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
26 static 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
37 static 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
43 static void hypfs_sprp_free(const void *data)
44 {
45 free_page((unsigned long) data);
46 }
47
48 static 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
68 static 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(data, 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(udata, data, PAGE_SIZE)) {
101 rc = -EFAULT;
102 goto out;
103 }
104
105 rc = copy_to_user(user_area, diag304, sizeof(*diag304)) ? -EFAULT : 0;
106 out:
107 kfree(diag304);
108 free_page((unsigned long) data);
109 return rc;
110 }
111
112 static 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(arg);
121 else
122 argp = (void __user *) arg;
123 switch (cmd) {
124 case HYPFS_DIAG304:
125 return __hypfs_sprp_ioctl(argp);
126 default: /* unknown ioctl number */
127 return -ENOTTY;
128 }
129 return 0;
130 }
131
132 static 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
139 void hypfs_sprp_init(void)
140 {
141 if (!sclp.has_sprp)
142 return;
143 hypfs_dbfs_create_file(&hypfs_sprp_file);
144 }
145
146 void hypfs_sprp_exit(void)
147 {
148 if (!sclp.has_sprp)
149 return;
150 hypfs_dbfs_remove_file(&hypfs_sprp_file);
151 }
152
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