xref: /openbmc/linux/arch/s390/hypfs/hypfs_sprp.c (revision cf1ffce2)
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 
__hypfs_sprp_diag304(void * data,unsigned long cmd)26 static inline unsigned long __hypfs_sprp_diag304(void *data, unsigned long cmd)
27 {
28 	union register_pair r1 = { .even = (unsigned long)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 
hypfs_sprp_diag304(void * data,unsigned long cmd)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 
hypfs_sprp_free(const void * data)43 static void hypfs_sprp_free(const void *data)
44 {
45 	free_page((unsigned long) data);
46 }
47 
hypfs_sprp_create(void ** data_ptr,void ** free_ptr,size_t * size)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 
__hypfs_sprp_ioctl(void __user * user_area)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 | GFP_DMA);
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 
hypfs_sprp_ioctl(struct file * file,unsigned int cmd,unsigned long arg)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 
hypfs_sprp_init(void)139 void hypfs_sprp_init(void)
140 {
141 	if (!sclp.has_sprp)
142 		return;
143 	hypfs_dbfs_create_file(&hypfs_sprp_file);
144 }
145 
hypfs_sprp_exit(void)146 void hypfs_sprp_exit(void)
147 {
148 	if (!sclp.has_sprp)
149 		return;
150 	hypfs_dbfs_remove_file(&hypfs_sprp_file);
151 }
152