kconfig: centralize the selection of semaphore debugging in lib/Kconfig.debug
[linux-2.6.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/slab.h>
13 #include <linux/sysctl.h>
14 #include <linux/proc_fs.h>
15 #include <linux/init.h>
16 #include <asm/uaccess.h>
17
18 static const char frv_cache_wback[] = "wback";
19 static const char frv_cache_wthru[] = "wthru";
20
21 static void frv_change_dcache_mode(unsigned long newmode)
22 {
23         unsigned long flags, hsr0;
24
25         local_irq_save(flags);
26
27         hsr0 = __get_HSR(0);
28         hsr0 &= ~HSR0_DCE;
29         __set_HSR(0, hsr0);
30
31         asm volatile("  dcef    @(gr0,gr0),#1   \n"
32                      "  membar                  \n"
33                      : : : "memory"
34                      );
35
36         hsr0 = (hsr0 & ~HSR0_CBM) | newmode;
37         __set_HSR(0, hsr0);
38         hsr0 |= HSR0_DCE;
39         __set_HSR(0, hsr0);
40
41         local_irq_restore(flags);
42
43         //printk("HSR0 now %08lx\n", hsr0);
44 }
45
46 /*****************************************************************************/
47 /*
48  * handle requests to dynamically switch the write caching mode delivered by /proc
49  */
50 static int procctl_frv_cachemode(ctl_table *table, int write, struct file *filp,
51                                  void __user *buffer, size_t *lenp, 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 (filp->f_pos > 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         filp->f_pos = 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, struct file *filp,
125                                 void __user *buffer, size_t *lenp, loff_t *ppos)
126 {
127         pid_t pid;
128         char buff[16], *p;
129         int len;
130
131         len = *lenp;
132
133         if (write) {
134                 /* potential state change */
135                 if (len <= 1 || len > sizeof(buff) - 1)
136                         return -EINVAL;
137
138                 if (copy_from_user(buff, buffer, len) != 0)
139                         return -EFAULT;
140
141                 if (buff[len - 1] == '\n')
142                         buff[len - 1] = '\0';
143                 else
144                         buff[len] = '\0';
145
146                 pid = simple_strtoul(buff, &p, 10);
147                 if (*p)
148                         return -EINVAL;
149
150                 return cxn_pin_by_pid(pid);
151         }
152
153         /* read the currently pinned CXN */
154         if (filp->f_pos > 0) {
155                 *lenp = 0;
156                 return 0;
157         }
158
159         len = snprintf(buff, sizeof(buff), "%d\n", cxn_pinned);
160         if (len > *lenp)
161                 len = *lenp;
162
163         if (copy_to_user(buffer, buff, len) != 0)
164                 return -EFAULT;
165
166         *lenp = len;
167         filp->f_pos = len;
168         return 0;
169
170 } /* end procctl_frv_pin_cxnr() */
171 #endif
172
173 /*
174  * FR-V specific sysctls
175  */
176 static struct ctl_table frv_table[] =
177 {
178         {
179                 .ctl_name       = 1,
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                 .ctl_name       = 2,
189                 .procname       = "pin-cxnr",
190                 .data           = NULL,
191                 .maxlen         = 0,
192                 .mode           = 0644,
193                 .proc_handler   = &procctl_frv_pin_cxnr
194         },
195 #endif
196         {}
197 };
198
199 /*
200  * Use a temporary sysctl number. Horrid, but will be cleaned up in 2.6
201  * when all the PM interfaces exist nicely.
202  */
203 static struct ctl_table frv_dir_table[] =
204 {
205         {
206                 .ctl_name       = CTL_FRV,
207                 .procname       = "frv",
208                 .mode           = 0555,
209                 .child          = frv_table
210         },
211         {}
212 };
213
214 /*
215  * Initialize power interface
216  */
217 static int __init frv_sysctl_init(void)
218 {
219         register_sysctl_table(frv_dir_table);
220         return 0;
221 }
222
223 __initcall(frv_sysctl_init);