diag304), GFP_KERNEL);
79 if (!data || !diag304)
80 goto out;
81
82 rc = -EFAULT;
83 if (copy_from_user(diag304, user_area, sizeof(*diag304)))
84 goto out;
85 rc = -EINVAL;
86 if ((diag304->args[0] >> 8) != 0 || diag304->args[1] > DIAG304_CMD_MAX)
87 goto out;
88
89 rc = -EFAULT;
90 udata = (void __user *)(unsigned long) diag304->data;
91 if (diag304->args[1] == DIAG304_SET_WEIGHTS ||
92 diag304->args[1] == DIAG304_SET_CAPPING)
93 if (copy_from_user(to: data, from: udata, PAGE_SIZE))
94 goto out;
95
96 cmd = *(unsigned long *) &diag304->args[0];
97 diag304->rc = hypfs_sprp_diag304(data, cmd);
98
99 if (diag304->args[1] == DIAG304_QUERY_PRP)
100 if (copy_to_user(to: udata, from: data, PAGE_SIZE)) {
101 rc = -EFAULT;
102 goto out;
103 }
104
105 rc = copy_to_user(user_area, diag304, sizeof(*diag304)) ? -EFAULT : 0;
106out:
107 kfree(objp: diag304);
108 free_page((unsigned long) data);
109 return rc;
110}
111
112static long hypfs_sprp_ioctl(struct file *file, unsigned int cmd,
113 unsigned long arg)
114{
115 void __user *argp;
116
117 if (!capable(CAP_SYS_ADMIN))
118 return -EACCES;
119 if (is_compat_task())
120 argp = compat_ptr(uptr: arg);
121 else
122 argp = (void __user *) arg;
123 switch (cmd) {
124 case HYPFS_DIAG304:
125 return __hypfs_sprp_ioctl(user_area: argp);
126 default: /* unknown ioctl number */
127 return -ENOTTY;
128 }
129 return 0;
130}
131
132static struct hypfs_dbfs_file hypfs_sprp_file = {
133 .name = "diag_304",
134 .data_create = hypfs_sprp_create,
135 .data_free = hypfs_sprp_free,
136 .unlocked_ioctl = hypfs_sprp_ioctl,
137};
138
139void hypfs_sprp_init(void)
140{
141 if (!sclp.has_sprp)
142 return;
143 hypfs_dbfs_create_file(df: &hypfs_sprp_file);
144}
145
146void hypfs_sprp_exit(void)
147{
148 if (!sclp.has_sprp)
149 return;
150 hypfs_dbfs_remove_file(df: &hypfs_sprp_file);
151}
152

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