ARM: tegra12: set CPU rate to 2.2GHz for sku 0x87
[linux-3.10.git] / arch / frv / kernel / sysctl.c
1 /* sysctl.c: implementation of /proc/sys files relating to FRV specifically
2  *
3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11
12 #include <linux/sysctl.h>
13 #include <linux/proc_fs.h>
14 #include <linux/init.h>
15 #include <asm/uaccess.h>
16
17 static const char frv_cache_wback[] = "wback";
18 static const char frv_cache_wthru[] = "wthru";
19
20 static void frv_change_dcache_mode(unsigned long newmode)
21 {
22         unsigned long flags, hsr0;
23
24         local_irq_save(flags);
25
26         hsr0 = __get_HSR(0);
27         hsr0 &= ~HSR0_DCE;
28         __set_HSR(0, hsr0);
29
30         asm volatile("  dcef    @(gr0,gr0),#1   \n"
31                      "  membar                  \n"
32                      : : : "memory"
33                      );
34
35         hsr0 = (hsr0 & ~HSR0_CBM) | newmode;
36         __set_HSR(0, hsr0);
37         hsr0 |= HSR0_DCE;
38         __set_HSR(0, hsr0);
39
40         local_irq_restore(flags);
41
42         //printk("HSR0 now %08lx\n", hsr0);
43 }
44
45 /*****************************************************************************/
46 /*
47  * handle requests to dynamically switch the write caching mode delivered by /proc
48  */
49 static int procctl_frv_cachemode(ctl_table *table, int write,
50                                  void __user *buffer, size_t *lenp,
51                                  loff_t *ppos)
52 {
53         unsigned long hsr0;
54         char buff[8];
55         int len;
56
57         len = *lenp;
58
59         if (write) {
60                 /* potential state change */
61                 if (len <= 1 || len > sizeof(buff) - 1)
62                         return -EINVAL;
63
64                 if (copy_from_user(buff, buffer, len) != 0)
65                         return -EFAULT;
66
67                 if (buff[len - 1] == '\n')
68                         buff[len - 1] = '\0';
69                 else
70                         buff[len] = '\0';
71
72                 if (strcmp(buff, frv_cache_wback) == 0) {
73                         /* switch dcache into write-back mode */
74                         frv_change_dcache_mode(HSR0_CBM_COPY_BACK);
75                         return 0;
76                 }
77
78                 if (strcmp(buff, frv_cache_wthru) == 0) {
79                         /* switch dcache into write-through mode */
80                         frv_change_dcache_mode(HSR0_CBM_WRITE_THRU);
81                         return 0;
82                 }
83
84                 return -EINVAL;
85         }
86
87         /* read the state */
88         if (*ppos > 0) {
89                 *lenp = 0;
90                 return 0;
91         }
92
93         hsr0 = __get_HSR(0);
94         switch (hsr0 & HSR0_CBM) {
95         case HSR0_CBM_WRITE_THRU:
96                 memcpy(buff, frv_cache_wthru, sizeof(frv_cache_wthru) - 1);
97                 buff[sizeof(frv_cache_wthru) - 1] = '\n';
98                 len = sizeof(frv_cache_wthru);
99                 break;
100         default:
101                 memcpy(buff, frv_cache_wback, sizeof(frv_cache_wback) - 1);
102                 buff[sizeof(frv_cache_wback) - 1] = '\n';
103                 len = sizeof(frv_cache_wback);
104                 break;
105         }
106
107         if (len > *lenp)
108                 len = *lenp;
109
110         if (copy_to_user(buffer, buff, len) != 0)
111                 return -EFAULT;
112
113         *lenp = len;
114         *ppos = len;
115         return 0;
116
117 } /* end procctl_frv_cachemode() */
118
119 /*****************************************************************************/
120 /*
121  * permit the mm_struct the nominated process is using have its MMU context ID pinned
122  */
123 #ifdef CONFIG_MMU
124 static int procctl_frv_pin_cxnr(ctl_table *table, int write,
125                                 void __user *buffer, size_t *lenp,
126                                 loff_t *ppos)
127 {
128         pid_t pid;
129         char buff[16], *p;
130         int len;
131
132         len = *lenp;
133
134         if (write) {
135                 /* potential state change */
136                 if (len <= 1 || len > sizeof(buff) - 1)
137                         return -EINVAL;
138
139                 if (copy_from_user(buff, buffer, len) != 0)
140                         return -EFAULT;
141
142                 if (buff[len - 1] == '\n')
143                         buff[len - 1] = '\0';
144                 else
145                         buff[len] = '\0';
146
147                 pid = simple_strtoul(buff, &p, 10);
148                 if (*p)
149                         return -EINVAL;
150
151                 return cxn_pin_by_pid(pid);
152         }
153
154         /* read the currently pinned CXN */
155         if (*ppos > 0) {
156                 *lenp = 0;
157                 return 0;
158         }
159
160         len = snprintf(buff, sizeof(buff), "%d\n", cxn_pinned);
161         if (len > *lenp)
162                 len = *lenp;
163
164         if (copy_to_user(buffer, buff, len) != 0)
165                 return -EFAULT;
166
167         *lenp = len;
168         *ppos = len;
169         return 0;
170
171 } /* end procctl_frv_pin_cxnr() */
172 #endif
173
174 /*
175  * FR-V specific sysctls
176  */
177 static struct ctl_table frv_table[] =
178 {
179         {
180                 .procname       = "cache-mode",
181                 .data           = NULL,
182                 .maxlen         = 0,
183                 .mode           = 0644,
184                 .proc_handler   = procctl_frv_cachemode,
185         },
186 #ifdef CONFIG_MMU
187         {
188                 .procname       = "pin-cxnr",
189                 .data           = NULL,
190                 .maxlen         = 0,
191                 .mode           = 0644,
192                 .proc_handler   = procctl_frv_pin_cxnr
193         },
194 #endif
195         {}
196 };
197
198 /*
199  * Use a temporary sysctl number. Horrid, but will be cleaned up in 2.6
200  * when all the PM interfaces exist nicely.
201  */
202 static struct ctl_table frv_dir_table[] =
203 {
204         {
205                 .procname       = "frv",
206                 .mode           = 0555,
207                 .child          = frv_table
208         },
209         {}
210 };
211
212 /*
213  * Initialize power interface
214  */
215 static int __init frv_sysctl_init(void)
216 {
217         register_sysctl_table(frv_dir_table);
218         return 0;
219 }
220
221 __initcall(frv_sysctl_init);